Diversity Maintenance in Variable Environments: Multiple Mechanisms at Multiple Scales

9307658本研究将理论和实验相结合，以奇瓦瓦沙漠一年生荒漠植物为例，定义和测量波动环境因素(例如，天气模式的时间变化、土壤水分或氮素含量的空间变化)影响共存的机制。PI将侧重于综合检查几个时间尺度上环境变化的影响，包括年内和年间，并同时测量几种不同共存机制的影响，其中两种依赖于可变的环境条件，一种依赖于经典的生态位差异。PI将沙漠一年生植物萌发和生长模型的开发与田间和实验室实验相结合，旨在测量植物对年内和年间温度和资源可获得性模式的反应，并检测非线性竞争相互作用。%需要对环境变异性在群落动态和多样性中的作用有一个良好的理解，以及一个理解多种因素对物种共存的贡献的框架。这一研究将有助于我们更好地理解多种相互作用在不同环境中的物种共存，加深我们对荒漠一年生植物生态和共存的理解。***

9307658 Huntly This research combines theory and experiments to define and measure the mechanisms by which fluctuating environmental factors (e.g., temporal variation in weather patterns, spatial variation in soil water or nitrogen content) influence coexistence, using desert annual plants of the Chihuahuan Desert as a test case. The PI's will focus on an integrated examination of effects of environmental variability at several temporal scales, both within and between years, and on simultaneous measurements of the effects of several different mechanisms of coexistence, two being dependent on variable environmental conditions and one being classical niche differences. The PI's combine development of models of germination and growth of desert annual plants with field and laboratory experiments designed to measure responses of plants to within- and among-year patterns of temperature and resource availability, and to detect non-linear competitive interactions. %%% A sound understanding of the role of environmental variability in the dynamics and diversity of communities is needed, as is a framework for understanding the contributions of multiple factors to species coexistence. This research will provide a better understanding of species coexistence in variable environments mediated by multiple interactions, and increase our understanding of the ecology and coexistence of desert annual plants. ***