DISSERTATION RESEARCH: The Effect of Plant Dispersal on Ecosystem Function

植物群落是生命其余部分的主要能源。生境丧失和碎片化--将大片区域转变为孤立的小区域--威胁着植物群落的多样性和生态系统功能(由植物提供的基本服务)。因此，我们必须了解如何维持植物群落，以及它们如何帮助生态系统发挥作用。该项目探讨了种子如何在碎片化的生境中传播有助于维持植物多样性，并促进营养循环和分解速率等生态系统功能。研究人员将研究栖息地碎片化是否对种子传播能力差的植物物种的丰富度产生异常大的影响，如果是这样，这些物种的丧失可能如何导致生态系统功能的丧失。参与该项目的科学家将通过讲座、研讨会和实习机会与公众接触。结果将有助于向美国陆军工程兵团及其保护使命提供信息。研究人员将利用南卡罗来纳州斯特罗姆瑟蒙德湖的一组岛屿，研究栖息地碎片化对植物群落和生态系统功能的影响。将在20个不同程度的空间隔离(近岸与远离海岸)和历史干扰的岛屿上测量植物群落、植物化学和物理属性以及土壤属性。具体地说，研究人员将量化植物物种的丰富度和多样性、这些物种的叶片特性、土壤氮素有效性和微生物分解率。这些数据将被用来检验空间隔离和干扰通过改变植物物种组成而影响生态系统功能的假设。统计模型将检验1)生态系统碳和养分通量是否是空间隔离、干扰历史和树叶属性的函数；2)岛屿空间隔离造成的扩散限制是否可以驱动功能组成。

Plant communities are the main source of energy for the rest of life. Habitat loss and fragmentation -- the conversion of large areas into isolated smaller areas -- threaten the diversity of plant communities and ecosystem functions (essential services provided by plants). Thus, it important that we understand how to maintain plant communities and how they help ecosystems function. This project explores how seed dispersal in fragmented habitats helps sustain plant diversity and promote ecosystem functions such as nutrient cycles and decomposition rates. Investigators will examine whether habitat fragmentation has an unusually large impact on the abundance of plant species that are poor seed dispersers and, if so, how loss of these species may result in loss of ecosystem function. Scientists working on this project will engage with the public through talks, a workshop, and internship opportunities. Results will help inform the U.S. Army Corp of Engineers and their mission of conservation. Investigators will study impacts of habitat fragmentation on plant communities and ecosystem functions, using a set of islands in Lake Strom Thurmond, South Carolina. Plant communities, plant chemical and physical attributes, and soil properties will be measured on 20 islands of different levels of spatial isolation (near shore versus far from shore) and historic disturbance. Specifically, investigators will quantify the abundance and diversity of plant species, leaf properties of those species, soil nitrogen availability, and microbial decomposition rates. These data will be used to test the hypothesis that spatial isolation and disturbance affect ecosystem function by altering plant species composition. Statistical models will test 1) whether ecosystem carbon and nutrient fluxes are a function of spatial isolation, disturbance history, and leaf properties; and 2) whether dispersal limitation caused by island spatial isolation can drive functional composition.