Field Research Technician Michigan State University Bozeman, Montana
Plant-herbivore interactions are the basis for higher trophic level interactions and thus a fundamental component of ecosystem functioning. It is thought that herbivores generally facilitate pathogen infection, resulting in a positive correlation between herbivory damage and pathogen damage. By understanding plant-herbivore-pathogen interactions on an elevational gradient, we can make predictions about the reshaping of communities as species ranges shift in response to climate change. At higher elevation sites, herbivory is thought to decrease due to both lower biotic pressure and harsher abiotic conditions, resulting in lower plant defenses. Additionally, plants at the limits of their habitable range often encounter stressful abiotic conditions and therefore are more likely susceptible to damage. In order to further understand these dynamics, we tracked plant-herbivore-pathogen interactions along a 1220 m elevational gradient in the Teton Range, in the middle Rocky Mountain region. Our study encompassed sagebrush steppe to alpine meadows and included 13 forb species each surveyed at three elevations. For each survey we recorded percent herbivore and pathogen damage on the leaves of 60 randomly selected plant individuals. Our results show mean herbivore and pathogen damage on plant populations as site elevation increases. We then discuss these results within the context of each plant species’ elevational range to suggest trends in the susceptibility of each species to damage.
