天童常绿阔叶林五个演替阶段凋落物中的土壤动物群落

Soil animal communities in the litter of the evergreen broad-leaved forest at five succession stages in Tiantong

为探讨森林凋落物中土壤动物群落的结构特征以及土壤动物群落随植被演替而发生的变化 ,于 2 0 0 3年冬季 ,对浙江天童常绿阔叶林 5个演替阶段凋落物中的土壤动物群落 ,按代表不同分解阶段的新鲜凋落物层、腐叶层和腐殖土层进行了调查研究。共获得土壤动物 13381只 ,分别隶属于 2门 8纲 2 0目。优势类群为蜱螨目 (Arcarina)和弹尾目 (Collem bola) ,二者共占总数的 94 .2 4 % ,A/ C为 7.6 6 ;常见类群为双翅目 (Diptera)。研究结果表明 :(1)凋落物中的土壤动物群落存在明显的有别于真土层的垂直分布 ,类群数和个体数总体表现为向下递增的趋势。共有 19类、5 9.0 3%的土壤动物分布在底部腐殖土层 ,仅 8类、5 .35 %的土壤动物分布在新鲜凋落物层 ,其余共 8类分布在中间腐叶层。而且 ,不同类群在各演替阶段的分布表现出一定的差异 ;(2 )凋落物中土壤动物群落随植物群落的演替而发生明显的变化 :个体总数和类群总数在演替顶极阶段最高 ,其次为中期阶段 ,演替初期最低。但是 ,在目这一分类等级上 ,各演替阶段凋落物中土壤动物群落的主要类群基本一致 ,均为蜱螨目、弹尾目、双翅目和鳞翅目 (L epidoptera) ;(3)相似性分析表明 ,演替中期凋落物中土壤动物群落与顶极阶段最为相似 ;但它们的Shannon-

Soil animals are aboundant in forest litter layer, but little attention has been paid to the vertical distribution of community structure of soil animals in the layer at different plant community succession stages. Forest litter layer can be divided into fresh litter layer (L), fermentation layer (F) and humus layer (H), which may represent different litter decomposition stages. The aim of the study is to ascertain the vertical distribution feature of soil animal community structure among the three litter layers and the change in the succession process of the evergreen broad-leaved forest(EBLF) in Tiantong, Zhejiang Province. Five plant communities at different succession stages were investigated in winter of 2003. Soil animals, which were extracted by using Tullgren funnels, amounted to a total of 13, 381 in number, falling into 2 phyla, 8 classes and 20 orders. The dominant groups were Arcarina and Collembola, accounting for 94.24% of the total individuals, with the number of Arcarina individuals 7.66 times that of Collembola. The common group was Diptera.The results indicated that there was a distinctive vertical distribution of the soil animal communities in the forest litter layer, but it differed from that in soil below the litter layer. Opposite to those in the soil, the soil animals in the litter layer generally tend to increase from top fresh litter layer to bottom humus layer both in group richness and density; altogether 19 groups and 59.03% of total individuals were found in the bottom layer, while only 8 groups and 5.35% of the individuals were seen in the top. Moreover, there were some variations in the distribution of the soil animals at different plant succession stages; 85.19% of Homoptera and 100% of Symphyla were found in the litter layer at the climax succession stage, while 75.61% of Thysanoptera found at the intermediate succession stage. Therefore these groups might be seen as indicative groups. The total numbers of soil animal groups and individuals in the litter layers greatly changed in the succession process of the EBLF. They both were greatest at the climax, moderate at the intermediate and smallest at the primary succession stage. However, the main soil animal groups in the litter at the different succession stages were essentially the same; they were Arcarina, Collembola, Diptera and Lepidoptera. Although similarity analysis revealed that the soil animal communities in the litter at the intermediate succession stage were most similar to those at the climax succession stage, they differed greatly from each other in the Shannon-Wiener diversity index. The Shannon index was highest at the climax succession stage and lowest at the intermediate succession stage. The Shannon-Wiener diversity index well represented the diversity of the soil animal communities in the litter at the five succession stages but was in negative correlation with the Simpson dominance index. Finally, the paper discussed the following three questions: the role of soil animals as indicators for different plant community succession stages; the role of different soil animal groups in litter decomposition at different stages; the major factors affecting the composition and distribution of soil animals in the litter. This paper would provide a new perspective for the research on the succession mechanism of plant communities and soil animals' decomposition functions.