Modeling land-use effects on forest soil food webs

拟议的项目旨在研究土地利用类型(针叶林、幼龄、中熟和成熟的山毛榉林、杨树林)和基本凋落物的基本化学计量比对三个生物多样性探索区森林土壤食物网的多样性(即物种数量)和拓扑结构(即网络结构)的影响。该项目包括三个工作包。第一个一揽子工作将分析在前两个供资期间建立的52个森林土壤社区(800个物种，5500个种群)的大型数据库。这些分析将探讨食物网结构、土地利用和元素化学计量学在确定群落多样性和结构方面的相互作用。这些分析将为第二个一揽子工作提供具体的假设，以解决栖息在动物群落中的凋落物(以多样性和食物网为特征)如何根据不同的周围生境(生物多样性探索的土地利用类型)和环境生态位(凋落物类型)聚集在一起。这项生物多样性组合实验将在24块林地上建立。在每个小区上，设置四个处理(三种凋落物类型：山毛榉、白蜡树、云杉，以及一个带小区凋落物的对照)，三个时间重复。测量将涉及微型、中型和大型动物在时间序列中的生物多样性(仅限于特定动物群体)、生物量分布和功能。本实验测试群落聚集是由生态位理论预测的生境特征(凋落物类型、生物地球化学)驱动的，还是由中性理论预测的周围社区(对照处理因地块不同而不同)驱动的。第三个工作包将讨论土地利用类型和凋落物的化学计量如何决定生物量在生物多样性探索实验室75个森林地块一级跨大小类的分布(大小谱分析)和大小类的多样性。这将把数据库分析和组装实验的结果推广到生物多样性探索的空间层面。

The proposed project aims at studying the effects of land-use types (coniferous forests, young, intermediate and mature beech forests, plenter forests) and the elemental stoichiometry of the basal litter on the diversity (i.e., species number) and topology (i.e., network structure) of forest soil food webs across the three Biodiversity Exploratories. The project comprises three work packages. The first work package will analyse a large data base on the 52 forest soil communities (> 800 species, > 5500 populations) that was established during the prior two funding periods. These analyses will address the interplay of food-web structures, land use, and elemental stoichiometry in determining diversity and structure of the communities. These analyses will provide specific hypotheses for the second work package addressing how the litter inhabiting animal communities (characterized by diversity and food webs) assemble depending on different surrounding habitats (the land-use types of the Biodiversity Exploratories) and environmental niches (litter types). This biodiversity assembly experiment will be established on 24 forest plots. On each plot, four treatments (three litter types: beech, ash, spruce, and a control with plot litter) will be established with three temporal replicates. Measurements will address the assembly of biodiversity (only specific animal groups), biomass distributions and functions in time series for micro-, meso-, and macrofauna. This experiment tests whether community assembly is driven by habitat characteristics (litter type, biogeochemistry) as predicted by niche theories or the surrounding communities (control treatments that differ according to plots) as predicted by neutral theory. The third work package will address how land-use types and the stoichiometry of the litter determine the distribution of biomasses across size classes (size spectrum analyses) and the diversity of size classes at the 75-forest-plot level of the Biodiversity Exploratories. This will generalize the findings of the data base analyses and the assembly experiment to the spatial level of the Biodiversity Exploratories.