Influence of plant water relation on ecosystem function and quantification of soil water fluxes for nutrient and carbon budgets

本研究的目的是了解生物多样性的作用，在耶拿实验中建立的DFG研究小组的草地群落内的水关系。特别是，我们想调查生物多样性是否有助于有效利用土壤水分，从而提高生态系统的生产力。此外，我们将研究一个给定的植物群落获得水的能力，当水在夏季变得有限。我们假设，深根植物的发生是在不同的社区比在不太多样化的，在不同的社区，更深的水资源的使用将缓解水压力。此外，有关垂直水流的结果将是有用的养分和碳budgets.To测试我们的假设，我们建议计算蒸腾和水分吸收剖面从土壤水分数据在高的空间和时间分辨率的计算。考虑到土壤水分测量设备的成本和数据量，我们将只对选定的地块和有限的多样性梯度（2，4，16种）进行仪器测量。这些测量将与逆向水文模型相结合，这是一种专门用于量化耶拿实验地下通量和蒸腾作用的装置，该项目将有助于了解生物多样性对水利用效率和资源分配的作用。特别是，这个项目揭示了这个问题，什么是感知增加蒸腾的生物多样性的增加的驱动因素。

The goal of this research is to understand the role of biodiversity for water relations within grassland communities established in the Jena Experiment by the DFG Research Group. In particular we want to investigate if biodiversity contributes to efficient soil water use, and hence higher ecosystem productivity. Furthermore, we will study the capability of a given plant community to gain access to water, when water becomes limiting in summer. We hypothesize that the occurrence of deep rooted plants is higher in diverse communities than in less diverse ones, and that in diverse communities the use of deeper water resources will alleviate water stress. Furthermore the results concerning vertical water flow will be useful for the calculation of nutrient and carbon budgets.To test our hypothesis we propose to calculate transpiration and water uptake profiles from soil moisture data in high spatial and temporal resolution. With the cost of equipment for the soil moisture measurements and the data load in mind, we will only instrument selected plots and a limited diversity gradient (2, 4, 16 species). The measurements will be combined with inverse hydrological modelling, a setup that is dedicated particularly for quantification of subsurface fluxes and transpiration at the Jena Experiment.This project will contribute to understanding the role of biodiversity on efficiency of water use and resource partitioning. In particular, this project sheds light on the question, what are the driving factors for the perceived increase in transpiration with increase in biodiversity.