Galloway, Laura , Lin, Susan .
Environmental context determines within and between generation consequences of herbivory.
Variation in environmental conditions within populations is ubiquitous. Response to herbivory may depend on local environmental conditions. We determined the probability of being browsed by deer as well as within and between generation consequences of browsing in light gap and understory habitats for the monocarpic herb, Campanulastrum americanum (Campanulaceae). Plants in light gaps were 43% more likely to be browsed and browsing occurred two weeks earlier than for understory plants. Understory plants were twice as likely to survive deer browsing as light gap individuals and those that did survive had 27% of the fruit production as uneaten plants whereas survivors in the light gap produced only 18% of the fruit of uneaten plants. Browsing also delayed the onset of flowering by an average of two weeks. C. americanum has both annual and biennial life histories. Because early flowering plants produce more annual offspring and late flowering plants produce more biennial offspring, browsing by deer is expected to increase the frequency of the biennial life history. However, there was no evidence of other differences in the offspring of eaten and uneaten plants. In summary, browsing by deer is expected to increase the frequency of biennials and decrease the frequency of C. americanum in the highly productive light gap habitats.
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1 - University of Virginia, Department of Biology, Charlottesville, Virginia, 22904-4328, USA
2 - University of Virginia, Mountain Lake Biological Station, Charlottesville, VA, 22904-4327, USA
Presentation Type: Oral Paper:Papers for BSA Sections
Location: Alpine B/Snowbird Center
Date: Tuesday, July 28th, 2009
Time: 2:00 PM