Survey Method on the Impact Distance of Town to Alpine Grassland Birds
英文关键字：Alpine grassland；Urbanization；Birds；Survey method
中文摘要：摘 要：城镇化过程占用了大面积的土地，对鸟类的影响巨大。然而，城镇对鸟类影响范围却一直缺乏有效的评估方法。本文以若尔盖高寒草地这种较为简单的单一生境为例，探讨了评估城镇对周边鸟类分布影响范围的评估方法。我们在若尔盖县唐克镇周边草地设置6条样线开展鸟类调查，并对距城镇不同距离的鸟类种类、数量与生物量进行了分析。相关分析表明，黑耳鸢、家燕和麻雀的数量与距城镇距离呈显著负相关，表现出对城镇的喜好，是喜城镇型的鸟类物种；而地山雀、角百灵和白腰雪雀等草地物种则呈现显著正相关，表现出对城镇的躲避。其它的鸟类物种的分布与距离城镇距离相关性不显著。分段回归分析显示，随着距城镇距离的增加，鸟类的数量和生物量都呈现先下降然后再缓慢上升的格局。研究发现，在距城镇339-630 m之间，存在一个鸟类分布的低谷带，在这个地带，鸟类的数量和生物量都达到最低值，而鸟类物种丰富度的低谷带在367-955 m之间。城镇周边存在的鸟类的低谷带可能是由于该区域的环境处于一个从城镇到草地的过渡带上，对喜城镇的鸟类物种而言，这一区域距离城镇过远，而对于草地物种而言，这一区域受到的城镇干扰又太大。
英文摘要：Abstract: A large area of land has been occupied during the process of urbanization, which has a
tremendous impact on bird. The method to estimate the distance of urban and town impacting on birds, whereas, still lack. This paper investigated the method to estimate the distance, with the birds in a Zoige alpine grassland, a simple and monotonous habitat. We set 6 transections in grassland beside Tangke town, Zioge. The species richness, counts and biomass of birds at different distances from towns were analyzed. Correlation analysis showed that the counts of Milvus migrans, Hirundo rustica and Passer montanus were negatively correlated with the distance from the town. It implied that those species show preferences to habitat near town. The distributions of Pseudopodoces humilis, Eremophila alpestris and Montifringilla taczanowskii significantly positive correlated with the distance from the town. Those species showed preferences to grassland habitat away from town. Whereas, other species show no significant preference between habitats near and far away from town. Piecewise regression analysis revealed the patterns of the counts, biomass and richness of birds changing along the distance from town, which characterized by decreasing first and then rising slowly. The results showed that, the counts and biomass of bird bottomed between 339-630 m away from town, while the richness bottomed between 339-630 m. The environmental factors changed from town to grassland habitat along those transections. Possibly, the distribution patterns of birds formed due to that the habitat in the bottom regions is too far from town for those birds prefer town while is too close for those grassland birds.