Multi-Species Metapopulation Dynamics: Experiments in a Model System

多物种种群动态：模型系统中的实验

• 批准号: 9629876
• 负责人: Marcel Holyoak
• 金额: $ 15万
• 依托单位: University of California-Davis
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1996
• 资助国家: 美国
• 起止时间: 1996-10-01 至 2000-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9629876&HistoricalAwards=false
• 关键词: Multi; Species; Metapopulation; Dynamics; Experiments

9629876 Holyoak How spatial structure affects populations dynamics, and how habitat fragmentation affects biodiversity are two of the most important questions in modern ecology. In metapopulations of single species, or sets of species that do not interact, subdivision of a habitat is expected to cause collapse to global ("metapopulation") extinction, such that species with the lowest dispersal rates will go extinct soonest. In contrast, metapopulation models of interacting species predict that an intermediate degree of subdivision can promote coexistence of otherwise unstably interacting species. The present study offers a unique opportunity to investigate how habitat subdivision influences the structure and persistence of species assemblages. This work will be conducted in aquatic microcosms containing an assemblage of protozoans in which the pair-wise and multispecies interactions are known. Two alternative hypotheses will be tested: (1) Increased subdivision always decreases the persistence of all species, with the poorest dispersers becoming extinct soonest, and (2) Subdivision promotes the persistence of some or all species, at least up to some intermediate degree of subdivision; this would imply that interactions between species are important. These hypotheses will be tested by measuring the persistence of a variety of species combinations in microcosms with different degrees of subdivision. Dispersal rates will also be measured, so that the sequence in which species go extinct can be recorded. The experiments will show whether the response of assemblages to habitat subdivision can be predicted from the dynamics of the particular species involved, versus the type and details of between-species interactions. This study will demonstrate whether habitat fragmentation (subdivision) promotes biodiversity. In particular, the experiments will test the parts of ecological theory that are most directly relevant to predicting the response of endangered species living in patchy habitats to varying degrees of fragmentation.

9629876 Holyoak空间结构如何影响种群动态，以及栖息地破碎化如何影响生物多样性是现代生态学中最重要的两个问题。 在单一物种的集合种群中，或在不相互作用的物种集合中，栖息地的细分预计会导致全球（“集合种群”）灭绝的崩溃，因此扩散率最低的物种将最快灭绝。 相反，集合种群模型的相互作用物种预测，一个中间程度的细分，可以促进共存，否则不稳定的相互作用的物种。 本研究提供了一个独特的机会，调查栖息地细分如何影响物种组合的结构和持久性。 这项工作将在水生微观世界中进行，其中包含原生动物的组合，其中成对和多物种的相互作用是已知的。 将检验两个可供选择的假设：（1）增加细分总是降低所有物种的持久性，最差的传播者灭绝最快，（2）细分促进部分或所有物种的持久性，至少达到某种中等程度的细分;这意味着物种之间的相互作用是重要的。 这些假设将通过测量在具有不同细分程度的微观世界中的各种物种组合的持久性来进行测试。 还将测量扩散率，以便记录物种灭绝的顺序。 实验将显示是否组合栖息地细分的响应可以预测从所涉及的特定物种的动态，与物种间的相互作用的类型和细节。 这项研究将证明栖息地破碎化（细分）是否促进生物多样性。 特别是，这些实验将测试生态理论的部分，这些理论与预测生活在斑块状生境中的濒危物种对不同程度的破碎化的反应最直接相关。