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

分解，即分解死亡的动植物材料，是影响土壤肥力和生态系统碳储存的基本过程。已知的关于分解的大部分知识来自于对降雨量大的地区的研究，但这种知识并不能很好地转化为旱地生态系统。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/水运输土壤与凋落物的混合程度是关键因素。这个项目试图通过亚利桑那州的一系列实验室研究和实地实验来解决这些相互矛盾的解释，这些研究和现场实验旨在测量这些因素之间的相互作用。这些联系将在木本植物入侵草原的背景下进行评估，这是一种全球范围的旱地植被变化。通过将植物群落生态学、生态系统科学和地球科学的学科结合到一个新的框架中，这项研究将对影响旱地土壤肥力和碳储存的过程产生新的见解。这一发现将在国内和国际上产生重要影响，因为旱地生态系统是美国和全球陆地面积的主要特征，可能是重要的碳汇。除了在科学界传播外，还将通过外联方案将结果传达给土地管理人员和组织。这项研究将为四名研究生和众多本科生提供培训机会。合作机构(亚利桑那大学、新墨西哥州立大学、肯塔基大学和洛约拉大学)有相当多的少数族裔入学，并将努力从代表性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.