Links and fluxes in forest soil micro-food webs under different land use intensity

它们的巨大数量，加上高度的物种和营养多样性，使线虫成为土壤食物网中的关键群体。研究了土地利用对3个试验区75个样地线虫区系的影响，重点研究了微食物网的结构和功能、微生物与动物食物网的联系以及干扰后生物多样性的聚集。应用线虫区系分析概念，将线虫作为食物网状况的指标，来确定土地利用和森林经营以及食物网资源的相关变化对土壤分解途径和能量通量的影响。脂质群落水平生理分析（CLPP）用于监测生物化学水平上营养多样性的变化，并评估微生物和动物性食物网之间的联系强度。据我们所知，这是CLPP在线虫田间种群中的首次尝试。此外，扰动后微食物网的重建让我们了解到功能多样性的维持是如何受到栖息地（土地利用类型）、资源（凋落物类型）和生物相互作用（如竞争）的影响。这项工作是与U. Brose、N. Eisenhauer、M. Maraun和S. Scheu的项目合作进行的，并补充了关键线虫群的区系分析。总体而言，线虫将作为受林地利用强度调节的微食物网资源分配、分配和转移的入门级指标。

Their great abundance, coupled with high species and trophic diversity, make nematode a key group in soil food webs. The proposed project investigates land use effects on the nematode fauna in 75 forest plots of the three exploratories with the focus on: (1) structure and function of the micro-food web, (2) links between microbial and faunal food web, and (3) biodiversity assembly after disturbance. By application of the nematode faunal analysis concept nematodes are used as indicators for food web conditions to assign how land use and forest management, and the related changes in food web resources, affect decomposition pathways and energy flux in soil. Community level physiological profiling (CLPP) of lipids is employed to monitor changes in trophic diversity at a biochemical level and to assess the strength of linkage between the microbial and faunal food web. To the best of our knowledge this is the first attempt of CLPP in nematode field populations. Further, re-establishment of the micro-food web after disturbance gives insight how the maintenance of functional diversity is shaped by habitat (land use type), resource (litter type) and biotic interactions (e.g. competition). The work is carried out in cooperation with projects of U. Brose, N. Eisenhauer, M. Maraun and S. Scheu, and complements the faunal analysis with the key group nematodes. Overall, nematodes will serve as entry-level indicators for resource allocation, partitioning and transfer in the micro-food web as modulated by forest land use intensity.