三峡库区水库蓄水对崖沙燕种群的影响

2003年三峡水库蓄水至139m高程,在蓄水前(2000年)和蓄水后(2003～2006年)对长江主河道尾水点所在的丰都至忠县江段和上游河道区域,以及支流河道的巫山县大宁河139m水位尾水点的崖沙燕(Riparia riparia)种群分布和数量进行了调查。结果表明,在水库蓄水至139m之后崖沙燕的种群数量明显减少。影响崖沙燕种群数量的关键因素是丧失繁殖地。随着三峡大坝工程的全面竣工和运行,三峡库区的崖沙燕有可能将会成为少见物种。

Effect to the Water Level in the Three Gorges Reservoir to the Population Size of Sand Martin

Filed surveys on population distribution and abundance of Sand Martin(Riparia riparia) were conducted in the Three Gorges Reservoir regions in winter before(2000) and after(2003-2006) the water lever reached to 139 m.This bird was common in the Yangtze River,especially in upriver from Fengdu to Zhongxian and Daning River,the tributary of Yangtze.The population size of this bird was declined rapidly after the water level was rose.The results indicate that key factors influenced the population abundance of Sand Martin was the loss of food resource,breeding habitat and perch sites during night were the key factors which influence the population distribution and abundance in the study area.As the Three Gorges Project completed,the Sand Martin will become a rare species in the Three Gorges Reservoir region.