Competition for Biotic Resources and Coexistence in Variable Environments

竞争是塑造生态群落的核心力量。经典竞争理论预测，能够共存的物种数量不应超过有限供应的资源数量。然而，自然群落通常拥有大量的物种，尽管通常资源数量有限。例如，一公顷的巴拿马雨林养育了18，000种甲虫。这么多物种怎么可能在大自然中共存而不面临灭绝呢？生态学家提出了无数的假设来解释理论和数据之间的这种差异。这个项目将通过实验来检验其中的一些假设。该研究将研究资源可用性随时间变化的后果，以及资源可用性随空间变化对物种共存的后果。工作将在实验室微生物微观世界中进行，其中包含以细菌为食的单细胞原生生物及其细菌资源。 该项目的结果将有助于科学家了解自然群落中物种多样性的维持机制。此外，该项目将通过培训研究生和本科生（包括代表性不足的少数民族学生），为本科生生态学课程提供案例研究，并促进K-12学生的科学学习，促进教育推广。

Competition is a central force shaping ecological communities. Classic competition theory predicts that the number of species that can coexist should be no more than the number of resources that are in limited supply. Natural communities, however, often harbor a large number of species, despite the typically small number of resources in limited supply. For example, one ha of Panamanian rainforest supports 18,000 species of beetle. How could such a large number of specie possibly coexist in nature without facing extinction? Ecologists have proposed a myriad of hypotheses explaining this discrepancy between theory and data. This project will experimentally test some of these hypotheses. The research will examine the consequence of changes in resource availability over time and the consequences of changes in resource availability across space for species coexistence. Work will be conducted in laboratory microbial microcosms containing bacteria-feeding single-celled protists and their bacterial resources. Results from this project will help scientists understand mechanisms of maintenance of species diversity in natural communities. Further, this project will contribute to educational outreach by training graduate and undergraduate students (including underrepresented minority students), providing case studies for undergraduate ecology courses, and facilitating science learning among K-12 students.