The functional role of soil biodiversity in grassland habitats: effects of land use and climate on niche properties, decomposition and greenhouse gas fluxes

草原生境中土壤生物多样性的功能作用：土地利用和气候对生态位特性、分解和温室气体通量的影响

• 批准号: 61150987
• 负责人: Professor Dr. Volkmar Wolters
• 金额: --
• 依托单位: ArbeitsgruppeTierökologie
• 依托单位国家: 德国
• 项目类别: Infrastructure Priority Programmes
• 财政年份: 2008
• 资助国家: 德国
• 起止时间: 2007-12-31 至 2015-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/61150987?language=en
• 关键词: functional; role; soil; biodiversity; grassland

Our previous studies carried out within the DFG Biodiversity Exploratories revealed a significant and very often non-linear response of soil fauna biodiversity and functioning in grasslands to land-use and climatic gradients. Now we need to understand the mechanisms driving these response patterns by asking whether modifications of soil biotic processes occur through changes in species composition of the community (species turnover) or through shifts within the existing community. The latter include both interspecific shifts (alterations of the dominance structure) and intraspecific shifts (changes in the expression of certain morphological, functional, behavioral or reproductive traits). The phenotypic plasticity of soil animals provides a particular challenging case, since trait shifts allow rapid and reversible changes of the species functional roles in response to changing environmental conditions. Considering that species turnover in soil is slow due to the low migratory potential of belowground biota, such intraspecific response mechanisms most probably are much more important than previously thought. Our key hypothesis is that individual species trait plasticity significantly contributes to the striking functional redundancy and resilience of soil animal communities under conditions of climate change and increasing land-use intensity. We further hypothesize that functional shifts of belowground food webs resulting from alterations in dominance and species composition can partly be compensated by trait-related functional expansion of the remaining species. Both compositional responses at the community level and trait responses at the species level will be quantified by continuing, extending and refining field studies as well as by experimental approaches in microcosms that have been successfully established in the two preceding projects (SoilFoodWeb, SoilFun). Concerning the extension of field studies, SoilTRAIT aims at collaborating with all projects addressing processes that are related to soil biodiversity in grasslands. Within this context, a particular focus will be on quantifying a wide range of functional traits of the soil fauna and their changes in response to varying environmental conditions. Community analyses based on soil samples will cover the broadest range of invertebrate taxa possible, but specific trait analyses will focus on representative groups of soil decomposers (millipedes, collembolans, oribatid mites, enchytraeids, and earthworms) and predators (gamasid mites, spiders, carabid beetles). Integrating these new insights into our food web approach to the functional role of soil animals in grasslands established in previous projects will not only increase the reliability of descriptive and predictive models on soil ecological processes, but it will also allow us to quantify the limits of soil community resilience and sustainability in the face of environmental change or of short-term stress.

我们以前在DFG生物多样性探索站进行的研究揭示了土壤动物多样性和草原功能对土地利用和气候梯度的显着且经常是非线性的响应。现在，我们需要了解驱动这些响应模式的机制，通过询问土壤生物过程的修改是否通过改变群落的物种组成（物种更替）或通过现有群落内的变化发生。后者包括种间转移（优势结构的改变）和种内转移（某些形态、功能、行为或生殖特征的表达变化）。土壤动物的表型可塑性提供了一个特别具有挑战性的情况下，因为性状的变化允许快速和可逆的物种功能的变化，以应对不断变化的环境条件。考虑到由于地下生物群的低迁移潜力，土壤中的物种周转缓慢，这种种内反应机制很可能比以前认为的要重要得多。我们的关键假设是，个别物种的性状可塑性显着贡献显着的功能冗余和恢复力的土壤动物群落在气候变化和土地利用强度增加的条件下。我们进一步假设，地下食物网的优势和物种组成的改变所造成的功能转变，可以部分地补偿其余物种的性状相关的功能扩展。将通过继续、扩大和完善实地研究以及通过在前两个项目（SoilFoodWeb、SoilFun）中成功建立的微观世界中的实验方法，对群落一级的成分反应和物种一级的性状反应进行量化。关于扩大实地研究，SoilTRAIT旨在与所有涉及草原土壤生物多样性进程的项目合作。在此背景下，一个特别的重点将是量化的土壤动物的功能特性和它们的变化，以应对不同的环境条件。基于土壤样本的群落分析将涵盖尽可能广泛的无脊椎动物分类群，但具体性状分析将侧重于土壤分解者（千足虫、弹尾虫、甲螨、enchytraeids和蚯蚓）和捕食者（革螨、蜘蛛、步甲）的代表性群体。将这些新的见解整合到我们的食物网方法中，以确定土壤动物在以前项目中建立的草原中的功能作用，不仅可以提高土壤生态过程描述和预测模型的可靠性，而且还可以量化土壤群落弹性和可持续性的极限。