Mechanisms of soil erosion, soil properties and Ecoscape analysis as a function of species richness and species composition in subtropical forests

亚热带森林中土壤侵蚀机制、土壤性质和生态景观分析作为物种丰富度和物种组成的函数

• 批准号: 43905265
• 负责人: Professor Dr. Thorsten Assmann
• 金额: --
• 依托单位: Institut für Ökologie (IE)
• 依托单位国家: 德国
• 项目类别: Research Units
• 财政年份: 2008
• 资助国家: 德国
• 起止时间: 2007-12-31 至 2018-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/43905265?language=en
• 关键词: Mechanisms; soil; erosion; properties; Ecoscape

Soil erosion is a major threat resulting in soil degradation and loss of soil and ecosystem functions. Our previous research in the framework of BEF-China shows that soil loss in general and matter fluxes with sediment discharge and overland flow are related to tree diversity. We ask to which extend carbon, nitrogen, phosphorous (CNP) and sediment fluxes are driven by both biodiversity effects and ground cover by biological soil crusts (BSC) and plant litter of the topsoil, along with general ecoscape properties like slope, curvature and soil properties. We assume that type and extent of ground cover and their role for soil erosion change over time with tree growth from biological soil crusts (BSC) and bare ground to a complete litter cover. This will cause changes in CNP and sediment fluxes along with biodiversity effects. Outgoing CNP fluxes are negatively related to tree growth and increasing ground cover by litter since the kinetic energy of raindrops is captured by litter cover and less CNP is washed-off by sediment discharge. Furthermore, higher tree diversity can promote the diversity of associated organisms, especially the litter decomposing macrofauna. To address these questions, runoff plots will be used as measuring device. The measurements in the Main Experiment of BEF-China will include surface runoff, sediment discharge, and particular and solute transport of CNP.First results indicate significant relations between spatial domains of soil and site properties and growth patterns of trees. We will delineate and analyse environmental co-variables for each plot, population and individual to control for environmental heterogeneity when testing biodiversity effects by defining a set of spatially homogenous response units as smallest components of the ecoscape at large. Such soil-ecological response units cover a unique set of spatial and temporal scale-free environmental variables that result from interrelations between soil, plant, topography and climate. Data mining techniques and multi-regression analysis will be applied in terms of integrated soil-microclimate-ecosystem-functioning analysis and modeling and to construct the full ecoscape across scales.Further studies of SP 6 will account for soil properties of the VIPs, especially heavy metals and soil CNP. Reading and maintenance of the erosion sticks in the CSPs and the Main Experiment will continue. Additional measurements in the Main Experiment will be done to continue the base line study of soil properties in order to account for changes in soil CNP stocks, soil acidity and exchangeable cations over time and their relation to a growing forest and biodiversity effects to feed the Ecoscape approach in Z1.

土壤侵蚀是造成土壤退化和丧失土壤和生态系统功能的一个主要威胁。我们在BEF-China框架下的前期研究表明，土壤流失以及泥沙和地表径流的物质通量与树木多样性有关。我们问到何种程度的碳，氮，磷（CNP）和沉积物通量的生物多样性的影响和地面覆盖的生物土壤结皮（BSC）和植物凋落物的表土，沿着一般生态景观属性，如坡度，曲率和土壤特性。我们假设，随着时间的推移，从生物土壤结皮（BSC）和裸露的地面到一个完整的枯落物覆盖的树木生长的地面覆盖的类型和程度及其对土壤侵蚀的作用。这将导致CNP和沉积物通量的变化沿着生物多样性效应。流出CNP通量呈负相关的树木生长和增加地面覆盖的凋落物，因为雨滴的动能被捕获的凋落物覆盖和较少的CNP被冲刷掉的泥沙排放。此外，较高的树木多样性可以促进伴生生物的多样性，特别是分解凋落物的大型底栖动物。为了解决这些问题，径流小区将被用作测量设备。在BEF-中国的主要实验的测量将包括地表径流，泥沙排放，和特殊的和溶质的CNP。第一个结果表明显着的关系，空间域的土壤和站点属性和树木的生长模式。我们将描绘和分析环境协变量为每个小区，人口和个人控制环境异质性时，通过定义一组空间同质的响应单元作为最小的组成部分，在大的生态景观测试生物多样性的影响。这种土壤生态响应单元涵盖了一套独特的空间和时间无标度环境变量，这些变量是土壤、植物、地形和气候之间相互关系的结果。应用数据挖掘技术和多元回归分析方法，对土壤-小气候-生态系统功能进行综合分析和建模，构建完整的跨尺度生态景观，并对SP 6进行进一步研究，以解释VIP的土壤性质，特别是重金属和土壤CNP。将继续对CSP和主实验中的腐蚀棒进行阅读和维护。将在主要实验中进行额外的测量，以继续对土壤性质进行基线研究，以说明土壤CNP储量、土壤酸度和可交换阳离子随时间的变化及其与森林生长和生物多样性影响的关系，从而为Z1的生态景观方法提供支持。