Testing Reaction-Diffusion Theory: Spatial Dynamics in a Bark Beetle-Predator System

Turchin反应扩散理论已被应用于生物学的几个分支，以理解和模拟空间模式的形成。在生态学家中，目前对空间异质性的重要性有广泛的认识，并且已经有理论认为，反应扩散理论为这种斑块性的产生提供了一个共同的机制。然而，这一理论解释尚未得到实证检验。反应扩散理论将在南松甲虫（SPB）、被南松甲虫攻击的松树和南松甲虫捕食者组成的生态系统中进行验证。该系统的特点是SPB攻击模式极其不完整；在一些被称为“保护区”的地区，所有的树木都被杀死，而在其他地方，只有很少的树木被杀死。反应扩散理论认为，SPB攻击的不连续模式至少部分是由于捕食者在斑点边界外不成比例地杀死SPB的影响。这个项目将模型与实验研究相结合。实地研究将用于测量模型的参数，并检验模型的预测。对这一理论最有力的检验将包括在现有的SPB地点增加捕食者。虽然这项研究的主要目的是基本的，但它也将产生与生态学应用方面高度相关的资料，例如空间异质性和碎片化对生物保护和虫害防治的影响。此外，如果发现捕食者在防止SPB斑点扩散方面发挥了重要作用，这将为生物防治SPB提供非常有用的工具，SPB是南方松树中最具破坏性的害虫。

9509237 Turchin Reaction-diffusion theory has been employed in several branches of biology in order to understand and model formation of spatial patterns. Among ecologists there is currently a wide appreciation of the importance of spatial heterogeneity, and it has been theorized that reaction-diffusion theory provides a common mechanisms by which such patchiness arises. However, this theoretical explanation has not been empirically tested. Reaction-diffusion theory will be tested in the ecological system consisting of southern pine beetles (SPB), pine trees that are attacked by SPB, and SPB predators. This system is characterized by an extremely patchy pattern of SPB attack; in some areas, called 'SPB spots', all trees are killed, while outside spots very few trees are killed. Reaction-diffusion theory suggests that the discontinuous pattern of SPB attack is due, at least partly, to the effect of predators disproportionately killing SPB just outside the spot boundaries. This project will combine modeling with experimental studies. Field studies will be used to measure the parameters of the model, and to test the model predictions. The strongest test of the theory will consist of adding predators to existing SPB spots. Although the primary thrust of this research is basic, it will also yield information highly relevant to applied aspects of ecology, such as the effects of spatial heterogeneity and fragmentation on biological conservation and pest control. Moreover, if predators are found to play an important role in preventing spread of SPB spots, this will provide a very useful tool for biological control of SPB, the most destructive pest of southern pines.