Optimal Control of Spatial-Dynamic Processes: The Case of Biological Invasions

This study examines the spatial nature of optimal bioinvasion control. We develop a spatially explicit two-dimensional model of species spread that allows for differential control across space and time, and we solve for optimal spatial-dynamic control strategies. We find that the optimal strategies depend in interesting ways on the shape of the landscape and the location, shape, and contiguity of the invasion. For example, changing the shape of the invasion or using landscape features to reduce the extent of exposed invasion edge can be an optimal strategy because it reduces long-term containment costs. We also show that strategies should be targeted to slow or prevent the spread of an invasion in the direction of greatest potential long-term damages. These spatially explicit characterizations of optimal policies contribute to the largely nonspatial literature on controlling invasions and our general understanding of how to control spatial-dynamic processes.