Understanding the dynamics of predator-prey populations dispersing in heterogeneous habitat

点击翻译按钮获取中文摘要

The goal of my research program is to expand current understanding of predator-prey system dynamics to novel situations of high relevance under the current pressures of climate change and increased habitat fragmentation. My focus is in spatially-explicit systems where predator-prey interactions are coupled with movement across patchy landscapes. Spatial variation in resource availability has a strong effect on population dynamics, and under current landscape reconfiguration pressures, an understanding of the effect of heterogeneous landscapes on population dynamics is highly relevant. When human interests dictate the need to disturb an ecosystem by, for example, applying pest management strategies or harvesting a resource, resident populations are displaced from their equilibrium distributions. These populations must then adjust, and these transient dynamics can lead either to a restoration of the initial equilibrium state, or to an entirely new state. For example, relatively stable insect communities can become wildly unstable after the application of insecticide. In this case, efforts to control an insect pest do initially reduce the pest population, but also remove the pest's predators. Because the pest has a much higher growth rate than its predators, the pest population recovers first and can grow exponentially. The unintended consequence of pest control, in this case, is creation of a pest explosion. Such secondary consequences can be prevented, or mitigated, with prior knowledge of system behaviour. My tools are differential equations and interacting particle systems models that I develop and analyze numerically and analytically. Specific applications of my work include the spread of transgenic pollen in insect-pollinated crops, maintenance of critical pollination services by wild bee populations, and preservation of biodiversity in managed forest ecosystems. I work closely with ecologists to create models that provide practical answers to mathematical and ecological research questions, while advancing our theoretical understanding of ecosystem dynamics in shifting and fragmented landscapes.