Distribution, Dispersal and Dynamics of Amphibian Populations

我的研究计划是由需要更好地理解生物多样性是如何分布和维护的，特别是考虑到目前的生态危机，生物多样性丧失和生物入侵与人为环境变化有关。控制种群生存能力和持久性的动态生态过程也是确定物种分布和物种范围动态的基础。种群水平动态和范围水平动态之间的因果联系是分散。当环境条件迅速变化时，人口可能无法迅速适应以应对。那些不能适应的生物必须分散生存。这被认为与具有两相生活史的动物特别相关，例如两栖动物，因为它们在其生命中作为幼虫和成年受到两种不同的选择制度。由于它们需要水生的繁殖栖息地，两栖动物的特点是有限的扩散能力和很强的地点保真度。那么，对于这些动物来说，它们是如何在新的栖息地定居的，占据了很大的地理范围，并在环境变化中生存下来的呢？以两栖动物为研究对象，我未来五年的目标是调和两栖动物分布模式与它们种群生态的复杂性和真正的扩散潜力。我将在不同的密度和竞争条件下，用实验池塘中的幼虫和陆地围栏中的幼鱼进行实地实验，以测试两相生活史的生态后果。我将通过操纵繁殖地点和避难所的可用性以及跟踪个体动物的运动来测试蟾蜍的分散和地点保真度。我将利用这种对扩散潜力的理解，利用物种分布模型验证两栖动物物种范围对气候变化的反应，这些模型与向北扩展范围的历史记录相对照。这些项目提供了培训高素质人才的机会。我的研究项目将大大有助于理解种群的动态，个体的分散和物种范围的生物学。

My research program is guided by the need to better comprehend how biological diversity gets distributed and maintained, particularly in view of the current ecological crises of biodiversity loss and biological invasions related to anthropogenic environmental change. The dynamic ecological processes that govern population viability and persistence are also fundamental to determining the distributions of species and the dynamics of species' ranges. The causative link between population-level dynamics and range-level dynamics is dispersal. When environmental conditions change quickly, populations may not be able to adapt rapidly enough to cope. Those that cannot adapt must disperse to survive. This is thought to be especially pertinent to animals with biphasic life histories, such as amphibians, since they are subjected to two differing selection regimes as larvae and adults during their lives. Because of their need for aquatic breeding habitats, amphibians have characteristically limited dispersal abilities and strong site fidelity. How is it possible, then, for such animals to colonize new habitats to the extent that they do, occupy large geographic ranges and survive environmental change? Using amphibians as my subjects, my objectives for the next five years are to reconcile patterns of amphibian distribution with the complexities of their population ecology and true potential for dispersal. I will test for the ecological consequences of biphasic life histories using field experiments with larvae in experimental ponds and juveniles in terrestrial enclosures under varying conditions of density and competition. I will test dispersal vs. site fidelity in toads by manipulating breeding site and refuge availability and tracking individual animal movements. I will use this understanding of dispersal potential to ask how amphibian species ranges respond to climatic changes using species distribution models validated against the historical record of northward range expansion. These projects provide opportunities for training highly qualified personnel. My research program will substantially contribute towards understanding the dynamics of populations, the dispersal of individuals and the biology of species' ranges.