越冬候鸟对鄱阳湖水文过程的响应

鄱阳湖是东亚地区主要的候鸟越冬地,平均每年约有105 种、34 万多只候鸟在此越冬。鄱阳湖独特的水文过程及五河入湖三角洲众多的碟形湖是形成鄱阳湖湿地生态系统特征和越冬候鸟栖息地的重要条件。论文根据每年的候鸟监测资料和鄱阳湖水位过程记录,通过分析各类候鸟越冬的取食对象和夜宿环境,采用定量与定性分析相结合的方法,研究了鄱阳湖水位对候鸟越冬的影响因素,揭示了越冬候鸟对鄱阳湖水文过程的响应规律。结果表明:①鄱阳湖处于平水年时,对候鸟越冬最为有利,候鸟数量最多;②鄱阳湖丰水期处于高水位时,食物缺乏,对候鸟越冬不利,影响最大的是雁、鸭、鹤和天鹅类候鸟,候鸟数量较少;③鄱阳湖枯水期处于高水位时,对鹳类、天鹅和鸻鹬类候鸟取食造成一定困难,有可能使候鸟数量减少;④鄱阳湖枯水期水位较低时,如果科学管理碟形湖的水位,对候鸟越冬不会产生明显的不利影响,但主湖区水位太低,对候鸟越冬不利。

Response ofWintering Migratory Birds to Hydrological Processes in Poyang Lake

Poyang Lake is the main overwintering area of migratory birds in East Asia. There are about 350000 migratory birds belonging to 105 species in every winter. The unique hydrological processes and a lot of the shallow lakes in the delta of the river mouth where Ganjiang River flows into Poyang Lake are the important conditions for the formation of wetland ecosystem characteristics and the winter migratory birds habitat in Poyang Lake. In this paper, the mechanisms for the hydrological processes effect on wintering migratory birds have been studied and the feeding object and overnight roost for all kinds of migratory birds have been analyzed, combined with monitoring data of migratory birds and the hydrologic data each year in Poyang Lake, using the quantitative and qualitative methods. The results show: 1) It is most favorable for the overwintering migratory birds and the number of wintering birds is the largest, when the Poyang Lake is at a normal water level year. 2) It is unfavorable for the overwintering migratory birds due to lack of foods and the wild gooses, wild ducks and swans are affected maximally, so the number of wintering birds is small, when the lake is at high water level in wet season. 3) The number of overwintering migratory birds may be reduced by feeding difficulties for storks, swans, snipe and so on, when the lake is at high water level in dry season. 4) If water level in the shallow lakes can be managed scientifically, wintering migratory birds will not have significant adverse impact, when dry season water level of Poyang Lake is low, but does not favor the migratory birds, if the water level is too low in Poyang Lake.