吴起县不同年限退耕还林地大中型土壤动物时空变化

Temporal and spatial changes of soil animals in returning farmland to forestland in different years in Wuqi County

为了解黄土丘陵沟壑区不同年份退耕还林地对土壤动物群落组成及结构的影响,阐明其群落多样性及群落结构在退耕还林地植被修复中的变化趋势,于2017年7~8月对吴起县6个样地进行调查。结果表明:此研究区优势类群共4类,分别为鞘翅目、半翅目、膜翅目和双翅目,各退耕还林地土壤动物多样性指数、类群数、个体密度和生物量均与撂荒地有显著性差异(P<0.05),且在垂直分布上具明显表聚特性。随着退耕年限的增加:土壤动物类群数变化较小,个体密度和生物量呈现先增加后减少的趋势;植食性和捕食性动物数量占比变化幅度较小,腐食性动物呈现为先增加后减小趋势,杂食性动物反之。

In order to understand the effects of returning farmland to forest land on the composition and structure of soil fauna in different loess hilly and gully regions,the changes of community diversity and community structure in vegetation restoration in returning farmland to forestland were clarified.From July to August 2017,Six plots in Wuqi county were investigated.The results showed that there are 4 dominant groups in the study area,they are Coleoptera,Hemiptera,Hymenoptera and Diptera.The soil animal diversity index,group number,individual density and biomass of each returning farmland to forestland are all different from the wasteland(P<0.05).There is a significant aggregation characteristic in the vertical distribution.With the increase of the years of returning farmland to forest land,the number of soil animal groups changes little,the individual density and biomass increase firstly and then decrease;the proportions of herbivorous and predatory animals are small,and the rotted animals show a trend of increasing firstly and then decreasing,while omnivorous animals are the opposite.