千岛湖雀形目鸟类群落嵌套结构分析

Nested analysis of passeriform bird assemblages in the Thousand Island Lake region

2006年4月至2007年11月,采用截线法对千岛湖20个岛屿上的雀形目鸟类种类组成进行调查,检验其群落是否符合嵌套式分布的格局。此外通过野外直接记录与辨认法对岛屿上的植物种类组成进行调查,同时通过查阅文献资料和野外调查获得鸟类体长、分布宽度和生境专属性等生活史特征参数,以及采用GIS分析测定岛屿面积和隔离度参数,进而分析和探讨雀形目鸟类群落嵌套格局的影响因素。结果显示,千岛湖岛屿雀形目鸟类群落呈现显著的嵌套结构,岛屿面积、植物物种丰富度和生境专属性对其嵌套结构具显著性的影响。千岛湖岛屿雀形目鸟类存在着选择性灭绝过程;植物物种丰富度和鸟类生境专属性则通过影响鸟类在不同生境下的分布对鸟类群落嵌套结构产生影响。上述结果表明千岛湖岛屿雀形目鸟类群落嵌套格局同时受到栖息地和物种两方面因素的影响,为此我们认为应更多地关注那些面积较大和植物物种丰富度较高的岛屿,以及生境专属性较高的种类等鸟类多样性及其栖息地的保护策略。

Between April 2006 and November 2007, we used line-transects to survey species richness of passeriform birds on 20 islands in order to test for nestedness within bird assemblages in the Thousand Island Lake region. To determine factors correlated with patterns of nestedness, we also conducted field surveys of plant species richness on these islands, and defined and valued some species-specific characteristics such as body length, distribution width, and habitat specificity using field surveys and literature searches. Area and isolation of islands were measured with a Geographic Information System （GIS）. Nestedness and correlation analyses showed that the passeriform bird community in the Thousand Island Lake region had a significant nested pattern that was influenced by area and plant species richness of an island, and habitat specificity of the bird species. Selective extinction was observed in the bird community. Plant species richness and habitat specificity of species impacted nestedness of bird assemblages through their influence on distributional patterns of birds. We showed that patterns of nestedness of passeriform bird communities were determined by both habitat and species-specific characteristics, and that more attention should be paid to large islands and those with high plant richness, and to bird species with high habitat specificity when making conservation plans.