Infectious agents are uniquely capable of causing TMIEs through their consumptive effects.
Direct and indirect effects of parasites: Parasitism is the most common consumer strategy on the planet, but only recently have parasites been incorporated in food webs. Like predators, parasites can have direct effects on their victims, and indirect effects on species with which their victims interact. These indirect effects might explain parasites’ profound effects in ecological communities. We are currently investigating the direct (consumptive and non-consumptive) effects of parasites on hosts, and the (density-mediated and trait-mediated) indirect effects that follow from them.
Increasing host density can increase or decrease infection risk (shown in shading), depending on study scale.
Scale dependence of host-parasite interactions: Epidemiological theory predicts that contact rate between hosts and parasites should increase with host density, thereby increasing parasite transmission and per capita infection risk. At the same time, for a given number of infective stages in the environment, high host density can decrease per capita infection risk because infective stages are divided (diluted) among all hosts in an area. We recently constructed a mathematical model demonstrating that whether the numerical or functional response dominates depends on study scale, and we are currently testing its predictions empirically.
Biodiversity-disease relationships: A major controversy in disease ecology is whether biodiversity protects against (dilution effect) or promotes (amplification effect) infectious disease. By adding another species to the host-parasite model described above, we recently demonstrated that biodiversity-disease relationships can be scale dependent. Dilution effects tend to dominate at small scales, whereas amplification effects occur at larger scales, although the opposite pattern is also possible. Stay tuned for empirical tests of this model!
My research has been funded through a variety of sources:
NSF Postdoctoral Research Fellowship (OCE PRF) 2015 - 2017
NSF Doctoral Dissertation Improvement Grant (DDIG) 2012 - 2013
OSU Zoology Research Fund (ZoRF) 2010 - 2012
Society of Wetland Scientists (SWS) 2009
NSF Graduate Research Fellowship (GRFP) 2008 - 2011
NSF Research Experiences for Undergraduates (REU) 2006
Howard Hughes Medical Institute (HHMI) 2005
Because effective communication of results to the public and the scientific community is an integral part of scientific research, I believe that my research benefits immeasurably from my teaching. Read more here about my teaching experience.