Effects of Landscape Spatial Heterogeneity on Host-Parasite Ecology

Landscape spatial heterogeneity interacts with ecological processes that influence pathogen emergence and infectious disease spread. Modification of landscape composition and configuration is hypothesized to alter host densities, frequency of host-parasite interactions, host community assembly processes, and dispersal processes of host, vector, and parasite populations. Understanding the spatial and environmental dependence on host-parasite interactions is, therefore, critical in predicting the response of disease dynamics to widespread habitat modification. I combine wildlife disease ecology with landscape ecological concepts and varied modeling techniques (i.e., multivariate redundancy analyses, network connectivity models, bipartite mutualistic networks, beta diversity analyses) to test the mediating role of landscape spatial heterogeneity on the spread of a vector-borne disease system (chapter 2), and the effect of urban landscape spatial heterogeneity on host exposure to parasitism (chapter 3), host-parasite interaction structure (chapter 4), and host-parasite beta diversity (chapter 5). My results demonstrate that landscape spatial heterogeneity has a differential influence on tick dispersal than pathogen dispersal by the movement of a host community, most critically mediated by stepping-stone habitat. I also provide evidence that urban landscape spatial heterogeneity affects the exposure likelihood of a single host population, the structure of host-parasite interactions in multiple host populations, and the spatial contributions of host and parasite beta diversity. My work demonstrates that landscape spatial heterogeneity has a mediating role in multiple disease systems whereby spatial and environmental factors play a critical role in the likelihood of short- and long-distance pathogen invasion, the persistence of environmentally-mediated parasites, and the selection of generalist host and parasite species in urbanized habitat. Overall my research contributes to our theoretical understanding of the multi-scalar ecological interactions between landscape change and disease dynamics and our applied understanding of the role of landscape in the emergence of infectious diseases.Ph.D