Abstract:

The Hong Kong Special Administrative Region lies within the tropics and experiences a maritime climate.As a part of the Guangdong coastal massif , it is characterized by a hilly terrain. The highest peak is Damaoshan Mountain(957 m) and hilly areas (altitudes above 150 m) account for three quarters of the total land area. Due to the general lack of flat land , urban development is concentrated along coastal areas. The developed areas (including urban areas and rural towns) account for about 20 % of the total land area , agricultural land about 5 % (most of which is abandoned) , and the rest is countryside including native woodlands and plantations (15 %) , shrublands (36 %) and grasslands (17 %) . The favourable climate and geographical conditions bring about a large variety of ecological environments , which in turn support an exuberant variety of both plants and animals making Hong Kong , such a small place of 1090 km2 , very rich in biological diversity. There are about 2500 species of native plants , including 1900 species of angiosperms , seven species of gymnosperms , around 220 species of ferns and about 300 species of bryophytes. For wild fauna , so far about 40 species of wild mammals , more than 459 species of birds , 23 species of amphibians , around 70 species of reptiles , about 100 species of dragonflies , about 220 species of butterflies and 2000 species of moths have been recorded. As well as having a huge variety , some of these species are protected by China’s government and others are endemic. For plants , there is one species (Spiny Tree Fern , A lsophila spinulosa) listed in Category I of the State Protection L ist , three species (e.g. Tetrathryrium subcordatum) in Category II and eight species (e.g. Amentotaxus argotaenia) in Category III. Moreover , there are 16 endemic plant species in Hong Kong. Examples are Osmunda mildei (Osmundaceae) , Asarum hongkongense (Aristolochiaceae) and Bulbophyllum tseanum (Orchidaceae) . For animals , there are nine species listed in Category I of the State Protection List (e. g. the Chinese White Dolphin , Sousa chinensis) , and 79 species in Category II. Endemic animals include Romer’s Tree Frog ( Philautus romeri) , Bogadek’s Legless Lizard ( Dibamus bogadeki) and many insects. To protect the varieties of wild animals , plants and their habitats , the Hong Kong SAR Government has formulated some ordinances and launched quite a few conservation measures. For instance , there are 21 country parks and 14 special areas , covering about 38 % of the total land area of Hong Kong. There are also two special restricted zones , three marine parks , and one marine reserve. The government has also set up 59 ”Site of Special Scientific Interest”(SSSI) so as to conserve and study various species of plants and animals , ecosystem , special geology and landscapes in Hong Kong.

Key words: Elymus, interspecific hybrid, meiosis, homology, genome, homoploid, speciation