广东境内珠江流域水生维管束植物区系的探讨

本流域已知有水生维管束植物(以下简称水生植物)131种,分别隶属81属,44科.其中珠江三角洲的种类最丰富为111种,西江75种,东江67种,北江57种.从植物地理分布方面进行分析:世界分布55种,占本流域总数的42%;热带亚洲分布35种,占总数的27%;热带-亚热带分布16种,占总数的12%;热带-温热带分布21种,占总数的16%;温带分布4种,占总数的3%.除世界分布种(种类最多)以外.热带亚洲分布种所占的比例(27%)显得最为突出.但它们只是热带植物区系成分向亚热带扩散的种类.热带-亚热带分布,其比例虽然只占12%,但它们当中的许多种是本流域水生植物群落的优势种,它们分布广、长势旺、繁殖力强.它们与热带-温带分布(16%)种类共同组成南亚热带植物区系的主要成分.温带分布的种仅占3%,对本流域水生植被的影响是微弱的.  

A SURVEY ON THE AQUATIC VASCULAR PLANTS OF THE PEARL RIVER BASIN IN GUANGDONG

There are 131 species of aquatic vascular plants in the Pearl River basin in Guangdong Province. They belong to 81 genera of 44 families. Among them, 111 species are found in the Pearl River Delta, 75 species in the Xijiang River (West River), 67 species in the Dongjiang River (East River), and 57 species in the Beijiang River (North River). The geographical distributions of these species are as follows: 41.9% (55 species) of the aquatic nvacro-phytes in the Pearl River basin have worldwide distributions; 27% (35 species) have distributions in the tropical Asia; 12% (16 species) have distributions in the tropical-subtropical zone; 16% (21 species) have distributions in the tropical-temperate zone; 3% (4 species) have distributions in the temperate zone.The species with distributions in the tropical Asia are second important in number (27%), only next to the group with world-wide distributions. However, only about ten of them, Including Kandelia cande, Aegiceras corniculatum, Cyperus malaccensis var. brevifolius .... etc., constitute of dominant species of the mangrove vegetation and aquiherbosa of the estuary of the Pearl River. Other species with distributions in the tropical Asia are sparsely distributed in the Pearl River basin and are not as important as the previous ones; they afe members of the tropical flora dispersed into the subtropical zone.Although species with tropical-subtropical distributions constitute only 12% of the total number, many of them are dominant species of this area. They have wide distributions, and high growth and reproduction rates. Together with those with distributions in the tropical-temperate zone (16%), they form the major part of the tropical macrophytes in South Asia.Species with distributions in the temperate zone make up only 3% of the total number and have minor influence on the aquatic macrophytes of this area.