Coordination Funds

森林地面（FF）是森林生态系统地上部分和地下部分之间的界面。它为各种生物提供栖息地，为植被提供苗床和生长基质，并作为有机物质、营养物质、水和气体储存、吸收和转化的中央生态系统枢纽。因此，FF的特性反映了生物和非生物生态系统成分之间复杂的相互作用，特别是与小气候和营养供应有关的相互作用。气候变暖对森林和相关服务的影响可能特别在温带地区，在那里，控制变量的微小变化可能导致从有机层为主的森林转变为矿物土壤为主的森林。我们的RU侧重于分析FFs的控制、属性和生态系统服务之间的因果关系。这些联系将使(i)确定通过FF与矿物表土的服务履行情况，（ii）评估气候变暖下FF的脆弱性，以及（iii）在给定气候条件和矿物土壤性质下使用FF属性作为服务履行的指标。这些目标是由RU的总体假设指导的：欧洲山毛榉森林的森林地面特性是由生物对土壤营养状况的适应所形成的。气候变暖对FF服务的影响取决于与这些适应的相互作用。这一假设框架将通过密切合作的11个单独项目的具体假设来实施，重点是欧洲山毛榉（Fagus sylvatica）森林与挪威云杉（Picea abies）和梧桐树枫（Acer pseudoplatanus）混合的磷(P)和温度影响。12个研究地点允许调查相互作用控制空气温度和土壤磷水平。在这些地点，我们将进行13C， 15N， 2H凋落物标签实验，以追踪和量化过程，我们将研究营养，碳和水动力学。我们的研究将通过对树木播种实验、微生物群落、土壤动物食物网以及根和菌根驱动过程的研究来补充。现有数据的时间序列分析和生态模型将支持过程理解、升级和情景估计。

The forest floor (FF) is the interface between above- and belowground parts of forest ecosystems. It provides habitat for a wide range of organisms, serves a seedbed and growth substrate for vegetation and acts as a central ecosystem hub where organic matter, nutrients, water and gases are stored, absorbed and transformed. As such, FF properties reflect complex interactions between biotic and abiotic ecosystem components, especially those related to microclimate and nutrient supply. An impact of climate warming on FF and associated services is likely especially in temperate regions where small changes in control variables may induce shifts from organic layer-dominated to mineral soil-dominated forests. Our RU focuses on analyzing the causal links between controls, properties, and ecosystem services of FFs. These links will enable (i) the determination of the service fulfillment through the FF in comparison to mineral topsoil, (ii) an assessment of FF vulnerability under climate warming and (iii) the use of FF properties as indicators for service fulfilment under given climatic conditions and properties of the mineral soil. These goals are directed by the overall hypothesis of the RU: Forest Floor properties of European beech forests are shaped by adaptations of organisms to the nutrient status of soils. The influence of climate warming on FF services depends on the interactions with these adaptations. This hypothetical framework will be implemented through specific hypotheses of 11 individual projects in close cooperation by focusing on combined phosphorus (P) and temperature impacts in European beech (Fagus sylvatica) forests admixed with Norway spruce (Picea abies) and sycamore maple (Acer pseudoplatanus). Twelve study sites allow the investigation of the interacting controls air temperature and P level of soils. At these sites, we will conduct 13C, 15N, 2H litter labelling experiments for process tracing and quantification and we will address nutrient, carbon and water dynamics. Our research will be complemented by studies addressing tree seeding experiments, microbial communities, soil fauna food webs, and root- and mycorrhiza-driven processes. Time-series analyses of existing data and ecological modelling will support process understanding, upscaling and scenario estimates.