Tree diversity effects on rhizodeposition and rhizosphere priming: the role of the mycorrhizal colonization in coupling C and N cycles in diverse tree stands

树木多样性对根际沉积和根际启动的影响：菌根定殖在不同树木中 C 和 N 循环耦合中的作用

• 批准号: 419348933
• 负责人: Professorin Dr. Ina Christin Meier
• 金额: --
• 依托单位: Department of Plant Science
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2019
• 资助国家: 德国
• 起止时间: 2018-12-31 至 2023-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/419348933?language=en
• 关键词: Tree; diversity; effects; rhizodeposition; rhizosphere; Tree; diversity; effects; rhizodeposition; rhizosphere

The majority of temperate tree species associates predominantly with either arbuscular mycorrhizal (AM) or ectomycorrhizal (ECM) fungi, which provide mineral nutrients to their host in exchange for carbon. Since the two mycorrhizal types differ fundamentally in their nutrient economy they were suggested to provide an integrated index of biogeochemical transformations relevant to carbon (C) cycling and nutrient retention in forests. Yet little is known about the group-specific role of the mycorrhizal type in the tree diversity–ecosystem functioning relationship. The central aim of this research project is to determine functional group differences in rhizosphere C fluxes and soil nitrogen cycling between diverse AM and ECM tree stands. Among the key biogeochemical processes I will focus on root exudation and decomposition, which represent cause and effect of the microbial priming effect to stimulate nutrient release from soil organic matter. On the basis of the assumed organic nutrient economy of ECM stands, I hypothesize that increased root exudation is a primary mechanism by which ECM trees sustain productivity in diverse stands, while diverse AM stands mainly depend on leaf litter effects on bulk soil processes. To achieve the objectives of this project I will combine an established tree diversity experiment that manipulates mycorrhizal type abundances with innovative and beyond state-of-the-art ecological and ecophysiological methods that are complemented by 3-D laser ablation tomography, solid-state 13C-CPMAS nuclear magnetic resonance spectroscopy, and metabolomics. This project will refine a conceptual model on the role of the mycorrhizal type in tree diversity effects on soil functions for the incorporation in global simulation models.

大多数温度树种类主要与杂草菌根（AM）或外生菌骨（ECM）真菌相结合，这些真菌为其宿主提供矿物质营养，以换取碳。由于两种菌根类型在其营养经济中从根本上有所不同，因此建议提供与碳（C）循环和养分保留在森林中相关的生物地球化学转化指数。然而，关于菌根类型在树多样性 - 生态系统功能关系中的群体特定作用知之甚少。该研究项目的核心目的是确定根际C通量和多样性AM和ECM树架之间的氮气中的功能群体差异。在关键的生物地球化学过程中，我将重点介绍根的经验和分解，这代表了微生物启动效应的因果，以刺激从土壤有机物中释放养分。在ECM的假定有机营养经济的基础上，我假设增加的根本经验是ECM树在多样性中维持生产力的主要机制，而潜水员AM的含量主要取决于叶子垃圾对散装土壤过程的影响。为了实现该项目的目标，我将结合一个已建立的树木多样性实验，该实验通过创新的和最先进的生态和生态生理学方法来操纵菌根类型的丰度，该方法由3-D激光消融层析成像完成，固态13C-CPMAS核磁共振磁共振磁共振磁共振镜像和代理学。该项目将完善有关菌根类型在树木多样性中的作用对全球模拟模型中就业的土壤功能的作用的概念模型。