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有关。因此，它们与能源和生物地球化学循环密切相关。在成土过程中，微聚集体是由物理、化学和生物过程的复杂相互作用形成的。虽然土壤功能在很大程度上受团聚体结构形成的控制，但在空间和时间上对微团聚体形成的速率和控制仍知之甚少。然而，这些知识对于将土壤的微结构与流体流动和运输、微生物活动、元素的周转和相互作用以及微聚集体本身的稳定性联系起来是必不可少的。该研究单位（RU）的宏伟目标是对这些基本土壤结构的形成、积累、组成、性质和稳定性获得基于模型的机制理解，并将其与土壤的基本目标功能：栖息地、碳汇和水储存联系起来。我们的目标是通过高分辨率成像和分析技术的独特结合，探索和定量表征微聚集体的组成、微结构、稳定性和特性。因此，RU被组织在不同的项目中，这些项目提供了微米到亚微米尺度上具有重叠尺度范围的土壤微团聚体的互补和特定的元素、化学、物理、地形和机械信息。我们预计，上述技术将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（在第二阶段另外一个时间序列）或从迄今为止独特的多稳定同位素标记微观实验中收集到的土壤微团聚体，从而在土壤目标功能的机制理解方面取得重大进展。标记实验旨在同时探索矿物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。我们的实验工作通过连续尺度上的明确建模方法进行整合，该方法不仅用于对可测量的模型进行建模，而且用于测试已经存在的和新开发的理论，并定量分析基于数据的土壤微团聚体形成，稳定性和周转的理论概念。在本建议中，我们提出了RU的中心协调任务以及我们计划如何完成这些任务。这些任务包括联合取样活动、中心微观世界实验、提供和生产标记化合物、联合开发和统一微聚集体分离和隔离协议、联合建模和解释努力、数据处理策略以及结果的传播。

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.