干扰对东北次生林生态系统土壤线虫群落的影响

Effects of disturbances on soil nematode communities in secondary forest ecosystems of Northeast China

土壤线虫作为土壤生态系统中重要的组成部分,在凋落物分解与物质循环中起着重要作用。为明确东北地区不同林型中土壤线虫状况,确定干扰对土壤线虫产生的影响,于2007年5、7、9月调查了次生林、落叶松人工林和裸地3种样地(其干扰强度:次生林<人工林<裸地)的线虫多样性。结果表明:随着干扰度的增加,土壤线虫丰富度与个体数均减少;通过土壤线虫区系划分,可以确定3种干扰强度下土壤线虫食物网的状况,即裸地环境受到胁迫,食物网受到威胁,其干扰程度最大;人工林与次生林食物网结构相对成熟,二者干扰程度较小。干扰改变了线虫群落的种类组成,随着干扰度增加,线虫多样性减少。上述结果表明,地上部分(森林植被)的干扰已经影响了地下生态系统。

Soil nematode is an important component of soil ecosystem, and plays important roles in litter decomposition and nutrient cycling. In May, July, and September 2007, investigations were made to study the effects of disturbances on the diversity of soil nematodes in secondary forest and larch plantation of Northeast China, with bare land as the control. The results Showed that the individual number and richness of soil nematodes decreased with the increase of disturbance intensity, being in the order of secondary forest 〈 larch plantation 〈 bare land. Based on nematode faunal analysis, which is helpful to understand the status of nematode food web under disturbances, the environment of bare land was under stress, and the nematode food web was threatened and disturbed most heavily. On the contrary, the structures of the food web in secondary forest and larch plantation were relatively mature and disturbed less heavily. Disturbances changed the species composition Of soil nematode community, i. e. , the nematode diversity decreased with the increase of disturbance. All of the results suggested that the disturbance aboveground part （forest vegetation） had irdluenced underground ecosystem.