DISSERTATION RESEARCH: Consequences of plant species and genetic diversity for microbial community composition and function

土壤微生物对生态系统功能至关重要。细菌和真菌分解死去的植物和动物的物质，并使其中所含的营养物质可供植物生长和其他功能使用；然后，这些活的植物材料可以被其他生物食用。尽管它们具有生态价值且无处不在，但人们对土壤微生物群落如何受到与其共存的植物群落多样性的影响知之甚少。单个植物物种培养不同的微生物群落，最近的研究表明，植物的遗传特性以及物种特性可能影响其相关微生物。本研究利用模拟自然界物种多样性和遗传多样性水平的人工沙丘植物群落，首次探讨了植物物种多样性和遗传多样性如何影响微生物群落的结构和功能。微生物群落将使用几种技术进行表征，提供有关微生物多样性及其在环境中的作用的详细信息。建立植物和微生物多样性之间的联系将阐明植物通过土壤影响生态系统功能的潜在途径。该研究结果将为生态系统保护和恢复生态学家提供有价值的信息，阐明多层次多样性在生态系统功能中的相对作用。此外，该项目将有助于恢复一个极度濒危的生态系统（淡水沙丘），并提供最佳恢复措施的信息。结果将广泛分发给保护组织，包括五大湖联盟、大自然保护协会和睡熊沙丘之友，以及政府机构，包括国家公园管理局和环境保护局。这项研究也为对野外生态学感兴趣的本科生提供了一些机会。

Soil microbes are vitally important to ecosystem function. Bacteria and fungi decompose dead plant and animal matter and make the nutrients contained within them available for plants to use for growth and other functions; the living plant material is then available for consumption by other organisms. Despite their ecological value and ubiquity, little is known about how soil microbial communities are affected by the diversity of the plant communities with which they co-exist. Individual plant species cultivate different microbial communities, and recent work is showing that the genetic identity of the plant, as well as the species identity, may affect its associated microbes. Using constructed sand dune plant communities in Michigan that mimic levels of species diversity and genetic diversity found in nature, this study is one of the first to address how plant species diversity and genetic diversity influence microbial community structure and function. The microbial community will be characterized using several techniques, providing detailed information on the diversity of microbes present as well as their roles in the environment. Establishing linkages between plant and microbial diversity will illuminate this potential avenue for plants to influence ecosystem function via soils. Results from this study will provide valuable information to conservationists and restoration ecologists by elucidating the relative roles of multiples levels of diversity for ecosystem function. Furthermore, this project will help restore a critically endangered ecosystem (freshwater sand dunes) and provide information on optimal restoration practices. Results will be widely distributed to conservation groups, including the Alliance for the Great Lakes, the Nature Conservancy, and the Friends of Sleeping Bear Dunes, and government agencies, including the National Park Service and the Environmental Protection Agency. This research also offers several opportunities for undergraduate students interested in field ecology.