Disease, Ecosystem Processes, and Humans

Human decisions and activities are increasing nutrient supply to the world’s ecosystems causing many impacts, including changes to infection dynamics in primary producers. Changes in host-pathogen interactions can have widespread ecological impacts, including changes to host physiology and community composition, which can in turn influence ecosystem processes that impact humans. While ecosystem ecology seeks to understand the global cycling rates of elements, and primary producers play a central role in these rates, the implications of changes in primary producer infection for elemental cycling has been overlooked. Yet, incorporating impacts of nutrient supply on infectious disease in living hosts, such as reduced photosynthetic rates or increased plant mortality, could substantially alter predictions for elemental fluxes in future, nutrient-enriched environments. Importantly, by changing carbon and nutrient cycling rates, changes in nutrient supply to ecosystems and primary producer infection dynamics may indirectly cause changes to ecosystem services such as water quality, including toxic algal blooms, carbon sequestration, grazing-land productivity, or biofuel cultivation.

This Pursuit will synthesize the relationships among rates of ecosystem eutrophication arising from human activities, host-pathogen interactions in primary producers, ecosystem processes, and their feedbacks to human health and well-being. The team will tackle this research with a multi-faceted approach, including developing new models that draw from both disease and ecosystem modeling approaches, synthesizing empirical data from marine, terrestrial, and freshwater ecosystems, and examining two case studies. This work will generate novel insights into the cross-ecosystem generality of disease impacts on elemental flux rates as well as the factors with the greatest potential to feedback and inform management for controlling disease impacts on elemental fluxes.