Integrating Linkages Among Aquatic and Terrestrial Components of Arid Landscapes

本研究将解决以下问题：在干旱的西南地区，大气中氮(N)的沉积超过了溪流和河流的输出。虽然测量结果表明，集水区的年储存量有巨大的（10倍）增长，景观中广泛的氮富集，但事实恰恰相反——可用的氮很少。陆地和水生初级生产都是氮有限的，在这两种环境中都有大量的固氮生物。该项目的目标是确定氮转化和保留的热点（在空间和时间上），从而解释流域水平的氮差异。研究人员将重点关注流动路径方法的方法开发；在高地、支流系统和河流-河岸走廊进行试验；并逐渐理解这些系统的差异。这项工作将集中于过程而不是模式，预期将为经验工作与目前正在发展的概念和数学模型之间的联系奠定基础。

Abstract 97-27311 Fisher Integrating linkages among aquatic and terrestrial components of arid landscapes This research will address the following puzzle: In the arid Southwest, atmospheric deposition of nitrogen (N) exceeds export by streams and rivers. While measurements suggest a huge (10-fold) annual storage increment in the catchment and widespread N enrichment of the landscape, the opposite is true - usable N is rare. Both terrestrial and aquatic primary production are N-limited, and N2 fixing organisms abound in both environments. The objective of this project is to identify the hot spots (in space and time) for N transformation and retention and thereby account for the catchment-level N discrepancy. The investigators will focus on methods development for the flowpath approach; experiments in the uplands, tributary system and stream-riparian corridor; and developing an understanding of variance in these systems. The work will concentrate on processes rather than patterns, and is expected to lay the underpinnings for linkages between the empirical work and conceptual and mathematical models now under development.