Ecological Distribution Of Collembola In The Litter Of The Damaged Evergreen Broad-leaved Forest In Tiantong

As an important integrant of litter layer in forest ecological system,collembola is indispensable to the breaking.There exists dynamic interplay between collembolan communities and plant communities.Seen from the angel of ecolotical system,the succession of plant communities above the ground will inevitably influence collembolan communities velow.By decomposing litter and moving in the soil,collembolan change physico-chemical properties of collembolan and thus directly or indirectly affect the structure,function and succession of plant communities.The sampling sites chosen for this study included four plant communities at different secondary succession stages of the damaged Evergreen Broad-leaved Forests(EBLF) and the five slashed plots that processed in 2003 in Tiantong national forest park in Zhejiang province.The four plant communities at different secondary succession stages are Ooropetalum chinensis-Lithocarpus glabre community, Pinus massoniana community. Schima superb community and Castanopsis farogesii community.The five slashed plots are (â… ) big trees with height>8 m and DBH>5 cm were removed but root collar sprouts were retained; (â…¡) ground surface vegetation was removed but litter was retained; (â…¢) all vegetation and 0-10 cm topsoil were removed; (â…£) undergrowth was removed but big trees were retained; and (â…¤) a control plot without any disturbance. An all-round four-season investigation was conducted into collembolan communities in the litter, from the autumn of 2009 to the autumn of 2010. Based on a comprehensive knowledge of the feature of collembolan community in the damaged EBLF and the disturbanced, the paper probed into the influence of secondary succession of plant communities and the different slash of communities on the structure of collembolan communities as well as the seasonal change. And analyzed the relevance of main environmental factors of the litter layer to collembolan communities. The research results are as follows:1,Influence on collembolan composition in different secondary succession stages of plant communitiesIn the hierarchy of family,the number of collembolan groups did not vary widely at different secondary succession stages, Isotomidae and Onychiuridae were the dominant groups throughout the four secondary succession stages. The number of Collembola community was as follows:Pinus massoniana community (29.01%)> Castanopsis farogesii community (28.49%)> Ooropetalum chinensis-Lithocarpus glabre community (26.38%)> Schima superb community (16.31%)There was a distinctive vertical distribution of collembola communities in the forest litter layer. The richness and density of the collembola in the litter layer generally tended to increase from top fresh litter layer to bottom humus layer. Most of individuals were found in the fermentation layer and bottom layer, accounting for 33.94% and 55.99%.The group composition of collembola did not vary widely in four seasons, but the density had changed a lot. The number of Collembola community was as follows: autumn> spring> summer> winter.The seasonal fluctuations of collembolan communities varied with different succession stages,which were generally of two types:â‘ In the Castanopsis farogesii community, Ooropetalum chinensis-Lithocarpus glabre. Community and Pinus massoniana community a large number of collembolans emerged in autumn;â‘¡In the Schima superb community a large number of collembolans emerged in spring,summerand autumn.Various of diversity indices were used to analyze collembolan community structure, and displayed different results. The sequence of Shannon-Wiener index and Pielou evenness index to collembolancommunity were Schima superb community> Castanopsis farogesii community>Ooropetalum chinensis-Lithocarpus glabre Community>Pinus massoniana community. Simpson dominant index were highest at Pinus massoniana community and lowest at Schima superb community. Margalef abundance index were highest at Castanopsis farogesii community and lowest at Pinus massoniana community.2,Influence on collembolan composition in different slashed plotsIn the hierarchy of family,the number of collembolan groups did not vary widely among the plots, Isotomidae and Entomobryidae were the dominant groups in four plots. The number of Collembola community was as follows:â…¡>â…£>â… >â…¤>â…¢.The group composition of collembola did not vary widely in four seasons, but the density had changed a lot. The number of Collembola community was as follows: autumn> summer> spring> winter.The seasonal fluctuations of collembolan communities varied with different plots,which were generally of three types:â‘ In siteâ…¡and siteâ…¤a large number of collembolans emerged in autumn;â‘¡In siteâ… and siteâ…£a large number of collembolans emerged in summer.â‘¢In siteâ…¢a large number of collembolans emerged in spring,summer and autumn.Various of diversity indices were used to analyze collembolan community structure, and displayed different results. The sequence of Shannon-Wiener index and Pielou evenness index to collembolancommunity wereâ…¤>â…¢>â…£>â… >â…¡. The sequence of Simpson dominant index to collembolancommunity wereâ…¡>â… >â…£>â…¢>â…¤. The sequence of Margalef abundance index to collembolancommunity wereâ…£>â…¡>â…¤>â… >â…¢.3,The impact on collembolan communities by environmentThe organic matter, total nitrogen and total phosphorus had obviously different among the plots.The density of collembola have positive correlation with organic matter and total phosphorus, but have no correlation with total nitrogen.4,The feeding of CollembolaOn the feeding of Collembola,the feeding environment should be as natural as possible.It is feasible to use litter not yeast for food in order to get rid of yeast's mold.