The Community Diversity Of Soil Animals In The Tropical And Subtropical Forests And The Phylogeny Of Collembola

The soil animal is a major component of the terrestrial ecosystem, and plays an important role in material recycling, energy conversion, and soil structure forming and improving. Collembola, Protura and Diplura are not only important groups of the soil animal biodiversity, but also one of the key groups in studying the evolution arthropod, because their phylogenetic position are critical to the understanding of the evloution of insect orders. Controversies about the origin and phylogeny of Collembola, and relationships among the basal hexapods have kept growing in recent years.Tropical rain forest is a hotspot of the current biodiversity conservation and research. Hainan is located at the edge of north tropical zone with the largest rain forest in China; therefore, it's one of the important regions for the biodiversity research. In the present study, Jianfengling tropical rain forest in Hainan and Tiantong subtropical evergreen broadleaf forest in Zhejiang were chosen as the study areas to investigate the community structure of soil animals, biodiversities of Collembola, Protura and Diplura. Combined with the investigation of southern subtropical forest in Dinghushan, the biodiversity characteristics and seasonal changes of soil animal in different zones were compared. In addition, the complete 18SrDNA and partial 28SrDNA sequences of 22 species Collembola were analyzed. Combined with the relative sequences of other hexapods and representative arthropods, the phylogenetic hypothesis was generated by using MP (Maximum Parsimony), ML (Maximum Likelihood), and BI (Bayesian Inference). The major results were as follows:1 .The community structure of soil animals in the tropical and subtropical forestsThe soil animals of tropical rain forest in Jianfengling Mountain were investigated. 37083 specimens were collected, which belonged to 4 phyla, 11 classes and 33 orders. Among them, the dominant groups were Acarina and Collembola, accounting for 87.20% of the total. The common groups were 5 sorts, while the raregroups were 25 sorts, accounting for 3.79%. 29454 specimens were collected in subtropical evergreen broadleaf forest in Tiantong Mountain, which belonged to 4 phyla, 8 classes and 26 orders. The dominant and common groups were 5 sorts, accounting for 97.44% of the total, while the rare groups were 21 sorts, accounting for 2.56%.2. Seasonal changes of soil animals community in the tropical and subtropical forestsA set of parameters was used to characterize and estimate the diversity of soil animals community. With changes of climate in a year, seasonal changes of forest soil animal community have their peculiarity in different vegetation types. The change tendency of soil animals in tropical montane and evergreen seasonal rain forest were as follows: the diversity were lower in autumn-winter than in spring-summer, however, in semideciduous seasonal rain forest, that in autumn-winter was higher than in spring-summer. The tendency of the diversity in subtropical evergreen broadleaf forest was lower in winter-spring than that in summer-autumn.3. Comparison on the community structure of soil animals in the tropical and subtropical forestsAcarina and Collembola were the dominant groups both in tropical and subtropical forest, their individual numbers ratio (A/C) were 2.75, 1.98和 1.15 respectively from Jianfengling to Dinghu to Tiantong Mountain. Macro soil animals composition varied in three different area. The most dominant group in Jianfeng and Dinghu Mountain was hymenoptera (ants), followed by Diptera and Coleoptera. In Tiantong Mountain the most dominant group was Diptera, followed by hymenoptera and Symphyla. The sorts and density-group index (DG) of soil animal community were the greatest in tropical montane rain forest, and the tendency was to decrease gradually from tropics to subtropics.4. The community structure of soil Collembola in the tropical and subtropical forests7345 specimens of soil Collembola in Jianfengling were collected. They belonged to 12 families, 43 genera and 90 species. 7920 specimens, belongi...