SP11: Networks and energy fluxes

SP11解决了沿植物多样性梯度的土壤食物网的数量结构和稳定性，这是研究单位5000的主要实验和抢救实验的结果。该项目基于这样的假设，即植物群落多样性和组成的变化对土壤食物网的结构和能量流动产生自下而上的影响。该项目在很大程度上建立在研究股前一阶段的成果基础上，但现在侧重于(1)植物多样性对主要实验(WP1)框架内调查的地下群落结构的时间(季节)和空间(深度分布)稳定性的作用，(2)植物多样性对主要实验(WP2)框架内调查的地下群落能量输送的时间(季节性)和空间(深度分布)稳定性的作用，(3)在抢救实验(WP3)的框架下，地下群落结构和能量通量对植物多样性和热旱干扰的响应。与研究股的第一阶段一样，能量通量分析将侧重于广泛的功能群体，如初级和次级分解者、草食动物以及捕食者。这将得到更详细的分析的补充，使用氨基酸稳定同位素的化合物特异性分析，从而将通量分离到细菌、真菌和植物的能量通道中。由此产生的数据将为受植物多样性影响的土壤食物网的能量结构变化提供独特的见解。地下消费者能量通量的差异将导致显著的反馈效应，这将是通过多营养相互作用机械地解释生物多样性-生态系统功能关系的关键。救援实验(WP3)框架内的调查将补充主要实验(WP1和WP2)中的研究，重点是地下食物网对植物多样性强烈干扰(干旱)的反应。在本实验中使用IDIV Ecotron设施将允许跟踪干旱对植物碳(使用13CO2脉冲标记)和化肥氮(使用15N标记化肥)进入地下食物网的影响，并调查植物多样性是否减轻了这一影响。因此，WP3将为植物多样性对地下食物网结构和功能的稳定性的作用的研究增加新的维度。

SP11 addresses the quantitative structure and stability of soil food webs along the plant diversity gradients of the Main Experiment and the ResCUE Experiment of the Research Unit 5000. The project is based on the assumption that changes in plant community diversity and composition exert bottom-up effects on the structure of and energy flux through soil food webs. The project builds heavily on the results of the previous phase of the Research Unit, but now focuses on (1) the role of plant diversity for the temporal (seasonal) and spatial (depth distribution) stability of the structure of belowground communities investigated in the framework of the Main Experiment (WP1), (2) the role of plant diversity for the temporal (seasonal) and spatial (depth distribution) stability of energy channelling through belowground communities investigated in the framework of the Main Experiment (WP2), and (3) the response of the structure of and the energy flux through the belowground community to plant diversity and a hot drought disturbance investigated in the framework of the ResCUE Experiment (WP3). As in the first phase of the Research Unit, the energy-flux analyses will be focused on broad functional groups, such as primary and secondary decomposers, herbivores, as well as predators. This will be complemented by more detailed analyses using compound-specific analysis of stable isotopes of amino acids allowing to separate the fluxes into the bacterial-, fungal-, and plant-based energy channels. The resulting data will provide unique insights into variations in the energetic structure of soil food webs as affected by plant diversity. Differences in energy fluxes to belowground consumers will result in significant feedback effects that will be key to mechanistically explain biodiversity–ecosystem function relationships through multi-trophic interactions. Investigations in the framework of the ResCUE Experiment (WP3) will complement the studies in the Main Experiment (WP1 & WP2) by focussing on the response of the belowground food web to a strong disturbance (drought) by plant diversity. Using the iDiv Ecotron facility in this experiment will allow to follow effects of drought on the incorporation of plant carbon (using pulse labelling with 13CO2) and fertiliser nitrogen (using 15N labelled fertiliser) into the belowground food web and to investigate if this is mitigated by plant diversity. Therefore, WP3 will add new dimensions to the investigation of the role of plant diversity for the stability of the structure and functioning of the belowground food web.