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Harvard Forest Symposium Abstract 2008

  • Title: Vegetation Patterns in the Champlain Hills and the Structure of Plant Communities
  • Primary Author: Jerry Jenkins (Wildlife Conservation Society)
  • Abstract:

    Plant communities, when worthy of the name, have a large-scale pattern: you can tell where they will occur and what they will contain. The rich-dry communities of the West Champlain have this sort of structure–their physiography, vegetation structure, species richness, and species composition all differ sharply and in a predictable way from the matrix forests around them. We were curious, both as ecologists and as conservationists, whether they differed in similarly predictable ways from one another or whether they had subcommunities arranged in orderly ways within them. After a study of about 20 sites, involving vegetation measurements at four different scales and comparisons between vegetation, rock types, and soil chemistry, we found they did not. Patterns of species composition and species richness differed strongly from site to site but did not correlate with bedrock, exposure, elevation, or soil chemistry. Patterns of local diversity and composition varied strongly within sites, but had no clear topographic pattern and did not show clear correlations between subfloras. We conclude that community patterns are strongly scale-dependent; in our case they are strong, predictable, and mappable at a scale of 100 to 500 meters, but uncorrelated and unpredictable at a scale of 1 to 100 meters. This has important implications for communities are defined and mapped, and how many examples need to be preserved to capture the full diversity.

  • Research Category: Biodiversity Studies, Physiological Ecology, Population Dynamics, and Species Interactions