COLLABORATIVE RESEARCH: Decomposition in drylands: Soil erosion and UV interactions

分解，即死亡植物和动物物质的分解，是影响土壤肥力和生态系统碳储存的基本过程。关于分解的大部分知识来自于对高降雨量地区的研究，但这种知识并不能很好地转化为旱地生态系统的知识。最近的一些研究表明，太阳紫外线辐射对旱地的分解有重大影响;然而，其他研究表明，风/水搬运的土壤与凋落物的混合程度是关键因素。该项目旨在通过一系列实验室研究和亚利桑那州的实地实验来解决这些相互竞争的解释，旨在衡量这些因素之间的相互作用。这些联系将在木本植物侵入草原这一全球范围的旱地植被变化的背景下进行评估。这项调查将在一个新的框架内结合植物群落生态学、生态系统科学和地球科学等学科，从而对影响旱地土壤肥力和碳储存的过程产生新的见解。研究结果将在国家和国际上具有相关性，因为旱地生态系统是美国和全球陆地面积的主要部分，可能是重要的碳汇。除了在科学界传播外，还将通过外联方案向土地管理人员和组织通报成果。这项研究将为四名研究生和许多本科生提供培训机会。合作机构（亚利桑那大学、新墨西哥州州立大学、肯塔基州大学和洛约拉大学）招收了大量少数族裔学生，将努力从代表人数不足的群体中招收学生。

Decomposition, the breakdown of dead plant and animal material, is a fundamental process that affects soil fertility and ecosystem carbon storage. Most of what is known about decomposition is from studies in high rainfall areas, but this knowledge does not translate well to dryland ecosystems. Some recent studies suggest solar ultra-violet radiation has a major influence on decomposition in drylands; however, other studies indicate the level of mixing of wind/water-transported soils with litter is the key factor. This project seeks to resolve these competing explanations through a series of laboratory studies and field experiments in Arizona designed to measure interactions among these factors. These linkages will be assessed in the context of woody plant encroachment into grasslands, a globally extensive vegetation change in drylands. This investigation will yield new insights into processes that affect soil fertility and carbon storage in drylands by combining the disciplines of plant community ecology, ecosystem science and earth science in a novel framework. The findings will be relevant nationally and internationally, as dryland ecosystems characterize major portions of the US and global land area, and may be significant carbon sinks. In addition to dissemination in the scientific community, results will be communicated to land management personnel and organizations through outreach programs. The study will provide training opportunities for four graduate and numerous undergraduate students. The collaborating institutions (University of Arizona, New Mexico State University, University of Kentucky and Loyola University) have substantial minority enrollments, and efforts will be made to recruit students from underrepresented groups.