Trophic-interaction, tree-diversity and soil-erosion effects on soil-plant stoichiometry

营养相互作用、树木多样性和土壤侵蚀对土壤-植物化学计量的影响

• 批准号: 498596177
• 负责人: Professorin Dr. Yvonne Oelmann
• 金额: --
• 依托单位: State Key Laboratory of Vegetation and Environmental Change
• 依托单位国家: 德国
• 项目类别: Research Units
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/498596177?language=en
• 关键词: Trophic; interaction; tree; diversity; soil

Wider research context: Nutrients are an essential link across trophic levels and networks. Tree diversity has been shown to influence nutrient cycles across trophic levels. However, the complexity inherent in each of the levels and interactions among trophic levels constrain our understanding of tree diversity effects on nutrient cycling that is required to predict the response of forest ecosystems to unprecedented rates of biodiversity loss. Hypotheses: Here we propose to study the redistribution of nutrients via erosion and the nutrient-related interactions between soil microorganisms (consumers) and plants (primary producers) along the tree diversity gradient of BEF-China. Our central hypotheses are: (1) Erosion redistributes nutrients along slopes and differentiates the nutrient pattern in soils available to soil microorganisms and trees. Eroded parts show lower nutrient availability and foster nutrient recycling while deposition areas are dominated by nutrient overyielding. (2) Soil microorganisms both recycle and take up nutrients more efficiently (‘nutrient overyielding’) in soil of diverse tree mixtures while nutrient overyielding dominates as the underlying process. (3) Trees also both recycle and take up nutrients more efficiently in diverse tree mixtures but recycling is more important. Consequently, the dominance of either one of the processes results in a divergence of stoichiometric responses of trophic levels to tree diversity.Methods: We will use a stoichiometric approach and assess tree diversity effects on trophic interactions in terms of nutrient cycling. We will combine state-of-the-art runoff-plot based sediment flux measurements, nutrient analyses in soil, plants, and animals and the determination of oxygen isotope signatures in phosphate to reach our aims. In addition, the project will comprise a full soil data baseline (all major nutrients and soil properties) as a courtesy to all projects involved in the research group.Innovation: We will continue the unique long-term monitoring of soil properties. We will study the influence of tree diversity on lateral matter transport by erosion including the redistribution of nutrients and other aboveground surface components like litter, pollen, plant debris, and organisms, which is a widely neglected mechanism in biodiversity research. Furthermore, we aim to resolve whether higher trophic levels, for example soil microorganisms that consume tree litter, share the same responses to tree diversity as lower trophic levels.Primary researchers involved: This project will be conducted by Yvonne Oelmann (PI), Steffen Seitz and Thomas Scholten (Co-PIs) (University of Tübingen) and in collaboration with our Chinese partners Yu Liang (Chinese Academy of Sciences) and Naili Zhang (Beijing Forestry University).

更广泛的研究背景：营养素是营养水平和网络之间的重要联系。树木多样性已被证明影响营养水平的营养循环。然而，固有的复杂性，在每一个层次和营养层次之间的相互作用限制了我们的了解树木多样性对养分循环的影响，需要预测森林生态系统的反应，以前所未有的速度的生物多样性丧失。假设条件：在这里，我们建议研究养分通过侵蚀的再分配和土壤微生物（消费者）和植物（初级生产者）之间的养分相关的相互作用沿着的树木多样性梯度的BEF-China。我们的主要假设是：（1）侵蚀使养分沿着坡重新分布，并使土壤微生物和树木可利用的养分模式发生变化。侵蚀部分显示较低的养分供应和促进养分循环，而沉积区主要是养分过剩。(2)土壤微生物都回收和吸收养分更有效地（“养分超产”）在土壤中的不同树木的混合物，而养分超产占主导地位的基本过程。(3)在不同的树木混合物中，树木也能更有效地回收和吸收养分，但回收更重要。因此，任何一个过程的优势，结果在分歧的营养水平的化学计量响应树diversity.Methods：我们将使用化学计量的方法和评估树的多样性营养相互作用的营养循环方面的影响。我们将结合联合收割机国家的最先进的径流小区为基础的沉积物通量测量，土壤，植物和动物的营养分析和磷酸盐中的氧同位素特征的测定，以达到我们的目标。此外，该项目将包括一个完整的土壤数据基线（所有主要的养分和土壤特性），作为对研究小组所有项目的礼遇。创新：我们将继续对土壤特性进行独特的长期监测。我们将研究树木多样性对侵蚀横向物质运输的影响，包括营养物质和其他地上表面成分（如凋落物，花粉，植物残体和生物体）的再分配，这是生物多样性研究中被广泛忽视的机制。此外，我们的目标是解决是否较高的营养水平，例如消耗树木凋落物的土壤微生物，共享相同的反应树的多样性作为较低的营养水平。主要研究人员涉及：该项目将由Yvonne Oelmann（PI）进行，Steffen Seitz和托马斯Scholten（共同PI）我们与中国合作伙伴于亮（中国科学院）和张乃力（北京林业大学）合作。