Coordination Funds

在土壤团聚体系统中，微团聚体被认为是最重要的，因为它们基本上与控制土壤成分相互作用、运输和周转的所有过程联系在一起。因此，它们与能源和生物地球化学循环密切相关。在土壤发生过程中，微团聚体是通过物理、化学和生物过程的复杂相互作用而形成的。虽然土壤功能在很大程度上受团聚体结构的形成控制，但人们对微团聚体在空间和时间上的形成速率和控制知之甚少。然而，要将土壤的微结构与流体流动和运输、微生物的活动、元素的周转和相互作用以及微团聚体本身的稳定性联系起来，这一知识是强制性的。该研究单位(RU)的宏伟目标是对这些基本土壤结构的形成、堆积、组成、性质和稳定性进行基于模型的机械理解，并将其与土壤的基本目标功能联系起来：栖息地、碳汇和储水。我们的目标是利用高分辨率成像和分析技术的独特组合，探索和定量表征微聚体的组成、微体系结构、稳定性和性质。因此，RU被组织在不同的项目中，这些项目提供关于微米到亚微米尺度的土壤微团聚体的补充和特定的元素、化学、物理、地形和机械信息，并具有重叠的尺度范围。我们预计，上述技术的同时应用于从土壤质地拓扑序列中分离出来的土壤微团聚体(第二阶段另外是一个时间序列)或从迄今唯一的多稳定同位素标记微宇宙实验中收集的土壤微团聚体，将在土壤目标函数的机理理解方面取得重大进展。标记实验旨在同时探索矿物质和有机质的关键成分和关键因素在土壤微团聚体形成中的作用。我们的实验工作与连续统尺度上的显式建模方法相结合，不仅将用于对可测量的模型进行建模，还将用于测试现有的和新开发的理论，并对基于数据的土壤微团聚体形成、稳定性和周转的理论概念进行定量分析。在本提案中，我们介绍了RU的中心协调任务以及我们计划如何完成这些任务。这些任务包括联合抽样运动、中央微观世界实验、提供和生产有标签的化合物、联合制定和统一微团聚体分离和分离方案、联合建模和解释工作、数据处理战略以及结果的传播。

Within the soil aggregate system, microaggregates are supposed to be of primary importance, as they are linked with essentially all processes which control interaction, transport and turnover of soil constituents. As such, they are intimately connected with energy and biogeochemical cycles. During pedogenesis, microaggregates are formed by a complex interplay of physical, chemical and biological processes. Although soil functions are to a large degree controlled by the formation of an aggregate structure, still very little is known about the rates and controls on microaggregate formation in space and in time. Yet, this knowledge is mandatory to link the microarchitecture of soils to fluid flow and transport, activity of microorganisms, turnover and interactions of elements, as well as to the stability of the microaggregates themselves. The grand goals of this research unit (RU) are to gain a model-based mechanistic understanding of the formation, build-up, composition, properties and stability of these basic soil structures and to relate that to fundamental target functions of soil: habitat, carbon sink and water-storage. Our objectives are the exploration and the quantitative characterization of the composition, the microarchitecture, the stability, and the properties of microaggregates with a unique combination of high-resolution imaging and analytical techniques. Thus, the RU is organized in different projects that provide the complementary and specific elemental, chemical, physical, topographic and mechanical information on the soil microaggregates at the micron to submicron scale with overlapping scale ranges. We expect that a major advancement of the mechanistic understanding of the target functions of soil will derive from the concomitant application of the above-mentioned techniques to both soil microaggregates isolated from a soil texture toposequence - in the second phase additionally a chronosequence - or collected from a so far unique multi-stable-isotope labeling microcosm experiment. The labeling experiment is designed to explore simultaneously the role of mineral and organic matter key components and key - actors - in the formation of soil microaggregates. Our experimental work are integrated by an explicit modeling approach on the continuum scale which will be used not only to - model the measurable - but to test already existing and newly developed theories and to quantitatively analyze the data-based theoretical concepts of soil microaggregate formation, stability and turnover. In this proposal we present the central coordination tasks of the RU and how we plan to accomplish these. These tasks comprise joint sampling campaigns, the central microcosms experiment, the provision and production of labelled compounds, the joint development and harmonization of protocols for microaggregate separation and isolation, the joint modeling and interpretation endeavor, the data handling strategy, and the dissemination of results.