The Interaction Between Resource Quality and Aggregate Turnover Controls Ecosystem Nitrogen and Carbon Cycling

对发达国家和发展中国家农业的可持续性和高昂的环境成本的关切是相关的。在这里，我们关注的是有机物质、矿物氮输入和土壤团聚体动态之间的相互作用如何控制不同气候带（即非洲湿润森林带、潮湿稀树草原带和干燥稀树草原带）自然和农业系统中的碳和氮循环。要对有机资源和矿产资源进行综合和生态健全的管理，就需要了解这些相互作用。团粒更替在OR和MR的相互作用中起着根本性的作用，因为团粒更替对土壤系统过程具有多种调节作用，如保护土壤有机质、决定微生物群落结构、限制O2扩散、调节水流、影响养分的吸附和解吸、减少侵蚀等。在广泛的生态系统中，对土壤中N同步、C周转和C + N储存的基本知识是我们预测生态系统行为和制定可持续生态系统管理实践的核心。OR和MR的结合使用是土壤肥力研究的整体方法，包括影响土壤系统可持续性的所有生物、物理、化学、社会、经济和政治因素。然而，为了充分利用这一方法，需要了解土壤结构动力学与资源利用效率之间的机制联系。这个项目在非洲和美国科学家之间形成了一个联盟，将使来自不同背景的研究生和本科生接触到一个具有挑战性的环境。学生将思考和学习跨越国家和大陆边界的生态系统科学的各种各样的问题。

Concerns about sustainability and high environmental costs of agriculture in developed and developing countries are pertinent. Here, we focus on how the interactions between organic materials, mineral nitrogen inputs and the dynamics of soil aggregates control carbon and nitrogen cycling in natural and agricultural systems across different climate zones (i.e. African Humid Forest zone, Moist Savanna zone, and Dry Savanna zone). An understanding of these interactions is needed for an integrated and ecological sound management of organic (OR) and mineral resources (MR). It is postulated that aggregate turnover plays a fundamental role in the interactions between OR and MR by the multitude of regulatory effects aggregates have on processes in the soil system, like the protection of soil organic matter, determining microbial community structure, limit O2 diffusion, regulate water flow, influence nutrient ad- and desorption, and reduce erosion. Fundamental knowledge of N synchrony, C turnover and C plus N storage in soil across a wide range of ecosystems is central to our ability to predict ecosystem behavior and develop sustainable ecosystem management practices. The combined use of OR plus MR is a holistic approach in soil fertility research that embraces the full range of biological, physical, chemical, social, economic and political factors influencing the sustainability of the soil system. However, to fully benefit from this approach, the mechanistic linkage between soil structural dynamics and resource use efficiency need to be understood. This project forms a consortium between African and American scientists and will expose graduate and undergraduate students from different backgrounds to a challenging environment. Students will think and learn about the widest variety of issues on ecosystem science across national and continental borders.