Evaluating the role of landscape in the spread of invasive species: The case of the biomass crop Miscanthus × giganteus

The introduction and spread of potentially invasive species present profound ecological challenges with major consequences for natural and cultivated ecosystems. The spread of invasive species is driven by both invader traits and the landscapes they are colonizing and there is a pressing need for objective and quantitative methods that integrate landscape details into predictions of biological invasions. Here we develop a new spatially explicit integro-difference equation model to predict the spread of invasive species over real landscapes. We use this model to evaluate the spread of a potentially invasive biomass crop, namely a fertile variety of Miscanthus giganteus, as a case study of how such models can be used to aid decision making when managing agricultural landscapes. We show that M. giganteus has the ability to invade large landscapes, but the rate and extent of that spread is strongly dependent on the landscape, including composition, spatial structure and the presence of dispersal corridors. Lastly, we discuss the potential application and value of spatial models in risk analysis and management of novel agricultural production systems that include potentially invasive crops.