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Harvard Forest Symposium Abstract 2008

  • Title: Dispersal Limitation and Competition in Yeasts Associated With the Purple Pitcher Plant
  • Primary Author: Primrose Boynton (Harvard)
  • Additional Authors: Aaron Ellison (Independent); Anne Pringle (University of Wisconsin - Madison)
  • Abstract:

    Researchers investigating macroorganisms have proposed two theories of community assembly to explain patterns of species composition in ecosystems: the neutral and niche theories of ecology. The neutral theory of ecology suggests that communities are composed of random assortments of organisms, and that these assortments are controlled by dispersal limitation. The niche theory of ecology suggests that competition is the primary force shaping community assemblage. The goal of this project is to investigate this dichotomy in microorganisms using wild yeasts as study organisms.

    We will be investigating these ecological theories using yeasts inhabiting the purple pitcher plant. This pitcher plant contains a variety of organisms including bacteria, yeasts, protozoans, and arthropods. Over the past two years, the Pringle lab has isolated and partially characterized several species of yeasts inhabiting these pitchers in the Harvard Forest. Over the course of this project, we will inoculate otherwise sterile pitcher plants in a greenhouse with different amounts of three different yeasts. The amounts of inoculum will be controlled by a direct count of yeast cells of the different species of yeasts. Throughout the summer, we will "feed" these pitchers with nutrient solution, and will monitor the numbers of cells of each species of yeast. A single yeast dominating the community regardless of inoculum size will indicate that competition strongly shapes these communities. Conversely, a strong effect of inoculum size on the resulting community will indicate that dispersal limitation strongly shapes the communities.

  • Research Category: Biodiversity Studies