江苏大丰盐沼鸟类群落空间结构的影响因素研究

Factors Affecting Spatial Structure of a Saltmarsh Bird Community at Jiangsu Dafeng Milu National Nature Reserve

鸟类的个体空间分布和群落空间结构有多种影响因素,以往多数研究主要关注生境偏好的重要作用,而忽略个体间相互作用的影响,原因之一是较难排除环境所起的作用。互花米草（Spartina alterniflora）作为一种外来入侵植物扩散到江苏大丰麋鹿国家级自然保护区之后,在当地盐沼生境形成了以互花米草为优势种的单优群落和与本土植被构成的混生群落。该群落生境类型为同时探究个体间相互作用及生境偏好在鸟类群落空间结构中的作用提供了一个十分难得的天然实验场。前期对保护区调查发现该生境中繁殖鸟的种类和数量都较少,斑背大尾莺（Locustella pryeri）为优势种。为揭示盐沼生境中鸟类群落空间结构的影响因素,我们于2014年3~5月共进行了4轮调查,通过观察确定雄鸟的领域范围,使用样方法采集8个生境植被参数;利用计算机模拟随机分配,使用多尺度分析的方法讨论了6个鸟种的36种关系。研究结果表明,个体间相互作用和生境偏好共同影响该盐沼鸟类群落的空间结构。本研究为探索鸟类在入侵植被中建群和扩散的机制提供了理论基础,有助于揭示鸟类如何适应迅速改变的环境提供了重要依据。

Many factors affect the spatial distribution of individual birds and community spatial struc- ture. Most research has focused on the important effect of habitat preference but has ignored the effect of individual interaction because of the difficulty of separating this from the influence of envi- ronment. Spartina altemiflora is an invasive species of grass that has developed dominant single- species communities and mixed communities that include native plants in saltmarsh habitat at Jiang- su Dafeng Milu National Nature Reserve. These habitats provide a valuable natural experimental field for simultaneously studying the influence of individual interaction and habitat preference on the spatial distribution of bird communities. Our field study showed that with increasing dominance of S. alterniflora, the numbers of birds and bird species declined while the passerine Locustella pryeri became the dominant bird species. To uncover factors that affect spatial structure of bird communi- ties in this saltmarsh, we monitored the territory of male birds during March to May 2014. Eight vegetation parameters were measured by using a quadrat method, and 36 relationships of 6 spe- cies were analyzed with random allocation by computer simulation at multiple scales. Individual in- teraction and habitat preference simultaneously influenced the spatial structure of bird communities. This study provides a theoretical basis for exploring mechanisms of how birds colonize and spread in response to invasive vegetation, and shed light on our understanding of how the birds adapt to rapidly changing environments.