TropSOC - Tropical soil organic carbon dynamics along erosional disturbance gradients in relation to variability in soil geochemistry and land use

土壤对侵蚀扰动的响应是预测温室气体从土壤到大气的通量以及未来地球系统动力学的最大不确定性之一。这主要是由于热带非洲等偏远地区缺乏数据，但也是由于从小规模到大规模的知识转让不足。热带非洲是气候和土地利用变化的热点地区。该区域面临着人口不断增长、原始森林遭到砍伐以及土壤侵蚀造成的土壤退化。因此，预计在本世纪，热带非洲的土壤地球化学循环和土壤、植物和大气之间的生态系统水平的碳（C）通量将发生重大变化。特别是，目前还不清楚如何C动态不同的热带地区相比，温带气候区，从我们的大部分机械过程的理解C循环是来自。重要的是要填补这一知识空白，因为热带生态系统提供具有全球重要性的服务，如植物和土壤中的碳储存，土壤肥力，植物生产力和最终的粮食供应。拟议的TROPSOC项目的主要目标是，在刚果盆地东部研究热带非洲土壤中碳的固存和释放的机理。这一区域提供了一个独特的组合：（一）地质上多种多样的土壤形成母质，（二）人类活动的不同程度的干扰，发生在潮湿的热带气候条件下，原始森林高比率地转化为农业用地。TROPSOC将为回答以下问题做出重大贡献：1.在热带系统中，土壤、植物和大气之间的养分通量和碳分配与矿物学、地形和植被等控制因素的关系如何演变和不同？2.地球化学是如何控制、影响或调节热带土壤临界区侵蚀扰动对碳循环的严重性的？3.我们如何以空间上明确的方式模拟热带土壤碳动态的控制机制？TROPSOC将为提高我们对引起热带土壤系统C的空间分布和命运的因素的理解做出重大贡献。到项目结束时，我们将更好地了解导致热带土壤中碳的空间分布和命运的因素。我们将制作基准数据产品和建模工具，这将有助于弥合图规模的过程理解和热带C循环的大规模建模之间的差距。这将最终有助于减少与陆地碳通量和土壤对干扰的反应相关的不确定性，这是当前地球系统模型和生态系统服务评估中最大的不确定性之一。

The response of soils to disturbance by erosion is one of the great uncertainties in predicting greenhouse gas fluxes from soils to the atmosphere and, hence, future earth system dynamics. This is largely due to a lack of data in remote areas, such as tropical Africa, but also due to an inadequate transfer of knowledge from smaller to larger scales. Tropical Africa is a hotspot of both climate and land use change. The region faces growing population, deforestation of primary forests and degradation of soils due to erosion. Hence, tropical Africa is expected to experience important changes to both soil biogeochemical cycling and ecosystem level carbon (C) fluxes between soil, plants and the atmosphere in this century. In particular, it is unclear how C dynamics differ in the Tropics compared to temperate climate zones, from which most of our mechanistic process understanding on C cycling is derived. It is important to fill this knowledge gap since tropical ecosystems provide services with global importance, such as C storage in plants and soils, soil fertility, plant productivity and ultimately food supply. The main objective of the proposed TROPSOC project is to develop a mechanistic understanding of C sequestration and release in the soils of Tropical Africa, studied in the Eastern part of the Congo Basin. This region provides a unique combination of (i) geologically diverse parent material for soil formation and (ii) different levels of disturbance by human activity, taking place under a humid, tropical climate regime, where pristine forests are converted into agricultural land at high rates. TROPSOC will make a significant contribution to answering the following questions: 1. How will nutrient fluxes and C allocation between soils, plants and the atmosphere evolve and differ in tropical systems in relation to the controlling factors: mineralogy, topography and vegetation? 2. How does geochemistry control, interact with or mediate the severity of erosional disturbance on C cycling in the critical zone of tropical soils? 3. How can we model the mechanisms controlling tropical soil C dynamics in a spatially explicit way? TROPSOC will make a significant contribution to improving our understanding of the factors that give rise to the spatial distribution and fate of C of tropical soil systems. By the end of the project, we will have a better understanding of the factors that give rise to the spatial distribution and fate of carbon in tropical soils. We will have produced benchmark data products and modeling tools that will help to bridge the gap between plot scale process understanding and large scale modeling of tropical C cycling. This will ultimately help to reduce the uncertainty associated with terrestrial C fluxes and the response of soils to disturbance, which is one of the greatest uncertainties in current Earth System Models and ecosystem service assessments.