The Significance of Nitrogen Uptake and Metabolism by Beech Roots for the Competition for Nitrogen in the Rhizosphere

本项目旨在（1）量化山毛榉根对无机和有机氮源的吸收，并阐明山毛榉根和土壤微生物对这些氮源的竞争，（2）分析竞争机制，（3）阐明它们对环境因素的依赖性，特别是对干旱的依赖性，石灰质土壤上山毛榉为主的落叶林。为此，将在田间条件下和温室中进行实验，研究山毛榉和土壤微生物之间竞争的生理学原理和模式。在该领域，短期和长期的影响，在水的可用性的差异将进行分析，在一个凉爽/潮湿（东北方面）和温暖/干燥（西南方面）的斜坡之间交换的微观世界。在受控条件下，将在不同水平的水的可用性和不同的温度下，量化的意义的殖民化的山毛榉根与菌根真菌的无机和有机氮的吸收。这些研究包括确定的吸收速率和吸收动力学的NH 4+，NO3-，氨基化合物结合N代谢产物分析山毛榉根。

This project is aimed (1) to quantify the uptake of inorganic and organic nitrogen sources by beech roots and to elucidate the competition between beech roots and soil microorganisms for these nitrogen sources, (2) to analyse the mechanisms of competition, and (3) to characterise their dependency on environmental factors, particularly on drought, in natural beech regeneration of nitrogen-limited, beech-dominated deciduous forests on calcarious soil. For this purpose, the physiological principles and patterns of competition between beech and soil microorganisms will be studied in experiments under field conditions and in the greenhouse. In the field, short-term and long-term consequences of differences in water availability will be analyzed in microcosms exchanged between a cool/moist (NE aspect) and a warm/dry (SW aspect) slope. Under controlled conditions, the significance of colonisation of beech roots with mycorrhizal fungi for the uptake of inorganic and organic nitrogen will be quantified at different levels of water availability and different temperatures. These studies include the determination of uptake rates and uptake kinetics of NH4+, NO3-, and amino compounds combined with N metabolite profiling in beech roots.