湖北省梁子湖水生植物的多样性

Diversity Study of Aquatic Plants in Lake Liangzi of Hubei Province,China

将断面法与地理信息系统(G IS)和全球定位系统(GPS)相结合,通过广泛的野外调查,研究了湖北省梁子湖水生植物物种多样性和群落多样性.结果表明:2002年梁子湖分布有水生植物34科、64属、96种,优势种为菹草、微齿眼子菜、密齿苦草、双角菱、野菱、金鱼藻、穗花狐尾藻、轮叶黑藻和菰;梁子湖的水生植被可划分为19个群丛类型,分布面积最大的为菹草群丛,物种多样性指数最高的是菰群丛;2002年植被覆盖率为37.88%,总生物量为3.037 5×108kg(鲜质量),全湖植被平均单位面积生物量为998.20 g/m2(鲜质量);10年来,植被覆盖率下降了62.12%,全湖总生物量降低了71.81%;竹叶眼子菜群丛、睡莲、萍蓬草已从梁子湖消失,微齿眼子菜的分布面积缩小了73.13%,荇菜群丛的分布面积下降了约100%.

The species and community diversity of aquatic plants in Lake Liangzi of Hubei Province, China were studied by use of Transect Method, Geographical Information System （GIS） Technique and Global Position System （GPS） Technique. The main results are summarized as follows： It was found that in 2002, there were 96 aquatic plant species belonging to 34 families and 64 genera in Lake Liangzl, among which Potamogeton crispus, Potaraogeton raaackianus, Vallisneria denseserrulata, Trapa bispinosa, T. iacisa, Ceratophyllum demersum, Myriophyllum spicatum, Hydrilla verticillat and Zizania latifolia were dominant species; With 37.88% of coverage, the vegetation could be divided into 19 associations; and it was found that the distribution area of Potamogeton crispus Ass was larger than that of any other association; and Zizania latifolia Ass displayed the highest species diversity index; The total and mean biomass of the vegetation were 3. 037 5×10^8 kg and 998.20 g/m^2, respectively （fresh weight） ; It was found that in the last ten years, Potaraogeton malaianus Ass and 2 aquatic plant species disappeared from the lakel and at the same time, the coverage and total biomass of the vegetation decreased by 62. 12% and 71.81%, respectively.