Field Parameterization and Experimental Tests of the Neutral Theory of Biodiversity

生态学的一个长期挑战是将对种群动态的机械性理解与群落结构的大规模聚集模式的产生联系起来，例如物种-多度和物种-面积关系。哈贝尔的生物多样性中性理论在海洋和非海洋系统中都显示出了实现这一目标的能力。如果这一理论是正确的，那么需要从群落如何组织的角度进行根本转变，最大限度地减少物种差异(生态位变化)的作用，并强调元群落动态、扩散/招募控制以及物种形成和灭绝动态的相互作用。过去对该理论的评估依赖于询问中性理论是否能适应聚集模式，如物种丰度分布。这种方法相对较弱，涉及两个关键模型参数的调整。该项目将在岩石潮间带群落中对该理论进行强有力的测试，方法是重新表述该理论以使其更具经验性，扩展关于空间利用过渡动力学的数据集，用该数据集对模型进行参数化，然后使用几个物种删除实验来提供对该理论的独立测试。实验方法还将放松中性理论的几个关键假设，包括没有招募限制或变异以及物种及其相互作用的差异，并探索这些假设的后果。除了对一项重要的综合理论进行强有力的检验外，这项研究还将扩大关于集合群落动力学的知识，这对于理解具有海洋运输的海洋系统特别相关，并将提供关于近岸环境中长期物种缺失的后果的经验信息。更广泛的影响。该项目将培训本科生、研究生和博士后科学家在定量和实地生态学的界面上，将涉及与部落自然资源管理者的互动，并将促进获得独特的长期多物种数据集，以探索基于过渡的环境科学方法，这可能为生物多样性丧失的后果提供一些预测性的洞察。

A persistent challenge for ecology is to connect a mechanistic understanding of population dynamics with the generation of large-scale aggregate patterns of community structure, such as species-abundance and species-area relationships. Hubbell's Neutral Theory of Biodiversity has shown promise in its ability to do this in both marine and non-marine systems. If the theory is correct, then a radical shift is needed in the perspective of how communities are organized, with minimal role for species differences (niche variation) and an emphasis on metacommunity dynamics, dispersal/recruitment control, and the interplay of speciation and extinction dynamics. Past evaluations of the theory have depended on asking whether the neutral theory can fit aggregate patterns, such as species-abundance distributions. This approach is relatively weak, involving tuning of two critical model parameters. This project will provide a strong test of the theory in a rocky intertidal community by reformulating the theory to make it more empirically accessible, extending a dataset on the transition dynamics of space use, parameterizing the model with this dataset, and then using several species deletion experiments to provide an independent test of the theory. The experimental approach will also relax several key assumptions of the neutral theory, including no recruitment limitation or variation and differences in species and their interactions, and explore the consequences of these assumptions. Aside from providing a strong test of an important synthetic theory, the research will expand knowledge of metacommunity dynamics, which are particularly relevant for understanding marine systems with oceanic transport, and will provide empirical information on the consequences of chronic species deletion in nearshore environments. Broader Impacts. This project will train undergraduate, graduate, and post-Ph.D. scientists at the interface of quantitative and field-based ecology, will involve interaction with tribal natural resource managers, and will facilitate access to a unique long-term multi-species dataset for probing transition-based approaches to environmental science that may provide some predictive insight into the consequences of biodiversity loss.