Intraspecific functional diversity in hosts and its effect on disease risk across a climatic gradient
Garrett, Karen A.
Zuñiga, L. N.
Forbes, G. A.
Mundt, C. C.
Nelson, R. J.
MetadataShow full item record
The effects of host biodiversity on disease risk may vary greatly depending on host population structure and climatic conditions. Agricultural diseases such as potato late blight, caused by Phytophthora infestans, provide the opportunity to study the effects of intraspecific host diversity that is relatively well-defined in terms of disease resistance phenotypes and may have functional impacts on disease levels. When these systems are present across a climatic gradient, it is also possible to study how season length and conduciveness of the environment to disease may influence the effects of host diversity on disease risk. We developed a simple model of epidemic progress to evaluate the effects on disease risk of season length, environmental disease conduciveness, and host functional divergence for mixtures of a susceptible host and a host with some resistance. Differences in disease levels for the susceptible vs. resistant genotypes shifted over time, with the divergence in disease levels first increasing and then decreasing. Disease reductions from host diversity were greatest for high host divergence and combinations of environmental disease conduciveness and season length that led to moderate disease severity. We also compared the effects of host functional divergence on potato late-blight risk in Ecuador (long seasons), two sites in Peru (intermediate seasons) in El Niño and La Niña years, and the United States (short seasons). There was some evidence for greater disease risk reduction from host diversity where seasons were shorter, probably because of lower regional inoculum loads. There was strong evidence for greater disease reduction when host functional divergence was greater. These results indicate that consideration of season length, environmental conduciveness to disease, and host functional divergence can help to explain the variability in disease response to host diversity.
Showing items related by title, author, creator and subject.
Using forest structural diversity to inventory habitat diversity of forest-dwelling wildlife in the West Kootenay region of British Columbia McCleary, K.; Mowat, G. (Kamloops, BC: FORREX-Forest Research Extension Partnership, 2002)Forest planners in British Columbia are being asked to consider wildlife species diversity in forest development plans. However, forest ecosystem inventories currently used in the province only document forest composition ...
Faculty Perspectives on Diversity and Inclusion at a Highly Diverse Institution: A Study of Organizational Culture Camargo, Elsa (Virginia Tech, 2017-04-14)U.S. demographic shifts are not being reflected in higher education institutions (U.S. Census Bureau, n.d.; U.S. Department of Education, 2013). While institutions recruit underrepresented students and faculty, retention ...
An Ethnographic Study of a Literacy Program in a High-Poverty, Ethnically Diverse Elementary School within the Context of No Child Left Behind Howard-Anzalone, Barbara L. (Virginia Tech, 2011-08-30)This is an ethnographic case study of a high poverty, ethnically diverse elementary school and the transformation that occurred there. The research describes what happened at the school within the context of No Child Left ...