The species richness of nonvolant mammals in Shennongjia Nature Reserve, Hubei Province, China: distribution patterns along elevational gradient

Abstract

The species richness of nonvolant mammals in different habitats at six sites of Shennongjia Nature Reserve was investigated during 1999 -2001. The habitats were classed into eight types: primary forest, selectively logged forest (primary forest with deadwood removal), secondary forest, shrub forest, grassland, rivers and streams, crop field, and residential areas. The small nonvolant mammals were investigated using steel removal traps. Large nonvolant mammals were studied through data on skin trade, line transects and survey of mammal trails. The vegetation of forests was sampled in plots of 10 mx 10 m. The results indicate that there are 59 species of nonvolant mammals in Shennongjia Nature Reserve (not including the introduced species Cervas nippon). At the same elevation, the primary forest usually has higher species richness than selectively logged forest and secondary forest, suggesting that logging has greatly reduced species richness. By comparing species richness at different elevations in the same habitat, it is found that the highest species richness occurs at the middle elevational zones (800 ~ 1700 m). In primary forest and secondary forest, species richness is highest at Dongxi at 1700 m elevation. In the selectively logged forest, species richness peaks at Jiuchong at 800 m elevation. Species composition at the six sites can be classed into two groups by cluster analysis: a higher elevational group (above 2100 m) and a middle-low elevational group (below 1700 m). The vertical distribution of species composition is matched with that of vegetation. The species richness of the mammals at different sites is correlated with average tree species richness in a unit area (100m ), number of habitat types and elevation. There is a correlation among average tree species richness, number of habitat types and elevation, suggesting that elevation has a very important effect on average tree species richness and the number of habitat types. Two conservation implications were formulated from the results. First, emigrant engineering and forest recovery for the reserve should begin at Jiuchong, which has the highest species richness, then be carried out at Dongxi and Xiagu. Second, the zone between the two fragments of the reserve should be set aside as a protected corridor to improve the flow of individuals and genes between the fragments.