Biogeography and Ecology of Turkmenistan

Özgür Coşkun

South-West and Central Asia are major centres of diversity in the genus Heliotropium. On the basis of detailed taxonomic studies and information gathered from the literature, a synopsis of 61 known species of Heliotropium and two species of Arguzia in the area is given. Iran, with 32 species and 14 (sub)endemic species, has the highest diversity. The photosynthetic pathways of 42 taxa were determined using the isotope composition method. Except for H. marifolium Retz s.l. and H. rariflorum Stocks, all remaining species analysed showed δ13C values characteristic for C3 photosynthesis. Evidently, by contrast with the families Chenopodiaceae and Polygonaceae, the Irano-Turanian area is not an authochthonous region of developing C4 species in Heliotropium. The distribution maps of 57 taxa are provided and their biogeographical importance is discussed in order to elucidate the distribution patterns in South-West Asia. In the Irano-Turanian region, the Irano-Anatolian province of Zohary, which extends from central Anatolia to the western Himalaya, is a very large and vaguely defined phytochorion that should be split into smaller units. The consideration of southern Iran and adjacent Pakistan as part of the Sudanian or Saharo-Sindian regions (sensu either Zohary or Léonard) cannot be accepted, because most endemic species in this area are either typical Irano-Turanian or isolated relicts. Furthermore, it is concluded that the Saharo-Sindian flora is not an autochthonous flora; most species are of transgressive origin from the surrounding phytochoria. Finally, a new species, Heliotropium ziegleri Akhani, is described from Iran. © 2007 The Linnean Society of London, Botanical Journal of the Linnean Society, 2007, 155, 401–425.

B I O G E O G R A P H Y A N D E C O L O G Y OF T U R K M E N I S T A N MONOGRAPHIAE BIOLOGICAE VOLUM E 72 SeriesEditors H.J. Dumont and MJ.A . Werger The titles publishedin this seriesare listedat the end of this volume. Biogeograph y and Ecology of Turkmenistan Edited by VICTO R FET Dept. of Biological Sciences,Loyola University, New Orleans, Louisiana,USA and KHABIBULL A I. ATAMURADO V Natural ConservationSociety,Ashgabat, Turkmenistan Springer-Science+Busines s Media, B.V. Librar y of Congress Cataloging-in-Publication Data Biogeography and ecolog y o f Turkmenista n / edite d b y Victo r Fe t and Khabibull a Atamuradov. p. cm. — (Monographiae biologica e ; v . 72 ) Include s index . ISBN 978-94-010-4487-5 ISBN 978-94-011-1116-4 (eBook) DOI 10.1007/978-94-011-1116-4 1. Biogeography—Turkmenistan. 2 . Ecology—Turkmenistan. I . Fet , V i c t o r . I I . Atamuradov, Kh. I . (Khabibull a Ishchanovich ) III . Series . QP1.P3 7 vol . 7 2 [QH191 ] 574 s~dc2 0 [574.958*5 ] 94-695 2 ISBN 978-94-010-4487-5 Printed on acid-freepaper A l l Rights Reserve d © 1994 Springer Science+Busines s Media Dordrecht Originally published by Kluwer Academic Publishers in 1994 Softcover reprint of the hardcove r 1st edition 1994 No part of the material protected by this copyright notice may be reproduce d or utilized in any form or by any means , electronic or mechanical , including photocopying , recording or by any information storage and retrieval system, without written permission from the copyright owner. Table of Contents List of contributors vii 1. Introduction: One hundredyearsof natural history in Turkmenistan V. Fet 2. Landscapesof Turkmenistan 5 A.G. Babaev 3. Climate of Turkmenistan 23 N.S. Orlovsky 4. Paleogeography of Turkmenistan 49 K.I. Atamuradov 5. Desertificationof the arid lands of Turkmenistan 65 N.G. Kharin 6. Vegetationof the desertsof Turkmenistan 77 I.G. Rustamov 7. Flora of Kopetdagh 105 D. Kurbanov 8. Kopetdagh-Khorassan flora: Regionalfeaturesof Central 129 Kopetdagh G.L. Kamakhina 9. Vegetationof SouthwestKopetdagh 149 G.N. Fet 10. Trees,shrubs,and semishrubsin the mountainsof Turkmenistan 173 K.P. Popov 11. Ecosystemstructureof subtropicalarid pistachiowoodlandsin SouthernTurkmenistan 187 R.I. Zlotin 12. Biogeographicposition of Khorassan-Kopetdagh 197 V. Fet 13. Vertebratesin the Red Data Book of Turkmenistan 205 A.K. Rustamov& O. Sopyev 14. Ecology of the beardedgoat (Capra aegagrusErsleben,1777) in Turkmenistan 231 V.M. Korshunov 15. Ecology of birds in the Karakum Desert 247 A.K. Rustamov vi Table of Contents 16. Ecological structureof the bird populationin the Transcaspian region: Cartographicanalysisand problemsof conservation E.A. Rustamov 17. Kidney structureand its role in osmoregulationin desertbirds M.A. Amanova 18. On the evolution of the pheasant(PhasianuscolchicusL.) in Middle Asia AV. Solokha 19. Zoogeographicanalysisof the reptiles of Turkmenistan N.N. Shcherbak 20. Reptilesof Kopetdagh C. Ataev, A.K. Rustamov& S. Shammakov 21. Geographicvariability of PhrynocephalusrossikowiNik. (Reptilia: Agamidae)in Turkmenistanand adjacentregions M.L. Golubev, V.V. Manilo & AA Tokar 22. Formationof the fish populationin the artificial hydrographic network of Turkmenistan(the AmudaryaRiver basin) V.B. Salnikov 23. Arthropodsinhabiting rodent burrows in the Karakum Desert V.A Krivokhatsky 24. Zoogeographyof Coleopterain Turkmenistan O.L. Kryzhanovsky& K.1. Atamuradov 25. Buprestidbeetles(Coleoptera:Buprestidae)from Kopetdaghand the adjacentregionsof SouthernTurkmenistan M.G. Volkovich & AV. Alexeev 26. Fauna,zoogeography,and ecologyof Orthopterain Turkmenistan T. Tokgaev 27. Encyrtid waspsof Turkmenistan(Hymenoptera:Encyrtidae) S.N. Myartseva 28. Zoogeographyand ecologicalaspectsof the formation of horse fly fauna (Diptera: Tabanidae)in Turkmenistan R.V. Andreeva 29. Ant-lions (Neuroptera:Myrmeleontidae)in Turkmenistan V.A Krivokhatsky 30. Faunaand zoogeographyof spiders(Aranei) of Turkmenistan K.G. Mikhailov & V. Fet 31. Faunaand zoogeographyof scorpions(Arachnida: Scorpions) in Turkmenistan V. Fet 32. Faunaand zoogeographyof molluscsof Turkmenistan Y.I. Starobogatov Bibliography Index of Taxa Index of Subjects 265 281 295 307 329 351 365 389 403 419 451 467 481 495 499 525 535 545 605 637 List of Contributors AMANOV A, M.B., Department of Biology, Turkmen State University, Ashgabat,Turkmenistan. ANDREEVA, R.V., 1.1. SchmalhausenInstitute of Zoology, Ukrainian Academyof Sciences,Kiev, Ukraine. ALEXEEV, A.V., PedagogicalInstitute, Orekhovo-Zuevo,Russia. ATAEV, Ch., Institute of Zoology, TurkmenAcademyof Sciences,Ashgabat, Turkmenistan. ATAMURADOV, K.I., Natural Conservation Society, Ashgabat, Turkmenistan. BABAEV, A.G., DesertInstitute, Turkmen Academy of Sciences,Ashgabat, Turkmenistan. FET, G.N., Department of Biological Sciences, Loyola University, New Orleans,Louisiana,USA. FET, V., Departmentof Biological Sciences,Loyola University, New Orleans, Louisiana,USA. GOLUBEV, M.L., Seattle,Washington,USA. KAMAKHINA, G.L., Institute of Botany, Turkmen Academy of Sciences, Ashgabat,Turkmenistan. KHARIN, N.G., DesertInstitute, Turkmen Academyof Sciences,Ashgabat, Turkmenistan. KORSHUNOV, V.M., Ecocenter,Ashgabat,Turkmenistan. KRIVOKHATSKY, V.A., Zoological Institute, RussianAcademyof Sciences, St. Petersburg,Russia. KRYZHANOVSKY, O.L., Zoological Institute, Russian Academy of Sciences,St. Petersburg,Russia. KURBANOV, Dz., Department of Biology, Turkmen State University, Ashgabat,Turkmenistan. MANILO, V.V., 1.1. Schmalhausen Institute of Zoology, Ukrainian Academy of Sciences,Kiev, Ukraine. MIKHAILOV, K.G., Zoological Museum, M.V. LomonosovMoscow State University, Moscow, Russia. Vlll List of Contributors MY ARTSEVA, S.N., Institute of Zoology, Turkmen Academy of Sciences, Ashgabat,Turkmenistan. ORLOVSKY, N.S., Desert Institute, Turkmen Academy of Sciences, Ashgabat,Turkmenistan. POPOV, K.P., Desert Institute, Turkmen Academy of Sciences,Ashgabat, Turkmenistan. RUSTAMOV, AK., Turkmen Institute of Agriculture, Ashgabat, Turkmenistan. RUSTAMOV, E.A, Department of Biology, Turkmen State University, Ashgabat,Turkmenistan. RUSTAMOV, I.K., Department of Biology, Turkmen State University, Ashgabat,Turkmenistan. SALNIKOV, V.G., Institute of Zoology, Turkmen Academy of Sciences, Ashgabat,Turkmenistan. SHAMMAKOV, S., Institute of Zoology, Turkmen Academy of Sciences, Ashgabat,Turkmenistan. SHCHERBAK, N.N., Zoological Museum, 1.1. SchmalhausenInstitute of Zoology, Ukrainian Academyof Sciences,Kiev, Ukraine. SOLOKHA, A.V., TurkmenInstituteof Agriculture, Ashgabat,Turkmenistan. SOPYEV, O.S., Turkmen Institute of Agriculture, Ashgabat,Turkmenistan. STAROBOGATOV,Ya.l., ZoologicalInstitute,RussianAcademyof Sciences, St. Petersburg,Russia. TOKAR, AA, 1.1. Schmalhausen Instituteof Zoology, UkrainianAcademyof Sciences,Kiev, Ukraine. TOKGAEV, T.B., Institute of Zoology, Turkmen Academy of Sciences, Ashgabat,Turkmenistan. VOLKOVICH, M.G., Zoological Institute, Russian Academy of Sciences, st. Petersburg,Russia. ZLOTIN, R.I., Departmentof Biogeography,Institute of Geography,Russian Academyof Sciences,Moscow, Russia. 1. Introduction: One HundredYears of Natural History in Turkmenistan VICTOR FET Brotherhoodis our custom, Friendship is our law. Makhtumkuli, Turkmen national poet (18th century) As part of the famous"GreatGame"betweenthe Russianand British Empires in CentralAsia, Turkmenistanwas the last colonial prize of the Russiantsars; its delineationfrom Afghanistanwas completedonly in the 1890s.The Russian Empire's TranscaspianRegion (Zakaspiiskaya Oblast) was roughly what Turkmenistanis today; its neighbors were the semi-independentemirate of Bokhara to the east and khanateof Khiva to the north, both remnantsof medievalMuslim empires. A stunningrate of technological,educational,and cultural progressin this desertland of nomadswas achievedin less than 30 years of imperial Russian rule (pahlen1963).The famousTranscaspian railroadran from Krasnovodskto Tashkent.Scientific research,which had never touchedthis remotecorner of Asia before, went in pace with advancesin road building, industry, and irrigation. Traditional interestsof nineteenthcentury Russiannaturalistsin Centraland Middle Asia, so lively portrayedin The Gift by Vladimir Nabokov (1952), naturally extendedto the newly colonized territories of Transcaspia. Since the 1880s, naturalistshave attemptedto describethe rich and peculiar flora and fauna of the magnificentsanddesertsof Turkmenistan. Early notesdescribedthe rich naturalresourcesin desertsand mountainsas well as the severedeforestation.Logging of juniper in the mountains,pistachio treesin the foothills, and saksaulshrubsin sanddesertbeganas early as in the Neolithic Age, when early farming settlementsemergedin the foothills of Kopetdagh (Shishkin 1981). It continued through the era of the ancient Parthian Empire, whose capital, Nisa, now lies in ruins a few miles from Ashkhabad,the capital of Turkmenistan.Timber was usedin construction,as firewood, and also as a charcoal supply for smelting of metals. Green and populous oases,with such centers of culture and education as Khwarazm (Khiva), thrived in the Transcaspiain the times of the magnificentempiresof Alexander the Great and his followers, only to be destroyed in the next millenium by Genghis Khan, Tamerlane, and other warriors. Humaninfluenced desertificationexpandedin thesetimes; extensivegrazing of sheep and camelsby Huns and, later, Turkic tribes, contributedto soil deflation and erosionby desertwinds and rare, but intensiverains. V. Fet & K.I. Atamuradov(eds.), Biogeographyand Ecology of Turkmenistan,1-4. © 1994 Kluwer AcademicPublishers. 2 Victor Fet An early naturalistofthe 1900s,comingby ferry acrossthe CaspianSeafrom well-establishedRussiansettlementsin the Caucasus,was able to seeherdsof largegameanimalssuchasgazelles,onagers,andwild sheep.Hyenas,leopards, cheetahs,and even Turanian tigers preyed on a variety of wild game. The TranscaspianRegion was immediately recognizedas an important area for scientific studies. The world-famous Repetek Sand Desert Station was establishedin 1912to studythe geologyof the Karakumsanddesert.Biological stationsand museumsfollowed; the first extensivecollectionswere madefrom the 1890sthrough the first decadeof the twentieth centuryfor major Russian natural history museumsin Moscow, St. Petersburg,and Tiflis. With the establishmentof the Soviet regime after 1917, Russiansciencewas artficially severedfrom European scientific thought. Original, mandatorily isolatedRussianschoolsof theory in ecology and biogeographydevelopedin the 1920s and 1930s. Primary data for this developmentflowed from many geographicalareasof the Soviet Union, including Middle Asia; the desertsand mountainsof Turkmenistancontinuedto be an important site of basic field research(Laptev 1934; Pavlovsky1934; Kryzhanovsky1965). Limited in their abilities to travel abroad,Sovietscientiststraveledto exotic, "colonial" domesticplaces.The desertsandmountainsof Turkmenistanwere a favorite "spring vacation"site for many Russianentomologists,herpetologists, and bird watchers.As a result, the rich faunasof this republic are extremely well-known as comparedto many other areasin Middle East or Central Asia (Kryzhanovsky and Atamuradov this volume; Shcherbak this volume; Rustamovthis volume). The well-known volumesof the "Faunaof the USSR" and even the more comprehensive"Flora of the USSR," publishedsince the 1930s,wereimportantlandmarksin the scientific developmentfor Middle Asia, similar to the work of British naturalistsin India. And, as was true of English for the former subjectsof the British Empire, Russianbecomethe only scientific and educationallanguagefor all Middle Asian republics.Scientific works were publishedalmostexclusivelyin Russian.This, on the one hand, preventedthe Turkmen languagefrom becomingthe tongueof learnedpeople,as Arabic or Farsi had beenin the past; on the other hand, it allowed free communication amongscientists.(I rememberbeing amusedmany times by listening to lively conversationsin Russianbetweenlocal Turkmen ornithologistsand visiting bird-watchers from Estonia or Lithuania. There, the Russian language performed a communication role among subjects of the Empire, with conversationotherwisehardly possible.) Study of the natural resoursesof Turkmenistanaccompaniedattemptsto preserveits biodiversity, even under the strongestpolitical pressureof the epoch. The famous RussiangeneticistNikolai Vavilov, who perishedin 1940 under Stalin's terror, establishedthe first plant breedingstation in Kara-Kala (SouthwestKopetdagh)to study the tremendousbiodiversityof wild ancestors of domesticplantsin the mountainsof Turkmenistan.Collection and selection work on hundredsof strainsof wild grape,apple, pear, pomegranate,almond, walnut, pistachio,barley, and oat allowed future geneticiststo explore the last Introduction 3 remnants of gene pools of these species. Badghyz Natural Reserve, established in 1941, became a refuge for the last existing population of the Turkmen onager (Equus hemionus onager) and a unique pistachio woodland. A new generation oflocal Turkmen scientists, many of whom were trained by the Russian researchers in the graduate schools of Moscow and Leningrad arose from the 1930s through the 1950s. The Turkmen Academy of Sciences and its journal, Proceedings (including the monthly biological series), served to record the results of diverse biological studies in the republic. While basic science in the Middle Asian republics rather gained from the Russian "colonial" influence, natural resources, in contrast, were severely damaged by the Soviet way of handling the economy and social issues. Severe environmental problems have been inherited by the now independent Turkmenistan, including overgrazed desert pastures, deforested mountains, depleted water resources, accumulated pesticides in cotton fields, declining populations of endangered species of animals and plants, and - worst of all progressing, human-caused desertification (Kharin this volume). In order to approach a solution to these problems, scientists and officials in the republic will need the close attention and help of the international scientific community. A so-called ecotourism, currently practiced in countries rich in biodiversity (e.g., Costa Rica and Belize), might be one way for Turkmenistan to finance the conservation of its natural protected areas, so vulnerable under the continuing aridization. There is enough to see in Turkmenistan: herds of bighorns and onagers in the wilderness of pistachio forests of Badghyz; a breathtaking view of ancient basaltic volcanoes in the midst of the pink-salt Lake Yeroyulanduz; the magnificent sand dunes of the Karakum Desert; flocks of flamingoes on the Caspian seashore; and the Kopetdagh Mountain valleys in early spring, blooming with almonds and hyacinths. Ecotourist facilities, as well as joint scientific environmental projects, could be based in the eight existing Natural Reserves (Krasnovodsk, Kaplankyr, Syunt-Khasardagh, Kopetdagh, Badghyz, Repetek, Amudarya, and Kugitang) which represent all major landscapes of the republic. Although, in the past, these reserves have never achieved the tourist attendance level or financial security of Western national parks, they have traditionally played the role of biological field stations, housing each year dozens of field researchers and university students. The newly independent republics of Middle Asia are economically likely to stay under the strong influence of Russia. Culturally and linguistically, however, Turkmenistan belongs to the Turkic-speaking part of the Islamic world. Today, it is important that the positive legacy of the last hundred years of Russian and Soviet influence, as well as the gained momentum in the scientific development of Turkmenistan, not be lost. Critical for the scientific community of the republic is its openness to international cooperation; combined with the solid level of existing research, such cooperation is bound to yield progress. This book combines the results of basic scientific research in biogeography and ecology; its purpose is to give a fairly comprehensive account of the nature 4 Victor Fet of Turkmenistan. It is also the authors' common desire to see its human population living in balance with this diverse nature, and the state of Turkmenistan being peaceful and prosperous. Acknowledgements This monograph could not have been completed without the tremendous help of Elsa Galbraith (Midwestern State University, Wichita Falls, Texas, USA) who volunteered to undertake the painstaking task of editing its English translation. Michael Golubev (Seattle, Washington, USA) advised on aspects of reptile taxonomy. Robert Vezzetti and Dana Pelligrin assisted with manuscript typing. One of the first expeditions to Badghyz, ca. 1935. Photo by Mikhail P. Rozanov. Restored by Vladimir M. Potapov, 1976. 2. Landscapes of Turkmenistan AGADZHAN G. BABAEV Abstract Lowland and mountainous desert landscapes of Turkmenistan are described, including the following regions of the republic: the Kopetdagh Mouintains with their northern submontane plain, the isolated Bolshoi Balkhan and Maly Balkhan Mountains, the Ustyurt Plateau (its part within Turkmenistan), the Krasnovodsk Peninsula, the Cis-Caspian Lowland, western sands of Chilmamed and Uchtagan, the Sarykamysh-Khwarazm Lowland, the Uzboi dry valley, the Karakum Desert, the area between the Tedzhen and Murghab Rivers, the Badghyz and Karabil Plateaus, the Amudarya River Valley, and the Kugitangtau Mountains. Landscape structure is determined by a complicated geological history and modern, extremely arid climate. The description of natural hydrographic network is given; the most important rivers are the Amudarya, Tedzhen, and Murghab. Ten lithoedaphic types of deserts are identified within Turkmenistan. Thirteen ecological regions are separated according to their physical-geographical features, climate, and potential for agricultural development. Introduction Turkmenistan is located in western Middle Asia between latitudes of 35° 08' N and 42° 48' N and longitudes of 52° 27' E and 66° 41' E. It extends from west to east for 1,100 km, and from north to south, for 650 km, and constitutes 488,100 km2 • Boundaries of the republic reflect historic and geographic features of migrations of the Turkmen people in Middle Asia. Turkmenistan borders Kazakhstan to the north, Uzbekistan to the east and northeast, Iran to the south and southwest, and Afghanistan to the southeast. To the west, Turkmenistan is limited by the Caspian Sea. The physical geography of Turkmenistan is determined primarily by the sharply continental climate with its extreme shortage of moisture and high V. Fet & K.I. Atamuradov (eds.), Biogeography and Ecology of Turkmenistan, 5-22. © 1994 Kluwer Academic Publishers. 6 Agadzhan G. Babaev summer temperatures. All landscapes of the republic - whether the Kopetdagh Mountains, the Ustyurt Plateau, or the Karakum sands - bear a desert image. Rivers which flow through the Turkmen lands do not change the desert appearance of surrounding plains and alter only the narrow strips of land in their valleys. Even the influence of the Caspian Sea is minute on its eastern shore, where landscapes are as dry, severe, and desert-like as inland. All green oases with dense populations, vast gardens, and fields are man-made. There are only a few relatively small natural oases in places where ground water reaches the surface; today these are mostly incorporated into larger artificial oases. Turkmenistan lies within the temperate desert zone, which is south of the semidesert zone. Within the Turanian Lowland, which includes the lowland part of Turkmenistan, Berg (1938) distinguished three desert subzones: northern Tertiary plateaus which intergrade in the north with the semidesert zone; a subzone of sand deserts; and a subzone of submontane loess plains. The southernmost part of the republic bordering Iran and Afghanistan is occupied by mountains which also have desert character as well as altitudinal zonality. Within Turkmenistan, the first desert subzone includes the southern promontories of the Ustyurt and Mangyshlak Plateaus. The subzone of sand deserts includes the great sand desert of Karakum. Finally, loess plains are well developed along the northern foothills of Kopetdagh. Relief of Turkmenistan More than 75% of Turkmenistan territory consists oflowlands. The mountains and plateaus occupy only the southern border and small isolated areas in the west (Fig. 1); these elevated areas do not reach snowline and were not glaciated even in the Ice Ages. The maximal altitude in Turkmenistan is 3,137 m in the Kugitang Mountains; the lowest point of the republic is - 92 m in the Akhchakaya Depression (the northwestern part of the Trans-Unguz Karakum); thus, the gypsometric amplitude is 3,229 m. Landscapes, however, do not exhibit significant altitudinal changes since maximal elevations are expressed only in the south and east of the state where the influence of increasing aridity and temperatures prevents the distinct expression of altitudinal differences. The lowlands of Turkmenistan lie primarily between 50 and 200 m above sea level. Only the Caspian Lowland and some depressions are located below this mark while the eastern and southeastern Karakum and parts of the Krasnovodsk and Ustyurt Plateaus are higher. In general, the lowlands of Turkmenistan are tilted from south toward north and from east toward west. Major mountain ranges of Turkmenistan exceed 1,500 m; e.g., Bolshoi Balkhan rises to 1,800 m; Kopetdagh, to 2,872 m (Mt. Chopandagh, southwest of Ashkhabad); and Kugitang (or Kugiutangtau), to 3,137 m. Other mountains and plateaus (such as Maly Balkhan, Badghyz, and Karabil) usually do not reach 1,000 m. Therefore, mountains of Turkmenistan can be classified as of medium height. Landscapes of Turkmenistan 7 I ,." ,; I, 1IIIlIll2 ~3 ........./ 4 Fig. 1. A schematic map of Turkmenistan. I - stabilized sands, 2 - semi-stabilized sands, 3 - drift sands, 4 - the Karakum Canal. The Kopetdagh Mountains are the northern range of the TurkmenoKhorassan mountain system. Kopetdagh stretches along the southern border of the republic for ca. 500 km between the meridians of the cities of Kazandzhik and Tedzhen. Turkmenistan includes only the northern portion of Kopetdagh, which is as narrow as 10 km in the east, 25 to 50 km in its central part, and 100 to 120 km in the west. Southern and almost all of eastern Kopetdagh lie in Iran. Within Turkmenistan, Kopetdagh is formed by a number of separate ranges which have their own names. Most of these ranges are anticlinal and are formed from Cretaceous sediments; exposure of maternal rocks is always well expressed. In the north, Kopetdagh is limited by the submontane plain, inclined from 300 to 50 m. Here are located main settlements of the republic, including its capital, Ashkhabad (altitude 255 m), and numerous agricultural oases irrigated by small Kopetdagh rivers and spring waters. The submontane plain is also inclined from east toward west and slightly dissected. Gullies, river beds, and depressions are well expressed next to the Kopetdagh piedmont, but flatten out farther from the mountains. The submontane plain is formed from alluvial fan deposits with coarse material concentrated next to the mountains, and fine fractions covering the main plain area. These deposits are usually covered by loess. The width of the submontane plain is 16 or 17 km next to the city of Kazandzhik, 40 km next to the Iskander Station, and 10 to 12 km next to Ashkhabad. In the north, the 8 Agadzhan G. Babaev submontane plain is limited by the sands of the Karakum; this boundary is not straight but forms a row of capes, bays, and semiclosed depressions among sands. Mudslide (seT) waters from the plain which reach these depressions form temporary lakes. Against the background of slightly inclined plain one can distinguish separate scattered low hills and clusters of dune or hill sands with scant vegetation. The isolated mountain ranges of Bolshoi and Maly Balkhan are located northwest of Kopetdagh. Maly Balkhan is a small (ca. 30 km) anticlinal range stretched from west-southwest to east-northeast, and is formed from Cretaceous and - partially - Tertiary sediments. It reaches 955 m and is asymmetric: the highest part of the range rises sharply above the northern submontane inclined plain. On this plain, at some distance from Maly Balkhan, stands a small ridge formed from Upper Tertiary sediments. The southern slope of Maly Balkhan is more extended and consists of several monoclinal ridges parallel to the main range. Both northern and southern slope are dissected by a network of ravines. From both sides, Maly Balkhan is limited by depressions ("corridors") which connect the Caspian Lowland and the Central Karakum. Bolshoi Balkhan is a more complex mountain system. Geologically, it is a diffuse anticline with its core comprised of Jurassic sediments, and its limbs, of Cretaceous ones. Bolshoi Balkhan proper reaches 1,880 m; it is stretched latitudinally and is bordered in the north by a rocky, sometimes vertical, cliff, while in the south it forms a steep slope, and in the west gives two offshoots. The southern-inclined surface of the Bolshoi Balkhan is dissected by numerous ravines. The eastern part of the range is lower (highest point 1,376 m) and its northern slope, dissected by short ravines, is less steep than the southern one. The Caspian, or West Turkmen, Lowland lies to the west of Kopetdagh and to the west and southwest ofKrasnovodsk and Balkhan Bays of the Caspian Sea and of Bolshoi Balkhan.lts elevation is between -27.6 and 100m. The Caspian shelf adjacent to the lowland is very shallow: the 10 m isobathe extends out 10 to 20 km from the shore. The shoreline forms a number of bays, peninsulas, islands, and alluvial sand banks. Most of the lowland is occupied by sand ridges and dunes, solonchaks, and takyrs (clay desert). In the north, the plateau-like summit of Nebit-Dagh (or Nefte-Dagh, 45 m) rises from the giant solonchak Kyolkor; farther to the east lie the mountain ranges of Monzhukly and Boyadagh (134 m). In the south of the Caspian Lowland lies the delta of the Atrek River. In the west, the lowland intergrades into the foothills of Kopetdagh, forming a submontane inclined plain tens of kilometers wide and dissected by dry mudslide beds. The Krasnovodsk Peninsula is bordered by the Caspian Sea to the west, by Krasnovodsk and Balkhan Bays to the south, and by the Kara-Bogaz-Gol Bay to the north. Most of the peninsula is occupied by the Krasnovodsk Plateau, which bears depressions (50 to 70 m in depth, with accumulated sand) and buttes. Average height of this plateau is 200 m; highest points in the south reach 320 m. In the south, southwest, and north, the plateau ends in high cliffs exhibiting outcrops of Tertiary rocks. In the northwest, the plateau gradually Landscapes of Turkmenistan 9 descends toward the seashore plain of the western part of the Krasnovodsk Peninsula. Most of this plain is covered by the sand massif, Oktum, formed by intermitting sand ridges and depressions; a strip of solonchaks stretches along the seashore. In the south, the plain turns into the long and narrow Krasnovodsk sand bank which separates Krasnovodsk Bay from the Caspian Sea, and in the north, it turns into a similar Karabogaz sand bank which separates Kara-Bogaz-Gol Bay from the Caspian. Between the Krasnovodsk Peninsula and Kara-Bogaz-Gol Bay in the west, the Ustyurt Plateau in the north, and Bolshoi Balkhan and the Uzboi dry bed in the south and southeast, lies an orographic ally diverse area which comprises a mountainous system of Tuarkyr. This territory, composed of dislocated Cretaceous and Jurassic beds, has narrow monoclinal ridges, steep cliffs, closed depressions, and buttes. The mountains of Irsarybaba and Tuarkyr are ca. 300 m high; mountains Begi-Arslan and Akkyr reach 400 m and higher. In depressions, the elevation drops to 100 m and even lower. Sands and solonchaks occupy small areas in the bottoms of closed depressions. Outcropping maternal rocks can be seen almost everywhere. To the south and east of the Tuarkyr area lie the sands of Chilmamed (or Chilmamedkum) and Uchtagan. The Chilmamed sands are located between Tuarkyr and Bolshoi Balkhan, increasing in altitude from 0 to 200 m toward the northwest. This massif includes sand ridges and interridge depressions stretching from northwest to southeast. The ridges are from 30 to 35 m, and sometimes even to 50 m high. Takyrs are absent; small clay desert areas appear only in the eastern part of the Chilmamed sands. The second sand massif, Uchtagan, lies eastward of Tuarkyr. Elevations here are from 22 to 120 m, rising toward the northwest. Large valley-like depressions filled by small ridged sands are intersected by high sand ridges. Main ridges are oriented 20 to 25° from northwest toward southeast. In some places, rocks of the Trans-Unguz continental formation and of Miocene age outcrop from under the sand. Between the Uchtagan sands and the Kaplankyr Plateau (which is a southern offshoot of the Ustyurt Plateau) lies a deep depression extending from northwest toward southeast. Its bottom lies at a level of -19 to +20 m and is occupied by the giant (ca. 100 km long) solonchak Karashor. In the west, Karashor is bordered by a terrace ca. 10m high. Of the Ustyurt and South Mangyshlak Plateaus, only the southern parts belong to Turkmenistan. The South Mangyshlak Plateau borders the KaraBogaz-Gol Bay from the north as a cliff with a good outcropping of Tertiary sediments. Its average altitude is from 100 to 130 m; some points are elevated from 5 to 20 m above this surface. In the southwest, the plateau declines and becomes a sand bank which separates the northern part of Kara-Bogaz-Gol Bay from the Caspian Sea. Small salt lakes and solonchaks can be found within this sand bank, especially in the transition zone from plateau to sand bank. The Ustyurt Plateau outlines Kara-Bogaz-Gol Bay from the east, and yields two offspurs to the south known as Chelyungkyr and Kaplankyr. These two plateaus, which reach the Uzboi dry bed at 40° N, are separated by the 10 Agadzhan G. Babaev abovementioned Karashor Depression and Uchtagan sand massif. In the west and south, Ustyurt often forms high cliffs (chinks) known under a variety of names. Especially impressive (from 300 to 320 m high) are the Kulandagh chink on the shore of Kara-Bogaz-Gol Bay and the chinks of Kaplankyr above the Karashor Depression, all of which exhibit excellent outcrops of Tertiary and Mesozoic sediments. Here, Ustyurt reaches its maximal absolute elevations (330 m in Kulandagh and 302 m in Kaplankyr); average elevation of the Ustyurt surface within Turkmenistan equals 200 to 250 m. This surface lacks large depressions (which appear farther north, in the Kazakh and Karakalpak portions of the plateau) but often possesses deep pan-like depressions, eroded hills and buttes next to the chinks. Since the Ustyurt surface is inclined toward the east and northeast, i.e., toward the direction opposite from the chinks, water runoff is directed toward the inside of the plateau, and the network of ravines along the Ustyurt chinks is, therefore, sparse. The Sarykamysh-Khwarazm Lowland includes the Sarykamysh Depression in the west and the alluvial plain of the Amudarya River in the east. The lowest point in the Sarykamysh Depression is - 45 m. The bottom of the depression (exposed before flooding by the discharged irrigation waters which formed modern Lake Sarykamysh) was covered by solonchaks and sand areas; its southern and eastern periphery included buttes, dry river beds, takyrs, and sand deposits. The Sarykamysh Depression is bordered southeasterly by the sands of the Karakum Desert. Outcrops of the maternal Tertiary rocks can be found in the Ustyurt escarps, in the buttes, and in the bottom of the Sarykamysh. The alluvial plain of the Amudarya River within Turkmenistan is inclined from the river westward. Within the plain, elevation falls from 70-80 to 50-55 m. The plain is dissected by numerous natural river beds and artificial canals and contains sparse, table-shaped buttes formed from maternal rocks. The Uzboi dry bed formerly was a river which carried surplus water from the ancient Lake Sarykamysh to the Caspian Sea. The Uzboi Valley divides two geologically different areas: a so-called Trans-Uzboi folded region, and the Karakum Desert. Most of the valley is excellently preserved; only locally are some beds eroded and smothered by sand due to recent denudation. Terraces of the former river are also quite well preserved. The Uzboi is 550 km long, and its valley is 2 to 3 km wide, with maximal depth of 40 m. The total gradient of the river is 75 m. The Uzboi Valley reaches the Caspian Lowland through the socalled Balkhan Corridor between the mountains of Bolshoi and Maly Balkhan, and it disappears in the Kyuolkor solonchack. The extension of the Uzboi is the Aktam dry bed, which stretches from Kyuolkor to Balkhan Bay of the Caspian Sea. The Karakum sand desert occupies a giant territory of 350,000 km between the Uzboi in the west, the Amudarya in the east, the Kopetdagh and Paropamiz mountains in the south, and the Kwarazm (or Khiva) Oasis in the north. This vast territory is divided into the Trans-Unguz and Lowland Karakum; the latter, in turn, is divided into the Central and Southeast Karakum. Landscapes of Turkmenistan 11 The Central Karakum lies northward from the submontane plain of Kopetdagh. Its absolute elevations vary from 20 m in the west to 200 m in the east. Sand ridges appear immediately at its commencement from the submontane plain and often contain hard clay takyrs in the interridge depressions. Especially stable is the takyr belt in the central and western parts (eastward to the Tedzhen delta), where it is from 30 to 80 km wide. Sand ridges which separate takyrs can rise 15 to 20 m, and sometimes (e.g., in the lower part of the Tedzhen Valley) can be more than 10 km long. Takyrs are of great importance in the desert since they are watersheds in which precipitation collects; wells and settlements (auls) are often located next to takyrs in the Karakum. In the southern part of the Central Karakum lies a latitudinal belt of solonchaks (shors) which increase in width from 10 to 40-45 km from east to west. The shor depth, commonly from 8 to 15 m, can reach 40 m. Northward from the shor belt ridge, sands reappear which stretch to the Unguz area. Ridges here are low, dense, and separated by interridge depressions, creating a ridgedepression relief. Many depressions are ocupied by takyrs. Primary ridges in the Karakum Desert are usually meridional or submeridional in their direction. The depressed area known as Unguz separates the Central and Trans-Unguz Karakum; it is a linear chain of depressions which lie at the same level. The Unguz can be traced from the Amudarya to the Uzboi Valley. Depressions are usually two to four km wide; their bottoms are often occupied by shors. Some depresssions are divided by massifs of maternal rocks, up to 40 m high. The Unguz is limited in the north by Trans-Unguz kyrs (flat-topped ridges) which are elevated from 60 to 80 m above depressions. The Trans-Unguz Karakum lies between the Unguz area and the Sarykamysh-Khwarazm Lowland. Its relief is highly dissected, with long meridional buttes, or kyrs, 20 to 30 m high (rarely 40 m in the western part), formed from Upper Tertiary rocks. Kyrs are tens of kilometers long and are separated by depressions one to three km wide which are usually filled by sands or occupied by takyrs. Facing the Unguz, these depressions form dissected chinks with deep "bays." About 50 km north of the Unguz, the maternal kyrs disappear under sands, and the landscape transforms into one of sand ridges with sparse takyrs in depressions. Absolute elevations of the Trans-Unguz Karakum vary from 220 m in the southeast to 100 in the north; some takyrs in the west lie at 50 to 75 m. A belt of dune sands from 10 to 50 km wide stretches along the eastern edge of the Karakum Desert, parallel to the Amudarya Valley between the cities of Kerki and Deinau. Some dune (barkhan) ridges here can reach 25 m. The Tedzhen and Murghab Rivers end blindly in the Karakum, forming wide subaerial deltas with branching dry beds which stretch far into the desert. Delta areas are rich in sand, and contain patches of takyrs along the dry river beds. These takyrs sometimes form flat valley-like depressions with low edges turning into sand ridges. The Southeast Karakum is formally separated from the Central Karakum by 12 Agadzhan G. Babaev the Chardzhou - Ashkhabad Railroad. This part of the Karakum lies higher than the rest of the desert, with elevation from 190 or 200 m next to the railroad to 300 to 350 m in the south. The desert continues to the south without any natural barriers. Between the lower parts of the Tedzhen and Murghab Rivers, which flow in the terraced valleys, stretch the uniform clay plains, rarely interrupted by sands or small hills. High and stable sand ridges appear farther southward between the Tedzhen and Murghab and at the right bank of the Murghab. Farther eastward lies the sand steppe (Obruchev Steppe) which is very slightly dissected by wind or water erosion. Here, the Southeast Karakum is penetrated by the so-called Kelif Uzboi, a linear strip of shors extending northwesterly. The foothills of the Paropamiz Mountains rise eastward from the Tedzhen River along the Afghanistan border. These foothills are separated from the Southeast Karakum by a wave-like plain with sparse buttes. The part of these foothills between the Tedzhen and Murghab is called Badghyz; the part to the east of Murghab, Karabil. These are desert plateaus with smooth relief. Badghyz rises up to 1,255 m; Karabil, to 950 m. These plateaus lack the extended network of rivers or ravines which appear farther south, in Afghanistan. Only the Tedzhen and Murghab Valleys branch into steep but deep ravines. Hills (bairs) in Badghyz reach sometimes 200 m of relative height; depressions between bairs often contain solonchaks, takyrs, and small lakes. Very characteristic of Badghyz are closed depressions: the largest, Yeroilan (or Yeroyulanduz) lies at 273 m, contains two salt lakes, and is distinctly expressed in the relief by its northern cliffs. Karabil is wider and lower than Badghyz, with uniform hilly relief. There are no rivers, and dry beds and depres<;ions are rare. The relief of the right bank of the Amudarya within Turkmenistan below the city of Kerki is not significantly different from the Karakum Desert. It includes plain desert, mostly occupied by the Sundukli sand massif; dune chains are expressed next to the valley (as well as in the left bank). The Sundukly sands descend to the Amudarya as a low but steep escarp. A few closed depressions with salt lakes or solonchaks in their bottoms are present. Across the Amudarya from the city of Chardzhou ends the dry bed of the Zeravshan River. There are numerous groove-like dry depressions, closed depressions, and dry beds separated by narrow plateau-like ridges of maternal rocks. Clay plain is predominant eastward from Kerki. Absolute elevations of the right bank of the Amudarya within Turkmenistan fall from 400 m in the southeast to 200 m in the northwest; bottoms of closed depressions lie at yet lower elevations. The mountains of the Gaurdak-Kugitang region, which belong to the Ghissar mountain system, rise in the easternmost part of Turkmenistan on the right bank of the Amudarya. The highest range (up to 3,137 m) is Kugitangtau (or Kugitang), which is comprised of Jurassic and Paleozoic rocks. It forms steep slope eastward toward Uzbekistan. The western slope of Kugitangtau, facing the valley of the Kugitang-Darya River, is less steep but dissected by deep ravines. To the west and south of Kugitangtau lie lower plateaus formed of Cretaceous and, partly, Jurassic rocks. These gradually decrease toward the Landscapes of Turkmenistan 13 southwest and approach the Amudarya Valley as ridges separated by wide takyr plains. Natural Hydrographic Network of Turkmenistan The natural hydrographic network in Turkmenistan is extremely weakly expressed. There are no significant rivers arising within the republic. Only small rivers originate from the mountains of Kugitangtau and Kopetdagh, and their water is spent for irrigation. Only the mighty Amudarya and, sometimes, Atrek, reach their base level of erosion. The dry beds which cross lowland Turkmenistan for tens and hundreds of kilometers emphasize the scarcity of an active river network. The Atrek River is the only river in Turkmenistan that belongs to the Caspian Sea basin. It originates from Iran and, west of the mouth of its tributary Sumbar, delineates the state border between Turkmenistan and Iran. The entire delta of the Atrek lies within Turkmenistan. The Atrek is 495 km long, of which 145 km flow within Turkmenistan; its drainage is ca. 40,000 km 2; its average annual debit is 10.4 m 3/sec. The river gradient is 1,265 m from Kuchan in Iran to the mouth; within Turkmenistan, where the Atrek flows along the Caspian Lowland, its gradient is only 84 m. In Turkmenistan, the Atrek is only 10 to 15 m wide and not more than 0.5 m deep; its water is completely spent for irrigation, and it reaches the Caspian Sea only during floods. The long-time deposits of the Atrek form a vast ancient delta. The largest tributary of the Atrek is the Sumbar River (203 km long), which, together with its tributaries Chandyr and Tersakan, forms the drainage of West and, partly, Central Kopetdagh. In its upper part, the Sumbar is a mountain river; its middle part flows across the wide and flat plain sparsely dotted with hills. The Sumbar normally does not reach the Atrek since its water is taken for irrigation. The Amudarya, the largest river of Middle Asia (2,287 km long), flows into the Aral Sea. It enters Turkmenistan from Uzbekistan below the mouth of the Surkhan-Darya and leaves the republic via Tyuamuyun Reservoir for Karakalpakistan. Unlike other rivers, the Amudarya has two flood periods: in spring and summer. The summer flood is the result of the thawing of snow and glaciers in the Pamir Mountains. The average annual debit of the Amudarya is 1,700-2,000 m 3/sec. Within Turkmenistan, the river flows in a wide but depressed valley; its bed is from 300 m to 5 km wide. Due to its fast flow, the Amudarya erodes banks in many places. The summer flood level is one to three meters higher than the low water bed; ramparts are constructed for protection against high floods. An enormous amount of deposits is carried by the river in the summer; these deposits form banks and islands and accumulate in river beds and canals. The valley is covered by tugai vegetation and is developed as oases. In Turkmenistan, the Amudarya has only one tributary, a small river named Kugitang-Darya. It is 75 km long, and collects water from the Kugitangtau 14 Agadzhan G. Babaev Mountains. This water, however, is primarily used for irrigation and only a small portion of it reaches the Amudarya. The remaining hydrographic network associated with the Amudarya includes dry beds and gullies that are filled by water only during the rare heavy rains. Only the lower portions of the Tedzhen and Murghab Rivers belong to Turkmenistan; these rivers' origins lie in Afghanistan. The Tedzhen (or Harirud) enters Turkmenistan at the juncture of the state borders of Turkmenistan, Afghanistan, and Iran. Above the town ofSerakhs, the Tedzhen forms the state border between Turkmenistan and Iran. Most water of the Tedzhen remains in Afghanistan where it is used for irrigation of the Gerat Valley; the remainder is used for irrigation in Turkmenistan. The drainage of the Tedzhen constitutes 77,700 km 2; its length within Turkmenistan (including the border region with Iran) is 320 km. The average annual debit of the Tedzhen is 25 m 3/sec. During the spring floods (March-April) the debit doubles or triples; in extraordinary cases, it can increase ten-fold for a short time. The Murghab River enters Turkmenistan from Afghanistan between the plateaus of Badghyz and Karabil and crosses the Southeast Karakum Desert from south to north. Commonly, the Murghab flows only 30 to 40 km north from the city of Mary, but in years rich in precipitation, flood waters of the Murghab extend 140 km north of the Chardzhou - Ashkhabad railroad. The drainage of the Murghab is 62,700 km2 . Its average annual debit is 49 m 3/sec, with maximum volume from April to May; the debit can fluctuate three-fold during the year. Below the city of Takhta-Bazar, the Murghab is up to 70 m wide; its flow rate there is normally up to 1 mlsec but can reach 4 mlsec during the flood. The Murghab accepts two tributaries in Turkmenistan, the Kash (or Kashan) and the Kushka Rivers. The Kash, within Turkmenistan, is 70 km long and contains water only in spring or during heavy rains. The Kushka River, 117 km long within Turkmenistan, holds a small amount of mineralized water which is used for irrigation. This river, usually shallow and quiet, can carry water with great speed during flooding, eroding its bottom and banks. The rivers of Kopetdagh are relatively numerous (ca. 80) but their debit is unequal. In summer many of them dry out or are spent for irrigation. The debit of Kopetdagh rivers is highest in spring when, during the heavy rains, they turn into large and threatening streams. Among the largest, we can list the following: the Arvaz, Kurkulab, Firyuzinka (or Firyuza), Artyk, Keshi, Lainsu, Archinyansu, Dushak, Kelatachai, Chaachachai (or Chaacha), Meanachai (or Meana), and Kazganchai Rivers. Kopetdagh rivers are used for irrigation and water supply of cities and settlements of the submontane plain. There are very few natural lakes in Turkmenistan. Several lakes around the Khwarazm Oasis are located in depressions between sand ridges bordering the Karakum Desert and are fed by discharged irrigation waters. Small and medium lakes are also found in the Amudarya Valley and in the bed of the western Uzboi where groundwater comes to the surface. Some closed depressions which are now dry were occupied by lakes in the recent geological past. During rains, Landscapes of Turkmenistan 15 many closed takyrs in the Karakum are filled by water and become shallow, temporary lakes. Swamps, in the precise sense, are absent from Turkmenistan (if one does not include swampy areas in the deltas of the Atrek and Amudarya). Under existing physiogeographical conditions, solonchaks (shors) are formed instead of swamps and lakes. There are numerous shors along the Uzboi, Unguz, Kelif Uzboi, under chinks of the Ustyurt, and in the Central Karakum. The largest shors are the Karashor and Kumsebshen north of the Uzboi, and the Kyolkor in the Caspian Lowland. Lithoedaphic Types of Deserts in Turkmenistan The following types of deserts are distinguished in Turkmenistan according to the lithology of maternal rocks and soils (Petrov 1973; Babaev and Orlovsky 1981): sand, sand-clay, sand-stony, stony submontane, clay-stony, gypsum, clay and loam, loess, salt deserts, and desert valley landscapes (Fig. 2). Below, we give a brief characteristic of each desert type. 1. Sand deserts (including drift, semi-stabilized, and stabilized dunes) differ from all other types in mobility of the substrate, lowest carbonate and salt content, and (with deep groundwater position), in the presence of the hanging moisture horizon which is 20 to 120 cm deep. Due to sand mobility, soils are weakly developed or lacking. Sandy sierozems are formed only in areas of stabilized by vegatation. The existence of the hanging moisture horizon allows for growth of psammophytes. Plants and animals of sand desert are adapted to living on a drifting substrate. Sand deserts have a characteristic, highly dissected ridge relief which differs sharply from the even surfaces of takyrs (clay deserts), solonchaks, or clay-stony plateaus. 2. Sand-clay deserts are regions with intermittent sand massifs and clay areas (usually takyrs). This desert type occupies the alluvial plain of the Central Karakum, northwest of the modern delta of the Tedzhen River. This area represents the ancient delta of the Tedzhen; strata of groundwater lie relatively close to the surface. Such landscape of alternating sand and clay desert is observed also in the ancient delta of the Murghab. 3. Sand-stony deserts are regions of sand deserts developed on the maternal rocks which often outcrop at the surface. These deserts are present, e.g., on the TransUnguz plateau with its numerous outcrops of Tertiary sandstone and kyrs, and on in the Badghyz and Karabil plateaus. These areas vary in the depth of the groundwater as well as in the mechanical composition of substrates. 4. Stony submontane deserts are formed on alluvial fan deposits in the piedmont area of Kopetdagh, Bolshoi Balkhan, and Maly Balkhan; they accumulate rubble and gravel and have low levels of substrate salinization. Soils here are desert sierozems (gray desert soils) covered by sagebrush or ephemerous vegetation. Groundwater is usually scattered and does not form strata. 16 Agadzhan G. Babaev 5. Clay-stony deserts are the second most widespread type (after sand desert). They have hard, usually salinized, substrates developed on maternal rocks. Presence of rubble facilitates leaching of the surface soil horizon; at a certain depth, however, gypsum crystals and crusts of calcium carbonate are formed. Presence of gypsum at some depth is characteristic for almost all stony deserts. Highly so10 nets-like brown and grey-brown soils develop on the stony loams. Plant and animal life here is impoverished. 6. Gypsum deserts are a variety of clay-stony desert with frequent outcrops of gypsum. In some places, especially in the Ustyurt Plateau, gypsum forms a layer between the soil and maternal rock, from 8 to 60 cm thick (sometimes up to 100 cm and more). In the middle and southern Ustyurt, gypsum is usually present at a depth from 5 to 30 cm, and it outcrops at small, elevated areas. Especially characteristic for the gypsum desert are grey-brown solonchak soils, or gypsum-bearing sierozems. Due to the high concentration of salts, vegetation here is very scarce and consists of a special group of gypsophytes. 7. Clay and loam deserts are developed at the sites of ancient river valleys, lakes, in the mouths of rivers (such as the Tedhzen and Murghab), and in piedmont areas, e.g., that of Kopetdagh. Heavy loam sierozems and takyr-like soils are formed on alluvial or, sometimes, alluvial fan deposits of clay and loam. Clay soils are weakly permeable, have low aeration, and are rich in nutrients; plants growing here usually have shallow, weakly branched root systems. Groundwater lies close to the surface, and heavy soils are often salinized; therefore, complicated melioration is required for their development. Clay deserts include also takyrs, vast areas with a smooth clay surface covered by a characteristic cracked hard crust and almost devoid of higher plants. 8. Loess (and gravel-loess) deserts are widespread in piedmont areas and are the transitional zone from the plain to the low mountain belts. Extremely fertile soils, typical sierozems, are formed on loess and are similar to loess in their mechanical and chemical composition. Most of these desert areas are used for agriculture with artificial irrigation. Characteristic for the loess desert is the seasonality in soil development, plant, and animal life due to the appearance of ephemerous vegetation during the short period of spring rains. Combination of high temperature and maximal precipitation in spring facilitates biochemical processes in soils. Loesses, and sierozems developing on them, are rich in carbonates, but salinization is low due to permeability and leaching. Since groundwater usually lies deep, soils are not solonchak-like. Sierozems have rich soil fauna (earthworms, insect larvae) which creates a "perforated" soil horizon. The air in loess desert landscape has a whitish haze due to the extremely fine loess dust carried by wind. 9. Salt deserts are found as large areas or as smaller solonchaks (shors, or sors) among different types of deserts. As a rule, they lie within river terraces, on coastal plains, and in the bottoms of depressions with close groundwater. Salt deserts are widespread due to the dry climate, presence of highly Landscapes of Turkmenistan ...... . ... .... [ill ............ I .'. .'.' ...... [:J]]JJ]' . " ... ':.. 17 g. ...... ., ., ., 2 ...... ·3 shauz II) lU o Fig. 2. Lithoedaphic types of deserts and their complexes in Turkmenistan. 1 - sand deserts, 2 complex of sand and clay deserts, 3 - complex of sand, stony, clay, and salt deserts, 4 - complex of sand and salt deserts,S - complex of sand and loess deserts, 6 - complex of sand and stony deserts, 7 - clay deserts, 8 - stony (gypsum) deserts, 9 -loess deserts, 10 - salt deserts, 11 - sand dunes, 12 - complex of sand dunes and salt deserts, 13 - oases, 14 - the Karakum Canal. salinized Tertiary and Quaternary deposits, and presence of numerous closed depressions and lowlands. High salt concentration prevents agricultural development of salt desert, although they are sometimes used as pastures. Vegetation here is impoverished and consists of highly specialized halophytes. Shors, which are 30 to 40 cm thick, often are completely devoid of vegetation and exhibit smooth salt-covered surfaces, which brilliantly gleam in the sunlight. 10. Desert valley (and delta) landscapes are formed on recent sand and clay alluvial deposits. Groundwater here lies close to the surface, and soil formation is constantly interrupted. A specific vegetation of riparian forests (tugais), meadows, and oases is present. Meadows, and especially tugais, have the most diverse and abundant plant and animal life of all the desert habitats. Ecological Regions of Turkmenistan Thirteen ecological regions are distinguished in Turkmenistan according to the climatic, lithological, and soil characteristics. These include: Cis-Ustyurt, West 18 Agadzhan G. Babaev Turkmen (or Coastal), Sarykamysh, Trans-Unguz, Karakum, Amudarya, Sundukli, Atrek-Sumbar, Kopetdagh, Kopetdagh Submontane, MurghabTedzhen, Karabil-Badghyz, and Kugitang Regions (Fig. 3). 1. Cis- Ustyurt Region (including the Krasnovodsk Plateau) is located in the far northwest of Turkmenistan. It includes narrow plateaus separated by narrow valleys, ravines, and depressions. The bottoms of depressions are occupied by solonchaks. Flat-topped buttes, or kyrs, reach 430 m. Large sand massifs within this region are, as a rule, stabilized by vegetation. Average annual temperature is 12 to 15 DC, absolute maximum is 43 DC, absolute minimum is - 30 DC; length of a frostless period is 210 to 225 days. Annual precipitation is ca. 100 mm. Vegetation is dominated by Salsola and Artemisia, sometimes combined with ephemers; the region'S feed value for domestic animals is low. 2. West Turkmen (or Coastal) Region is a lowland plain with sand-salt and claysalt desert, recently exposed by the Caspian Sea. Un stabilized dune sands are well developed here; like solonchaks, they lack vegetation. Groundwater (usually highly mineralized) lies from 0.3 to 2.0 m deep. The climate is influenced by the Caspian Sea. Average annual temperature is 15.4 DC, absolute maximum is 44 DC, absolute minimum is -18 DC; length of a frostless period is 260 days. Annual precipitation is ca. 150 mm. The impoverished vegetation is comprised mostly of halophytes which do not form a continuous cover and have low feed value. 3. Sarykamysh Region lies between the Tashauz Oasis and the Ustyurt Plateau, including the Sarykamysh Depression. The surface of this area is formed by alluvial deltaic deposits; its relief is a lowland inclined westward. Ancient river beds (e.g., Daryalyk, Daudan, and Akdarya) can be distinctly traced. Takyrs and sands are widespread; sand massifs usually lie next to dry beds. Solonchaks are found within the Sarykamysh Depression. Groundwater lies at a depth of ca. 20 m. Average annual temperature is 12 DC, absolute maximum is 43 DC, absolute minimum is - 32 DC; length of a frostless period is 222 days. Annual precipitation is 100 mm. Vegetation is dominated by Salsola richteri, S. orientalis, Haloxylon aphyl/um, Anabasis salsa, and various ephemers. Stands of Tamarix are preserved only in the Sarykamysh Depression. 4. Trans-Unguz Region is an elevated, mostly ancient alluvial plain dissected by large (30 to 60 m high) submeridional ridges. The surface of many sand ridges is stabilized by the ancient waste mantle (kyrs) which includes carbonates and gypsum. Such ridges have a rather complicated origin; their formation is due to combined action of eolic processes, erosion, and other mechanisms. Between the ridges, in depressions, are developed sand desert soils and, rarely, takyrs. In the south the Trans-Unguz Karakum is limited by the shor depressions of the Unguz. Average annual temperature is 15.4 DC, absolute maximum is 45 DC, absolute minimum is - 30 DC; length of a frostless period is 233 days. Annual precipitation is 110 mm. Groundwater is mostly Landscapes of Turkmenistan 5. 6. 7. 8. 19 mineralized and lies at a depth of 15 to 40 m. Pastures of this region are rarely used due to the absence of fresh water sources. Vegetation is dominated by psammophytes and ephemers (Carex physodes); typical shrubs include Haloxylon spp., Calligonum spp., Ephedra strobilacea, and Salsola richteri. Karakum Region occupies the largest part of the Lowland and Southeast Karakum Desert. Sands, which are well developed here, represent alluvial deposits of the ancient Amudarya as well as of the Murghab and Tedzhen. These deposits were subject to ancient river erosion and subsequent wind erosion, which led to the creation of various forms of eolic relief. Various sand ridges extend predominantly from northeast to southwest. The eastern part of this region is occupied by sand dunes (barkhans) known as the Amudarya barkhan belt. Average annual temperature here is 15.8 DC, absolute maximum is 45°C in the north of the region and 50 °C in the south, absolute minimum is - 33 °C in the north and - 28°C in the south; length of a frostless period is ca. 230 days. Annual precipitation is 115 mm in the north and 130 mm in the south. Vegetation includes psammophyte trees, shrubs, semi-shrubs, and herbaceous plants (e.g., Ammodendron conollyi, Haloxylon spp., Calligonum spp., Ephedra strobilacea, Salsola richteri, Stipagrostis spp., and Carex physodes). The richest vegetation is present in the eastern part of the Karakum region where are found large massifs of Haloxylon aphyllum and H. persicum. Amudarya Region is an area of well developed Quaternary and modern deposits. It includes a narrow strip from northwest to southeast in the middle part of the Amudarya Valley. Average annual temperature is 12°C in the north and 16.7 °C in the south, absolute maximum is 43°C in the north and 47 °C in the south, absolute minimum is - 32°C in the north and - 24 °C in the south. Length of a frostless period is ca. 200 days. Annual precipitation is 110 mm in the delta of the Amudarya, and 170 mm in the southern part of the region. The landscape is almost entirely transformed by human activity: it is an important agricultural region for cotton, rice, kenaf, melons, watermelons, vegetables, fruits, and grapes. Sundukli Region lies on the right bank of the Amudarya and is a southern offshoot of the Kizylkum Desert which lies within adjacent Uzbekistan. Its complicated relief includes ridge-like hills and buttes with altitudes from 275 to 280 m, separated by wide depressions which often include shors or salt lakes. Fresh and weakly mineralized groundwater lies ca. 20 m deep. Average annual temperature is 16°C, absolute maximum is 45 DC, absolute minimum is - 30°C; length of a frostless period is 220 days. Annual precipitation is 120 mm. Sand massifs possess psammophyte vegetation with predominance of Calligonum spp. and Ammodendron conollyi. Atrek-Sumbar Region is located at the very southwest of Turkmenistan and includes only the lowland portion of these rivers' drainages. The climate is mild and subtropical. Average annual temperature is 17.1 DC, absolute maximum is 48°C, absolute minimum is - 16 dc. Annual precipitation is 187 20 9. 10. 11. 12. Agadzhan G. Babaev mm. High amounts of sunlight and a long frostless period (271 days) allows cultivatinon of suchvaluable subtropical crops as olive, fig, pomegranate, and date palm. The groundwater is highly mineralized and lies close to the surface. Less salinized territories are used for agriculture; irrigated areas are small and scattered. Kopetdagh Region includes parallel; mountain ranges comprised of Cretaceous and Paleogene sediments (sandstone, limestone, clay, and marl) which in the foothills are covered by younger Quaternary loess deposits. This region has high seismic activity. The relief is highly dissected by erosion; slopes, especially northern ones, are usually steep and have cliffs. These slopes are dissected by a dense network of deep transverse ravines and gorges. Cuestas are often developed in southern slopes. Average annual temperature is ca. 10 °C, absolute maximum is 35°C, absolute minimum is - 24 °C; length of a frostless period is 190 days. Annual precipitation is 300 mm, and at certain elevations, non-irrigated agriculture (bogara) is possible. There are many small rivers, whose water is completely spent for irrigation. Vegetation is extremely diverse; in higher belts, shrubs and trees (juniper, maple, and others) are present as well as herbaceous plants. Mountain grasses such as species of Elytrigia, Stipa, and Festuca have high feed quality. Kopetdagh Submontane Region includes the narrow inclined submontane plain next to the northern slope ofKopetdagh. It is formed from alluvial fan deposits and loess deposits represented by heavy and light loams. Climate is similar to that of the Karakum Desert but is somewhat softened by the influence of the Kopetdagh Mountains. Average annual temperature is 16°C, absolute maximum is 48 °C, absolute minimum is - 26 °C; length of a frostIess period is 230 days. Annual precipitation is 228 mm. The plaIn includes a developed agricultural zone (grapes, vegetables, fruits, and cotton). Murghab-Tedzhen Region embraces the valleys and deltas of the Murghab and Tedzhen Rivers which are separated by the Karakum Desert. Sand and clay deposits are developed here. In the deltas lie irrigated lands; sand massifs often surround the oases. This region is a typical arid zone landscape transformed by human culture. Average annual temperature is 16.5 °C, absolute maximum is 48°C, absolute minimum is -26°C; length ofa frostless period varies from 210 to 248 days. Annual precipitation is 130 mm. Climatic conditions allow cultivation of thin-fiber cotton strains with significant yield. Groundwater in the irrigated part of the region lies from 1 to 3 m deep, and at its periphery, from 3 to 8 m deep. Construction of the Karakum Canal has connected the formerly separate Murghab, Tedzhen, and Kopetdagh submontane oases and created conditions for their concerted development. Karabil-Badghyz Region is formed from thick continental deposits of finegrained clay sandstone, loam, and loamy sand. Wide ancient valleys and depressions represent erosion forms of relief. Generally, the relief is soft and Landscapes of Turkmenistan 21 Fig. 3. Ecological regions of Turkmenistan. 1 - Cis-Ustyurt, 2 - West Turkmen (or Coastal), 3 Sarykamysh, 4 - Trans-Unguz, 5 - Karakum, 6 - Amudarya, 7 - Sundukli, 8 - Atrek-Sumbar, 9Kopetdagh, 10 - Kopetdagh Submontane, II - Murghab-Tedzhen, 12 - Karabi1-Badghyz, 13 Kugitang Region. hilly with a semidesert-steppe landscape. Average annual temperature is 16.8 °C, absolute maximum is 47°C, absolute minimum is - 32 °C; length of a frostless period is ca. 230 days. Annual precipitation varies from 200 to 240 mm. Vegetation is dominated by ephemers and ephemeroids (annual and perennial herbaceous plants with winter-spring growth). The western part of Badghyz is especially rich in herbaceous vegetation and is used for pastures throughout the year. 13. Kugitang Region is located in the very southeast of Turkmenistan. It has desert landscapes on mountainous/valley relief, highly dissected by ravines. Southward and westward the relief turns into foothills with ridges and cuestas, and then, into alluvial fan plain. Karst processes are developed in areas containing leaching carbonate rocks. The only river in this region, the Kugitang-Darya, has a low debit and does not reach the Amudarya. Average annual temperature is 17°C; average temperature in January is above 0 °C; average temperature in July is 31°C; length of a frostless period is 233 days. Annual precipitation is ca. 150 mm. Climatic conditions allow non-irrigated (bogara) cultivation of feed crops. In conclusion, we should note that the geographic zonality does not strictly determine formation of certain litho ecological types of deserts in Turkmenistan. The characteristics of the ecological regions listed above are defined by local 22 Agadzhan G. Babaev geological formations, geomorphology, and climatic conditions rather than by general zonality. Therefore, the landscapes of Turkmenistan have a complex structure. In lowland areas, the most common type of complex landscape is a combination of sand, salt, and clay (takyr-like) deserts in the ancient dry river valleys or in dry lake depressions. Walnut (Jug/ans regia) forest along the Aidere River Valley, Southwest Kopetdagh. Photo by I.A. Mukhin. 3. Climate of Turkmenistan NIKOLAI S. ORLOVSKY Abstract Detailed characteristics of the climate of Turkmenistan are given, including data on climate-forming factors, distribution of separate meteorological elements throughout the republic of Turkmenistan, and climatic features of seasonality. Turkmenistan has a very continental and exceptionally dry climate. It is determined by the low latitude position of this area, its significant distance from the oceans, features of atmospheric circulation, character of the underlying surface, and presence of mountain ranges in the southwest, south, and southeast. The continentality of climate in Turkmenistan is expressed by the sharp daily and annual changes of meteorological elements, the contrast transition between seasons, and high probability of dust storms, strong frosts, and late spring and early fall cold spells. Dryness of the climate is expressed by the very low precipitation, low air humidity, low cloudiness, high evaporation, and frequent droughts and dry winds. Ecological conditions in Turkmenistan are favorable for the development of natural vegetation only in the cold period ofthe year, when wet and humid winter-spring periods facilitate growth of ephemers and ephemeroids. This type of vegetation dries up in the hot and dry summer period. Growth of agricultural crops in Turkmenistan is possible only under artificial irrigation. Introduction Climate is one of the most significant factors influencing human activity and environmental conditions. It determines development of vegetation and soils, defines the image of landscapes, and creates a background for agriculture. Climate of a territory depends on its geographic location and underlying surface. Turkmenistan is located in the center of the Asian continent and is neighbored by the Mediterranean Region, Indostan, Central Asia, and Siberia. This geographic location determines four climatic features of the republic: significant sunshine duration, high temperatures of air and soil, sharp continentality, and extreme dryness. V. Fet & K.I. Atamuradov (eds.), Biogeography and Ecology of Turkmenistan, 23-48. © 1994 Kluwer Academic Publishers. 24 Nikolai S. Orlovsky The meteorology of Turkmenistan is well known. The first meteorological stations were established in 1869 in Krasnnovodsk and in 1876 in Kizyl-Arvat. By 1917, the territory of Turkmenistan possessed 24 active meteorological stations. Today, there are 56 stations and 44 posts conducting meteorological observations. Table 1 gives a list of representative stations and their altitudinal position. We should note that only lowland Turkmenistan is well characterized climatically. In the mountains, climate is more complex, and the number of existing stations is not sufficient for thorough monitoring: there are only four stations located at altitudes from 500 to 1,000 m (Kushka, Germab, Firyuza, and Kuitan), two stations located from 1,000 to 2,000 m (Saivan and Gaudan), and only one above 2,000 m (Kheirabad). Table 1. A list of basic meteorological stations in Turkmenistan. Station Tashauz Kunya-Urgench Shakhsenem Bekdash I Danisher-Kala Kara-Bogaz-Gol Yekedzhe Chagyl Kizyl-Kun Dargan-Ata Koshoba Kuuli-Mayak Darvaza Davali Krasnovodsk Zeagli Yaskhan Dzhebel Akmolla Ilchik Cheleken Aidin Yerbent Deinau Altitude (m) 87 80 62 -26 137 -23 59 115 -17 142 104 -22 94 46 -13 139 -9 -10 108 175 -14 -16 87 181 Station Altitude (m) Kazandzhik 33 Ogurchinsky Island -26 Chardzhou 188 Kizyl-Arvat 98 200 Sayat Bakhardok 87 Cheshme 147 Bekibent 208 Repetek 185 Bugdaili -1 Archman 157 1,036 Saivan Burdalyk 211 Kara-Kala 312 Bakharden 159 Geok-Tepe 204 Uch-Adzhi 185 Chat 90 Germab 988 227 Ashkhabad Firyuza 660 Chashkent 200 Kuitan 790 Kheirabad 2,028 Station Altitude (m) Kerki Chaskak Gaurdak Gaudan Kizyl-Atrek Mary Bairam-Ali Nichka Charshanga Gasan-Kuli Tedzhen Kaakhka Iolotan Dushak Tedzhenstroi Ata Serakhs Sary-Yazy Pulikhatum Takhta-Bazar Kushka 241 235 482 1,486 32 222 240 232 265 -25 187 308 259 248 215 235 275 306 395 349 625 We used data published in five issues of the Reference Book on the USSR Climate (Spravochnik po klimatu SSSR, 1964-1969, 144 tables) and in the Scientific and Applied Reference Book on the USSR Climate (Nauchnoprikladnoi spravochnik po klimatu SSSR, 1989, which contains 147 climatic criteria). We also used data from published literature, including the author's publications. Climate of Turkmenistan 25 Climate-forming Factors The climate of lowland Turkmenistan is very continental and extremely dry. These climatic features are due to the geographic location of this territory at low latitudes, its significant distance from the oceans, atmospheric circulation, the character of its underlying surface, and presence of mountain systems in the southwest, south, and southeast. Solar Radiation. Turkmenistan's southern location provides for a high position of the sun. During the winter solstice, its height at noon is from 26° to 32°, and during the summer solstice, it is from 72° to 75°. High noon position of the sun and low cloudiness in the warm period of the year determine long sunshine duration. The probability of clear sky is 90 to 95%; there are only 25 to 30 days in a year without sun. As a result, annual sunshine duration varies from 2,600 to 3,100 hours or even more (Spravochnik 1966; Yurin and Myagkov 1959). This is comparable to sunshine amount in such southwestern American states as Utah, California, and New Mexico (Babushkin 1981). Areas of maximal sunshine duration include the eastern part of the Lowland Karakum, southern part of the low Amudarya, and the entire middle part of the Amudarya. Sunshine duration decreases north, west, and southwest of these areas. The republic's southern location and long sunshine duration also provide high sun radiation. The annual direct sun radiation varies from 63 to 73% and equals ca. 4,000 to 4,600 Mjlm2 (Table 2). Global radiation varies from 6,000 to 6,800 Mj/m 2 (Table 2), which is the maximum observed in Middle Asia (Orlovsky and Shlikhter 1975). About 25 to 30% of the global radiation is reflected from the earth; the absorbed portion varies in Turkmenistan from 4,300 to 5,200 Mj/m2 • In winter, due to the distribution of snow cover with its high albedo, 62 to 75% of the global radiation is absorbed; in summer, the absorbed portion is from 70 to 80% (Table 2). The annual radiation balance is rather low; in the Lowland Karakum, it reaches 2,000 Mjlm2 ; in oases, it exceeds 2,500 Mjlm 2 and reaches 2,940 Mj/m 2 in the middle part of the Amudarya Valley. The radiation balance is spent in the turbulent heat exchange between the atmosphere and surface, the heat flow to the soil, and evaporation. The structure of the heat balance determines the heat regime of the air and its humidification. Fig. 1 demonstrates the annual dynamics of the components of heat balance for different natural regions of Turkmenistan. It illustrates the relationship between physical/geographical conditions and components of the heat balance and their changes under hydromeliorative transformations. Especially characteristic is the structure of heat balance in the warm period of the year. In summer, minimal heat (4 to 7%) is spent in evaporation from the soil in deserts, while from 72 to 88% of heat balance is spent in heating of the air. Therefore, in summer the Karakum Desert is the center of the formation of overheated air. Average July temperature here is 32° C and can maximally reach 50° C. 26 Nikolai S. Orlovsky Table 2. Solar radiation at horizontal surface, in Mj/m2 (Nauchno-prikladnoi ... , 1989) Meteorological station Period KaraBogaz-Gol Bekibent GasanKuli Annual 3,976 101 December July 587 3,963 141 517 3,761 139 520 2,091 Annual December 109 251 July 2,316 103 273 2,467 106 302 Annual 6,067 December 210 July 838 6,279 247 790 6,226 244 774 Annual 4,324 December 155 July 612 4,303 163 557 4,538 188 570 Annual December July 2,002 30 317 2,317 44 332 nla nla nla Yaskhan Akmolla Direct radiation 4,207 4,511 88 110 603 668 Diffuse radiation 2,206 2,120 102 96 239 229 Global radiation 6,715 6,327 184 212 842 897 Absorbed radiation 4,546 4,659 134 147 640 612 Radiation balance 1,898 nla 20 nla nla 313 Chardzhou Ashkhabad 4,610 107 704 3,958 101 592 2,206 105 216 2,183 94 248 6,816 213 920 6,139 195 839 5,250 159 700 4,584 147 608 2,914 34 450 2,147 22 332 Atmospheric Circulation. A year in Turkmenistan is distinctly divided into two periods: a very dry warm period with stable hot weather, and a relatively humid cold period with extremely unstable weather. During the cold period, the republic is influenced by the southwestern periphery of the Siberian anticyclone as well as by air mass inbreaks from the northwest and north (Table 3). Cyclonic inbreaks from the south also playa significant role during the cold period. The frequent repetitiveness of cyclones produces unstable winter weather, increased cloudiness, shifts from dry weather to rain and snow, and sharp changes in air temperature and humidity. Inbreaks of cyclones from the south of the Caspian Sea, from the upper parts of the Murghab, Tedzhen, and, more rarely, from the upper Amudarya River carry tropical air; thus, sudden cold attacks in winter often are followed by short periods of warming. As a result, snow cover in Turkmenistan is not formed every year. Winter weather varies depending on the prevalence of certain atmospheric processes. If cyclones carrying warm air prevail, anomalous warm winters occur. In contrast, the predominance of cold inbreaks results in very severe winters with long frost periods, especially if the Siberian anticyclone develops significantly. Summer brings hot dry weather, and the role of radiation increases. The intensity of atmospheric processes weakens, and cyclonic activity almost ceases. Local tropical air forms which is very similar to the tropical air carried from Climate of Turkmenistan '",,' j 27 4 2 2.5;,4 .,&7,& 8:3,8 0 -8:3,8 III V VII MONTHS IX XI III V VII IX XI MONTHS Fig. 1. Annual dynamics of the components of heat balance: (I) Tedzhen Oasis, (2) Murghab Oasis, (3) Central Karakum, (4) Southwest Turkmenistan. P - heat balance, P -- turbulent heat exchange with the air, E - heat spent on evaporation, B - heat flow to the soil. Asia Minor and the eastern part of the Mediterranean Sea. Intensive heating of the underlying surface of this tropical air leads to the formation of thermal lows above southeastern Turkmenistan, resulting in cloudless skies, dusty hazes, very high temperatures, and low relative air humidity. During the warm period, cold air invasions may osccur from northwest and north, usus ally under cloudless skies and accompanied by strong wind, dust storms, a temperature drop of 4 to 6°, and increased humidity. West and northwest invasions cause rainstorms and heavy rains on the eastern shore of the Caspian Sea and in northwestern Kopetdagh, but clouds rarely reach central Turkmenistan. Significant cooling occurs rarely, and only during multiple invasions of cold air. Therefore, during the year a successive change of air masses takes place: air masses of temperate latitudes prevail in winter, whereas continental tropical air January February March April May June July August September October November December Month northwest 16 17 17 13 22 32 23 19 21 21 16 16 Upper Amudarya 4 5 3 6 4 2 0 0 2 3 2 4 South of the Caspian Sea I 7 10 7 I 2 0 12 10 3 0 II 10 11 10 11 11 6 3 0 0 7 12 Murghab and Tedzhen Invasions from Inbreaks from Table 3. Probablility of basic circulation types (number of years) (Bugaev et al. 1957). 11 8 8 11 5 5 9 9 10 9 15 16 north 12 17 20 27 33 31 22 19 18 12 12 10 west 27 24 23 26 19 0 0 0 40 38 35 34 0 0 0 0 0 5 22 17 2 0 0 0 Southwest Thermal low periphery of the Siberian anticyclone ~ C;;;; ~ .." a ~ ~ -. c ~ 00 N Climate of Turkmenistan 29 A Fig. 2. Dynamics of the formation of the climate of Middle Asia (after Bugaev et al. 1957). (A) in the cold period of year: 1 - northwestern cold invasion, 2 - southwestern periphery of the anticyclone, 3 - northern invasion, 4 - western invasion, 5 - South Caspian cyclone, 5 - Murghab cyclone, 7 - wave activity, 8 - Upper Amudarya cyclone. (B) in the warm period of year: 1 northwestern cold invasion, 2 - southwestern periphery of the anticyclone, 3 - northern invasion, 4 - western invasion, 5 - thermal depression, 6 - South Caspian cyclone. prevails in summer. Fig. 2 shows the general routes of air masses during the year. Role of the Underlying Surface. Along with the radiation regime and atmospheric circulation, formation of the climate depends on orographic features (e.g., relief character, altitude, slope exposure, and location of 30 Nikolai S. Orlovsky mountain ranges); on presence of, and distance from, water bodies; and on the character of soil and vegetation. Lowland Turkmenistan is occupied by deserts; desert also influences the mountainous part of the republic. In the warm period, enormous sand desert areas facilitate significant transformation of incoming Atlantic air masses. Thus, the climate of Turkmenistan acquires its extreme dryness. A specific lowland regime of atmospheric circulation is somewhat modified in the foothills and mountains. Changes in altitude, slope orientation, and steepness are followed by changes in temperature, humidity, cloudiness, and precipitation. In winter, temperature inversions are often observed in the mountains. Mountains cause formation of foehn winds and mountain-valley circulation. Elevated areas form barriers against air masses and change wind direction and speed, and sometimes also serve as a barrier against cold air invasions. For example, the Kopetdagh mountain range prevents invasions of cold air masses from the north and northwest to the southwest areas of Turkmenistan; these southwestern areas are, therefore, much warmer in winter than southern and southeastern parts of the republic. The Caspian Sea affects only the shore area where, compared to other lowlands, humidity increases, the annual maximum humidity occurs in August, and breezes circulate. Existing large oases also affect climate, especially during warm periods in calm and clear weather. In oases, temperature in summer is lower, and humidity, higher. Temperature inversion forms above the wide irrigated areas, wind speed decreases, and a specific microclimate forms. Geographic Location. Due to its southern location, Turkmenistan receives a great deal of heat from the sun. Summer is long, hot, and very dry, and winter is short and generally has a non-stable temperature regime. The climate of Turkmenistan belongs to the warm climates of the earth. However, the immediate proximity of temperate areas with continental climates, exposure of the territory in the north, and the republic's separation from the subtropical zone by large mountain systems in the south determine some temperate features of the climate. Turkmenistan's position close to the center of the giant Eurasian continent and far from the oceans provides sharp continentality of its climate, expressed in the large annual amplitude of air temperature, significant and often sudden changes of meteorological elements and their very sharp fluctuations from year to year, as well as significant daily changes in weather. Continentality is also expressed in sharp contrasts during the transition between seasons. General Characteristics of the Climate Air Temperature. In lowland Turkmenistan, daily and annual air temperature varies significantly. Average annual air temperature varies between 12 to 13 DC in the north (12.4 DC in Tashauz) and 17 to 18 DC in the Central and Southeast Climate of Turkmenistan 31 Fig. 3. Air temperature distribution. (a) January, (b) April, (c) July, (d) October, (e) annual. Karakum (18 °C in Charshanga). Air temperature is lower in the mountains (Gaudan, Lekker) and on the Caspian Sea shore (Krasnovodsk, Gasan-Kuli, Kara-Bogaz-Gol); there, the rule of zonal increase of annual air temperature from north toward south is broken (Fig. 3). The sharpest decrease in average annual air temperature toward the south is observed in the Trans-Unguz Karakum, whereas in the Central and Southeast Karakum the thermal regime is relatively homogeneous. Average amplitude of annual air temperature is 30 to 34°C in the northeastern Turkmenistan, and 23 to 25 °C in the southwest and on the Caspian shore. The lowest average monthly air temperatures are recorded from December to February when, in northern Turkmenistan, the temperature falls below 0 0c. 32 Nikolai S. Orlovsky Average maximal monthly temperature during these months in the daytime is from 0 to 5 °C in the north, and from 5 to 10 °C within the remaining lowland part of Turkmenistan. Average minimal monthly temperature in Turkmenistan (except in the southwest) is below 0 °C from December to February; it varies from - 5 to - 9 °C in the north, and from 0 to - 2 °C in the southeast. The average absolute maximum varies from 1 to - 5 °C in the north, and from 3 to 10 °C in the southeast. Average amplitude of daily temperature is from 7 to 11 °C in the most areas. From March to May, average monthly air temperatures sharply increase, from 7 to 10°C every month throughout the republic. This period is optimal for vegetation. Average monthly air temperature in March is 5-6 °C in the north, and 9-10 °C in the southeast. In May, average temperature in the Central and Southeast Karakum reaches 24 to 25°C; in the rest of the lowland territory, it is above 25 0c. Average amplitude of daily temperature varies from 9 to 12°C in the coastal areas, and from 12 to 15 °C in the rest of Turkmenistan. The highest air temperatures occur from June to August. The hottest month is July (except in the Caspian coastal zone, where it is August), but in June and August the average monthly air temperatures are only 1 to 2 °C lower than in July. Such a high thermal background is formed due to the stability of the radiation balance of the surface, which also is responsible for the lowest average amplitude of daily temperatures. Generally, June and July are characterized by monotonous hot weather, especially in the Central and Southeast Karakum. Average maximal monthly temperatures during these months reach from 35 to 40°C (from 31 to 34 °C on the Caspian shore). Average amplitude of daily temperature is from 15 to 20°C (from 8 to 12 °C on the Caspian shore). The absolute maximum (50°C) temperatures were recorded from Repetek and UchAdzhi in 1915, 1925, and 1937. In fall (September and October), a sharp decrease of the average, maximal, and miminal monthly air temperatures occurs everywhere at a rate similar to their increase in spring. Average monthly temperatures fall from 21 to 26°C to 4 to 5 °C in the north, and from 23 to 24°C to 8 to 10°C in the rest of the republic. Average maximal air temperature falls from 26 to 28 °C to 12 to 18°C and from 31 to 35 °C to 16 to 18°C, respectively. Generally, this period of the year is also favorable for the development of vegetation. However, precipitation is much lower in fall than in spring, and many desert plant species resume their growth after the summer dormant period only with the onset of the first fall rams. Soil Temperature. The thermal regime of soils is an important ecological element. Due to the dry climate of Karakum, almost all incoming solar radiation is spent on soil warming; therefore, soil temperature during the warm period is high everywhere. Average monthly soil surface temperature in July varies from 32 to 38°C (Table 4) and, on certain days, can reach a maximum of 76 to 78 0c. Average annual temperature of soil surface varies from 14 to 15°C in the northern Karakum, and from 18 to 20°C in the Central and Southeast Kunya-Urgench Leninsk Tashauz Yekedzhe Chagyl Zeagli Yaskhan Dzhebel Aklmolla Chardzhou Kizyl-Arvat Bekibent Repetek Kara-Kala Ashkhabad Kerki Kizyl-Atrek Bairam-Ali Tedzhen Kaakhka Iolotan Serakhs Lekker Takhta-Bazar Kushka Station -5 -5 -4 -4 -2 14 14 15 15 18 18 18 20 19 18 19 19 19 19 19 19 21 19 19 19 18 20 17 19 16 2 3 0 3 2 I 0 3 1 3 1 2 5 2 2 I 0 3 0 -I January annual (0C) 34 32 34 35 36 37 38 37 38 34 37 35 38 36 37 35 36 37 36 37 35 36 34 37 32 July Soil surface temperature Table 4. A temperature regime of soils in Turkmenistan. 5143 4943 5268 5441 5832 6133 6320 6470 6316 5846 6214 6194 6596 6409 6317 6198 6918 6269 6490 6280 6144 6460 5508 6502 5356 surface 5123 4774 nla 5306 5759 5989 6093 6554 6160 5654 6149 6079 6745 6238 6031 6232 6918 6103 6416 6231 6049 6550 5458 6468 5197 at 10 cm 5034 4683 nla 5206 5619 5956 6128 6617 6178 5821 6159 6088 6736 6147 6098 6252 6928 6075 6160 6231 5885 6554 5349 6849 5134 at 20 em Sums of temperatures higher than 10°C 209 207 213 215 224 235 238 250 235 237 237 250 246 257 241 251 274 242 255 246 246 255 228 251 233 surface 218 212 n/a 222 232 244 250 266 248 248 249 259 259 263 251 268 282 255 263 254 258 268 240 259 249 at 10 cm 222 216 nla 226 238 252 256 278 256 256 254 265 269 265 259 274 290 263 269 261 266 275 246 270 255 at 20 cm Days with temperatures higher than 10 ° 1.27 1.16 nla 1.13 1.21 1.15 1.15 1.21 1.14 1.12 1.16 1.18 1.27 1.22 1.13 1.18 1.26 1.16 1.19 1.18 1.20 1.21 1.28 1.20 1.14 H-index w w ;::: S ;::: 0:;. <1l ~ * ~ ~ ~ l:> Q §. 34 Nikolai S. Orlovsky Karakum. The sum of temperatures varies from 4,900 to 6,900 DC, both at the soil surface and at a depth of 20 cm (Table 4). Dimo (1968) proposed an index of soil heat ability (H) which is a ratio between the sum of soil temperatures at a depth of 10 cm and the sum of air temperatures. This index characterizes the relationship between the climate of the surface air layer and climate of the soil. The H-index values for Turkmenistan (Table 4) indicate a high ability of soils to absorb heat. Cloudiness. The length of sunshine duration is related to cloudiness. Average annual cloudiness in Turkmenistan is from 3 to 4 points. The lowest cloudiness is recorded from June to August (l point); it increases toward winter (6 to 7 points in January). Total number of cloudy days varies from 45 to 80 a year. The maximum is observed on the Caspian shore (from 60 to 80 days) and in the foothills (60 to 70 days). The minimal number of cloudy days is recorded for the Trans-Unguz and Southeast Karakum. The average annual number of cloudless days is maximal in the Southeast Karakum (from 166 to 185); the minimal average annual number of cloudless days (100) is recorded from the Caspian shore. Precipitation. Distribution of precipitation in the territory of Turkmenistan reflects both zonality and local features (relief, underlying surface, large water bodies, and industrial activity). Average annual precipitation varies from 110 mm (Kara-Bogaz-Gol Bay in the northeast of the republic) to 398 mm (KoineKesir in the Kopetdagh Mountains). Precipitation is minimal in the TransUnguz Karakum; it increases to the south, southeast, and west of this area. Four regions can be distinguished within Turkmenistan according to the level of annual precipitation: (1) the northeasterly portion of the republic (Trans-Unguz Karakum and Kara-Bogaz-Gol Bay, with precipitation less than 110 mm); (2) the Lowland Karakum, with precipitation from 110 to 150 mm; (3) the foothills of the south and southeast, with precipitation from 150 to 200-250 mm; and (4) mountains, with precipitation more than 250 mm (Fig. 4). Low precipitation in the areas of the Trans-Unguz Karakum and KaraBogaz-Gol Bay is due to the lesser significance of such precipitation-forming synoptic processes as outbreaks of southern cyclones and wave activity at the mountain-based atmospheric front. In these areas, precipitation is primarily formed only during western or northwestern invasions of temperate air or during slow-moving high cyclones over the lower part of the Amudarya River. Another feature of the precipitation regime in Turkmenistan is its great fluctuation in time and significant variation of annual and monthly averages compared to a multi-year average (Table 5), especially in the warm period of the year. Throughout the territory, precipitation occurs predominantly from October to May, with monthly maximums from March to April (Fig. 4). From June to September, occasional precipitation may reach the surface in the west and north of the republic, due to the invasion of western or northwestern temperate or wet Mediterranean air masses which contain high humidity. In Climate of Turkmenistan 35 Fig. 4. Average annual and monthly precipitation (mm). summer, the effect of heated surface on these air masses is their rapid tranformation into tropical ones, with a high level of condensation of the water vapor. In the west and north, such transformation is less intensive, but occasional precipitation does occur; in the east and southeast, however, water either does not precipitate from the completely transformed air, or precipitation does not reach the surface. A prolonged summer drought, from June to September, is common for eastern Turkmenistan. For instance, in Bairam-Ali a total of only 23 mm of precipitation was recorded from June to August during a 10 year period; in Iolotan, only 6 mm was recorded in the same months during 30 years. These features of precipitation are reflected also in its daily distribution, which is determined by the combination of moisture content in the tropospheric air and the transformational influence of the underlying surface. In the east of the republic, where transformation of the invading air masses is the most significant, daily maximum precipitation is observed from March to April (Balashova et al. 1960; Chelpanova 1963) although maximal moisture content in the air throughout the republic is observed during July and August (Kuznetsova 1983). The daily maximum precipitation in the Caspian coastal areas is observed from July through August due to the moisture content of the invading air masses. Throughout the rest of lowland Turkmenistan, the daily maximum precipitation is observed from May through July. In the east, the stationary cyclone in the lower part of the Amudarya River can cause up to 60 to 75 mm of daily precipitation. In western Turkmenistan, the daily maximum precipitation depends on western and northwestern air invasions and usually occurs in short, heavy bursts. Its distribution, affected by the relief, varies from 70 to 80 mm on the 36 Nikolai S. Orlovsky Table 5. Precipitation in Turkmenistan Station Average precipitation (mm) annual Tashauz Chagyl Darvaza Bakhardok Cheshme Chardzhou Kerki Charshanga Uch-Adzhi Bairam-Ali Tedzhen Takhta-Bazar Lekker Kushka Kaakhka Ashkhabad Bakharden Kazandzhik Kizyl-Arvat Krasnovodsk Bekibent Gasan-Kuli Kizy1-Atrek 90 102 97 124 97 116 172 149 118 135 139 241 255 260 200 230 190 148 205 103 165 196 188 warm period cold period (from April to (from October) November to March) 37 51 39 49 38 38 40 34 35 40 47 53 54 57 74 97 82 60 85 40 83 91 81 53 51 58 75 59 78 132 115 83 95 92 188 201 203 126 33 108 88 120 63 82 105 107 Maximal monthly precipitation (mm) Maximal daily precipitation (mm) 64 n/a n/a nla nla 115 89 n/a nla 109 97 122 nla 167 nla 128 n/a 92 132 n/a nla 107 110 38 nla 43 nla nla 63 40 nla n/a 44 41 58 nla 73 n/a 56 n/a 40 77 77 n/a 79 91 Caspian shore to 90 to 100 mm in the foothills and mountains. For example, in July, 1928, Kizyl-Arvat had 110 mm of precipitation, whereas the multi-year average was 5 mm for July and 77 mm for the entire warm period of the year; of the 110 mm, 91 mm (or 18 times the monthly average) was recorded on July 5. The highest daily maximum of 123.8 mm was recorded in September, 1963, in Khodzha-Kala (West Kopetdagh). Air Humidity. The regime of air humidity in Turkmenistan is defined by high summer temperatures, shortage of precipitation, and absence of large water bodies. Average annual absolute air humidity in the Central Karakum varies from 6 to 7 mb (8 to 9 mb in oases). On the Caspian shore, it reaches 11 to 14 mb; and in the Amudarya Valley, 7 mb in the north (Danis her-Kala) and 9 mb in the south (Kerki). In winter, the absolute air humidity is less dependent on the underlying surface and is distributed more evenly, increasing from north to south from 3 to 5 mb. The highest maximal absolute air humidity in summer is recorded from the Caspian shore (21 to 26 mb); it ranges from 14 to 16 mb in the Amudarya Valley, and 10 mb in the center of the Karakum Desert. Climate of Turkmenistan 37 The relative air humidity reaches its maximum in January when it is distributed rather evenly throughout the republic (although varying from 75 to 78% in the Trans-Unguz Karakum, the foothills of Kopetdagh, and on the Caspian shore). In the driest period, from June to September, the relative air humidity in the Karakum Desert is from 20 to 30%. It is rather high in summer in the coastal zone (69%, Gasan-Kuli) and in oases (30 to 35%); in the Amudarya Valley relative air humidity in summer is from 37 to 41%, which is higher than in the adjacent non-irrigated areas. On certain days, minimal air humidity in the Central Karakum can fall to 2 to 3%. On the Caspian shore, days with 100% relative air humidity may occur, but they are extremely rare (0.3% of all days). No days with humidity less than 10% have been recorded in summer on the shore, where humidity often can reach 50 to 70% at noon. In the Kopetdagh Mountains, daytime humidity in July usually varies from 20 to 40%. The lowest values of air humidity deficit are recorded in January, when it is as low as 1.0 to 1.5 mb in northern Turkmenistan, increasing to 3.0 to 3.8 mb toward the south. It sharply increases beginning in February and reaches its maximum in July (32 to 33 mb in the Trans-Unguz Karakum, 37 to 41 mb in the Central Karakum, and 40 to 42 mb in the Southeast Karakum). In certain years, the monthly humidity deficit in the Southeast Karakum can reach 70 mb (absolute maximum was recorded as 73 mb for Uch-Adzhi). In the coastal areas, the maximal monthly humidity deficit is observed in August when air temperature reaches its maximum. Evaporative Capacity. High values of air humidity deficit facilitate intensive evaporation from the water surface. Annual evaporation from the water bodies of lowland Turkmenistan varies from 1,000 to 2,300 mm and is highly dependent on physical-geographical conditions, air humidity, and air temperature. It reaches the maximal value (from 2,000 to 2,300 mm) recorded for Middle Asia in the Central Karakum. Westerly and easterly from this area, evaporation decreases; it is 1,000 mm in the narrow coastal zone of the Caspian Sea, 1,600 mm in the Amudarya Valley, and from 1,400 to 1,600 mm in the Murghab and Tedzhen oases. Annual evaporation in the foothills of Kopetdagh and in Karabil varies from 1,500 to 1,600 mm; in the Tashauz oasis, from 1,200 to 1,400 mm. In Badghyz and in the submontane plain of Kugitangtau, increased humidity deficit and wind speed lead to an increase of evaporation up to 2,000 to 2,200 mm annually (Durdyev and Orlovsky 1984). Wind. During the year, northeasterly winds prevail in northern Turkmenistan; easterly winds, in the central part of the republic and along the the submontane plain of Kopetdagh; and northerly winds, in the Southeast Karakum. In some regions in the southeast, northern winds become northwesterly due to the relief. Average annual wind speed in lowland Turkmenistan is from 3.2 to 4.2 mlsec. In oases with their high trees, wind speed does not exceed 3.1 mlsec. Wind speed changes discernably during the year, with maximal average monthly values usually occuring in spring and summer; only on the Caspian shore and in 38 Nikolai S. Orlovsky Kopetdagh is maximal wind speed recorded in winter. Minimal wind speed is observed in fall. Weak and moderate winds (from 0 to 5 m/sec) prevail throughout the republic (75 to 85% of all speed records). Only on the Caspian shore and on the northern slopes of Kopetdagh are wind speeds from 6 to 9 m/sec. The number of days in a year when wind speed exceeds 15 m/sec is from 5 to 10 in the Central Karakum, and from 3 to 8 in the Southeast Karakum; it increases on the northern Caspian shore (40 days), and in the eastern foothills of Kopetdagh and in the Amudarya Valley (54 days). Strong winds are commonly recorded from March to April, and only in the southeast is maximal occurence of strong winds shifted to the summer. Wind speed in the Central Karakum and in the deltas of the Murghab and Tedzhen can reach 16 to 18 m/sec; in the southwest and north of the republic, 20 to 21 m/sec; and on the Caspian shore and in the Amudarya Valley, 22 to 25 m/sec (Semenova 1961). Atmospheric Events. During strong winds, dust storms appear in lowland Turkmenistan, especially in spring and summer. They occur more often during cold invasions from the west, northwest, and north. The maximal annual number of days with dust storms is recorded in Nebit-Dagh (60 days); the number ranges from 30 to 40 days in the Central Karakum and in the Southeast Karakum. Dust storms are rare in the mountains and oases. Unfavorable weather events include fogs, hail, glaze, and rime deposit. Fogs are most common on the Caspian shore (from 20 to 30 days a year); annual number of foggy days is 16 to 17 in the north of the republic, and from 8 to 10 in the sourhern and southeastern parts of the Karakum Desert. In the lower Amudarya, number of foggy days increases to 20 to 25. Fog there forms primarily from November to March; fogs are very rare in the lowlands from April to September except in the middle part of the Caspian shore, where fogs in summer occur three to four times more often than in winter. Hail is very rare event in Turkmenistan. In the lowlands, an average of one to five days with hail occur per 10 years. Maximum hail is recorded in the mountains of Kopetdagh. Glazed frost and rime deposits also are rare weather events. Glaze is observed from November to March (in mountains, from October to May), with maximum of glaze days in December or, sometimes, in January. In the lowlands, there are, on an average, up to three days a year with glaze. In certain years, the number of days with glaze increases to 9 to 13 in the lowlands, and to 17 in Kopetdagh. Rime deposit forms more often than glaze and is observed in the lowlands from November to March, with a maximum of 13 to 20 days a year. Rime is recorded from one to two days every year in Central Karakum, from 4 to 7 times every 10 years in the southern Turkmenistan, and even more rarely on the Caspian shore (two to four times every 10 years). Climate of Turkmenistan 39 Climatic Seasons in Turkmenistan Winter. Climatic seasons are defined by the thermal regime, humidity, and features of the development of pasture vegetation. In Turkmenistan, the climatic seasons do not coincide with the calendar (astronomical) seasons. Winter season in the lowlands begins when the stable average daily air temperatures fall lower than 5 °C (Balashova et al. 1960; Babushkin 1964). This time is marked by the beginning of a relatively dormant phase in many shrubs and semishrubs, and with massive falling of branches and fruits of saksaul (Haloxylon spp.). In 30 to 35% of all years, winter period begins simultaneously throughout the republic except in the southwest, which is influenced by the non-freezing Caspian Sea from the west and protected by Kopetdagh from the southeast. In 40 to 45% of all years, winter first begins in the north (early November) and northwest (mid-November). From late November to early December, winter begins in the Krasnovodsk Plateau, in the Central Karakum, and in the foothills of Kopetdagh. Somewhat later (mid- and late December) winter begins on the southern Caspian shore, and finally (from late December to early January) it comes to Southwest Turkmenistan. Time of the winter arrival varies from year to year. For example, if an average arrival of winter in the Central Karakum is late November, it may begin from early November (once every 20 years) or even in late October; at other times, it may be delayed until mid-December. Duration of the winter decreases from north to south. It lasts from 101 to 130 days in the north, averaging 90 days in the Central Karakum (from 74 in Bairam-Ali to 105 in Zeagli), and decreases to 83 in Badghyz, 76 in the foothills of Kopetdagh, and 53, in the Southeast Karakum. Especially short is the winter in Southwest Turkmenistan (from 10 to 30 days). Within the winter, so-called "real" winter periods exist which are characterized by average daily air temperatures lower than 0 °C and by the complete dormancy of vegetation (Babushkin 1964). Such periods are almost absent in the southwest, in most parts of the submontane plain of the Kopetdagh, in the south of the Central Karakum, in the Southeast Karakum, in Badghyz, and in Karabil. Farther to the north, "real" winter periods occur more often; e.g., in the northern part of the Central Karakum 30 to 60 days a year (40% of the winter season) have an average daily air temperature oflower than o°C. These periods increase from 60 to 102 days in northern Turkmenistan and include from 49 to 54% of all winter days in northwestern Turkmenistan, and from 65 to 74% in the Trans-Unguz Karakum (Orlovsky and Volosuyk 1974). In some years, the "real" winter spreads throughout the entire republic (e.g., 1929-1930, 1932-1933, 1933-1934, 1934-1935, 1936-1937, 1944-1945, 19481949, 1968-1969; Babushkin 1964). Sharp winter cold spells are due either to invasions of Arctic or temperate air masses from the northwest, north, or, sometimes, from the northeast, or by radiation cooling inside an air mass. During especially strong cold invasions, temperatures can drop to a range of - 26 to - 35°C even in the south. Only Southwest Turkmenistan, protected by 40 Nikolai S. Orlovsky Kopetdagh, has higher absolute temperature minimums (from - 15 to - 20°C). Warm winters can occur as well as severe cold ones. Cold invasions during warm winters are rare and not intensive; relatively warm air masses (temperate Turanian and South European air) prevail in these years (Bugaev et al. 1957). In warm periods some pasture plant species, usually ephemeroids and ephemers, start growing. Winter precipitation brought by cold air masses from the north and west, can occur as rain or as snow. In lowland Turkmenistan, the snow cover is not stable and may form and thaw several times. Usually, snow cover forms in the lowlands beginning in late December; on the Caspian shore, snow forms from late December to early January; and on the submontane plain of the Kopetdagh, in Badghyz, and in Karabil, it appears usually in mid-December. In early winters, snow sometimes appears 45 days earlier than average. Thaws occur almost everywhere in late February, except in the northwest (average March 2). The latest thaw is usually near the end of March, but in Badghyz and Karabil snow may remain until early April (record date, April 13). In Turkmenistan, there are no areas without occasional snow cover. Even in the warmest southwestern part of the republic (Kizyl-Atrek) there are 5 to 6 days a year with snow (maximum, in 1969, was 20 days in Kizyl-Atrek and 25 in Kara-Kala). Maximal number of days with snow is recorded for the high mountain belt of Kopetdagh, the areas of Badghyz and Karabil, and the northwest of the republic. In Badghyz and Karabil snow cover stays from 16 to 18 days on average (with maximum 61 to 64 days); in the northwest, the average is 21 days of snow cover, and maximum, 73 days. In the rest of northern Turkmenistan, the average number of days with snow cover varies from 11 to 13 (maximum, 51 days, in Kunya-Urgench). The highest daily snow cover (excepting Kopetdagh) has been recorded in Badghyz and Karabil areas and is, on average, 10 cm (with maximums from 37 to 43 cm). The highest snow height, 68 cm, has been recorded in Akar-Cheshme (the Badghyz Reserve). Average height of the snow cover in the southwest, northwest, and in part of the Central Karakum, is 4 to 5 cm; in some winters, however, it has reached 19 cm (Kizyl-Atrek) or 20 cm (Kara-Kala). In the southern and central parts of the Central Karakum and in the Southeast Karakum, average snow height is from 6 to 8 cm. Maximums recorded are 37 cm (Bairam-Ali), 41 cm (Tedzhen), 43 cm (Zeagli), and 56 cm (Darvaza) (Balakirev 1972). Spring. In the beginning of March in the lowlands (or in February in the south), air temperature rises and begins to exceed 5 0c. Stable average daily temperature higher than 5 °C marks the beginning of spring; it corresponds to the start of active plant growth, and appearance of herbaceous vegetation and flower buds on fruit trees. Spring begins early, on average before February 10, in the far southwest (Kizyl-Atrek) and southeast (Charshanga); by February 20, it comes to the rest of the southwest, to the south of the Central Karakum, to the Southeast Climate of Turkmenistan 41 Karakum, and to Badghyz. By March 1, spring begins in most of the Central Karakum and in Karabil and is established in the north by March 20. Therefore, for the entire republic the transition from winter to spring extends between 50 to 60 days. Duration of the spring increases from north to south from 48 to 80 days. The southwest has the longest spring (from 90 to 105 days); the Caspian Sea shore, from 80 to 87 days. During the spring, temperature rises and precipitation increases. Already in March, maximal daytime temperature can reach 30 to 39°C. However, the weather is still unstable due to the intensification of cyclonic activity. Warm periods may change to sudden colds. Sometimes, near-winter weather appears, with short but significant frosts and snow formation. For example, in March of 1959 and 1960, snow cover was observed in Badghyz and Karabil for 16 days; its maximal height reached 32 cm. During this time, air temperature fell to -15 °C; average maximum wind speed was 6 m/sec. In the Central Karakum and in the northwest of Turkmenistan, the number of the days with snow in March in certain years has varied from 8 to 10, with maximal snow height 12 to 15 cm. Temperature during these periods fell to -21 to -24°C; average maximum wind speed was 9 to 11 m/sec (Balakirev 1972). Returning cold weather is very characteristic for the spring. On average, final cold spells occur commonly in early March in the southwest of the republic and in mid-March on the submontane plain of Kopetdagh and in the Central Karakum. Final cold spells in the north and in Karabil occur as late as early April. During warm springs, colds occur from February in the south to early March in the north; during cold springs, however, last colds have been recorded as late as April 1 in the southwest, and from April 17 to 21 in the Central Karakum. Late spring colds are dangerous for the growth and development of trees and shrubs, most of which by this time have fully developed leaves, and some of which are in bloom. One-year shoots of such desert plant species as Haloxylon aphyllum, H. persicum, Calligonum spp., Salsola richteri, Ammodendron conollyi, and Astragalus spp., are completely killed by late spring frosts (Nechavea 1958; Dubyansky and Nardina 1963). Spring colds also cause the decrease of pasture phytomass and seed production, and kill germinating wild and agricultural plants. A warm spring period with sufficient precipitation facilitates growth of pasture vegetation, which develops earlier in wet and warm springs than in dry and cold ones. Warmth-loving plants begin to vegetate during average daily air temperatures from 8 to 14°C. For example, the growth of white saksaul (Haloxylon persicum) begins when average daily air temperatures reach 8 to 9 °C (Kharin 1966; Gringof 1967) (Fig. 5). The growth of black saksaul (Haloxylon aphyllum) begins 5 days later; growth of Ammodendron conollyi, 18 days later; and growth of Calligonum spp. and Salsola richteri, 22 days later than that of white saksaul (Kharin 1975). In April, increase of air temperature and dryness and decrease in precipitation cause increased evaporation; soil starts to lose moisture, and soil 42 Nikolai S. Orlovsky __._--_._---, ,-------------------_. Fig. 5. Beginning of the growth of white saksau1 (Haloxylon persicum) (after Kharin 1975). drought develops by the end of spring period. Vegetation begins to dry out. On average, soil drought occurs in most parts of Turkmenistan before April 15; on the submontane plain of Kopetdagh, by the end of April; and in Badghyz and Karabil, by early May (Babushkin 1964). Summer. Transition from spring to summer is marked by stable increased average daily temperature above 20°C. Then, increase of the air temperature slows down, late spring colds disappear completely, and dry weather begins (Balashova et al. 1960). In northern areas, in the southwest, and on the submontane plain, summer begins in early May. It comes somewhat later to the coastal areas (late May to early July in Kara-Bogaz-Gol). The earliest summer (late April) is observed in the Central and Southeast Karakum. At this time, pasture vegetation dries up extensively (Fig. 6). Summer is the longest season in Turkmenistan. It lasts everywhere more than 100 days: 110 on the Caspian shore; 120 to 130 in Badghyz, Karabil, and in the north of the republic; 140 in the Krasnovodsk Plateau; 150 in the southwest and in the submontane plain of Kopetdagh; and slightly more than 150 in the Central and Southeast Karakum. In summer, precipitation sharply decreases. In the Southeast Karakum, practically no precipitation occurs from June to September; in Badghyz and Karabil summer precipitation constitutes about 1% of the annual sum, and occurs primarily in June. From July to August, 4% of the annual precipitation occurs in the Central Karakum; about 7%, in the Trans-Unguz Karakum; and 8%, on the submontane plain. In the west and southwest of the republic the amount of summer precipitation is higher; from June through August 10 to 14% of the annual precipitation occurs in this area. Climate of Turkmenistan 43 r-------------------~----------------------- Fig. 6. Dates of the drying of sand sedge (Carex physodes) (after Kharin 1975). Decreased precipitation in summer is accompanied by a rapid increase in temperature. Air temperature reaches its maximum in July (Fig. 3); only in the coastal area is maximal air temperature observed in August. In the daytime, summer air temperature exceeds 40 DC (maximum 46 to 48 DC in the Southeast Karakum, and 49 DC in the Central Karakum). Accompanying high temperatures is low humidity. Relative humidity in desert areas in summer falls to 22 to 25%, with a minimum of 2 to 5%. It is higher in the coastal areas due to the influence of the Caspian Sea (60% in Gasan-Kuli) and in the mountains (47% in Kheirabad). In the Amudarya Valley, humidity is 37 to 41%, which is higher than in adjacent non-irrigated areas. Probability of drought is from 50 to 75% during summers with extremely high temperatures and low humidity (Table 6). Yield of non-irrigated crops (bogara) in drought years decreases from 40 to 60%; even in irrigated areas, dry winds cause a 30%-decrease of yield. Drying of pasture vegetation occurs 15 to 20 days earlier under drought, and phytomass decreases from 30 to 65%. Droughts, which facilitate degradation of soil and plant communities, act as catalysts of desertification. According to a humidity deficit measured at 13:00 hours, five levels of air drought are distinguished in Turkmenistan: weak (humidity deficit 50 to 60 mb), medium-level (60 to 70 mb), strong (70 to 80 mb), very strong (80 to 90 mb), and severe drought (more than 90 mb). Weak droughts are observed throughout the southern Karakum Desert. Medium-level droughts are recorded every summer (except in Southwest Turkmenistan, where probability of medium-level drought is from 60 to 93%, and the Amudarya Valley). Strong droughts happen almost every year in the southeast; their annual probability in the well-irrigated areas Years of observation 72 93 95 57 60 90 Station Cheleken Ashkhabad Bairam-Ali Kushka Repetek Chardzhou 41 45 37 33 30 60 Years with drought Table 6. Droughts in Turkmenistan. 32 32 44 23 22 48 weak 9 7 7 3 6 medium 5 3 4 0 3 3 3 3 2 3 2 very strong strong Category of drought 4 8 5 9 8 4 2 2 2 2 3 0 0 2 1 2 4 4 2 0 0 0 5 Duration of drought (years) 2 2 2 0 2 2 25 ~ ;;; is" ...a ~ c a ~ ;;;.: +>+>- Climate of Turkmenistan 45 (Murghab Oasis, the Amudarya Valley) is lower (from 20 to 27%). In the drier Tedzhen Oasis and on the submontane plain, probability of a strong drought is from 60 to 80% (Orlovsky and Volosyuk 1974; Orlovsky 1981). Very strong droughts occur often only in the southeast (80% in Nichka, 67% in TakhtaBazar, and 33% in the far southeast); in the Tedzhen Oasis and on the submontane plain, the probability of very strong drought is from 7 to 20%. Very strong droughts have not been recorded in the Murghab Oasis, but in the Amudarya Valley they occur in 7% of total years recorded, and in the sQuthwest, in 13 to 15%. Severe droughts during the last 20 years have been recorded only in the southeast (10 to 13% of total years). In the irrigated areas, strong and very strong droughts are very rare, and severe droughts have never been recorded (Orlovsky 1981). Fall. Stable dry and hot weather begins to change in late August or, usually, in September, and the air drought decreases. The beginning of fall corresponds to a stable decrease of average daily air temperature to below 20°C. First signs of fall appear in early September in Badghyz and Karabil, and in mid-September in the northern regions of Turkmenistan. In late September, fall comes to the Southeast and Central Karakum and to the submontane plain of Kopetdagh, and in early October, to the southwest. Fall in Turkmenistan is short, averaging of 52 days. It lasts 54 to 56 days in the northern Central Karakum; 62 to 69 days in the southeast of this area; a week or two longer on the submontane plain, in the Southeast Karakum, and in the far northwest; and more than 70 days in Badghyz, Karabil, and in the southwest (95 days in Kara-Kala). The first half of the fall season is characterized by stable warm weather. By October, the thermal depression completely disappears; western and northern cold invasions become less frequent but more significant. Gradual decrease of the air temperature is interrupted by incoming cold air masses which cause frosts. Clouds appear, and precipitation begins. In November, cooling of the air progresses. The temperate air front shifts to the south of Turkmenistan, causing more frequent cyclonic activity. Precipitation becomes more frequent and more intensive. Due to frequent fall precipitation, soil humidity increases, which facilitates completion of development in some shrubs (Haloxylon spp., Salsola richeri, and S. arbuscula) and semishrubs (Artemisia spp.); during this time, their fruits and seeds are formed (Nechaeva 1958). In warm and humid years, Carex physodes and some annual spring ephemers renew their growth in the fall. The more frequently such years occur, the more favorable is the local climate for desert pasture vegetation (Nechaeva 1958). Babushkin (1971) estimated the duration of the humid fall period except for the areas of northwest Turkmenistan and northern Central Karakum (Table 7); maximal duration of the humid fall period was recorded as 68 days in the southwest. Fall begins early (late October) in Kopetdagh and the Sumbar Valley; in early November, on the submontane plain of Kopetdagh; in mid-November, in the north, in the Central Karakum, and in the Murghab and Tedzhen Oases; and in late November, in the Southeast 46 Nikolai S. Orlovsky Table 7. The humid fall period in Turkmenistan. Station Beginning Duration (days) % of years without the humid fall period Krasnovodsk Chagy1 Yekedzhe Tashauz Zeag1i Kerki Repetek Tedzhen Bairam-A1i Kazandzhik Ashkhabad Firyuza Germab Gaudan Kheirabad Kizy1-Atrek Nov. 13 Nov. 13 Nov. 19 Nov. 19 Nov. 19 Nov. 19 Nov. 21 Nov. 19 Nov. 13 Nov. 7 Nov. 3 Oct. 27 Oct. 24 Oct. 27 Oct. 24 Nov. 3 36 2 6 8 4 25 9 19 22 26 34 38 32 32 13 68 12 45 55 57 42 22 35 27 24 21 14 10 16 16 32 2 Karakum. Very rarely, the humid fall period begins in the lowlands in midOctober, and in some places even in early October (Babushkin and Kogai 1971). Lowland Turkmenistan can be divided in five regions, according to the favorability of climate for fall-winter vegetation of desert pastures: (1) the submontane plain of Kopetdagh, Badghyz, and Karabil, where the humid fall period occurs and fall-winter vegetation develops 80% (or more) of the time; (2) the central part of the Lowland Karakum and the Southeast Karakum (from 50 to 70% of the time); (3) the northern and western parts of the Lowland Karakum (40 to 45% of the time); (4) the northern part of the Trans-Unguz Karakum (10 to 15% of the time); and (5) the north of the republic, where the humid period on average begins after air temperature drops below 5 °C and, thus, fall-winter vegetation is absent (Nechaeva 1960). Natural Changes of the Climate Fluctuations of climate significantly affect many natural processes, such as river debit, evaporation, productivity of vegetation, and distribution of animals. Only a few meteorological stations in Turkmenistan maintain observations long enough to study climatic fluctuations. We analyzed the secular variations of average annual air temperatures and annual sums of precipitation using data from these stations (Fig. 7). Alteration of the following climatic rhythms was revealed: warm and dry, cold and humid, cold and dry, and warm and humid. In the west of the republic (Cheleken), the warm and humid period during the 1930s was followed by a cold Climate of Turkmenistan 47 MM ::!"' -"""",,,O~~--------;f-~\ ~ JtOc g ~ ~ 14,0 :;: tOe f ---.::~-____,c:::::.=~---F=--=-----=::-r ~ :::~M I-------,~,.__".....___::.....-.....,..,..,.,.~~ _ _ _- I~O 100 :~j 1----:~-~+------'~r"""~--_;.----="_<::f"""":...JoL.-.:.... tSOr 16,0 t5,o '"if N <P '" 0 ':' 0 '"~ r,., 0 ~ YEARS :il ... 0 ~ Fig. 7. Sliding II-year average air temperatures and precipitation. (a) Cheleken, (b) Bairam-Ali, (c) Chardzhou. and dry one which lasted until the early 1960s. Since the 1960s, a warm and humid climatic rhythm has again been observed. In the Kazandzhik area, two climatic rhythms have been observed within last 50 years: a warm and dry period (from the late 1930s to the late 1960s), and warm and humid (since the late 1960s). In the Ashkhabad area, five climatic rhythms were observed from 1892 to 1981. The cold and dry rhythm of 1892-1912 was followed by a warm and dry one which lasted until the early 1930s. In the 1930s, a cold and humid rhythm replaced it and, in the 1940s, was itself replaced by a prolonged warm and dry period. Since the late 1970s, the current cold and humid rhythm has been established. In Bairam-Ali, four rhythms were recorded from 1892 to 1981. The warm and dry period of 1892-1912 was followed by a long cold and dry period, which changed to a warm and dry rhythm in 1944. That was followed by a warm and humid rhythm in the mid-1950s. 48 Nikolai S. Orlovsky Cheleken 300 < a h o~~~__~__~~_ 1~l\2. 1~20 \'.12'0 19~o Ashkhabad ~oo :~~ Kllshka 500 <00 i9it 1<352 \960 \968 1976 ~ ~ <>:: 300 "- Repetek ;0 2S0 250 \900 \922. \936 1954 YEARS \970 f<;lS6 ~'~'7~'~"~S~'9'~'~"~"~"~'~~'~"~1~'9=15~'='" ~h~ I~ ~ \ YEARS precipitation Chart/zho/l. '300 250 i995 ISH \927 i~4!J YEARS t959 i97S \'Hl3 trend Fig. 8. Variation of annual sums of precipitation. (I) annual sums of precipitation, (2) trend of variation. In southernmost Turkmenistan (Kushka) within the last 50 years, three climatic rhythms have been observed: cold and dry before the early 1940s, warm and dry from the 1940s to the late 1950s, and warm and humid since 1956. In the Southeast Karakum (Repetek, Chardzhou, and Kerki stations) the amplitude of the annual sum of precipitation is not so high; the air temperature, however, experiences more clear-cut rhythms. For example, five climatic rhythms have been recorded in Chardzhou from 1895 to 1981. In general, since the 1950s and 1960s the southern part of Turkmenistan has been characterized by a warm and humid climatic rhythm (Fig. 8). Exceptions are Ashkhabad and Kerki, where the humid climatic rhythm has been expressed by air temperatures close to average multi-year values. 4. Paleogeography of Turkmenistan KHABIBULLA 1. ATAMURADOV Abstract The paleogeographic history of Turkmenistan since the Upper Cretaceous period is reviewed, with emphasis on climatic changes and development of the biota. In the Cretaceous, climate become more differentiated; seasonal temperature changes and latitudinal zonality of vegetation appeared; and the desert climatic regime was established. In the Paleogene, the remnants of the Tethys Sea covered only the lowest portions of lowlands; in the early Eocene, the sea spread over a significant area of the modern Karakum Desert. Most of lowland Turkmenistan from the Paleocene to the Lower Oligocene was covered by tropical savanna with sparse vegetation. The Neogene was a period of intensive tectonic movements and fluctuations of the Proto-Caspian Sea. Since the late Miocene and early Pliocene, most of Turkmenistan has been a continental land. By the Middle Pliocene, only two small lakes, Khachmas and Lenkoran, remained as relicts of the Pontic Sea; they were divided by the Kilyazi-Krasnovodsk mountains, which connected the Greater Caucasus and Bolshoi Balkhan and disappeared by the end of the Balakhanian age. In the Upper Pliocene, the so-called Akchagylian Sea expanded over Turkmenistan, and it receded again by the very end of the Pliocene. The aridization and continentalization of the climate of Turkmenistan continued in the Pliocene; vegetation differentiated into lowland and mountain types, and active plant speciation took place. New land surfaces emerged where the littoral flora could give rise to various types of xerophytes. The fauna of open arid landscapes existed in Turkmenistan in the Neogene.ln the Quaternary, the tectonic activity in the plains ceased, and the eolic relief of the Karakum Desert was formed. The climate remained within a desert or semidesert regime. The Turkmenistan lowlands experienced four sea transgressions, the Amudarya River turned northward, and deltas of the Murghab and Tedzhen were formed. By the middle of the Quaternary, plant communities of the sand desert were completely formed; shiblyak and forest became reduced in the Kopetdagh Mountains by the middle of the Holocene. The continuing mountain uplift resulted in further, ongoing formation of young, endemic mountain biota of Kopetdagh. V. Fet & K.I. Atamuradov (eds.), Biogeography and Ecology of Turkmenistan, 49-64. © 1994 Kluwer Academic Publishers. 50 Khabibulla I. Atamuradov Introduction This review is based on known data on the paleogeography (Luppov 1956; Sinytsin 1962), paleobotany (Krishtofovich 1936; Vasilevskaya 1949, 1957; Vakhrameev 1964), paleoclimatology (Sinytsin 1965, 1967, 1980; Yasamanov 1978), paleoecology (Korovin 1934a), paleontology of mammals (Vereshchagin and Batyrov 1967; Ishunin and Tetyukhin 1989), and geology (Geologiya Turkmenistana 1958, 1984) of Turkmenistan and adjacent regions of Middle, Southwest, and Central Asia. Following Kryzhanovsky (1965), we begin detailed discussion of the paleogeography of Middle Asia from the Upper Cretaceous. However, we first will give a brief survey of the Jurassic paleogeography. Jurassic Period In the Lower and Middle Jurassic, modern Middle Asia and Kazakhstan were a dry land, with well pronounced differences between its western and eastern portions. The western part was a lowland (which it remains today) with sparse hilly areas in the areas of Balkhan, Tuarkyr, Mangyshlak, and Sultan-Uizdagh; the eastern part was occupied by elevated areas of Tien Shan and by the denudational plateau of Kazakhstan. In the Lower Jurassic, all of Middle Asia and Kazakhstan possessed a humid climate. Elevated areas were occupied by coniferous and ginkgo forest; high lowlands, by mixed forests with sago palms and bennetites; and coastal plains, by fern vegetation. Uplift of the Middle Asian lowlands began in the second half of the Middle Jurassic. The receding sea formed groups of evaporating lagoons and, facilitated by the humid climate, coal deposits formed: e.g., in Tuarkyr in the western Turkmenistan sedimentation had already ceased in the late Jurassic, and erosion of sediments had started. Further south, in Bolshoi Balkhan and Kubadagh, gradually drying lagoons appeared, and the processes of sedimentation coninued. A large enclosed lagoon appeared in the Gaurdak-Kugitang area and farther to the east (within modern southern Uzbekistan and Tajikistan). The Kopetdagh geosyncline emerged in the Lower and Middle Jurassic and existed throughout the Jurassic, Cretaceous, and Paleogene. In the Upper Jurassic, climate become drier; the lowlands of Middle Asia were occupied by arid woodlands with tree-like ferns and conifers (Sinytsin 1966) and savannas. Aridization of climate, however, facilitated deforestation: first, ferns, club mosses, and horsetails disappeared; then, mesophylic cycads. The estimated average annual temperature in the arid Middle Asia-Kazakhstan area in the Jurassic was 12° to 15°C, and annual sum of precipitation was from 500 to 800 mm (Sinytsin 1966). Paleogeography of Turkmenistan 51 Cretaceous Period The western, relatively low portion of Middle Asia-Kazakhstan (including the Turan plateau, Cis-Aral area, and southwestern partt of the Tajik Depression) in the Cretaceous was dominated by coastal landscapes with lagoons and river deltas. In the Valanginian, sea water covered only Mangyshlak and parts of Kopetdagh and adjacent areas. In the Barremian, the sea expanded over the Krasnovodsk Peninsula and Tuarkyr; there, thin sand and clay deposits accumulated in vast shallow waters. The sea also expanded toward the east, where it filled the Gaurdak-Kugitang area and penetrated far into the Tajik Depression. Throughout the Aptian time of the Cretaceous period, thick sand and clay sediments were formed in Kopetdagh. The northern areas of Turkmenistan and adjacent parts ofUstyurt and Mangyshlak were further covered by the sea in the early Aptian; for the first time the sea which covered Turkmenistan was connected with the sea of the Russian Platform to the north. In the Upper Aptian and Lower Albian, more land was submerged, and the coastal line moved farther east. Marine basins of southwestern Turkmenistan had a homogeneous, humid climate. In the Lower Albian, islands of this sea were covered by tropical vegetation, and, in the Upper Albian, by the vegetation of a temperate and warm climate. In the Cenomanian and Turonian times of the Upper Cretaceous, climate in Middle Asia differentiated: it was hot in the south, and warmer and more temperate in the north. Korovin (1961) concluded that climatic conditions during this time were not favorable for dispersal and exchange of paleofloras. Also, the existence of extensive water bodies and numerous islands should have facilitated regional differentiation of the floras, thus creating known Cenomanian floristic types. The end of the Cretaceous period was characterized by uplifts which resulted in sea retreating westward. In the Danian, the sea liberated areas adjacent to the Amudarya River, and probably most of the Karakum Desert. In Badghyz and East Kopetdagh, large lagoons were formed with accumulation of gypsum and red-colored, gypsum-bearing deposits. Farther to the west, the sea remained during the Danian. Coastal vegetation included Taxodiaceae, other conifers, ferns, and some palms. The inland lowlands of Middle Asia during this time had dry savannatype landscapes, with solitary oases and riparian forests along the rivers. In the Lower Cretaceous, these forests included xerophile conifers, ginkgo, and sago, and, in the Upper Cretaceous, angiosperms such as laurels and myrtles. In the north (Mangyshlak and Ustyurt areas), climate was colder, with an annual temperature in the Maestrichtian from 11 0 to 18 DC (Yasamanov 1978). In general, during the Cretaceous period climate became more differentiated; seasonal temperature changes occured; latitudinal zonality of vegetation evolved; and the desert climatic regime appeared in Middle Asia. 52 Khabibulla l. Atamuradov Paleogene Middle Asian relief in the Paleogene partially resembled the modern one, with a primarily lowland western portion and alternating mountain ranges and depressions in the east. The sea covered only the lowest parts of the lowlands (Southwest Turkmenistan and edges of the Karakum). Mangyshlak, Tuarkyr, and the Balkhans were marine islands. In the early Eocene, sea spread over a significant area of the Karakum and penetrated to the Kizylkum Desert. This transgression continued in the middle Eocene and waters completely covered the Karakum, Kizylkum, and the northern Cis-Aral area. In the Lower Oligocene, large shoals with island groups emerged, and, by the mid-Oligocene, the Karakum, Kizylkum, Cis-Aral area, and Tashkent area became exposed. By the Upper Oligocene, the sea again receded and covered only western Turkmenistan. No Oligocene marine sediments are known from East Kopetdagh, Badghyz, or the Gaurdak-Kugitang area. Volcanic activity in Badghyz is dated by the mid-Paleogene; a large cover of effusive rocks (andesites and basalts) formed here during three separate eruption events. Volcanic formations of approximately the same age are found in Bolshoi Balkhan. Most of lowland Middle Asia during the Paleocene, Eocene, and Lower Oligocene was covered by sparse tropical savanna, although riparian forests and a few oases flourished in the river valleys. A well-studied fossil flora of Badghyz (Korovin 1934a, 1934b, 1958; Vasilevskaya 1949, 1957; Abuzyarova 1956; Sikstel and Khudaiberdyev 1968; Pulatova 1971) is commonly dated by the Eocene (although some authors ascribe it to the Lower Oligocene). This flora includes 36 species belonging to 14 families (e.g., Proteaceae, Anacardiaceae, Myrtaceae, Rhamnaceae, Sapindaceae, Myricaceae, Melastomaceae, Araliaceae, and Lauraceae) which now either have entirely tropical distribution or are found both in the tropics and within the Ancient Mediterranean region. Recent palynological data (Pulatova 1971) show dominance of such plants as palms, Ephedra, Myrica, and Rhus, in the Eocene floras of Badghyz. General composition of flora indicates climatic conditions of high temperature and periodic dryness. Vasilevskaya (1957) suggested that the Eocene flora of Badghyz existed in a climate with an average annual temperature of 15° to 20°C, and annual precipitation from 250 to 1,000 mm, with most precipitation occurring in winter. Korovin (1934a) estimated that the Paleogene climate of Badghyz had an average annual temperature of 16°C, and annual precipitation of 500 mm. The modern climate of Badghyz (average annual temperature of 15°C, and annual precipitation 250 mm) does not allow for growth of Eocene-type plant species. The Eocene climate was definitely warmer and more humid than now, probably resembling the modern climate of the southern Mediterranean. A record of palms in the Eocene flora of Badghyz, and especially of mangrove palms (Gladkova 1962) that currently grow only in the tropics, indicates that, in the Upper Eocene, average annual temperature in Badghyz could have been about 20°C. In general, the Eocene vegetation of Paleogeography oj Turkmenistan 53 southern Turkmenistan may have been similar to that of modern tropical or subtropical savannas. Krishtofovich (1936) demonstrated that the territory of the former USSR in the Eocene-Oligocene was shared by the Poltava, Turgai, and Greenland paleofloristic provinces (Fig. 1). Of these, the Poltava Province was an area of combined tropical and European floras, while the Turgai Province was an area of temperate forests. The territory of Turkmenistan lay within the tropical Poltava Province. The southern border of the Turgai flora was between 47° and 50° N, and its southernmost known record is the north shore of the Aral Sea. Therefore, two distinct botanico-geographic provinces existed within Middle Asia in the early Paleogene (Korovin 1958). A significant part of Tien Shan and a number of islands had mesophytic mixed forests, whereas the southern mainland (including parts of modern Turkmenistan) had xerophyte woodlands. Among the modern families representing the legacy of the xerophyte Oligocene flora, are Zygophyllaceae, Capparidaceae, Asparagaceae, Tamaricaceae, Rutaceae, Pedaliaceae, Chenopodiaceae, Fabaceae, Asteraceae, Lamiaceae, and Plumbaginaceae. The Tertiary flora of southern Middle Asia possibly gave rise to xerophyte tree and shrub communities of so-called protoshiblyak, and, later, to the true shiblyak (Kamelin 1965, 1973; Kurbanov 1992). Among modern representatives of these communities found in the valleys of Southwest Kopetdagh are Ziziphus jujuba, Rhus coriaria, Celtis caucasica, Punica granatum, Ficus carica, Jasminumjruticans, and Euonymus velutina (Kurbanov 1992). Along with these plant species, ancient floras of Kopetdagh and Badghyz included those of broadleafforests; e.g., fossils from Akarcheshme in Badghyz .. Fig. 1. Ecological provinces in the Paleogene (after Korovin 1934a): I - Poltava Province, II - Greenland Province, In - Turgai Province. 54 Khabibulla I. Atamuradov contained Carya typica as well as pollen of Juglans, Alnus, Betula, Quercus, and species of Taxodiaceae and Cupressaceae. A number of ancient sand desert genera such as Eremosparton, Ammothamnus, and Ammodendron, probably emerged in the late Oligocene in Kopetdagh and adjacent sand semideserts and foothills. Korovin (1961) suggested that these genera are the direct descendants of the Eocene Badghyz flora. Continental plains of Turan were inhabited by the ancestral species of Haloxylon, Halothamnus, and Salsola as early as the Tertiary (Kurbanov 1992). In the late Eocene, the climate became colder, and vegetation differentiated according to the thermic regime. The arid belt became drier, and the zone oftrue deserts was established. Detailed fossils of the Paleogene terrestrial mammals in Eurasia are known first from rhe Upper Eocene; no Paleogene mammals are known from Turkmenistan. In surrounding areas, the second half of the Paleogene witnessed the change from a so-called brontotherium fauna of Upper Eocene and Lower Oligocene to an indricotherium fauna of Middle and Upper Oligocene. Brontotherium fauna (named after an elephant-size ungulate) was connected to humid, swampy habitats. It ranged from England and France to Japan; most fossils of this fauna are concentrated in the periphery of the arid zone; similar fossils have been found in Europe, Kazakhstan, Kyrghyzstan, Ferghana, Mongolia, China, and the Far East (Sinytsin 1965). The so-called indricotherium fauna comprised two ecological complexes: animals of riparian forests and swamps, and animals of savannas. Typical savanna species included giant rhinoceroses, burrowing rodents, and tortoises. Indricotherium mammalian fauna of the Middle Oligocene is known from Transcaucasia, Kazakhstan, Mongolia, and China. In the Late Oligocene, it included a variety of lagomorphs, rodents, tapirs, swine, and deer found in the Caucasus, Kazakhstan, Central Asia, and Pakistan (Zoogeography of the Paleogene of Asia 1974). In general, the primary difference of the Paleogene climate and the modern one was an absence of a defined cold season. However, beginning in the middle of the Lower Oligocene, the climate became colder, and a temperate warm climatic zone began to move southward. Climate in Middle Asia became more differentiated and continental due to the drying of the sea. Well-developed denudational surfaces appeared, and the relief became more pronounced and elevated due to tectonic movements oflarge blocks (Agakhanyants 1981). New climatic conditions should have stimulated evolutionary processes. Therefore, the inner arid regions of Asia could have been an important center offormation of xerophile flora and fauna as early as the Paleogene (Kryzhanovsky 1965). Neogene In Turkmenistan, the Neogene was a period of intensive tectonic movement which drastically changed the appearance of this territory and defined basic Paleogeography of Turkmenistan 55 features of the modern landscapes. Since that time, the history of this area has been associated with the development of the Caspian Sea basin, which sometimes had a broad connection to the basin of the Black Sea. Lowlands of Middle Asia underwent uplift in the Oligocene, and the sea gradually receded westward. In the very beginning of the Miocene, modern Turkmenistan was completely liberated from water. In the Early Miocene, the sea existed only northward to the modern Ustyurt Plateau. In the Late Miocene, the so-called Sarmatian transgression flooded the Ustyurt and West Turkmenistan. In East Turkmenistan, the continental climate persisted, with inner lakes containing accumulating painted clay sediments. Mangyshlak, Bolshoi Balkhan, Kubadagh, Tuarkyr, and West Kopetdagh were islands in the Sarmatian sea. Later, the sea subsided, and by this post-Sarmatian time, the mountain climatic regime was formed in Kopetdagh and other mountains. In the Upper Pliocene (the Akchagylian), regression stopped, and the sea expanded, again flooding West Turkmenistan and the western part of the Karakum Desert. Later, it retreated again and, by the end of the Pliocene, the sea existed only within the Caspian Depression, where, by the beginning of the Quaternary period, it was enclosed. In the Late Miocene - Early Pliocene, the folded structure of Bolshoi Balkhan and Kubadagh was completely formed. Orogenesis was also expressed in the areas adjacent to Turkmenistan. In the Miocene, due to the uplift of the Iranian Plateau, the island arch of ElburzParopamiz was replaced by a mountain range. Zagroz (still surrounded by the sea from both sides, to the west from Mesopotamia, and to the east, from the Central Iran) also became a mountain range. Other high mountain chains, such as Pamiro-Alai and Mekran, were created as well. At the same time, most continental alluvial deposits in the Trans-Unguz and Southwest Karakum were formed due to the Paleo-Amudarya River (Babaev and Fedorovich 1970) which originated in the high mountains ofPamiro-Alai. Other rivers participating in the formation of the Neogene continental deposits in the Karakum were the Paleo-Murghab and Paleo-Tedzhen, which originated in the Paropamiz Mountains, as well as - in the east - rivers originating from the western offspurs of Tien Shan. Formation of the closed depressions in Turkmenistan is dated to the post-Sarmatian time (Sidorenko 1952). Therefore, in the Late Miocene - Early Pliocene the sea either completely liberated the territory of Turkmenistan or covered only small portions next to the modern shore of the Caspian Sea. Since that time, most of Turkmenistan has been a continental land, allowing free dispersal oflowland flora and fauna from the northeast and southwest. In the Middle Pliocene, a tectonic depression involved significant portions of Turkmenistan, including the Caspian Lowland. One of the reasons for the sea regression in the Pontian was a deep tectonic depression in the area of the southern Caspian Sea. At the end of the Pontian, due to large ascending tectonic fluctuations, two lakes (North Caspian and South Caspian) were formed in the Caspian area, separated by land with a central strait (Fig. 2). Continuing tectonic movements closed this strait, connecting by land the Knvnovodsk and 56 Khabibulla I. Atamuradov Fig. 2. Upper Pontian basin of the Caspian Fig. 3. Relicts of the Pontian basin of the Region (after Ali-Zade 1961). Caspian Region (after Ali-Zade 1961). Kilyazi Peninsulas (Fig. 3). Only two relatively small lakes, Khachmas and Lenkoran, remained by this time as relicts of the Pontian Sea. Ali-Zade (1961) concluded that by the beginning of the Balakhanian (Middle Pliocene), the relict Lake Lenkoran was bordered to the north by a low KilyaziKrasnovodsk mountain chain, which connected the Greater Caucasus and Bolshoi Balkhan. To the south, however, the relict Lake Lenkoran was bordered by high mountains (Greater Caucasus, Lesser Caucasus, Talysh, Elburz, Bolshoi Balkhan, and Kopetdagh), neighbored by vast depressed lowlands. The relict Lake Khachmas was bordered to the east by the Krasnovodsk, Ustyurt, and Mangyshlak Plateaus, and to the north by the CisCaspian Lowland with a well-defined hydrographic network (e.g., Paleo-Volga, Paleo-Ural, and Paleo-Emba Rivers). All these rivers probably reached the relict Lake Khachmas. In its turn, the Cis-Caspian Lowland was bordered to the northeast, north, and northwest by the Mugodzhary Mountains, the southern offshoots of the Urals, the Common Syrt, and the Volga Plateau (Fig. 4). The Paleo-Uzboi, Paleo-Atrek, and other rivers eroded Kopetdagh, Bolshoi and Maly Balkhan, Kubadagh, the Krasnovodsk Mountains, Karakum Plateau, and Elburz, and deposited material which formed the Balakhanian stage of the Caspian Lowland westward to West Kopetdagh. The main source of the material for the Balakhanian deposits of the Apsheron Peninsula could only have been located in the central part of the Kilyazi-Krasnovodsk Mountains (Ali-Zade 1961). These mountains were destroyed and leveled by the Paleogeography of Turkmenistan 57 Fig. 4. Paleomorphology of the Caspian Region before the Balakhanian Age (after Ali-Zade 1961): I - relicts of the Upper Pontian basin; 2 -lowlands, plains, and valleys; 3 - plateaus; 4 - mountains. end of the Balakhanian, and their final descent under water effectively liquidated the Middle Caspian land mass. The Middle Pliocene tectonic depression involved partially the Central Karakum, therefore beginning its separation from the Trans-Unguz area. At this time, the Paleo-Amudarya and its tributaries, Paleo-Tedzhen and PaleoMurghab, eroded a deep valley to the Caspian Sea. Therefore, the expressed dissection of the surface of Turkmenistan occurred in the Middle Pliocene, before the Akchagylian transgression. In the Upper Pliocene, the so-called Akchagylian Sea expanded over Turkmenistan eastward to Uchadzhi, and northward (via the Uzboi corridor) to Karakalpakistan (Fig. 5). The non-flooded areas were Kopetdagh, Balkhans, Badghyz, Karabil, portions of the Ustyurt, and the Trans-Unguz and Southeast Karakum. The Akchagylian Sea was an inland sea which was only temporarily connected via a narrow strait to the Black Sea basin. 58 Khabibulla I. Atamuradov _1 ~3 .... 1:-':'.:';12 [Z]4 I 35 Fig. 5. Geomorphology of Turkmenistan in the Middle Pliocene (after Yurevich 1966; Gorelov 1972): I - mountains, 2 -lowland swamps and primarily sand desert foothills, 3 - desert plateaus, 4 - river valleys and erosion valleys, 5 - water bodies. By the very end of the Pliocene, the sea receded again until it covered only westernmost Turkmenistan. At this time, new tectonic activity involved the Turkmeno-Khorassan Mountains, including Kopetdagh (Kalugin 1977) as well as Gaurdak-Kugitang. In contrast, the Caspian Lowland at the end of the Pliocene continued tectonic depression and became covered by the waters of the Apsheronian Sea. This sea also covered the western part of the Krasnovodsk Peninsula, approached the western offshoots of Kopetdagh, and penetrated the western Karakum. The Apsheronian Sea, like the Akchagylian Sea, was closed. Lowland Karakum was also tectonically depressed at the end of the Pliocene. In the Trans-Unguz Karakum, formation of eolic sand ridges commenced (Luppov 1956; Fedorovich 1960). The first known inland water bodies in the depressions of Sarykamysh and Aral (without any Caspian connection and fed by rivers) also are dated by the Upper Pliocene. The aridization of the climate of Turkmenistan continued in the late Pliocene. Sinytsin (1967) notes that the annual precipitation in the area between the Caspian Sea and Amudarya was 200 to 300 mm, and average monthly temperatures were from 0° to 5 °C in the coldest month and 25° to 30°C during the hottest month. Therefore, temperate deserts (although somewhat drier than modern ones) could have existed there in the late Pliocene. The Middle-Asian vegetation differentiated into lowland and mountain types in the Pliocene (Korovin 1958), along with the mountain uplift. Palynological data show that the Middle Asian lowlands in the Pliocene already possessed flora similar to Paleogeography of Turkmenistan 59 that of modern deserts and included species of Haloxylon and Ephedra (Fedorovich 1946). Petrosyants (1956) analyzed the early Akchagy1ian palynological samples from the Central and Southwest Karakum. Xerophytic plants (species of Haloxylon, Anabasis, Salsola, Calligonum, Artemisia, and Ephedra) were not abundant, whereas a high number of mesophytes and even hydrophytes (e.g., Crepis, Matricaria, Centaurea, and other non-identified Asteraceae) was present. Such diversity of pollen can be explained by the existence of mesophile vegetation along the rivers and lake shores; the xerophyte pollen could easily have been brought by wind from the surrounding deserts. In the Repetek deposits, remnants of such hydrophytes as Carex and Scirpus have been found (Raevsky 1969). In West Kopetdagh, elements of tropical and subtropical flora have been found as fossils (Cinnamommum polymorpha; Ali-Zade 1961) as well as pollen of grasses and poplars, which suggest a tugai landscape (Ushko and Isaeva-Petrova 1959). Tugai fossil flora (Phragmites, Populus, Cercis, and Periploca) (Kara-Murza et al. 1953) is known from the Pliocene deposits of Cheleken as well as pollen of desert plant species (Gladkova 1957). Large amount of xerophyte pollen was also discovered in the Upper Pliocene deposits of the Balkhan Corridor near Yaskhan (Malgina 1958). All these sites reveal similarity to typical modern plant communities of desert Middle Asia. The Akchagylian fossils of Turkmenistan include also the typical Meditrerranean algae Acucularia italica, Ovulites renata, and Chara meriane. A number offossil insect species associated with forest-type vegetation was found in the Akchagylian deposits ofSyrtlanli, Boyadagh, and Monzhukly, including Trypaniedae, Dolichopodidae, Fungivoridae, Limoniidae (Diptera), and a mesophile forest beetle Palandra sp. (Coleoptera: Prinoidae) (Ali-Zade 1961). Korovin (1961) derived the forest communities of Middle Asia from the Miocene flora; the Miocene and Pliocene forests were dominated by such large trees as species of Platanus and Populus. With progressing aridization and cooling of the climate in the Oligocene and Miocene, local vegetation differentiated into two major complexes. The first one occupied the ancient continental surface (e.g., species of Pistacia, Ficus, Sageretia, Cissus, Rhamnus, Ammothamnus, Ammodendron, Eremoparton, and Smirnowia). Plants belonging to the second complex dispersed along the beds of erosion which dissected the Tertiary plateaus and occupied accumulative valleys with high humidity. Some of these plants (e.g., Erianthus, Alhagi, and Halimodendron) still inhabit riparian communities (tugais) of the river valleys in Middle Asia (Ovchinnikov 1940; Korovin 1958). Modern ranges of many plant genera, e.g., Cousinia, Verbascum, Amygdalus, Aegilops, Onobrychis, Acantholimon, Medicago, and Tragacantha, confirm the active process of speciation in arid Asia (Agakhanyants 1981). Kamelin (1979) suggested that florocoenotypes of Turkmenistan Salsola species (S. botschantzevii, S. kopetdaghensis, S. iljinii, and S. bungeana) originated in the Neogene on the lowlands of Turan, Iran, and Central Asia from the Ancient Mediterranean ancestors of the temperate warm zone. Due to the constant 60 Khabibulla I. Atamuradov aridization and continentalization of climate in Middle Asia, evolution of xerophyte flora here is considered one of the main florogenetic trends (Ilyin 1950; Korovin 1961; Ovchinnikov 1948; Agakhanyants 1981). Due to the multiple sea regressions, new land surfaces emerged; these new substrates were colonized by species derived from the Paleogene flora (Korovin 1958) or by the salt-tolerant flora of the subtidal zone. Ilyin (1947) demonstrated that tidal (littoral) flora could have given rise to various types of xerophytes. Radiation of the continental Chenopodiaceae (e.g., of Anabasis, A rhrophytum , Nanophyton, Hammada, and Nitraria) around the Ancient Mediterranean Sea (the Tethys Sea) is dated by the Miocene but probably not later (Grubov 1966; Yemelyanov 1972). Plants belonging to the so-called "hammada" vegetation of stony or gypsum deserts (Popov 1927), including species of Zygophyllum, Limonium, Goniolimon, Reaumuria, Cleome, Thesium, Haplophyllum, Ferula, Trichanthemis, and Aristida, became adapted to the new salt-bearing substrates. Endemic solonchak species of Salsola and Suaeda were formed on the shores of drying coastal salt lakes of the Aralo-Caspian basin (Korovin 1958). In general, by the Neogene the following plant communities could have existed in Middle Asia: broad-leaf forests, riparian forests (tugais), solonchak vegetation, gypsum hammada, and xerophyte shrub and tree community (shiblyak) (Kame1in 1979). Desert climatic regime was established by the Pliocene, since the first stages of the Cenozoic orogenesis. Accompanying mountain buildup, a new vegetation type of mountain xerophytes evolved, as well as savanna-type herbaceous vegetation and mountain forests. Neogene fauna of Middle Asia was highly diverse. Due to the climatic changes since the second half of the Miocene, swamp subtropical forests in the valleys and lowlands of the arid zone were transformed into dry broad-leaf forests; interfluvial woodlands became savannas and then turned into steppes and semideserts. Cooling and aridization of the climate caused the dispersal of the so-called Hipparion fauna of the Upper Miocene and Pliocene. In Turkmenistan, there is fossil evidence of the fauna of open arid landscapes existing at this time. The fossil record of a giraffe is known from the sands of the so-called Esenbai stratum of the Upper Miocene and Pliocene in Badghyz (Godina and Dubyansky 1963) and a record of a tooth of a fossil horse, Equus caballus fossilis, near Kara-Bogaz (45 km north from Kizyl-Arvat; Amursky 1961). A small bear, cheetah, and a small gazelle are known from the Pliocene of the Trans-Unguz Karakum (the Aktash Well) (Vereshchagin 1956). In the Pliocene deposits of West Kopetdagh are found camels, gazelles, wild sheep, and wild cat (Amanniyazov et al. 1979). The sandstones of the Gokcha stratum (the Upper Pliocene) yielded remnants of monitors, agamids, and other arid lizards (Ananyeva and Gorelov 1981). Fossils of the Upper Pliocene and the very beginning of the Pleistocene contain animals connected with steppe landscapes with shrubs and pockets offorest vegetation; these are hipparions (a small three-toed horse), saber-tooth cats, bears, wolves, camels, and ostriches (Vereshchagin and Batyrov 1967; Gorelov 1969; Babaev and Fedorovich 1970; Paleogeography of Turkmenistan 61 Dubrovo and Nigarov 1990). An interesting fossil elephant, Palaeoloxodon turkmenicus Dubrovo, has been found in the Upper Pliocene pebble strata near Krasnovodsk (Dubrovo 1960). This animal could have inhabited savanna or steppe landscapes and fed on branches, leaves, and grass. Remnants of other ancient elephants have been also found in Uzboi area (Okladnikov 1956) and between Khudaidagh and Monzhukly (Fedorov 1946). Quaternary Period In the Quaternary, the territory of Turkmenistan experienced decreasing tectonic activity, fluctuation of the Caspian Sea level, wandering of the Amudarya River, and formation of the eolic relief of the Karakum Desert. Alteration of pluvial (more humid) and xerothermic (more arid) climatic periods occurred within the Quaternary time, with corresponding movements of the biotas. In Middle Asia the climate remained within a desert or semidesert regime (Fedorovich 1952; Luppov 1956). It differed from the dry Pliocene climate in that cold winters appeared, and rainy seasons disappeared (Fedorovich 1952). In the Pleistocene, the lowlands of Middle Asia were more affected by the cooling of the climate (during the glaciation in Tien Shan and Pamir) than the more southern deserts of Iran, which were protected from the northern air masses by the mountain chains of Elburz and Paropamiz. In the Quaternary period, lowlands bordering the Caspian Depression experienced four sea transgressions (Baku, Khazarian, Khvalynian, and New Caspian). In the first half of the Quaternary (during the Baku and Khazarian), the sea expanded primarily over the Caspian Lowland, sometimes covered the western edge of the Krasnovodsk Peninsula, and penetrated slightly to the western part of the Central Karakum. The sea fluctuated back from and forth toward West Kopetdagh, creating the lowland coastal plain which to the south contacted the delta of the Proto-Atrek, and to the north, the delta of the ProtoAmudarya. The Lowland Karakum in the late Pliocene - early Quaternary was occupied by a vast alluvial plain of the Proto-Amudarya. This river was especially large in the Khazarian, when most of the alluvial material was deposited which later was transformed by the wind. The end of the Baku and the Khazarian experienced a more humid climate which might have been responsible for the formation of large mountain slides along the chinks of Ustyurt (Fedorovich 1946). Around this time, large mammals such as elephants (Fedorov 1946) penetrated to the east shore of the Caspian Sea along the Proto-Amudarya Valley. The eroding activity of the Proto-Amudarya and its left tributaries in the east and southeast during the first half of the Quaternary period resulted in the dissection of the Neogene plain and the formation of the Murghab and Tedzhen Valleys and the Obruchev Steppe. In the north, the modern and ancient (or Kunyadarya) deltas of the Amudarya were filled with sediments, due to the 62 Khabibulla I. Atamuradov activity of a river network beginning in Kazakhstan and connected to the Amudarya near the southern end of the Upper Uzboi corridor (Yamnov and Kunin 1953). In the middle of the Quaternary period, two major geological events changed the paleogeography of the plains of Turkmenistan. First, the Amudarya turned toward the north. It left the Lowland Karakum, cutting through the Neogene land between the Trans-Unguz Karakum and Kizylkum, and flowed toward the Aral Depression. That event led to the transformation of the alluvial plain of the Lowland Karakum by the wind, resulting in the creation of the modern sand desert. The second major event was the Khvalynian transgression of the Caspian Sea, which rose 75 m higher than its modern level. The Khvalynian Sea covered most of the Caspian Lowland and the western part of the Krasnovodsk Peninsula, and it penetrated deep into the Karakum, reaching the meridian of the city of Kizyl-Arvat. At the end of the Khvalynian, the Amudarya turned toward the Sarykamysh Depression and filled it as well as the Assake-Audan Depression and most of the Upper Uzboi corridor. Thus, the Uzboi River was created, which originated in the Sarykamysh and flowed into the Caspian Sea. Later, when the Amudarya turned entirely toward the Aral Sea, Lake Sarykamysh started drying out, and the Uzboi River disappeared. The latest (New Caspian) stage of the geological history of the Caspian basin continues today. It is characterized by a new increase of the sea level (with the highest mark during the New Caspian period, however, only 7 m higher above the modern one). In the second half of the Quaternary period, subaeral deltas of the Murghab and Tedzhen were formed which ended blindly in the Karakum Desert; four subsequent deltas, partially overlapping, have been found in the lower reaches of the Murghab (Fedorovich and Kes 1934). At this time, the tectonic activity in the plains of Turkmenistan practically stopped. Mountains continued their uplift, but in Kopetdagh this process was interrupted; up to six terraces were created in Kopetdagh river valleys during the Quaternary time (the highest is now elevated 100 m or more above riverbeds). In the Gaurdak-Kugitang area, Quaternary tectonic movements are also well expressed; in Badghyz and Karabil, Quaternary geological history reflects the uplift of the Paropamiz Mountains, which resulted in deep erosion of the Murghab and Tedzhen Rivers and creation of several terraces. On the other hand, no Quaternary uplift has been found in Bolshoi Balkhan and Kubadagh; terraces which exist there in mountain valleys were probably formed during the fluctuation of the Caspian Sea. The Quaternary vegetation of lowland Middle Asia was similar to that of modern deserts, and in the river valleys, to that of tugais (Fedorovich 1946; Korovin 1958). Its development was influenced by the arid centers of speciation in Central Asia. By the middle of the Quaternary period, the plant communities of the sand desert had been completely formed. At this time, psammophiles of Paleogeography of Turkmenistan 63 Tertiary origin (e.g., species of Calligonum and Astragalus sect. ammodendron) experienced radiation. The sand desert flora became enriched by modified hammada and sublittoral solonchak species (Kultiasov 1946; Korovin 1958). Formation of the loess deposits allowed a new avenue for speciation of plants and accounted for emerging dry herbaceous steppes or semi-savannas on the periphery of the mountain ranges (Ovchinnikov 1940; Kultiasov 1946; Korovin 1958). In the Pliocene-Pleistocene, modern endemic species of sagebrush (e.g., Artemisia balchanorum, A. turcomanica, and A. deserti) as well as such steppe grasses as species of Stipa, Festuca, and Poa became dominant in the mountain vegetation (Kurbanov 1992). In the Quaternary, steppes in the mountains of Middle Asia expanded, and the area occupied by mesophile plant communities (including broad-Ie afforests and mountain meadows) decreased. The Turkmen juniper (Juniperus turcomanica) replaced broad-leaf trees in Kopetdagh mountains, forming complexes with maple (Acer turcomanicum) and various shrubs, and in the foothills, semisavannas, sagebrush desert, and salt desert plant communities replaced communities of shiblyak (Kamelin 1979). Due to general aridization, shiblyak and forest communities became reduced in the middle and lower belts of Kopetdagh by the middle of the Holocene; however, fragments of forest vegetation (e.g., Juglans regia, Allium paradoxum, and Jasminumfruticans) were preserved in refugial deep valleys. The fossil record of the Quaternary fauna of Middle Asian plains is not rich, which confirms its desert character at this time. Fossil data on small desert and semi-desert mammals are known from Ustyurt (Nastyukov 1976), Mangyshlak (Gromov and Fokanov 1961), and Badghyz (Fokanov 1961; Gorelov 1972). Knyazev (1976) demonstrated that the fauna of small mammals in Badghyz did not significantly change during the middle and late Holocene. Since the formation of sand and clay deserts in the late Pliocene, constant complexes of desert Turanian species have emerged. Such complexes could have been formed via a combined dispersal of desert fauna from other regions as well as by autochthonous evolution; some forms could have dispersed from the southern deserts of Iran and North Africa (Kashkarov et al. 1929). Finally, the continuing mountain uplift and dissection resulted in further differentiation of mountain faunas and formation of a wide array of young endemic species in the mountains of Turkmenistan (Kryzhanovsky 1965). 64 Khabibulla I. Atamuradov Dinosaur footprints on the Jurassic limestone, Kugitangtau Mountains. Photo by K.1. Atamuradov. 5. Desertification of the Arid Lands of Turkmenistan NIKOLAI G. KHARIN Abstract Desertification in Turkmenistan is described, with various processes indicating desertification level on different scales. Local, regional, and zonal criteria of desertification characterizing this process can include, e.g., data on species composition, vegetation, and productivity in specific plant communities. Such criteria were used for map construction, including the desertification map of Turkmenistan on the scale 1:4,000,000. The basic types of desertification include degradation of vegetation, deflation, water erosion, pasture swamping, salinization of irrigated lands, and formation of solonchaks. Introduction Desertification is one of the global problems acknowledged by the United Nations. Experts define desertification as the degradation of lands in arid, semiarid, and sub humid areas caused by the destructive activities of man (Odingo 1990). In this definition, "lands" include soil, local water resources, land surface, natural vegetation, and agricultural crops. The process of desertification includes the degradation of vegetation, wind and water erosion, technogenic desertification, and soil salinization. The global estimate of desertification performed by UNEP shows that, by 1985, in arid zones worldwide, 80% of all pastures (3,100 million ha), 30% of irrigated arable land (40 million ha), and 60% of non-irrigated arable land (80 million ha), had been subjected to desertification. Annual losses of agricultural production due to desertification are estimated as $ 25 billion. The definition of desertification given above characterizes the degradation of land as an anthropogenic process due to such activities as an increase of cattle grazing, road construction, population growth, or mining in the desert. However, if these activities were combined with protective measures, it would be possible to stop desertification at its current level or even to restore degraded areas. At the same time, many natural factors influence the rate of V. Fet & K.I. Atamuradov (eds.), Biogeography and Ecology of Turkmenistan, 65-76. © 1994 Kluwer Academic Publishers. 66 Nikolai G. Kharin desertification, and these factors should be analyzed for an understanding of this process. Approaches to the Study of Desertification Our long-term studies in the Desert Institute of the Academy of Sciences of Turkmenistan have resulted in compilation of a database on desertification (Appendix 1) and construction of mathemathical models. The size of an area under desertification is defined as y= (Xb X2, X3, X4), where Xl is grazing load, X2 is population density, X3 is rate of desertification, and X4 is internal danger of desertification defined by stability of an arid ecosystem. The grazing load in desert pastures is the major factor in natural ecosystems. In Turkmenistan, of the 39 administrative districts studied, 16 had a high grazing overload, 10 had moderate overload, and only 13, slight overload (Kharin et al. 1989). Table 1 presents the regression equations showing the relationship between the grazing overload (expressed in per cent of a regular grazing load) and desertified area. These data show high statistical significance for three regions of Turkmenistan. Table 1. Relationship between the desertified area (y) and grazing load (x) in Turkmenistan Regions' Number of districts' Regression equation Krasnovodsk Ashkhabad Mary Chardzhou Tashauz 6 8 8 10 7 y y y y y =30.095 + 6.198x =25.431 + 0.341x = 30.851 + 0.240x =26.014 + 0.179x = 17.831 + 0.541x Rb 0.674 0.808 0.364 0.485 0.954 • According to the administrative division of Turkmenistan in 1985 b Coefficient of correlation To estimate desertification, we must know its background level corresponding to natural conditions in arid ecosystems. In Turkmenistan, as well as in most arid regions of the world, there are virtually no ecosytems undisturbed by humans. Fig. 1 shows our basic approaches in dealing with the problem of background (natural) level of desertification. These approaches include: 1) Scale consisting of five classes. Using this approach, one has no knowledge of the background level of desertification; instead, a given condition of ecosystems in a certain time period is used. For example, during creation of the desertification map (25 km in 1 cm) for the arid territories of the former Desertification of the Arid Lands of Turkmenistan 67 USSR, we (Kharin et at. 1988) used 1965 desertification as a background level. The map demosntrated changes that occured from 1965 to 1985. 2) Scale consisting of four classes. This approach is used in the rare case when background level is known or can be calculated; it can be used for studies of long-existing protected territories (Natural Reserves). 3) Scale consisting of three classes. Background level is not known; a scale is used for schematic desertification maps of small scale. This approach was used for the creation of the desertification map of Turkmenistan given below. Fig. 1. Scales of desertification. Indicators and Criteria of Desertification Various types of processes characterizing the degradation of arid geosystems can be used as indicators of desertification (Nechaeva 1973). Diagnostics and monitoring of desertification are based upon criteria which allow qualitative and quantitative estimation of these processes. Such criteria may be local, regional, and zonal. Local criteria of desertification characterize this process within a separate geosystem. They can include, e.g., data on species composition and vegetative cover in specific plant communities. We have used such criteria for construction of large-scale desertification maps of separate key plots. Regional criteria of desertification are established for geographic regions (such as administrative districts or regions of new land development) and include generalized data on anthropogenic environmental changes. For example, during the creation of the desertification maps of Turkmenistan we used criteria characterizing Karakum Desert desertification such as the decrease in productivity of vegetation (in kglha) (Kharin et al. 1983). Zonal criteria of desertification are even more generalized: for example, to characterize the degradation of vegetation, we measured decreases in productivity of vegetation not in kglha but in percentages. This approach allows one to compare desertification among different types of deserts where the absolute productivity can vary. The estimation of desertification is complicated by the presence of various factors. For example, in sand desert such as the Karakum, decrease of area covered by vegetation and development of wind erosion are caused by shrub logging for fuel, by overgrazing, and by automobile movement. These details 68 Nikolai G. Kharin can be reflected separately only on large-scale desertification maps (0.1 km in 1 cm to 0.25 km in 1 cm), whereas small-scale maps should either reflect the predominant process or characterize desertification as a complex of estimates. In Turkmenistan, the basic types of desertification include degradation of vegetative cover, deflation, water erosion, soil swamping in pastures, salinization of irrigated lands, and formation of solonchaks due to the closure ofKara-BogazGol Bay of the Caspian Sea. We estimated desertification using a scale consisting of three classes defined by the degree of degradation of geosystems: low desertification, when geosystems are rated from non-disturbed to slightly disturbed; moderate, when geosystems are moderately disturbed; and high, when geosystems are rated from seriously disturbed to having completely lost bioproductivity (Fig. 2). Rates of desertification were estimated by comparison of theme maps created during 1965 to 1990. We have also used remote sensing materials, statistical data, population surveys, and field observations. Rates of degradation -- - Classes of degradation weak low moderate moderate strong high Fig. 2. Estimation of the degradation rates of geosystems. Degradation of vegetative cover caused by human activities is the most common type of desertification in Turkmenistan (Tables 2, 3, and 4; Kharin et al. 1983). An important qualitative indicator of such degradation is a succession of dominant plant species. Succession effects qualitative changes in community productivity as well as amount and quality of food plants in desert pastures. A special case of vegetation degradation in the Karakum Desert is "moss formation," in which soil surface becomes covered by a thick layer of a desert moss (Tortula desertorum). In some desert areas, where there is no grazing due to the absence of water sources, this moss covers up to 40% of the surface (Fig. 3) (Kalyonov 1977). Moss cover suppresses shrubs and herbaceous vegetation and reduces reproduction of pasture plants and bioproductivity of desert ecosystems. Moderate grazing, on the other hand, supports plant reproduction because animals break the moss cover and loosen the soil. A separate type of the degradation of vegetative cover is techno genic desertification (Table 5). Common in all Turkmenistan deserts, it is due to the construction of canals, roads, and gas pipelines, as well as to random automobile movement, etc. An especially barbaric degradation is caused by the dragging of the oil drilling equipment from rig to rig. These ulcers on a desert's face are easily detected on satellite pictures. Technogenic desertification is especially hard to rehabilitate. Desertification of the Arid Lands of Turkmenistan 69 Fig. 3. Distribution of the desert moss Tortula desertorum in the western Trans-Unguz Karakum Desert based on airplane remote photo (1 :28,000). I - sands, 2 - moss, 3 - solonchaks, 4 - takyr (after Kalyonov 1977). Table 2. Criteria of degradation of vegetation Classes of desertification Criteria Plant communities Decrease in productivity (%) Sand desert Gypsum desert Clay desert Foothill loess desert Mountains: Low belt Middle and high belts Decrease in area covered by climax vegetation (%) Sand desert Gypsum desert Clay desert F oothillloess desert Mountains: Low belt Middle and high belts Low Climax, or slightly modified Moderate Long-time derived High Short-time derived <15 <20 <35 <20 15-35 20-40 35-70 20-40 >35 >40 >70 >40 <20 <15 20-40 15-30 >40 >30 <10 <10 <20 <20 10-35 10-50 20-45 20-40 >35 >50 >45 >40 <10 <5 10-50 5-40 >50 >40 70 Nikolai G. Kharin Table 3. Dynamics of plant communities under desertification in different types of deserts in Turkmenistan Classes of desertification Plant community Moderate High Extremely high I. Sand desert Haloxylon persicum - Carex physodes Haloxylon persicum - Stipagrostis pennata + Carex physodes Salsola richteri - Stipagrostis pennata Stipagrostis karelinii - Bromus tectorum Stipagrostis karelinii Background Low Moderate High Extremely high 2. Gypsum desert Artemisia badhysi + Salsola orientalis - Carex pachystylis Artemisia badhysi + Salsola orientalis - Carex pachystylis Ephedra distachya + Artemisia badhysi Ephedra distachya + Horaninovia anomala Peganum harmala Background Low Moderate High Extremely high 3. Clay desert Salsola gemmascens + Artemisia kemrudica - Gamanthus gamocarpus Salsola gemmascens + Artemisia kemrudica - Gamanthus gamocarpus Artemisia kemrudica + Salsola gemmascens Artemisia kemrudica + Climacoptera lanata Peganum harmala Background Low Moderate High Extremely high 4. Foothill loess desert Carex pachystylis + Poa bulbosa Carex pachystylis + Poa bulbosa Poa bulbosa + Carex pachystylis Poa bulbosa + Iris songarica Peganum harmala Background Low Number of plant species 42 36 17 8 3 31 29 19 14 3 35 25 11 8 3 50 47 30 26 3 Soil deflation in sand desert was studied at the Desert Instiute of Turkmenistan by Znamensky (1958), Dobrin (1964), and Ivanov (1972). Criteria for deflation are given in Table 6. Sand particles smaller than 0.04 rom can be carried great distances by the wind. Particles from 0.04 to 2.0 mm in size, however, are transported by wind in a suspended condition along the sand surface. Sand can form eolic deposits, i.e., wind-born sediments capable of surface movements. These movable eolian landforms can be either formed in situ or transported from elsewhere; the thickness of the deflated non-sand layer may be partially compensated for later by dust sedimentation. The surface layer of the atmosphere contains layers with various whirlpool structures; 97% of the sand is transported by the wind within 15 cm from the surface (Znamensky 1958). In the sand desert, deflation is not caused exclusively by human disturbance. Eolic landforms there occupy about 15% of the area (data of G.S. Desertification of the Arid Lands of Turkmenistan 71 Table 4. Changes in food value in sand desert pastures (food unitslha) Classes of desertification Seasons Spring Summer Fall Winter 1. Ridge-hill sands; Haloxylon persicum - Carex physodes community Background Low Moderate High 88 92 103 73 134 132 76 36 119 91 17 16 80 63 7 6 2. High ridge sands; Calligonum rubens - Mausolea eriocarpa - Carex physodes community 195 112 61 30 Background Low 219 136 83 35 Moderate 100 83 45 20 High 65 60 34 12 3. Small hill sands; Salsola arbuscula - Artemisia kemrudica Background 170 160 Low 193 117 Moderate 109 50 High 70 45 - Carex physodes community 71 73 38 28 30 36 18 14 Table 5. Criteria of technogenic desertification Classes of desertification Criteria Disturbance of vegetation a) logging of trees and shrubs (% of total area) b) destruction of turf (% of turfed area) Low Moderate High <25 25-50 >50 <25 25-50 >50 Erosion due to the irregular movement of cars and mechanisms (% of total area) <10 10-25 >25 Area occupied by technogenic sands (% of total area) <10 10-25 >2 Roads (km/100 sq. km) <40 40-80 >80 Kalyonov) and include sand dunes (barkhans), deflation hollows, and other disturbances of vegetation caused by natural factors. Tables 7 to 9 characterize other desertification processes. Water erosion (Table 7) is expressed primarily in mountainous Turkmenistan. Soil swamping in pastures (Table 8) occurs due to discharge of irrigation waters from oases to desert. Productivity in this case increases; however, plant succession takes place, and cattle-forage species commonly are replaced by non-edible ones. Finally, 72 Nikolai G. Kharin Table 6. Criteria of deflation in the sand desert Criteria Classes of desertification Area of drift sands (%) Turfness (%) Coverage of vegetation (%): a) shrubs b) herbaceous vegetation Low Moderate High 15-30 30-50 30-70 10-30 >70 <10 10-15 40-65 5-10 10-40 <5 <10 Table 7. Criteria of water erosion Criteria - Type of water erosion Classes of desertification Low - Sheet erosion (single cavities) Moderate Sheet erosion (up to 10 cavitieslkm, formation of single gullies) High - Gully erosion (more than 10 cavities/km) Area of drift sands (%) Ablation of surface soil layer (cm) 15-30 <5 30-70 5-20 >70 >20 Coverage of vegetation (%): a) trees and shrubs b) herbaceous vegetation <20 <20 20-50 20-50 >50 >50 Table 8. Criteria of pasture swamping Criteria Classes of swamping Low Coverage of hygrophilous vegetation (%): a) Tamarix ramosissima, Alhagi persarum b) Tamarix ramosissima, Alhagi persarum, Karelinia caspia c) Phragmites australis, Glycyrrhiza glabra, Alhagi persarum Moderate High <30 30-70 >70 Depth of fresh or low mineralized ground water (m) 5-10 2-5 <2 Soil humidification regime automorphic semihydromorphic hydromorphic Desertification of the Arid Lands of Turkmenistan 73 Table 9. Criteria of salinization in the irrigated lands Criteria Classes of desertification Low Moderate High Degree of salinization total solid residue, % Cl-, % Na+,% 0.210-0.400 0.001-0.030 0.023-0.046 0.410-0.600 0.030-0.100 0.047-0.092 >0.610 >0.101 >0.093 Mineralization of ground water (gil) 3-6 6-10 10-30 Mineralization of irrigation water (gil) 0.5-1.0 1.0-1.5 <1.5 Decrease in raw cotton yield (% of background level) <15 15-40 40-80 Seasonal salt accumulation a)% b) tlha 0.21-0.30 30-45 0.31-0.60 45-90 6.0-11.0 (moderate) >11.0 (high) 0.11-0.20 16-30 Degree of pollution of irrigation water (ratio of 1.0-6.0 (weak) content of toxic chemicals to their allowed concentration) great economic damage is caused by the salinization of irrigated lands (Table 9), due to incorrect use of water resources for irrigation and insufficient melioration. Desertification Map of Turkmenistan A desertification map of Turkmenistan based on remote satellite pictures (Fig. 4) was created on the scale 1:4,000,000 (40 km in 1 cm) (Fig. 5). Although such a small scale does not allow for depiction of all details of degradation of the arid ecosystems in Turkmenistan, it gives a general picture of the distribution of desertification in this republic. Especially strong human influence is manifested in oases and adjacent territories. Extremely high salinization, for example, is demonstrated for the Tedzhen oasis. Another ecological danger zone is the dried-up Kara-Bogaz-Gol Bay of the Caspian Sea. A vast solonchack (salt pan), from which salt is now carried by the wind to adjacent areas, has been formed here due to the closure of the bay by an artificial dam in 1983. This decision was made in order to "save" the Caspian Sea, whose level was predicted by some to decrease in the near future. This forecast has been proved incorrect: the Caspian Sea level, on the contrary, has been increasing from 1988 to 1992, flooding settlements, roads, and industrial structures. The lowest levels of desertification are recorded along the Turkmenistan border with Iran and Afghanistan (Fig. 5: 11). This protected territory is close to the background level of desertification, due to restrained development of this area. 74 Nikolai G. Kharin Fig. 4. Territory of Turkmenistan (after Meteor satellite remote photo). Darker areas represent oases, lighter areas represent deserts and solonchaks. Acknowledgements The author thanks G.S. Kalyonov, A.A. Kiriltseva, and P. Esenov (Remote Sensing Laboratory of the Desert Institute, Academy of Sciences of Turkmenistan) for their help in creation of the desertification map of Turkmenistan and in establishment of the criteria of desertification. Structure of the Database of Desertification Data (maintained in the Desert Institute, Academy of Sciences of Turkmenistan, Ashgabat) I. Causes of desertification (C). CN - natural causes; CNa - air temperature,CNb - albedo, CNc - precipitation, CNd - air humidity, CNe - wind speed, CNf - dust storms. CH - anthropogenic causes; CHa centralized norms of planned economy, CHb - control figures of economic development by separate regions, CHc - reported data on fulfilment of economic plan by separate regions, CHd - population density, CHe - area of deforestation, CHf - grazing load on pastures, CHg - areas not used for Desertification of the Arid Lands of Turkmenistan 0 v v 1 § . v. v 75 2 ~ I Vv Vl li -v - v 3 • 5 ~6 ~ 8708: B9 I•• 110 i; il~~- --~:=i-J.--l ~. =±:l;:::.:::::;~~~;;j":::.±;~=l :;;:;;:±l,:;:;;:=.-jl==.. Fig. 5. Desertification Map of the Arid Territories of Turkmenistan (l :4,000,000). I - low degradation of vegetation, 2 - moderate degradation of vegetation combined with deflation, 3 - degradation of mountain vegetation (70%) combined with water erosion (30%), 4 - low salinization of irrigated lands, 5 - moderate salinization of irrigated lands, 6 - high salinization of irrigated lands, 7 - technogenic desertification, 8 - deflation, 9 - pasture swamping, 10 - the solonchak formed in place of the former Kara-Bogaz-Gol Bay, II - protected border territories, 12 - automorphic solonchacks, 13 - drift sands of natural origin, TI-low desertification rate, T2 - moderate desertification rate, T3 - high desertification rate. crops, CHgl - area used for roads, CHg2 - area used for residence and construction, CHg3 - area used for industry, CHh - ploughed area, CHiirrigated area. II. The process of desertification (D). DV - degradation of vegetation; DVa species composition of vegetation, DVb - bioproductivity, DVc - forested areas separated by classes of productivity, DVd - forest deposits, DVe area under pastures, DVf - pasture productivity, DVg - area of dried forests, Dvh - disappeared plant species. DS - soil degradation; DSa areas under wind erosion, DSb - areas under water erosion, DSc - areas with decreasing humus content, DSd - areas with hardened soil, DSe areas with salinization and swamping. DE - deterioration of water resources; DEa - river water debit, DEb - lake water volume, DEc amount of surface runoff, DEd - level of ground water, DEe - quality of surface and ground waters. DA - changes in animal populations; DAb animal species composition, DAc - disappeared animal species, DAd diseases of animals. 76 Nikolai G. Kharin III. Consequences of desertification (A). AS - social consequences; ASa number of nomadic population, ASb - migrations of population, ASc number of new settlements, ASd - sanitary conditions, ASe - birth rate, ASf - death rate, ASg - specific human diseases, ASh - life span. AE economic consequences; AEa - crop structure, AEb - yield of agricultural crops, AEc - number of cattle, AEd - food consumption, AEe - water consumption, AEf - fuel consumption, AEg - per capita income. IV. Measures against desertification (L). LS - monitoring of desertification; LSa - criteria of desertification, LSal - criteria of cxurrent conditions, LSa2 - rate criteria, LSa3 - internal danger, LSa4 - grazing load, LSa5 density of population, LSa6 - methodology. LM - measures against desertification; LMa - areas where measures against wind erosion were undertaken, LMb - areas where measures against soil salinization were undertaken, LMc - areas where measures against soil hardening were undertaken, LMd - areas of meliorated pastures, LMe - areas of low productive arable lands where melioration was undertaken, LMf meliorated forested areas, LMh - usage of mineralized water, LMhl deposit of mineralized water, LMh2 - area of irrigated crops, LMh3 - yield of irrigated crops, LMi - areas where complex measures against desertification were undertaken. LP - forecast of desertification; LPa models of desertification, LPb - climate forecast, LPc - population density forecast, LPd - economic development forecast. V. Archive materials (AR). ARa - topographic maps, ARb - theme maps, ARc - airplane remote photographs, ARd - satellite remote photographs, ARe - field descriptions, ARf - bibliography. Sand dunes in the Repetek Reserve, Karakum Desert (1 of 2) Photo by H.R. Levenshtein. 6. Vegetation of the Deserts of Turkmenistan IGOR G. RUSTAMOV Abstract The desert vegetation in Turkmenistan consists predominantly of semishrub sagebrush-halophyte and psammophyte communities, with dominant formations of Haloxyleta, Salsoleta, Calligoneta, and Artemiseta. We have separated plant communtites into 26 formations and 28 groups of associations with a relatively simple phytocoenological structure and homogeneous species composition. The community structure is usually determined by a few dominant species of semishrubs which also provide most of the phytomass. Other sin usia, such as herbaceous cover, are built mainly by annual ephemerous species which do not playa significant role in the community structure. In deserts, which occupy more than 80% of the territory of Turmenistan, vegetation is a valuable feed resource for the livestock industry. Desert areas are used throughout the year for sheep and camel grazing. Desert vegetation provides an important ecological role by stabilizing the sand. Several natural reserves and other protected areas have been established to preserve desert vegetation and landscapes in Turkmenistan. Introduction The desert vegetation of Turkmenistan is relatively well studied. All basic plant communities have been described and characterized and a number of studies conducted on the dynamics and productivity of many desert plant communities as well as on the role of natural and anthropogenic factors. This review is based on data published by other authors as well as on our original data gleaned from many years of studies in the various desert regions of the republic. Desert vegetation strongly depends on climatic conditions. In the deserts of Turkmenistan, the severe water deficiency (annual precipitation does not exceed 120 to 130 mm, and in some regions is even as low as 75 mm), an unequal seasonal distribution of this scarce precipitation, and high summer temperatures have resulted in many specific evolutionary adaptations in desert V. Fet & K.I. Atamuradov (eds.), Biogeography and Ecology of Turkmenistan, 77-104. © 1994 Kluwer Academic Publishers. 78 Igor G. Rustamov plants. For instance, desert plants may partially lose leaves (or lose assimilating branches that replace leaves) in the summer; leaves may possess protective hairs or wax cover; fewer stomata may be present than in non-desert species, and their size may be smaller or they may become embedded in the leaf tissue; the root system can be extremely developed and reach the level of ground water or the horizon of capillary moisture; and a system of accessory roots may develop in plants growing on sand dunes. Characteristics of Desert Vegetation Deserts of Turkmenistan present various types of habitats and plant communities. The vegetation in the sand desert of Karakum is dominated by such shrub species as saksaul, cherkez, and kandym, with an herbaceous cover of sand sedge (Carex physodes) and ephemerous plants. The black saksaul (Haloxylon aphyllum) sometimes forms peculiar "desert forests." Clay deserts (takyrs) are almost devoid of vascular plants but possess specific communities of algae and lichens. Vast clay and gravel plateaus of West Turkmenistan are dominated by semishrub sagebrush-halophyte communities. Below, we present a classification scheme for the desert vegetation in Turkmenistan (Table 1), and give characteristics of its formations and associations. Each subdivision in this classification has a number code referred to in the text. 1. Euxerophyte Desert Vegetation This vegetation type embraces the most common plant communities found both in the sand desert and low plateaus. Within this type, we distinguish between two classes offormations: desert semi shrub and small shrub vegetation (1.1) and desert shrub and large shrub vegetation (1.2). The most common small semi shrub communities are characterized by formations of sagebrushes and halophytes. Shrub and large shrub vegetation is found in sand deserts and on thin kyr sands underlaid by maternal rocks. In the Karakum and Chilmamedkum sand deserts, the most characteristic communities are those of saksaul and psammophite shrubs (the latter dominated by cherkez, dzhuzgun, or syuzen). 1.1. Desert Semishrub and Small Semishrub Vegetation This class of formations includes communities dominated by a typical desert ecobiomorph of small semishrubs; these are predominantly various sagebrush (Artemisia) species of the subgenus Seriphidium, species of Salsola (S. gemmascens and S. orientalis), biyurgun (Anabasis salsa and A. ramosissimum), and sarsazan (Halocnemum strobilaceum). Desert small semishrub vegetation is diverse and dominates the desert vegetation. Within this class offormations, we typical Reaumuria associations; ephemerous and ephemeroid Reaumuria associations typical boyalych associations; ephemerous and ephemeroid boyalych associations 1.1.4. Small halophyte shrub 1.1.4.1. Boyalych formation deserts (Salsola arbuscula) 1.1.4.2. Reaumuria formation (Reaumuria spp.) typical sarsazan associations 1.1.3. Succulent-halophyte deserts 1.1.3.1. Sarsazan formation (Halocnemum strobilaceum) typical biyurgun associations 1.1.2.3. Biyurgun formation (Anabasis salsa) -.l 1.0 § <;;. ~ ~ ~ ~ f:i" ..... ~ tl ~ s. ~ typical kevreik associations 1.1.2.2. Kevreik formation (Salsola orientalis) ~ §. ~ ~ typical tetyr associations; ephemerous and ephemeroid tetyr associations typical Badghyz sagebrush associations; ephemerous and ephemeroid sagebrush associations 1.1.1.2. Badghyz sagebrush formation (Artemisia badhysi) 1.1.2.1. Tetyr formation (Salsola gemmascens) typical Kernrud sagebrush associations; ephemerous and ephemeroid Kernrud sagebrush associations; psammophyte Kemrud sagebrush associations 1.1.1.1. Kemrud sagebrush formation (Artemisia kemrudica) 1.1.1. Sagebrush deserts 1.1. Desert semishrub vegetation I. Euxerophyte desert vegetation 1.1.2. Halophyte semishrub deserts Groups of associations Formation Group of formations Class of formations Vegetation type Table 1. Classification of desert vegetation of Turkmenistan 2. Mesoxerophyte desert vegetation Vegetation type Table 1. Continued 2.1. Desert herbaceous vegetation 1.2.1. Saksaul deserts 1.2. Desert shrub and large shrub vegetation 2.1.1. Large perennial herbaceous vegetation 1.2.2. Psammophyte shrub deserts Group of formations Class of formations typical cherkez associations typical bordzhok associations 1.2.2.2. Cherkez formation (Salsola arbuscula) 1.2.2.4. Bordzhok formation (Ephedra strobilacea) 2.1.1.2. Yuzarlik formation (Peganum harmala) 2.1.1.1. Selin formation (Aristida pennata) typical dzhuzgun associations 1.2.2.2. Dzhuzgun formation (anthropogenic) (Calligonum spp.) typical mixed saksaul associations 1.2.1.3. Mixed saksaul formation (Haloxylon persicum and Haloxylon aphyllum) typical syuzen associations typical (shrub) black saksaul associations; ephemerous and ephemeroid black saksaul associations; moss/black saksaul associations 1.2.1.2. Black saksaul formation (Haloxylon aphyllum) 1.2.2.1. Syuzen formation (Ammodendron conollyz) typical (shrub) white saksaul associations Groups of associations 1.2.1.1. White saksaul formation (Haloxylon persicum) Formation ~ c ~ ~ '" ~ ;:: G'l ~ c ..., 0 00 Class of formations 3.1. Desert thallomous vegetation Vegetation type 3. Psychroxerophyte desert vegetation Table 1. Continued 3.1.3. Moss vegetation 3.1.2. Lichen vegetation (on takyrs) 3.1.1. Algal vegetation (on takyrs) 2.1.3. Annual halophyte vegetation 2.1.2. Ephemerous-grass vegetation Group of formations 2.1.3.2. Ketgen formation (Salsola paulsenii) 2.1.3.1. Ebelek formation (Ceratocarpus utriculosus) 2.1.2.2. Arpagan formation (Eremopyrum orientale) 2.1.2.1. Yepelek formation (Anisantha tectorum) 2.1.1.3. Agropyronformation (Agropyron fragile) Formation Groups of associations ~ 00 § 0::;. ~ [ ~ ~ r;;- ~.... So "" b ~ ""~ 5' ::! <ltl 82 Igor G. Rustamov separate three groups: sagebrush deserts, halophyte small semi shrub deserts, and succulent-halophyte deserts. 1.1.1. Sagebrush Deserts Sagebrush communities are typical in the deserts of Turkmenistan, where they are widespread and well-studied (Prozorovsky 1940; Rodin 1940,1963; Korovin and Granitov 1949; Momotov 1953; Kogan 1954; Nechaeva 1956; Rodin and Rubtsov 1956; Rachkovskaya 1957; Korovin 1961; Rustamov 1962; Granitov 1967). Sagebrush communities are present on the vast lowlands of the Krasnovodsk and Ustyurt Plateaus, in the modern and old deltas of the Amudarya River, and in the Trans-Unguz Karakum. In the Karakum Desert proper, relatively homogeneous sagebrush communities are found in lowland and small-dune sands. Formations of sagebrush are represented also in the underhill lowland and foothills of Kopetdagh (Rodin 1963). Soils under sagebrush communities are loams, sandy loams, grey-brown soils, and sometimes light serozyoms. Dominant in sagebrush communities are Artemisia kemrudica, A. badhysi, A. badhysi var. arenico/a, A. halophida, and A. santolina. The most characteristic, widespread, and prevailing formation is that of Artemisia kemrudica (Table 2). Table 2. The vegetation of the formation Artemisieta kemrudicae Species Shrubs: Salsola richteri Calligonum alatum Salsola arbuscula Small shrubs: Ephedra distachya Semi shrubs: Astragalus turcomanicus Small semishrubs: Halothamnus subaphyllus Salsola orientalis Salsola gemmascens Artemisia kemrudica Perennial herbaceous species: Stipagrostis pennata Iris longiscapa Carex pachystylis Carex physodes Gagea reticulata Alliumfibrosum Tulipa sogdiana Ferulafoetida Annual herbaceous species: Ceratocarpus utriculosus Height (cm) Abundance (Drude scale) Coverage (%) Density (plants/ha) 70 40-60 30-80 Sol Sol Sp-COpl 1-2 1-2 5-15 200 200 1,400-3,800 10-30 Sol 200 35-40 Sol 200 25 20-30 10-15 20-45 Sol Sp Sp COpl-3 <1 1-2 1-2 20-55 100-200 100-700 1,400-3,800 6,000-22,000 20-40 10-20 10-20 15-20 8-15 15-20 10-12 35-40 Sol Sol COpl-3 Sp Sol-Sp Sol Sol Sp 1-2 <1 2-5 2-5 <1 <1 <1 2-3 1 500 5-10 Sol <1 Vegetation of the Deserts of Turkmenistan 83 Table 2. Continued Species Climacoptera lanata Ceratocephala falcata Hypecoum pendulum Roemeria hybrida Goldbachia laevigata Strigosella grandi/lora Strigosella sp. Tetracme quadricornis [satis minuta Leptaleum filifolium Astragalus oxyglottis Erodium oxyrrhynchum Lappula semiglabra Nonea caspica Arnebia decumbens Koelpinia linearis Senecio subdentatus Amberboa turanica Eremopyrum orientale Anisantha tectorum Atriplex dimorphostegia Lallemantia royleana Height (cm) Abundance (Drude scale) Coverage (%) 15-20 2-5 10-20 10 8-10 25-30 10-15 10-12 30-40 4-5 5-6 5-6 20 5-10 5-20 5-20 8-12 5-10 10-15 15-20 2-3 3-4 Sol Sol Sol Sol Sol Sp Sol Sol Sp Cop I Sol Sol Sol Sol Sol-Sp Sol Sol Sol Sp-COp2 Sol-Sp Sol Sol <I <I <I <I <I I <I <I I I <I <I I <I <I I <I <I Density (plants/ha) 1-2 1 <I <I The Kemrud sagebrush commumtIes occupy large areas in Northwest Turkmenistan, on the Krasnovodsk, Ustyurt, and Beltau Plateaus, and in the modern and old deltas of the Amudarya River, and are found on grey-brown sandy loams and light loams, covered by gravel, with gypsum-bearing rock located at a depth of 50 to 70 cm. These communities are rather homogeneous in structure: the upper layer, when present, is 60 to 100 cm high and consists of sparse shrubs of low Haloxylon aphyllum and Calligonum spp.; sometimes, on sandy soils, it includes sparse Salsola richteri and Halothamnus subaphyllum var. arenaria. The major layer is the second one, built by Artemisia kemrudica, with participation of Salsola arbuscula, S. gemmascens, and occasional Astragalus turcomanicus. This layer is usually 20 to 40 cm; however, such species as Salsola arbuscula and Astragalus turcomanicus often form a separate superlayer up to 60 cm or higher. The dominant species, Artemisia kemrudica, is always outstanding and conspicuous. This plant is 30 to 60 cm high; its perennial portion is up to 15 cm long, and annual one is 15 to 30-35 cm long. During wet years, the annual shoots of this small semi shrub c~n reach maximal length of 43 em (Nechaeva 1956), whereas in dry years their length is 6 to 20 cm long. Lifespan of the Kemrud sagebrush is 15 to 20 years. The vegetative period of Artemisia kemrudica begins in late February to early 84 Igor G. Rustamov March; growth occurs in April and May; flowering begins in late August and continues until September; seed production occurs in October. The root system of sagebrush changes significantly with age. In young plants, the main root is well developed, going down to 60 cm and producing a number of side roots. Later, the sagebrush root system develops primarily as side roots, and the main root almost completely disappears; this developmental peculiarity is a result of the differentiation of branches of an original plant which receives nutrition through side roots. The diameter of a sagebrush root system is about two meters, and the system can penetrate to a depth of 70 to 80 cm. Also typical for Artemisia kemrudica growth is the change in aboveground to underground biomass ratio: juvenile plants can have two to three times more biomass above ground than underground (Nechaeva et al. 1973), whereas in adult plants these biomasses are almost equal. Among other species that can subdominate in sagebrush communities are Salsola arbuscula, S. gemmascens, and S. orientalis; their abundance, however, is insignificant in ephemerous and ephemeroid Kemrud sagebrush communities. About one to two per cent of coverage in the main sagebrush layer can be contributed by Ephedra distachya, Convolvulus sp., and Haplophyllum ramosissimum. Rodin (1963) gives a total list of 20 species of semishrubs found in the Kemrud sagebrush communities; on the description plots this number does not exceed eight species. The lowest (third) layer in the Kemrud sagebrush communities consists of herbaceous, primarily ephemerous and ephemeroid vegetation. A total list of20 to 25 species is given for sagebrush pastures of Northwest Turkmenistan by Nechayeva (1956). On concrete plots there are five to ten, rarely up to fifteen, species of ephemers and ephemeroids. They develop primarily in the spring although growth is highly dependent on annual weather conditions. Within the Kemrud sagebrush formation, four groups of associations can be found: typical, semisavanna, ephemerous and ephemeroid, and psammophyte. Species diversity is highest in typical and ephemerous and ephemeroid Kemrud sagebrush associations (up to 50 species of plants and more). More than 50% of this list consists of annual species, primarily ephemerous ones; plants with a short vegetative period (ephemers and ephemeroids combined) represent 55 to 66% of the species list in these communities. There are six species of semishrubs and small semishrubs, and five to six species of shrubs and small shrubs (altogether 22 to 24% of the species list). Less diverse are psammophyte Kemrud sagebrush communities, but here also more than half (54%) of the species are plants with a short vegetative period. In total, 60% of species present in the Kemrud sagebrush formation have a short vegetative period, and 22% are shrubs and semishrubs. 1.1.2. Halophyte Small Semishrub Deserts This group of formations includes the typical desert zone small semishrubs tetyr (Salsola gemmascens), biyurgun (Anabasis salsa), and kevreik (Salsola orientalis) . Vegetation of the Deserts of Turkmenistan 85 1.1.2.1. Tetyr Formation (Salsola gemmascens) (table 3). Although tetyr formation is not the most widespread, it is one of the most typical desert formations of vegetation. Communities of Salsola gemmascens are represented in the Uzboi dry bed, in the southern Ustyurt and Krasnovodsk Plateaus next to the Karabogazgol Bay of the Caspian, and in the western Trans-Unguz area. Patches oftetyr communities are also found throughout the Karakum Desert in takyrs and takyr-like habitats among sand dunes. S. gemmascens is found on grey-brown solonets loams and sandy soils bearing gypsum as well as on grey-brown primitive soils of takyrs (the latter may have a certain percentage of gravel and gypsum). The dominant species of this formation, Salsola gemmascens, is a small (30 to 50 cm) shrub which is a typical xerophyte and, to a certain degree, a halophyte. Individual plants live for 10 to 15, and sometimes to 20 or 25 years, and can Table 3. The vegetation of the formation Salsoleta gemmascentes Species Shrubs: Salsola arbuscula Small semishrubs: Salsola orientalis Salsola gemmascens Artemisia kemrudica Perennial herbaceous species: Heliotropium sp. Astragalus xiphioides Carex pachystylis Gagea reticulata Allium sp. Tulipa sogdiana Annual herbaceous species: Halimocnemis villosa Ceratocephala falcata Hypecoum pendulum Roemeria hybrida Strigosella grandiflora Strigosella sp. Leptaleum filifolium Astragalus arpilobus Astragalus oxyglottis Lappula semiglabra Nonea caspica Arnebia decumbens Koelpinia Iinearis Senecio subdentatus Eremopyrum orientale Epi/asia hemilasia Height (cm) Abundance (Drude scale) 20-40 Sp 20-30 10-15 20-30 Sol-Sp COp2-3 Sol-Sp 2-3 10-25 1-2 nla Sp Sol COpl-2 Sp Sol Sol <1 <I 1-2 <1 Sp COpl Sol Sol Sp-COp2 Sol Sp-COp2 Sp Sol Sol Sol Sol Sol Sp Sol-Copl Sol <1 1 <1 <I 1-2 <1 1-2 1 <I <I <I <I <1 <1 1-2 <1 5-10 10-20 5-8 15-20 5-10 5-6 2-4 8-15 8-10 20-30 5-7 3-15 3-5 3-6 5-12 5-15 8-10 10-15 20-25 7-20 10 Coverage (%) 2-3 <I <1 Density (plants/ha) 600 600-800 7,600-28,100 300-500 86 Igor G. Rustamov annually produce up to 600 seeds. Seven- to ten-year old plants form an expressed crown and root system (which is superficial and reaches 70 to 100-125 cm; Nechaeva et al. 1973). Habitus and condition of Salsola gemmascens vary with soil conditions. On the gravel- and gypsum-bearing soils of Krasnovodsk Plateau and areas south from Ustyurt, tetyr plants are depressed and small-sized (7 to 15 cm); their crown is poorly developed. On the other hand, on grey-brown soils with low content of gypsum and disrupted surface S. gemmascens grows more vigorously, develops a normal crown, and reaches a height of 20 to 40 cm. Depending on the habitat, coverage of tetyr can vary from 10 to 25%, and its density varies from 12,000-16,000 to 24,000-28,000 plants/ha (our data; Pelt 1956). Floristically, this formation is relatively poor (the total list has 30 to 35 species; the concrete plots house 12 to 17 species). As in other desert formations, most of these species (especially ephemerous ones) are annual herbaceous plants (62 to 64% of the total list). The combined number of annual and perennial herbaceous species with spring and fall vegetative period (i.e., ephemers and ephemeroids) represent 57 to 75% of all species in the tetyr formation. Semishrubs and small semishrubs contribute 11 to 13%, and shrubs and small shrubs, only 4 to 8% of the species list. Certain shrubs that participate in this formation, such as Calligonum setosum, Salsola arbuscula, and Haloxylon aphyl/um, are so depressed there that they rarely reach a height of 50 or 60 cm. Vertical structure in tetyr communities is weakly expressed; it basically comprises two layers, but the lower layer is expressed only in the spring period, as in the sagebrush communities. The upper layer (20 to 40 cm high) is composed of S. gemmascens, with some participation of Artemisia kemrudica, Salsola orientalis, and S. arbuscula. Plants of the latter species can be taller than S. gemmascens but are sparse. The lower (herbaceous) layer, formed by 20 to 23 species of ephemers and ephemeroids, is no higher than 20 cm. The dominant species here is the desert sedge Carex pachystylis; other co-dominant ephemers are Eremopyrum orientale, Ceratocephala falcata, and the species Leptaleum filifolium, which is specific for some tetyr communities. In summer and fall, there is significant participation of annual plants with extended vegetative periods, such as Climacoptera lanata, Salsola sc/erantra, Halimocnemus villosa, and H. karelinii. Soil in tetyr communities is covered by clusters of specific flourwhite lichens. In total, the tetyr formation is one of the most "desert" kinds, judging from the sparse coverage, poor species diversity, and low biomass/ha values. Within this formation, four goups of associations can be separated: typical, petrophyte, psammophyte, takyr, and halophyte communities of S. gemmacsens. Of these, typical tetyr associations are the most common ones. 1.1.2.2. Biyurgun Formation (Anabasis Salsa) (table 4). Biyurgun formation is widespread in the deserts of Middle Asia and Kazakhstan, especially in the subzone of northern deserts, and is fairly well described and studied. Kuznetsov (1959, 1966) conducted a study of biyurgun formation for the entire arid zone Vegetation of the Deserts of Turkmenistan 87 Table 4. The vegetation of the formation Anabaseta salsae. Species Shrubs: Atraphaxis spinosa Semishrubs: Nanophyton erinaceum Salsola gemmascens Salsola orienta lis Artemisia kemrudica Anabasis salsa Anabasis eriopoda Annual herbaceous species: Ceratocarpus utriculosus Suaeda arcuata Climacoptera lanata Halimocnemis karelinii Ceratocephala falcata Strigosella africana Leptoleum filifolium Goldbachia laevigata Tetracme quadricornis Arnebia decumbens Nonea caspica Senecio subdentatus Amberboa turanica Eremopyrum orientale Lepidium perfoliatum Height (cm) Abundance (Drude scale) 40-50 Sol 5-10 15-20 25-40 20-25 15-30 (40) 10-15 COpl Sp-COpl Sol-Sp COpl-2 COp3 COpl-3 5-10 20-30 10-12 5-7 2-3 5-6 3-5 5-10 5-10 5-10 5-10 5-8 5-10 5-7 5-15 Sol Sol Sol Sol Sol COpl Sol Sol-Sp Sol Sol Sol-Sp Sol Sol Sol Sol Coverage (%) 4-5 2-3 I 2-3 30-35 20-55 Density (plants/ha) 2,500-5,600 3,000-5.000 300-600 2,000-3,500 12,000-50,000 6,000-22,000 <I <I <I <I <I I <I <I <I <I <I <I <I <I <I the former USSR; in separate deserts, this formation was studied in detail by Korovin and Granitov (1949), Kogan (1954), Kubanskaya (1956) and Rodin (1963). The communities of Anabasis salsa are especially characteristic for the Ustyurt Plateau and takyrs of the ancient delta of the Amudarya; small patches ofbiyurgun are found also within the sand dunes of the Trans-Unguz Karakum. Biyurgun formation is found on grey-brown, solonchaks, loams and greybrown primitive (takyr) soils with a compressed surface covered by a film of algae. The dominant species, Anabasis salsa, is a small shrub or semishrub, 10-15 to 20-40 cm high; pure A. salsa communities cover 20 to 30% of the soil surface, with the density 40,000 to 50,000 plants/ha. This number can drop to 14,000 to 18,000 plants/ha in the communities when other species co-dominate (e.g., Artemisia kemrudica or Salsola gemmascens; Nechaeva 1956); generally, the density can vary from 10,000 to 80,000 plants/ha (Korovin and Granitov 1949). Communities of A. salsa usually appear to have only one (upper) layer (15 to 30 cm high) formed primarily by biyurgun, rarely in combination with Artemisia 88 Igor G. Rustamov kemrudica, Salsola gemmascens, or S. orientalis. Another species typical of this layer (but somewhat smaller, 5 to 15 cm high) is Nanophyton erinaceum. A lower, herbaceous layer may sometimes be expressed. It is homogeneous and includes such ephemers as Leptaleum filifolium, Strigosella africana, Lepidium perfoliatum, Goldbachia laevigata, Ceratocephala falcata, Arnebia decumbens, and Eremopyrum orientale, as well as annual plants with summer and fall vegetative periods such as Climacoptera lanata, Suaeda arcuata, and Halimocnemis karelini. The diversity of species within this formation in Turkmenistan deserts is low (20 to 25); interestingly, Kubanskaya (1956) found 122 species for biyurgun formation in the Betpakdlala Desert (Kazakhstan), and Kuznetsov (1959) listed 218 species found within this formation throughout the arid zone of the former Soviet Union. Annual herbaceous species constitute 40 to 90% of the species list, with annual ephemers representing 30 to 60%. The absence of perennial herbaceous species (including ephemeroids) is notable, and there are one to five (10 to 50%) species of semishrubs. Four groups of associations are separated within the biyurgun formation: typical, petrophyte, and takyr associations. 1.1.2.3. Kevreik Formation (Salsola Orientalis) (table 5). These communities are not as well studied as others, probably due to their limited distribution. Granitov (1967) found that S. orientalis is relatively common in the Southeast Kizylkum Desert (Uzbekistan) but rarely dominates plant communities. The kevreik formation was studied by Korovin and Granitov (1949), Nechaeva (1956), Rodin (1963), and Granitov (1967). In Turkmenistan, kevreik communities are common in the ancient alluvial plain of the Kunyadarya River and in the Meshed-Messerian Plain (Rodin 1963). Large areas covered by kevreik communites were recorded on the kyr plateau which lies between Koimat and the Uchtagan Sands (Nechaeva 1966), as well as in the Tashauz Region of Northwest Turkmenistan, near Edikhauz and Butentau. These communites grow mainly on the lands of ancient irrigation (Rodin 1963), on grey-brown, slightly loamy or sandy soils (rarely on sands). The dominant species, Salsola orientalis, is a small semishrub, 30 to 50 cm high; it covers 20 to 30% of the soil surface and has a density of 5,000-7,000 to 1O,000-12,000/ha. Community structure is similar to that of S. gemmascens; the upper layer is formed by Salsola orientalis, with sparse Artemisia kemrudica, Salsola arbuscula, and S. gemmascens. Rare Haloxylon aphyllum can form a sparse superlayer. The second (lower) layer is built of ephemers (15 species), ephemeroids, and certain annual Chenopodiaceae with a summer - fall vegetative period. In spring, the most conspicuous plants are Carex pachystylis, Ceratocephalafalcata, Leptaleumfilifolium and Eremopyrum orientale. Among less abundant species are Strigosella grandijlora, S. circinata , Astragalus oxyglottis, Lappula semiglabra, Arnebia decumbens, and Koelpinia linearis. In summer and fall, the annual species of Chenopodiaceae found in these communities areClimacoptera lanata, Salsola $clerantha, Halimocnemis karelinii, Ceratocarpus utriculosus, and Girgensonnia oppositijlora. Floristically, Vegetation of the Deserts of Turkmenistan 89 Table 5. The vegetation of the formation Salsoleta orientales Species Trees: Haloxylon aphyllum Shrubs: Salsola arbuscula Small semi shrubs: Salsola orientalis Salsola gemmascens Artemisia kemrudica Anabasis eriopoda Perennial herbaceous species: Carex pachystylis Annual herbaceous species: Ceratocarpus utriculosus Climacoptera lanata Salsola sclerantha Halimocnemis karelinii Ceratocephala falcata Hypecoum pendulum Strigosella grandijlora S. circinata Leptaleum filifolium Tetracme quadricorris Astragalus oxyglottis Arnebia decumbens Lappula semiglabra Nonea caspica Koelpinia linearis Epilasia hemilasia Amberboa turanica Eremopyrum orientale Girgensonnia oppositijlora Height (cm) Abundance (Drude scale) 80-100 Sol 40 Un 35-40 10-20 20-30 10-15 COp2 Sp Sp Sol-Sp 10-150 Cop! 1-2 5-10 10-15 10-12 5-6 2-3 10-15 20-25 10-15 5-10 5-10 5-6 8-10 10-12 5-10 10-12 10-15 5-10 5-6 10 Sol Sol Sol Sol Sp-Cop! Sol Sp Sp Sp-Cop! Sol Sol-Sp Sol Sol Sol Sol Sol Sol-Sp Sol Sol-Cop! <I <I <I <I I <I Coverage (%) Density (plants/ha) <I 20-25 2-3 1-2 5,000-12,000 2,300-3,400 1,400-2,000 1-2 <I I <I <I <I <I <I <I <I <I <1 I this formation is not very different from that of S. gemmascens; the list of species for kevreik formation includes 20 to 60 species (Rodin 1963; Rustamov 1973). Of these, 66 to 75% are annual plants (mostly ephemers), and 13 to 27 species are small semishrubs. Perennials are represented here only by Carex pachystylis. Within the kevreik formation, we separate typical and psammophyte kevreik groups of associations. 1.1.3. Succulent-Halophyte Deserts Communities belonging to this group of formations are widespread on salt areas (solonchaks) and solonchak soils. The most typical formation is that of 1.1.3.1. Sarsazan (Halocnemum Strobilaceum) (table 6). Characteristics of these communities can be found in many sources (Prozorovsky 1940; Korovin 90 Igor G. Rustamov Table 6. The vegetation of the formation Halocnemeta strobilaceae Species Trees: Haloxylon aphyllwn Shrubs: Tamarix sp. Halostachys caspica Nitraria schoberi Lycium ruthenicum Reaumuria fruticosa Salsola arbuscula Small shrubs: Limonium subfruticosum Small semishrubs: Halocnemum strobilaceum Salsola gemmascens Perennial herbaceous species: Frankenia hirsuta Alhagi persarum Annual herbaceous species: Climacoptera lanata Salsola sclerantha Halimocnemis longifolia Petrosimonia glauca Height (cm) Abundance (Drude scale) Coverage 40-70 Sp 2-3 100-300 40-60 60-80 60-70 30-40 40-50 40 Sol Sol Sol Sol Sol Sol 1-2 1-2 1-2 1-2 1-2 200-400 200-300 200 200-300 200 100-300 35-40 Sol 1-2 200-400 20-40 10-15 COpl-3 Sol 20-30 20-30 Sol-Sp Sol <I <1 10-20 10-15 10-15 10 Sol-Sp Sol Sol-Sp Sol <1 <I <1 <I (%) I 10-20 (25) I Density (plants/ha) 700-4,500 300 Granitov 1949; Kogan 1954; Kubanskaya 1956; Korovin 1961; Rustamov 1962; Rodin 1963; Granitov 1967); however, only a few of these authors published descriptions of concrete plots and floristic lists. Sarsazan communities are found on typical solonchaks and in solonchak depressions covered by specific small salt hills (chokalaks). The largest areas occupied by H. strobilaceum are located in Southwest Turkmenistan around the ancient delta of the Atrek River, along the Kelkor solonchak, and on the shores of Karabogazgol Bay. These communities can be also found in combinations with other succulent-halophyte desert vegetation. In the Karakum Desert, small areas occupied by H. strobilaceum are typical for the solonchak depressions with close ground waters. The dominant species, Halocnemum strobilaceum, is a stem succulent, leafless, small semishrub, 20 to 40 cm high. Its growth is not depressed even with high salt concentration in the soil. Roots of sarsazan can penetrate to the depth from 40-50 cm (Rumyantseva 1953) to 130-140 cm if ground water lies deep (Rustamov 1962). Sarsazan plants cover 10 to 20% of the soil surface, very rarely up to 25%. Its density varies from 700-1,200 to 2,200-4,500 plants/ha. Typical sarsazan communities have only one layer, often formed exclusively by H. strobilaceum. Its characteristic flat crowns can be seen on small (50 to 100 cm high) hills of salt (chokalaks) standing two to three meters apart; there is Vegetation of the Deserts of Turkmenistan 91 virtually no vegetation between chokalaks. When mineralized groundwater lies at deeper levels, sarsazan communities can include a number of species less tolerant to salt concentrations, such as Halostachys caspica, Limonium subfruticosum, Nitraria schoberi, and Frankenia hirsuta. Very rarely are found depressed shrubs of Tamarix hispida, Haloxylon aphyllum, and Lycium ruthenicum. Under lower soil salt content, the herbaceous cover is built mostly of annual Chenopodiaceae: Climacoptera lanata, Salsola sclerantha, Halimocnemis longifolia, and Petrosimonia glauca; sometimes, Alhagi persarum is present. Usually, there are no herbaceous species with winter-spring development. Diversity in sarsazan communities in Turkmenistan is very low, totalling about 15 species. Granitov (1967) described fifteen sarsazan associations from the Kizylkum Desert (Uzbekistan); of these, thirteen had one to sixteen species, and only two were unusually rich (31 and 39 species, including 5 or 6 species of ephemers). Kubanskaya (1956), however, listed 59 species for the sarsazan formation in the Betdpakdala Desert (Kazakhstan), and 53 species for the sarsazan association proper (including five species of ephemers and ephemeroids); interestingly, the coverage on these plots reached 50 to 65% which is a very significant figure for the communites of H. strobilaceum. About 50% of all species in sarsazan communites are arboreal plants (mostly shrubs and semishrubs), about 25% are annual non-ephemerous species, and there are no ephemers. Even fewer species (13%) are small semishrubs and perennial herbaceous species. Within the sarsazan formation, we separate two groups of associations: typical and meadow sarsazan associations. 1.2. Desert Shrub and Large Shrub Vegetation This class of formations is represented by two groups: saksaul deserts (1.2.1) and psammophyte shrub deserts (1.2.2.). Desert shrub and large shrub vegetation is widespread in sand deserts, in clay desert (takyr) lowlands, and in modern and ancient river deltas. 1.2.1. Saksaul Deserts This group includes formations of white saksaul (Haloxylon persicum), black saksaul (Haloxylon aphyllum), and a mixed formation with both Haloxylon persicum and H. aphyllum. 1.2.1.1. White Saksaul Formation (Haloxylon persicum) (table 7). This is the most characteristic formation of the sand dunes of the Karakum Desert. Within Turkmenistan, the white saksaul communities are widespread in the TransUnguz, Lowland and Southeast Karakum, as well as in the sand massifs of Uchtagan, Kumsebshen, and Chilmamedkum; they are found typically in sand dunes, more rarely in lowlands, depressions, and intradune depressions. These communities are found not only on sands proper, but also on the thick sand deposits covering maternal rocks. Haloxylon persicum also grows on weakly 92 Igor G. Rustamov Table 7. The vegetation of the formation Haloxyleta persica Species Shrubs: Haloxylon persicum Calligonum caput-medusae Calligonum setosum Salsola richteri Ephedra strobi/acea Perennial herbaceous species: Stipagrostis pennata Astragalus flexus Rheum turkestanicum Eremurus anisopterus Carex physodes Gagea divaricata Tulipa sogdiana Annual herbaceous species: Ceratocephala falcata Consolida rugulosa Hypecoum pendulum Roemeria hybrida Streptoloma desertorum /satis minima Strigosella circinnata Strigosella grandiflora Tetracme recurvata Astragalus arpi/obus Erodium oxyrrhynchum Arnebia decumbens Lappula semiglabra Nonea caspica Koelpinia linearis Microcephala lamellata Senecio subdentatus Amberboa turanica Epi/asia hemilasia Eremopyrum orientale Anisantha tectorum Cutandia memphitica Height (cm) Abundance (Drude scale) (%) Coverage Density (plantslha) 140-250 140-200 80-110 140 50-100 COpl-3 Sol Sol-Sp Sol Sol-Sp 15-25 2-3 2-4 1-2 2-3 400-900 100-200 100-300 100 200-400 40-50 25-30 20-30 30-40 15-20 5-7 10-15 Sp Sol Sol-Sp Sol COpl-3 Sol-Sp Sol-Sp 2-3 <I 1-2 100-300 5-6 30-35 20-30 25-40 10-20 50-60 30-40 40-55 20-25 10-15 15-25 20-25 20 15-20 25 10-12 20-25 25-30 25-30 15-20 25-30 20-30 Sp-COpl Sol Sol-Sp Sol Sol Sol Sol-Sp Sol Sol Sp-COpl Sol-Sp Sol-Sp Sol Sol Sol Sol Sol-Sp Sol Sol Sol Sp Sol-Sp 10-15 <1 <I 1 <I 1 <I <I <I <I <1 <I 2-3 <1 <I <I <I <I <1 <I <1 <I <I I <I developed sandy soils of grey-brown type, which are humus-poor and sometimes low in salt content. The communities of H. persicum have probably the most complex structure of all the desert plant communities of Turkmenistan; they contain several layers - at least two or three. The upper (first) layer is 1.5 to 2 meters high and consists of H. persicum and other large shrubs such as Salsola richteri, Calligonum caputmedusae, C. setosum, C. eriopodum, and Ephedra strobilacea. The second layer is represented by shrubs and semishrubs which are up to one meter high: Vegetation of the Deserts of Turkmenistan 93 Ephedra intermedia, Artemisia kelleri, and Astragalus spp. A special sublayer can be formed by small semishrubs such as Convolvulus divaricatus, C. korolkovii, and Acanthophyllum sp. The third (herbaceous) layer is formed by a large cespitose grass, Stipagrostis pennata, as well as by other perennials (Heliotropium argusioides, Tournefortia sibirica, and Astragalus chivensis and biennial Cousinia oxiana). Among perennial species with short vegetative periods (ephemeroids), a significant role is played by a desert sedge, Carex physodes, which creates thick turf; also found are Rheum turkestanicum and Eremurus anisopterus. Most herbaceous species are ephemerous (especially in years with high precipitation, when up to 30 or more species can be detected). The white saksaul formation, therefore, is floristically diverse and may include representatives of almost all desert ecobiomorphs. Rodin (1963) listed more than 150 species for this formation in West Turkmenistan; within the associations, this number varies from 30 to 80, and on concrete plots there are usually 30 to 35 species. In Northwest Turkmenistan, white saksaul communities include about 70 species (our data); in Southwest Kizylkum (Uzbekistan), from 28 to 48 species (Granitov 1967); and in the sand deserts of Kazakhstan, white saksaul communities also include several dozen species (Kurochkina 1966). Annual herbaceous plants prevail (51 to 64% of all species), especially ephemers (42 to 64%). The combined share of perennial and annual herbaceous plants is often more than 50% of the species list, and in ephemerous or ephemeroid white saksaul associations this share reaches 79%. Shrubs constitute 10 to 15% of all speCIes. The dominant species, Haloxylon persicum, is a large shrub, 3 to 5 meters high. It forms a short trunk (10-20 cm) and can produce six to seven levels of branches (Nechaeva et al. 1973). White saksaullives to 30 years; its vegetative propagation and seed production do not occur every year. It has a root system of universal type which penetrates down to a depth offour to six meters (Petro v 1935; Nechaeva et al. 1973). The ratio of aboveground to underground dry biomass is 1:0.6. Haloxylon persicum does not form dense thickets but rather grows as solitary bushes, with a density 100-200 to 400-700 plants/ha, and coverage of 10 to 30%. White saksalul communites are valued as pastures although they produce low edible biomass (0.3 to 0.5 ton/ha); they are used in all seasons (although primarily in winter). Size of white saksaul shrubs varies significantly with ecological conditions, as do number and abundance of species in these communities. Extensive grazing and woodcutting for many years in certain areas has led to the replacement of white saksaul communities by those of kandym (Calligonum sp. div.). Rodin (1963) separated three groups of associations within the white saksaul formation in West Turkmenistan: typical, ephemerous and ephemeroid, and moss/white saksaul associations. In the West Uzboi area we (Rustamov 1962) found three associations: Haloxylon persicum - Stipagrostis pennata + Carex physodes ass.; Haloxylon persicum - Carex 94 Igor G. Rustamov physodes ass.; and Haloxylon persicum + Calligonum sp. div. - Stipagrostis pennata + Carex physodes ass. For the Karakum Desert, Rodin (1963) listed seven common associations; the most widespread there are communities of Haloxylon persicum and Carex physodes. Within these communities, H. persicum is usually abundant and well developed. 1.2.1.2. Black Saksaul Formation (Haloxylon aphy/lum) (table 8). These communities are found primarily in modern and ancient river deltas, as well as in depressions within the sand deserts of Middle Asia. Within Turkmenistan, the major areas covered by black saks

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