【摘要】 1997～ 2 0 0 0年对汉江中下游 8个江段水生植物种类组成、分布、生物量做了调查。汉江中下游共有水生植物 1 8科2 2属 3 4种 ,以世界广布种为主 ,R/ T值为 0 .67。中游以沉水植物群落为优势 ,建群种为轮叶黑藻 (Hydrilla verticillata)、穿叶眼子菜 (Potamogeton perfoliatus)和微齿眼子菜 (P. maackianus) ;下游主要为挺水植物群落 ,建群种为东方香蒲 (Ty-pha orientalis)和芦苇 (Phragmites communis) ,生物量为 5 7.5～ 2 1 0 0 g/ m2 ;α-多样性在丹江口最高 (0 .5 46) ,老河口次之(0 .5 1 7) ,仙桃最低 (0 ) ;生活型多样性在中游丹江口最大 (0 .40 2 ) ;β-多样性在时间梯度 6～ 8月份在所有样点 β=0 ,水平梯度β=0 .79,垂直梯度β=1 .48;γ-多样性在汉江中游为 2 9种 ,在下游为 1 0种。中游地区水生环境适合水生植物生长 ,而下游人类活动导致水环境趋于恶化限制了水生植物分布更多还原

【Abstract】 The species composition, distribution, biomass, diversity of aquatic plants in eight sections of Hanjiang River were surveyed during 1997~2000. There were 34 species belonging to 22 genera and 18 families in the middle\|reaches and the lower reaches of Hanjiang River which were dominated by the cosmopolitan species and the R/T value was 0 67. In the middle reaches ,they were mainly dominated by the submerged plant communities, and the constructive species were such as: Hydrilla verticillata, Potamogeton perfoliatus and P. maackianus. Comparatively, they were mainly dominated by the emergent plant communities in the lower reaches, and the constructive species were Typha orientalis and Phragmites communis. However, the maximal biomass of the plant communities was 2100g/m 2 and the minimal value was 57 5g/m 2. α \|diversity was the highest in Danjiangkou section(0 546), following by Laohekou section(0 517) and the lowest in Xiantao section(0). Life\|form diversity was maximal in Danjiangkou section of the middle reaches(0 402). β \|diversity was zero for all sample plots from June to August along time gradient. In addition, β \|diversity were 0 79 along horizontal gradient and 1 48 along vertical gradient. γ \|diversity was higher in middle reaches (29 species) than in lower reaches (10 species) of Hanjiang River. As a result, aquatic plants are rich in the middle reaches of Hanjiang River where water is comparatively healthy, but lower in the lower reaches because of water pollution.更多还原