Function of mycorrhiza in the competition for water and nitrogen

本研究的目的是探讨外生菌根（EM）群落对山毛榉（Fagus sylvatica L.）并了解这些功能如何受到干旱的影响。15 N标记将被用来调查在现场和控制条件下的山毛榉植物和外生菌根的N吸收，以探讨EM 15 N富集和植物N吸收之间的关系。将合成来自一系列干燥和潮湿场地的特定场地EM群落。干旱胁迫将作为一种手段来调节碳供应的根，从而影响EM的竞争关系。EM将根据物种收集，并将确定其丰度并与N-吸收相关。为了剖析菌根效应，还将研究非菌根山毛榉。15 N富集和吸收率将在控制实验EM山毛榉协会与选定的真菌物种进行分析，以找出不同的EM物种的能力存在差异，以提供山毛榉在良好的浇水和干燥条件下的N。

The goal of this proposal is to investigate the function of ectomycorrhizal (EM) communities for nitrogen acquisition of beech (Fagus sylvatica L.) and to understand how these functions are affected by drought. 15N labelling will be used to investigate N uptake of beech plants and ectomycorrhizas under field und controlled conditions to explore relationships between EM 15N enrichment and plant N uptake. Site-specific EM communities from a range of dry and moist sites will be synthesized. Drought stress will be applied as a means to modulate carbon supply to roots, thereby affecting the competitive relations of EM. EM will be collected according to species and their abundance will be determined and related to N-uptake. To dissect the mycorrhizal effect, non-mycorrhizal beeches will also be studied. 15N enrichment and uptake rates will be analysed in controlled experimental EM-beech associations with selected fungal species to find out if differences in the abilities of different EM species exist to supply beech with N under well watered and dry conditions.