芦苇收割对太湖国家湿地公园冬季鸟类多样性和空间分布的影响

Impact of Reed Cutting on Bird Diversity and Spatial Distribution in Taihu National Wetland Park in Winter

芦苇(Phragmites australis)收割是芦苇湿地管理的主要手段。2010年12月至2011年2月,在苏州太湖国家湿地公园,分别比较了芦苇收割前、后鸟类群落及鸟类的空间分布。结果表明,芦苇收割当月的鸟类物种数比收割前一个月明显减少,有10种鸟消失,而收割后一个月比收割前一个月另增加了6种鸟。除了一些鸟类物种消失外,收割导致了7种鸟的密度大幅下降,消失和密度下降的鸟的物种多为对芦苇较为依赖的物种。芦苇收割当月与收割后一个月的鸟类群落相似性系数最高,为0.647;收割后一个月与收割前一个月的相似性系数最低,为0.423。芦苇收割后一个月的多样性指数最大,为0.859 7,收割前一个月的多样性指数(0.734 6)次之,收割当月的多样性指数(0.604 4)最小;收割后一个月的均匀度指数(0.698 6)最大,收割当月的均匀度指数(0.580 4)次之,收割前一个月的均匀度指数(0.564 6)最小;收割当月的优势度指数(0.434 5)最大,收割前一个月的优势度指数(0.367 2)次之,收割后一个月的优势度指数(0.240 3)最小。在水平空间上,收割前一个月与收割次月鸟类物种分布特征一致,鸟的数量在芦苇湿地—水域、芦苇湿地—陆地区域较多。在垂直空间上,收割前一个月鸟的种类和数量在芦苇丛的下层居多。研究认为,芦苇收割的即时效应为对芦苇依赖性强的鸟的物种消失;之后则有新的物种加入;鸟类多样性经历短暂降低后,最终高于收割前。当地芦苇整体收割的方式对鸟类密度、冬候鸟越冬、特化种觅食影响很大。基于对鸟类群落和种群的保护,芦苇收割可以采取适当保留水域和陆地边缘芦苇带的管理方式。

The reed cutting is a main measure of reed wetland management.The bird community and spatial distribution of birds in reed cutting area were researched in Taihu National Wetland Park,Suzhou City from June 2010 to May 2011.The bird species number declined sharply during the month of reed cutting compared with that one month ago,ten species disappeared;but 6 species were newly discovered in one month which did not appear during the month before cutting.Besides the species disappeared,the density of 7 species decreased greatly owing to the reed cutting.The species which disappeared or decreased in density relied well on reed.The Jaccard similarity coefficient of bird communities was the highest（0.647） between the cutting month and the post-cutting month;while it was the lowest（0.423） between the post-cutting month and the pre-cutting month.The diversity index of post-cutting month was highest（0.859 7）.The Evenness index of post-cutting month was the highest（0.698 6）.The Dominance index of cutting month was highest（0.434 5）.In horizontal space,the distribution of species had a consistent feature during pre-cutting month and post-cutting month,and a larger number of birds were discovered in reed-water area and reed-land area.In Vertical space,the species and numbers were mainly identified at the bottom layer of reed vegetation.The research suggested that instant effect of reed cutting caused the species which mainly relied on reeds to disappear;then some new species appeared;bird diversity experienced a temporary decrease,but it was finally higher than that during pre-cutting month.The overall reed cutting in local area had a huge impact on the avian density,winter visitor over wintering,as well as the foraging of specialized species.It was recommended that some water-land edge of reed should be kept as the bird habitat in the winter,and this management mode could be beneficial to the protection of bird community and population.