Abstract:

Dajinshan Island is part of Jinshan Three-Islands Marine Natural Reserve. Soil on the island has not been polluted by human activities and it is therefore an ideal place to study island ecosystem diversity. To understand the composition and ecological distribution of soil fauna communities in different natural forest vegetation types on Dajinshan Island, the soil fauna communities in three natural forests including bamboo forest, arboreal forest, and shrubbery were investigated during autumn 2015. Each forest included both north slope and south slope regions. A total of 12,769 individuals of soil fauna belonging to 28 groups were collected. The dominant groups were Acari and Collembola, accounting for 70.15% and 19.27%, respectively. The common groups were Protura, Hemiptera, Hymenoptera and Enchytraediae, and they accounted for 7.06% of the total in terms of individual numbers. The dominant groups were Acari (74.26%, 65.32%) and Collembola (16.52%, 22.49%) in both north slope and south slope regions, but differed in common groups and rare groups. The soil fauna communities were different in the three natural forests. In both north and south slope region, the density of soil fauna followed the order of: shrubbery > arboreal forest > bamboo forest, but the number of groups of soil fauna followed the order of: shrubbery > bamboo forest > arboreal forest. Different ecological indexes of soil fauna communities in the three natural forests were different. Shannon-Wiener index, Pielou index, and Simpson index followed the following order: shrubbery > arboreal forest > bamboo forest in both north and south slope regions. The Shannon-Wiener index was significantly different in the three natural forests. The higher soil fauna diversity in shrubbery was probably induced by the favorable microenvironment.

Key words: Island, natural vegetation, community density, slope