中文摘要：

为了解三峡水库运行初期消落区的植被状况,2009年5月、7月和9月对小江流域消落区高程150、160和170m处植物的种类组成、生物量和多样性等特征进行了调查与分析。结果表明,小江流域消落区维管束植物共有140种,隶属于38科113属,以草本植物或旱生植物为主。群落优势种主要有香附、苍耳、小白酒草、狗牙根等18种。生物量均值999.9g/m2,变幅140.7～2055.6g/m2;烘干重均值310.7g/m2,变幅为26.5～932.6g/m2。植物多样性Margalef指数、Shannon-Wiener指数、Simpson指数和Pielou均匀度指数等均在5月最小,7月最大,9月略下降,在高程150m处最小,160m处最大,170m处次之。并对小江流域消落区植物的演替趋势、生态恢复、影响因素和利用前景进行了初步探讨。

英文摘要：

In order to know vegetation status during preliminary operation stage of Three Gorges Reservoir, investigations were conducted on plant species composition, biomass and biodiversity in water-level-fluctuation zone in Xiaojiang watershed during May,July,and September in 2009. The results showed that there were 140 species of vascular plant in 113 genera belonging to 38 families,most of which were herbaceous terrestrial plants. There were 18 species of the dominant species of plant communities,for example Cyperus rotundus, Xanthium sibiricum,Comnyza canadensis,Cynodon dactylon and so on. Plant biomass （fresh weight） ranged from 140.7 to 2 055.6 g/m2 with an average of 999.9 g/m2.Plant dry weight ranged from 26.5 to 932.6 g/m2 with an average of 310.7 g/m2. In addition,several plant diversity indices including Margalef index, Shannon-Wiener index,Simpson index,and Pielou index were calculated and compared across months and locations surveyed.Plant diversity was highest in July,while September the second and May the lowest. The decrease order of plant diversity indices were 160 m, 170 m and 150 m during July and September.The succession trends and its impact factors,restoration and utilization of the vegetation in water-level-fluctuation zone were also discussed.