Collaborative Research: Maintaining High Species Diversity in Communities

摘要合作研究：维持群落的高度物种多样性生态系统通常包含进化上和生态上相似的物种。然而，这种多样性究竟是由直接促进共存的机制维持的，还是从系统中缓慢丧失的，目前尚不清楚。人们提出了许多促进物种在局部和区域尺度上无限期共存的机制。这些共存机制只有在生命速率（生存、生长、繁殖）随环境变化而变化以及单个物种对相同环境变化有不同反应时才会出现。另一种说法是，物种对环境的反应并没有什么不同，而是通过一个被称为“生态漂移”的随机过程慢慢消失。在这个过程中，一个物种相对于另一个物种的种群规模是由生存、生长和繁殖中固有的不可预测性决定的。这一过程类似于“随机遗传漂变”，即由于遗传过程的不可预测性，所谓中性基因的相对丰度发生了随机进化变化。本项目将通过将共存机制纳入这些“中性”生态模型，详细阐述最近的生态漂移模型。像中性模型一样，新理论的发展将利用决定物种多样性模式的生态机制和决定遗传多样性的进化过程之间的类比。这项研究的目标是发展一套预测，包括生态漂变和在地方和区域尺度上运作的各种共存机制。这些预测将与当地和区域尺度上现有的社区多样性数据进行统计比较。这项研究将为形成群落多样性的机制提供间接但高度实用的测试。

ABSTRACTCOLLABORATIVE RESEARCH: MAINTAINING HIGH SPECIES DIVERSITY IN COMMUNITIESEcosystems frequently contain species that are evolutionarily and ecologically similar. However, whether this diversity is actually maintained by mechanisms that directly promote coexistence or rather is lost very slowly from systems is unclear. Many mechanisms have been proposed that could promote the indefinite coexistence of species on both local and regional scales. These mechanisms of coexistence are only present when vital rates (survival, growth, reproduction) vary with the environment and when individual species have different responses to the same environment change. The alternative is that species do not differ in their responses to the environment and are slowly being lost through a random process called "ecological drift" in which the population size of one species relative to another is determined by the unpredictability inherent in survival, growth, and reproduction. This process is akin to "random genetic drift" in which random evolutionary changes among the relative abundances of so-called neutral genes occur due to unpredictability in the process of inheritance. This project will elaborate recent models of ecological drift by incorporating mechanisms of coexistence into these "neutral" ecological models. Like the neutral models, development of the new theory will take advantage of analogies between the ecological mechanisms that determine species diversity patterns and the evolutionary processes that determine genetic diversity. The goal of the research is to develop a set of predictions that incorporates both ecological drift and various coexistence mechanisms that operate on local and regional scales. These predictions will be statistically compared with existing data on community diversity across local and regional scales. The research will provide indirect but highly practical tests for mechanisms that shape community diversity.