Dissertation Research: Non-Equilibrium Competition and Coexistence: Experimental Tests of Mechanistic Models

理论研究表明，非常量的资源供给在维持物种多样性方面起着重要作用。然而，对于大多数生物来说，由于资源变化而导致物种共存的明确机制尚不清楚。在拟议的研究中，将研究磷(P)和光照变化在维持藻类群落物种多样性方面的作用，并将测试潜在的共存机制。其中包括高效的资源储存和光合作用的快速诱导。在对多种藻类群落进行筛选实验后，将选择在几种恒定和波动的光照和磷供应条件下生长能力不同的六种藻类。然后将确定它们依赖于磷和光的生长动力学。接下来，一个数学模型将使用这些动力学来预测在广泛的光和磷波动范围内的竞争动态。这些预测将在众多的竞赛实验中得到验证。这种生理学和社区实验与机械理论的结合，将允许明确地测试理论和非平衡条件在这些社区中的作用。因此，这将表明物种生理学知识可以在多大程度上用于预测竞争群落的动态和结构。

Theoretical investigations suggest that nonconstant resource supplies play an important role in maintaining species diversity. However, for most organisms, explicit mechanisms enabling species coexistence due to resource variation are unknown. In the proposed study, the role of phosphorus (P) and light variations in maintaining species diversity in algal communities will be investigated, and the potential mechanisms of coexistence will be tested. Among these are the role of efficient resource storage and rapid induction of photosynthesis. After screening experiments with multispecies algal communities, six algal species that differ in their abilities to grow under several regimes of constant and fluctuating light and P supply will be chosen. Their kinetics of P- and light-dependent growth then will be determined. Next, a mathematical model will use these kinetics to predict the competitive dynamics over a wide range of light and P fluctuations. These predictions will be tested in numerous competition experiments. This combination of physiological and community experiments wit h mechanistic theory will allow the explicit testing of theory and of the role of non-equilibrium conditions in these communities. Thus, this will indicate the degree to which the knowledge of species physiology can be used to predict the dynamics and structure of competitive communities.