The interaction between plant functional diversity and soil hydrological conditions - an ecohydrological process model approach

本研究的目的是阐明植物多样性影响土壤垂直水分通量的过程。为此，我们将研究（1）植物多样性如何影响土壤水力参数（通过土壤有机碳含量的变化，和土壤孔隙分布的变化，包括大孔隙）（2）这些变化如何影响含水量和垂直水流（方向和数量）沿着植物物种多样性梯度。我们的研究将基于测量和建模相结合的方法。我们将测量土壤水力特性（饱和和非饱和导水率，孔隙度，孔径分布）沿着多样性梯度（2-4-8种，区块I和II）。结果将涉及生态系统变量，如物种多样性，地上生产力（SP Z），土壤有机碳含量（SP 10），根系生物量（SP 7），土壤活性（SP 4）和根系吸水深度（SP 11）的信息。直接测量的土壤水力参数将被集成到垂直水流模型中。该模型将被应用于了解如何强烈的植物多样性引起的土壤水力参数的变化影响所产生的垂直水通量和水相关的溶质在土壤中的传输。

The aim of this research is to elucidate the processes by which plant diversity influences vertical water fluxes in the soil. For this we will investigate (1) how plant diversity influences soil hydraulic parameters (via changes in soil organic carbon content, and change of soil pore distribution including macropores) (2) how these changes influence water contents and vertical water flow (direction and quantity) along a plant species-diversity gradient. Our investigation will be based on a combined measurement and modelling approach. We will measure soil hydraulic properties (saturated and unsaturated hydraulic conductivity, porosity, pore size distribution) along a diversity gradient (2-4-8 species, Block I and II). The results will be related to ecosystem variables, such as species diversity, above ground productivity (SP Z), soil organic carbon content (SP 10), root standing biomass (SP 7), earthworm activity (SP 4) and information on depth of root water uptake (SP 11). The directly measured soil hydraulic parameters will be than be integrated in a model for vertical water flow. This model will be applied to understand how strongly plant diversity induced changes of soil hydraulic parameters affect the resulting vertical water fluxes and water related solute transport in the soil.