DISSERTATION RESEARCH: Leaf litter leachate and the fate of phosphorus in seasonal lowland tropical forests

磷是植物生长的关键元素，因此土壤中磷的有效性对世界粮食生产和陆地生态系统的碳循环至关重要。然而，对磷循环的控制还没有得到很好的理解，预计这些控制将随着全球气候变化和持续的土地利用转换而变化。了解低地热带地区的磷循环尤其重要，因为该地区的许多土壤含有极大地阻碍这种营养物质流动的矿物成分。本研究的目的是提高我们的理解如何叶凋落物渗滤液（水提取物的衰老叶片）影响磷循环在季节性低地热带森林。这项研究将评估是否叶凋落物渗滤液是重要的养分返回到土壤中，如果淋溶潜力可以预测从结构和化学特性的凋落物。研究人员还将调查垃圾渗滤液在多大程度上控制植物-土壤-微生物环境中的磷循环。这项研究的更广泛的影响，包括它的贡献，我们的理解之间的关系垃圾沥滤和降雨模式，以及这些结果的预测和减轻气候变化的影响的应用。对自然系统如何循环磷的更好理解也可以应用于改善管理系统的生产，而无需大量投入肥料。在这项研究的过程中，学生将通过由史密森热带研究所在巴拿马主办的课程辅导本科生，并通过从事佛罗里达大学本科生在这项研究。

Phosphorus is a key element for plant growth, so phosphorus availability in the soil is critical for world food production and carbon cycling by terrestrial ecosystems. Yet the controls on phosphorus cycling are not well understood, and these controls are expected to change with global climate change and continued land-use conversion. Understanding phosphorus cycling in the lowland tropics is especially critical because many soils of this region have mineral constituents that greatly hinder the mobility of this nutrient. The goal of this study is to improve our understanding of how leaf litter leachate (water extracts of senesced leaves) affects phosphorus cycling in seasonal lowland tropical forests. This study will evaluate whether leaf litter leachate is important for the return of nutrients to the soil, and if leaching potential can be predicted from structural and chemical characteristics of litter. The researchers will also investigate the extent to which litter leachate controls phosphorus cycling within the plant-soil-microbe environment. The broader impacts of this research include its contribution to our understanding of the relationships between litter leaching and rainfall patterns, and the applications of these results for predicting and mitigating the effects of climate change. An improved understanding of how natural systems cycle phosphorus could also have applications for improving production in managed systems, without high inputs of fertilizer. During the course of this research, the student will mentor undergraduate students through coursework hosted by the Smithsonian Tropical Research Institute in Panama, and by engaging University of Florida undergraduates in this research.