Effects of habitat fragmentation on species diversity of ground dwelling beetles in the Thousand-Island Lake region, Zhejiang, China.

Abstract

The ground dwelling beetles on 20 land-bridge islands and 8 mainland sites in the Thousand-Island Lake region were collected by pitfall trap methods for six times from July 2012 to April 2014 (in three seasons, spring, summer and autumn). The species abundance, composition, diversity and seasonal dynamics of ground dwelling beetles were analyzed. Besides, the relationship between island spatial attributes (e.g., island area and isolation) and the diversity of ground dwe-lling beetles were studied. There were 3370 litter-dwelling beetle individuals belonging to 26 families and 101 species.For species richness of ground dwelling beetles, there were significant diffe-rences between the large islands and mainland sites, the mean density on small islands was significantly higher than on mainland sites. The species turnover was higher among mainland sites than among islands. The species richness on islands was significantly associated with island area, and the density was significantly associated with the distance to mainland. The species richness of islands in summer was higher than that in spring and autumn. Shannon, Simpson and Pielou indices of islands and mainlands were all highest in summer and lowest in autumn.