The Study On Biodiversity Of Soil Fauna In Baishanzu Nature Reserve Of Zhejiang Province

On 20 December 2006, the United Nations proclaimed 2010 to be the International Year of Biodiversity at the 83rd plenary meeting. The goal of this UN initiative is to increase public awareness of biodiversity and to encourage people to protect it. Soil animals, the constituents of terrestrial ecosystem, are important consumers and special decomposers, and they are unusually significative to ecosystem. Investigation of soil animals diversity has extremely high learning significance and practical value.So far, there were no reports about soil animals in Baishanzu Nature Reserve of Zhejiang Province. To promote this work, in April, July, September and December from 2008-2009, four investigations of soil fauna were carried out on five different sample plots along an altitudinal gradient in Baishanzu Nature Reserve. The purpose is to provide important theoretic basis information for protecting biodiversity in this region.The paper divided into six main parts:composition of soil fauna; biodiversity; similarity; seasonal dynamics; vertical distribution and coefficients between the soil fauna and the environmental factors. The results were as follows:1) 2409 soil animal individuals belonging to 18 orders,7 classes and 3 phyla were collected in 300 soil sample from five sample plots. Acarina and Collembola were dominant orders, accounted for 44.02% and 36.99% respectively. Hymenoptera(4.36%), Coleoptera(3.24%), Symphyla(2.24%), Hemiptera(2.08%), Psocoptera(1.58%), Diptera(1.37%) are the common groups, the rest are rare groups, account for 4.12%. The result shows the soil fauna Baishanzu species has high heterogeneity. Most individuals are concentrated in very few groups, and most groups have a very small number of individuals. The ratio between Acarina and Collembola (A/C value) is close to 1, consistent with the universal law of temperate regions. 2) The diversity index were analysed, the results showed that Margalef index, Shannon-Wiener index and Pielou index were decreasing with the altitude increasing. In 1570 m ofâ…¡plot, the trend fluctuated, Margalef richness index, Shannon-Wiener index, Pielou index all showed a higher value, these were related to the special vegetation and the environment. Trend of species is:â…¡>â…£>â…¤>â… >â…¢. The individuals of soil fauna, were the maximum in plotâ…¢, fewer in plotâ… , followed byâ…£>â…¡>â…¤. Densities of plotâ…¢and plotâ…£were with very high similarity, and plotâ… was very dissimilarity from others. The results showed that the altitude was one but not key factor affecting the distribution of soil animals, and the distribution was without any regulation.3) From the analysis of seasonal dynamics, Margalef index was the highest in summer, was slowly lower in autumn and winter, and was the lowest in spring. Shannon-Wiener index was slowly increased from spring to autumn, then decreased, the overall trend was as follow:autumn> summer> spring> winter. The change in Pielou index was almost consistent with that in Shannon-Wiener index, and Simpson index was almost opposite to Shannon-Wiener index. Changes of community depend on dominant groups. Seasonal dynamics are still relate to the environment.4) The vertical distribution of soil fauna is evidently upright delaminated, concentrated in the surface. The individual numbers and varieties decrease with the increasing of soil depth. The density of soil fauna is maximum in layer D1(0-5cm), fewer in layer D2(5-10cm), minimum in D3(10-15cm). Surface accumulation rate between four seasons is:winter> autumn> spring> summer.5) The ralationship between soil fauna density and environmental variables was analysed by Primer5 software(BIO-ENV). The results showed that pH values had maximum variance contribution (54.2%) in principal, indicating that relationship between pH value and community structure most closely. Other variables, such as volume weight, TN, C/N did not affect on the community structure. Spearman correlation was also analyzed. The analysis proved that pH value of soil was the major factor which affected the distribution of soil fauna, it was positively correlated with pH value, correlation coefficients between them was 0.661. The fauna was little influenced by TN dosage. The change of environmental factors combination is the best explanation of community structure in this study, but it does not mean that there were related directly. Selecting best combination of changes in several environmental variables can reflect the community conditions, but it required more researches.