The productivity - stoichiometry - diversity concept in grasslands: disentangling intra- and interspecific variance in resource use

该子项目将分析植物多样性与多种生态系统过程和营养相互作用的生态化学计量之间的关系。生态化学计量学是一个理论框架，允许预测竞争和营养相互作用的基础上相互作用的物种之间的资源供应和资源需求的平衡。在Jena实验中，将在植物多样性和物种组成的梯度上研究土壤、植物及其消费者中多种元素（C、N、P和K）的平衡。在主要实验中，我们将沿着物种丰富度和功能多样性的实验梯度追踪植物和昆虫化学成分的化学计量。我们将测试（一）植物多样性是否提高了社区水平上的多种元素的吸收，从而内容，以及（二）是否差异化学计量将改变昆虫食草动物的消费模式。在基于性状的实验中，我们将解决化学计量的元素在特定物种的基础上，问植物多样性是否改变资源含量和比例的植物物种，这取决于他们的性状和性状的共同发生的物种。我们将测试是否（iii）更高的覆盖率的资源利用性状增加资源利用效率的多种元素，以及（iv）植物化学计量是否可塑性的竞争环境。因此，我们将解决物种多样性如何影响生态系统多功能性的问题，即，是否需要更多的物种来维持不同元素的加工。此外，我们将分析是否发生功能性转换，即，不同物种是否在资源利用效率和营养转移中具有跨时间的功能。

This subproject will analyze the relationship between plant diversity and the ecological stoichiometry of multiple ecosystem processes and trophic interactions. Ecological stoichiometry is a theoretical framework allowing the prediction of competitive and trophic interactions based on the balance between resource supply and resource needs of interacting species. The balance of multiple elements (C, N, P, and K) in the soil, plants and their consumers will be investigated across the gradient of plant diversity and species composition in the JenaExperiment. In the main experiment, we will track the stoichiometry of plant and insect chemical composition along the experimental gradients of species richness and functional diversity. We will test (i) whether plant diversity enhances the uptake and thus content of multiple elements on the community level, and (ii) whether differential stoichiometry will change consumption patterns by insect herbivores. In the trait-based experiment, we will address stoichiometry of elements on a species-specific basis, asking whether plant diversity alters the resource content and ratios of plant species depending on their traits and the traits of their co-occurring species. We will test whether (iii) higher coverage of the resource use traits increases resource use efficiency for multiple elements, and (iv) whether plant stoichiometry responds plastically to the competitive environment. Thereby we will address the question how species diversity affects ecosystem multifunctionality, i.e., whether more species are required to maintain the processing of different elements. Moreover, we will analyze whether functional turnover occurs, i.e., whether different species carry function in resource use efficiency and trophic transfer across time.