Since for many years it has been deprived of the interest of botanists, information regarding the flora of Diyarbakır and especially the Tigris Valley was restricted to that under the main heading of Turkey. Yet this region has a plant diversity of more than 1500 species. Besides, 80 of these are rare plants that grow either only in Diyarbakır, or in a few other sites across the world at most.

The region’s flora diversity, endemic plants and threats this richness faces were examined by A. Selçuk Ertekin.

Surrounded by hills and mountains, the central areas of Diyarbakır form a hollow basin. Also referred to as the Diyarbakır Basin, the axis of this area is the wide Tigris Valley that extends along a west-to-east direction.

The Tigris Valley, extending along the course of the Tigris riverbed, comprises the rich ecosystems of the river and its environs, which begin at the Bismil Plain key biodiversity area and end at the Devegeçidi Dam key biodiversity area. These KBAs are home to many species on the Red List of Threatened Species prepared on the world scale according to the criteria of the International Union for Conservation of Nature (IUCN).

Diyarbakır and its environs possess a lush flora of approximately 1500 plants. Especially the mountainous regions surrounding the province, changing geographical and climatic factors, its vegetation structure and habitat diversity mean that the area is home to unique wild life. Around 80 of the plants that grow here are endemic to Diyarbakır. Some of them grow either only in Diyarbakır, or in a few other sites across the world at most.

With its incarnadine sprig flowers Akşamyıldızı [lit. night star] (Hesperis hedgei) and its racemous, purply flowers, Gelin Baklası [lit. bride’s pod] (Lathyrus trachycarpus) grow only on the Karacadağ steppes.

Urfa Koruğu (Rosularia haussknechtii), adaçayı, a type of sage, (Salvia balssiana), Çivit Otu (Isatis constricta and Isatis demiriziana), Düğün Çiçeği [lit. wedding flower], a type of buttercup, (Ranunculus bingoeldaghensis) are endemic plants that are observed only at a few other sites outside Diyarbakır.

Ova Fiği (Vicia esdraelonica) is an endemic type of vetch which only grows in Israel and the environs of Diyarbakır, and is globally endangered. Süslü Geven [lit. ornate milkvetch], a type of vetch, (Astragalus erythroaenius) is a rare species that only grows in Syria and the foothills of Karacadağ.

The Tigris Valley is located to the east of Diyarbakır city centre and with its broad sand dunes on the shores of the Tigris River, incorporates habitats that display diversity in a relatively confined area.

Although the main branch of the river has suffered widespread destruction, the smaller streams that form its branches resemble a gallery forest formed of dense trees. In addition to the dominant tree species such as various types of willow trees and the Euphrates Poplar, there are also vines, and at lower areas, bushes and herbaceous plants.

Right beside these gallery forests, we come across dense shrubbery and reed-beds formed of plants including blackberry, liquorice, reed, tamarisk and the like. Rich habitats that also include marshes, meadows and steppes are home to many different species.

Rare and Endemic Plants of the Tigris Valley – II

Kirpi Nohutu [lit. Hedgehog Chickpea] (Cicer echinospermum)
Native to the Southeastern Anatolia Region, this is a highly common chickpea species that prefers the steppes around Diyarbakır. The plant also grows in the Tigris Valley and is in the Vulnerable [VU] category according to the Red Data Book of Turkish Plants.

Uzuza (Colchicum balansae)
Native to the Mediterranean and Southeastern Anatolian region, Uzuza is a crocus that flowers in autumn. The Tigris Valley forms the eastern border of the plant’s range. Represented by a small population in the area, this species is in the Low Risk [LR (lc)] category according to the Red Data Book of Turkish Plants.

Boz Sarmaşık (Convolvulus galaticus)
A field bindweed native to Turkey with a wide range. This plant is seen across broad expanses of the Tigris Valley, and mainly prefers field sides and steppes. This species is in the Low Risk [LR (lc)] category according to the Red Data Book of Turkish Plants.

Sarı Batalak [lit. yellow camel calf] (Hedysarum kotschyi)
It is known that this rare plant, with two listings in the Flora of Turkey so far, grows in the provinces of Kahramanmaraş and Diyarbakır. In the Diyarbakır area, it has only been recorded in the Tigris Valley. According to the Red Data Book of Turkish Plants, it is in the Vulnerable [VU] category.

Interferences to the ecosystem cause direct or indirect damage on all of its components. Certain human activities that continue to be carried out in the Tigris Valley have a direct impact on plants and animals and all types of habitats.

The expansion of urban settlement areas, the transformation of riverside areas in order to build restaurants or create picnic areas and changes made to natural structure that focus solely on human needs come first among such threats and no doubt also negatively impact plant diversity.

Logging of natural vegetation along the branches of the Tigris River also creates great direct harm to the ecosystem. Since such areas are home to many different living beings and are closely interconnected with the existence of other habitats, the scope of the damage grows further.

When the ecosystem is perceived as a whole, not only logging but also any attempt to adapt plants that do not exist in the system, for instance pine trees, causes great problems in terms of biodiversity. On the other hand, the burning of reed-beds and shrubbery in the area to transform the land for agricultural production, leads to the loss of the habitat along with all the living beings of the area.

We must also mention that especially in recent years, the transformation of steppes into agricultural areas, and the use of pesticides in these new zones have disrupted the habitats of many natural and endemic plant species and endangered their survival.