关键词: 岛屿生境, 群落多样性, 聚类分析, 小型兽类

Abstract: During autumn 2007 and spring 2008,we surveyed 14 islands and 2 peninsulas,sampling with a total of 20 400 traps,for small mammals in Qiandao Lake,Zhejiang to determine their community diversity of mammals. The captured small mammals belonged to 13 species,9 genera,3 families and 2 orders,including 10 species of murids (Muridae),1 species of cricetid (Cricetida)and 2 species of soricids (Soricdae). The results showed that there were significant between-season differences in the diversity index,evenness index,and dominance index,and the preponderant species changed among the 14 islands as well. Through an analysis of stepwise linear regression on factors that could influence species diversity on islands such as area,distance to the nearest mainland,distance to the nearest bigger island and plant species richness,we discovered that only plant species richness had significant effect on the species richness of small mammals. The 16 sample sites were classified by the constituent proportion of species,with Xuyuan and 14 islands being the same category,and Yaojia the separated one. This result was also supported by the similarity index. Our conclusions are
(1)in Qiandao Lake,habitat fragmentation has resulted in a decline of ecosystem stability yielding dramatic seasonal changes in species diversity;(2)with the increase of island size,the species richness of the small mammals doesn’t always increase but shows a small island effect;(3)Xuyuan and 14 islands had been a continuous habitat before the reservoir was formed because the proportion of species within the communities was similar in these two regions.

Key words: Cluster analysis, Community diversity, Island habitat, Small mammals