人类干扰对安庆沿江湿地植物多样性的影响

在安徽安庆沿江滩地湿地，研究了天然芦竹、芦苇湿地，次生旱柳林和意大利杨人工林3种湿地生态系统的植物多样性。结果表明：杨树人工林的多样性指数和丰富度指数均高于旱柳林，也高于自然芦竹、芦苇湿地。旱柳林的生态优势度最大，杨树人工林次之，天然芦竹、芦苇湿地的最小，而天然芦竹、芦苇湿地的生态优势度则不那么明显；同时也说明在长江中下游滩地湿地上，天然次生旱柳林的生态优势度较高，而杨树人工林的生态优势度较小，它的物种丰富程度要高于旱柳天然次生林。人工杨树林的均匀度指标高于天然芦竹、芦苇湿地，也高于天然次生旱柳林。不同高程不同生态系统内植被群落的重要值的总体变化趋势是随着高程的升高，物种总数量降低，但植物多样性指数随高程增加而增加。在不同林龄的林分中植物物种的多样性和丰富度没有明显的变化规律。

Impact Study on the Biodiversity of Yangtze Beaches Wetland in Anqing with Human Interference

Anqing beach wetland is a typical wetland along the lower and middle reaches of Yangtze River. The wetland is very important in maintaining the stability and the biodiversity riches of the ecosystems in the region. Biodiversity is an important function of wetland ecosystem. The plantation of wetland in Anqing varies greatly with reeds, Arundo donax, Salix matsudana, Populus deltoids. The paper mainly studied the functions of the three kinds of wetland: Salix matsudana wetland, Arundo donax wetland, and Populus deltoids wetland,compared the differences of plant biodiversity among the three kinds of wetlands. It is showed that the indexes of diversity and species richness were the highest in Populus deltoids wetland, and the lowest in Arundo donax wetland. The Simpson index was the biggest in Salix matsudana wetland, and smallest in Arundo donax wetland which indicated that the species dominance focused on a few plant species, but it is not so definite in the Arundo donax wetland. In the beach wetland of the middle and lower reaches of Yangtze River the herbs species were more concentrated. The index of eneness was the highest in planted Populus deltoids wetland, and lowest in Salix matsudana wetland. The biodiversity also varied according to the difference of altitude of wetlands. The law is that with the growth of altitude, the biodiversity will decrease. In Populus deltoids forest,the difference of forest age did nothing to the biodiversity and to the richness of plant species.