EAGER: The role of demographic stochasticity in community assembly

生态学中最大的难题之一是解释相似的物种如何在一个群落中共存;据推测，一个物种应该是一个更好的竞争者，并导致所有相似物种的灭绝。植物共存特别难以解释，因为植物共享的有限资源数量相对较少，这应该极大地限制了可以共存的物种数量。那么，一些植物群落怎么可能有数百种物种共存呢？ 至少有两个因素，除了限制资源的数量，可能会促进共存：条件，如土壤养分的可用性可能会有所不同，在一个社区（环境异质性）和个别植物可能有不同的发芽率和死亡率，由于随机的机会（人口统计随机性）。伯恩斯博士和她的合作者将在凯斯西储大学进行一项新颖的实验，以探讨：在创造允许多种植物共存的条件方面，环境异质性和人口随机性的相对重要性是什么？拟议的实验将操纵土壤环境的异质性，并将物种引入属于同一物种和密切相关物种的种群中。这项实验将首次明确区分环境异质性和人口统计学随机性的相对重要性，以确定哪些物种可以在一个特定的社区中被发现。伯恩斯博士和她的合作者与当地政府组织克利夫兰大都会公园密切合作，以回答重要的地方管理问题，并确保科学家和土地管理者之间的公开沟通。克利夫兰大都会公园是一个约8000公顷的公园系列，环绕着大克利夫兰地区。克利夫兰大都会公园自然资源部致力于维护公园的健康和多样性。维持植物群落多样性对维景提供基本生态系统服务的能力至关重要，例如为克利夫兰地区提供清洁用水。这个项目将提高我们对共存的理解，并将帮助管理人员预防和控制生物入侵，保持植物群落的多样性。例如，如果更异质的地点更有可能被害虫物种入侵，管理人员可以针对这些地区进行监测，以防止新的和潜在的有害生物入侵。

One of the great puzzles in ecology is explaining how similar species can coexist in a community; presumably, one species should be a better competitor and cause extinction of all similar species. Plant coexistence is especially difficult to explain, because plants share a relatively small number of limiting resources, which should greatly restrict the number of species that can coexist. So, how it is possible for some plant communities to have hundreds of coexisting species? At least two factors, in addition to the number of limiting resources, might promote coexistence: conditions such as soil nutrient availability might vary within a community (environmental heterogeneity) and individual plants might have different rates of germination and death due to random chance (demographic stochasticity). Dr. Burns and her collaborators will conduct a novel experiment at Case Western Reserve University to ask: what is the relative importance of environmental heterogeneity and demographic stochasticity in creating conditions that allow for many species of plants to coexist? The proposed experiment will manipulate heterogeneity of the soil environment and introduce species into populations belonging to the same species and a closely related species. This experiment will be able to clearly distinguish for the first time the relative importance of environmental heterogeneity and demographic stochasticity in determining which species can be found together in a particular community.Dr. Burns and her collaborators work closely with a local government organization, Cleveland Metroparks, to answer important local management questions and ensure open communication between scientists and land managers. Cleveland Metroparks is an ~8000 ha series of parks that ring the greater Cleveland area. The Cleveland Metroparks Natural Resources Division is committed to maintaining the health and diversity of the parks. Maintaining plant community diversity is essential for Metropark's ability to provide essential ecosystem services, such as providing clean water to the Cleveland area. This project will enhance our understanding of coexistence, and will help managers prevent and control biological invasions and maintain plant community diversity. For example, if more heterogeneous sites are more likely to be invaded by pest species, managers can target those areas for monitoring to prevent new and potentially detrimental biological invasions.