涠洲岛湿地对鸻鹬类水鸟的承载力评估

【目的】评估候鸟迁徙季节涠洲岛湿地对鸻鹬类水鸟的承载力。【方法】调查监测候鸟迁徙季节涠洲岛湿地生物量和鸻鹬类水鸟群落,由水生生物热量和鸻鹬类群落的综合代谢率估算涠洲岛湿地食物量对鸻鹬类水鸟的承载力。【结果】鸻鹬类水鸟在涠洲岛的觅食地面积为158.54hm~2,包括库塘面积40.58hm~2,沼泽面积69.56hm~2以及涠洲岛东岸潮间带面积48.40hm~2。鸻鹬类群落由35种鸟类组成,涠洲岛湿地对鸻鹬鸟类春秋季承载力分别为874~1 236只和1 001~1 302只。觅食地承载力密度(只/hm~2)春季库塘10.7沼泽5.6潮间带4.8,秋季沼泽6.8库塘4.3潮间带3.6。淡水湿地密度高于潮间带密度。1990年以来潮间带觅食地面积损失了86%,单位面积平均生物量下降了55%。【结论】湿地面积、水生生物丰度影响涠洲岛湿地对鸻鹬类的承载力,修复湿地可提高承载力。

An Evaluation of Wetland Carrying Capacity of Shorebirds on Weizhou Island

Objective] To evaluate the carrying capacity of shorebirds in the Weizhou Island wetland during the migration season.Methods] A survey was conducted to monitor the biomass of aquatic organisms and shorebirds communities in the Weizhou Island wetland during the migratory season.The amount of food on the shorebirds carrying capacity of the Weizhou Island wetland was estimated according to the calories of aquatic organisms and the shorebirds comprehensive metabolic rate.Results] Feeding size for shorebirds on Weizhou Island was 158.54 hm² including 40.58 hm² of ponds, 69.56 hm² of marsh and 48.40 hm² of intertidal zone in the east coast of Weizhou Island.The shorebirds community consisted of 35 species of birds.The carrying capacity of shorebirds was 874~1 236 birds in spring and 1 001~1 302 birds in autumn.The carrying capacity density of feeding sites (birds per hectare) was ponds 10.7 > marsh 5.6 > intertidal zone 4.8 in spring and marsh 6.8 > ponds 4.3 > intertidal zone 3.6 in autumn respectively.The carrying capacity density in fresh wetland was higher than that in intertidal zone.Conclusion] The carrying capacity of shorebirds depends on the size of wetland and the abundance of aquatic organisms in Weizhou Island wetland.Wetland restoration will help to increase the carrying capacity.