Document: STE-3-21-5

Why be a carnivorous plant?: The importance of life history and plasticity in changing environments.

BREWER, J.S.*

Department of Biology, University of Mississippi ¹

Abstract:
Despite numerous studies of the benefit of carnivory to plants, to date no study has examined how the benefit of carnivory varies according to life history. I present results of field experiments examining the responses of three cooccurring species of carnivorous plant with different life histories to varying levels of competition. Experimental reduction in aboveground competition increased both trapping effort and prey capture. Capture of prey enhanced the growth of the long-lived species, Sarracenia alata, only when there was also a sustained (1 yr) reduction in competition, suggesting that a significant fraction of prey-derived nutrients is stored in the short term. Only the short-lived species, Drosera capillaris and Utricularia juncea, had significantly greater numbers of reproductively mature adults during the first growing season of competition reduction. In addition, experimentally disturbed patches were colonized at a much higher rate by the short-lived species than by Sarracenia. Despite the fact that all three species were adapted to infertile soils, they exhibited differing life-history strategies, ranging from stress-tolerant/sit-and-wait forager to ruderal/fugitive. Thus, there is no single answer to the question, why be a carnivorous plant? The benefit of carnivory depends on the plant's life history. In conclusion, I discuss the relevance of these results to testing allocation-based hypotheses of resource competition in plants.

Keywords: competition, nutrient stress, allocation

This abstract is being presented at: 8:05 AM in session:
Symposium # 19: Carnivorous Plants as Model Ecological Systems.