Located along the northern fringe of the tropics and bordered on to the Pacific Ocean, Hong Kong's topography and subtropical climate contribute to the very diverse habitats within its territory. From woodland, shrubland and grassland to special ones such as coastal and freshwater habitats, this wide range of habitats support the rich variety of flora in Hong Kong.
The original woodlands in Hong Kong no longer exist after centuries of human disturbances through fire and axe. The existing woodlands in Hong Kong are the secondary forests developed in the latter half of the twentieth century after the Second World War, and the majority belongs to southern subtropical evergreen broad-leaved forest. Dominant families include the Euphorbiaceae, Sapotaceae, Moraceae, Sterculiaceae, Myrtaceae, Fagaceae, Lauraceae, and Theaceae. Four types of plant communities can be classified by the characteristics of eco-physiognomy and species composition: (1) river-bank woodland, (2) lowland woodland, (3) low-hill forests, and (4) montane forests. There are also small but well-developed woodlands associated with many of the older villages and temples. These are sometimes called the "Fung Shui Woods" ("Sacred or Lucky Groves"), which owe their existence to the protection afforded by the villagers in accordance with ancient traditions. Besides, many hillslopes have been reforested with Taiwan Acacia (Acacia confusa), Chinese Red Pine (Pinus massoniana), Slash Pine (Pinus elliottii), Eucalyptus species and Brisbane Box (Lophostemon confertus). In recent years, more native trees have been planted on hillslopes, including Chekiang Machilus (Machilus chekiangensis), Castanopsis (Castanopsis fissa), and Schima (Schima superba). The most common plants found in shrubland are the Dwarf Mountain Pine (Baeckea frutescens) – Rose Myrtle (Rhodomyrtus tomentosa) – Hong Kong Gordonia (Polyspora axillaris) community. In addition, bamboo and fern are often present in local shrublands. Also, common grasslands in Hong Kong include the Tre-awned Minireed (Arundinella setosa) – Grey Lemongrass (Cymbopogon mekongensis) – Dichotomy Forked Fern (Dicranopteris pedata) community and the Chinese Silvergrass (Miscanthus sinensis) – India Duck-beak (Ischaemum ciliare) community.
During these years, there were species new to Hong Kong and even new to science found and recorded locally. Up until now, approximately 3,300 species and varieties of vascular plants have been recorded, of which about 2,100 are native. Poaceae, Fabaceae, Asteraceae, Cyperaceae and Orchidaceae are the top five plant families in Hong Kong. Despite having a total area of just 1,100 km2, the floral biodiversity that Hong Kong has is one of the most diverse in China.
