Collaborative Research: Maintaining High Species Diversity in Communities

摘要COLLABORATIVE研究：在COMMUNIESE系统中保持高度的物种多样性经常包含在进化和生态上相似的物种。然而，这种多样性是否实际上是由直接促进共存的机制维持的，或者更确切地说，是非常缓慢地从系统中消失尚不清楚。已经提出了许多机制，可以在地方和区域范围内促进物种的无限期共存。只有当生命率(生存、生长、繁殖)随环境变化，以及个别物种对同一环境变化有不同反应时，这些共存机制才会出现。另一种选择是，物种对环境的反应没有什么不同，正在慢慢地通过一种称为“生态漂移”的随机过程而消失，在这种过程中，一个物种相对于另一个物种的种群规模由生存、增长和繁殖所固有的不可预测性决定。这一过程类似于“随机遗传漂移”，即所谓中性基因的相对丰度因遗传过程中的不可预测性而发生随机进化变化。该项目将通过将共存机制融入到这些“中性”生态模型中来详细阐述最近的生态漂移模型。与中性模型一样，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。这项研究的目标是开发一套预测，既包括生态漂移，也包括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范围内关于社区多样性的现有数据进行统计比较。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.