Influence Of Different Slash In Evergreen Broad-leaved Forest On Soil Animal Community In Tiantong

Deforestation is a common phenomenon, which is an important part of forestry production and management. It can generate disturbance in forest ecosystem, and had greater effects in nearby, which can affected farther. It is significantly to study the influence of different slash in evergreen broad-leaved forest on soil animal community.In order to understand the soil animal community in evergreen broad-leaved forest, we chosen the five slashed plots that processed in 2003 in Tiantong national forest park in Zhejiang province. On the basis of the former research, we followed it to continue research on the influence of different slash in soil animal community. We used the five following treatments in five sites: (I) big trees with height>8 m and DBH>5 cm were removed but root collar sprouts were retained; (II) ground surface vegetation was removed but litter was retained; (III) all vegetation and 0-10 cm topsoil were removed; (IV) undergrowth was removed but big trees were retained; and (V) a control plot without any disturbance. An all-round four-season investigation was conducted into the soil animal communities, including macrofauna, mesofauna and the wet type of soil animal in the litter and soil in the above plots from the July of 2007 to October of 2008. Based on a comprehensive knowledge of the feature of soil animal community in the disturbanced, the paper probed into the influence of the different slash of communities on the structure of soil animal communities as well as the seasonal change. The influences on the environment by different slash are discussed and the correlations between the change of environment and soil animal communities are analyzed, and compared to the community which had not been slashed, slashed for a month and for a year. The research results are as follows:1,Influence on composition and density of soil animal in different slashed plotsThe group composition and density of soil animal were obviously different among the plots. Group number in site III was lest and the site V was more than III. The group number in the other three plots were close to each other. The number of soil animal was most in site I, mainly group Acarina and Collembola were also mostin site I ,and lest in site III.2,Vertical distribution of soil animal in different slashed plotsThe vertical distribution of soil animal with different treatment have obvious surface segregation. More than 85% soil animal lived in 0-10 cm layer, and the number of groups and density decrease with the depth of soil. However, the group number in the different layer showed an inverse distribution.3,Seasonal change of soil animal in different slashed plotsThe group composition of soil animal did not vary widely in four seasons, but the density had changed a lot. The seasonal fluctuations of soil animal community in different slashed plots can be represented as: In the litter layer, the density in site I,II,V were highest in autumn, and site III reached the maximum in winter and the site IV reached the maximum in summer. In the soil layer, the site I, IV,V reached the highest in winter and the site II,III were in autumn reached their maximum.4,The diversity change of soil animal in different slashed plotsVarious of diversity indices were used to analyze the soil animal community structure, and displayed different results. The density-group index can comprehensive express the factor, and the sequence of the density-group index to soil animal community were atutmn> summer> winter> spring. density-group index in different slashed plots showed I >IV> II > V>III.5,The impact on soil animal by environmentThe temperature and humidity among the five plots had obviously different not only in litter but also in soil layer. Total nitrogen and total phosphorus have no obvious different among these plots both in litter and soil layer. In the litter layer, the density of soil animal have positive correlation with pH value and total nitrogen, but have no correlation with the organic matter and total phosphorus. In soil layer, the density of soil animal have positive correction with pH value, organic matter and total nitrogen, and have no correlation with total phosphorus. 6,The soil animal response to different disturbanceThe soil animal composition had changed a lot between before and after slash. Some group disappeared while other recurred after several years recover. A year after slash ,the density of soil animal in litter layer was far lower than that unslash. After five years recover, the density of soil animal was also lower than before. The density of soil animal in soil layer decreased in a month and a year after slash, but after five years recover, the density of soil animal exceed before slashed.