The application of systems thinking to ecological communities centers on the ecosystem concept and has been the basis of significant research activity in ecological science since the 1960's (4) . Much of the focus has been on describing and understanding energy and nutrient fluxes across different kinds of ecosystems, and more recently emphasizing the human dimensions of global environmental change (45) . Although global scale ecosystem change has been considered in reference to human and infectious diseases (13, 46) , no systematic framework has yet been presented in this regard. The evidence presented has been anecdotal.