Identifying mechanisms driving spatiotemporal disease dynamics in converted landscapes

Around the globe, landscapes are being converted from natural habitats into a mosaic of agriculture and other human-dominated landscapes. These shifts in land use impact plant and animal species and usually lead to declines in biodiversity compared to undisturbed landscapes. Concomitant to this decline in biodiversity is a change in abundance and diversity of the pathogens that infect the animals and plants present. Transmission of a pathogen can decline or increase due to changes in availability of suitable hosts, changes in the abiotic environment, altered movement of hosts or some other impact of changing landscapes. It is timely and critical to quantify changes in pathogen burden, as there is an ongoing increase in frequency and scale of landscape conversion globally. We currently lack the ability to accurately predict the response of a particular pathogen in a landscape undergoing conversion.

In this project I will use a combination of approaches to disentangle factors affecting pathogens in changing landscapes: 1) I will establish a longitudinal survey of small mammals at sites that have been converted from natural forests to smallholder agricultural fields from 1 to 15 years prior. I will then examine how the small mammal abundance and diversity changes across time and determine how that impacts prevalence of a parasitic nematode. 2) I will investigate how the types of environments and distribution of different habitats across the regional landscape affect movement of hosts and pathogens between populations. 3) I will develop models and analyze a global database to investigate which underlying host, parasite, and environmental traits are important for predicting short-term responses to land conversion. This approach is expected to lead to an improved understanding of how pathogen transmission is altered in dynamic landscapes and provide a better ability to predict how transmission may change in the future, particularly with different anthropogenic induced land use change.