江苏启东兴隆沙岛秋冬季鸟类的十年变迁

兴隆沙位于长江入海口，1990年11月至1991年2月和2001年10月至2002年2月，用路线统计法对兴隆沙鸟类多样性和栖息环境进行了调查，发现在过去的10年间该岛的生态环境发生了巨大变化。受开发力度加强、人口密度增加等各种因素的影响，大量的滩涂植被为农田、村庄所替代。调查结果表明，鸟的种类减少了45％，其中冬候鸟减少了52％，旅鸟减少了60％，国家重点保护鸟类减少了80％，鸟类多样性指数由1990年秋季的3．872减少到2001年秋季的3．016，鸟类最高密度减少了61％。通过对该岛鸟类现状的分析，对岛屿开发与鸟类保护提出了建设性的意见。

Species Diversity Change of Birds Inhabiting during Autumn and Winter at Island Xinglongsha (Qidong, Jiangsu) in the Ten Year Period

In the periods of Nov. 1990 to Feb. 1991 and Oct. 2001 to Feb. 2002, we conducted a field survey for bird diversity in the island Xinglongsha located in the estuary of Yangzi river by recording bird along belt transects. A great change of bird species diversity was detected. Total of 47 species of bird was identified from Oct. 2001 to Feb. 2002, however that number was reduced as much as 45% comparing to the record made in ten year ago (82 species of bird). About 52% of winter birds and 60% of wandering birds has been missing with the ten year period. The ShannonWeiner index of bird diversity has been reduced from 3.872 (Nov. 1990) to 3.016 (Nov. 2001) and the density (per./km~25day) has been declined from 1?239 birds to 478.The great change in environment of the Island resulted from agricultural activity and immigration settlement in the last ten years has been the major reason for the decline of bird species diversity and population density. We provided suggestion on the measures that should be taken at the Island for the bird diversity conservation.