浙江天童栲树林土壤动物群落结构及其季节变化

Community Structure and Seasonal Change of Soil Animals in Castanopsis Fargesii Forest at Tiantong,Zhejiang Province

2003年9月～2004年7月，对浙江天童栲树林中的土壤动物群落按凋落物层和0～15cm土层，进行了四季调查．凋落物层包括新鲜凋落物层、腐叶层和腐殖土层．共获得大型、中型和湿生土壤动物32657只，分属于10纲27个类群．大型土壤动物以鞘翅目、膜翅目和蜚蠊目为优势，中型土壤动物则以蜱螨目和弹尾目为主，湿生土壤动物以线虫为主．对调查结果的分析表明：（1）凋落物层中的类群数和密度均高于0～15cm土层；（2）土壤动物在凋落物层中的垂直分布不同于0～15cm土层，类群数表现为向下增加的趋势，底部腐殖土层最多，为18类；大量的土壤动物个体集中分布在中间腐叶层和底部腐殖土层，腐叶层较多，两层共占总数的77．04%；（3）密度-类群DG指数反映出土壤动物群落多样性的季节变化为：秋季〉春季〉冬季〉夏季；（4）优势类群的垂直分布随季节发生有规律的变化，从而影响整个群落垂直分布的季节变化．

A four-season investigation was conducted on the soil animals in the litter layers and soil layers depth of 0-15 cm of Castanopsis fargesii forest at Tiantong, Zhejiang province dur ing September, 2003 and July, 2004. The litter layer includes fresh litter layer （L）, fermenta tion layer （F） and humus layer （H）. Soll animals amount to a total of 32, 657 in number, including macrofauna, mesofauna and wet types, falling into 10 classes and 27 groups respectively. For soil macrofauna, the dominant groups are Coleoptera, Hymenoptera and Blattoptera, while for mesofauna, they are Acarina and Collembola and for wet type ones, Nematoda. The results of the investigation indicate that： （1） the group numbers and density are all greater in the litter than in the ,soil depth of 0-15 cm; （2） the vertical distribution of soil animals in the litter differs from that in the soil, the group numbers in the former tend to inerease gradually from top to bottom, with those in bottom humus layer the largest; altogether 18 groups are found in it;large numbers of individuals are seen in the middle fermentation layer and in the bottom humus layer, with those in the former greater, both accounting for 77.04% of the total; （3） the DG index （density-group index） reveals a seasonal change of soil animal community diversity as autumn ）〉 spring）〉 winter）〉 summer; （4） the vertical distribution of dominant groups varies with seasons in a regular manner, thus influen cing the seasonal change of the vertical distribution of the entire community,