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Harvard Forest Symposium Abstract 2018

  • Title: Effects of ungulate browsers and canopy disturbance on the herbaceous layer in disturbed hemlock forests
  • Primary Author: Edward Faison (Highstead, Inc.)
  • Additional Authors: Audrey Barker Plotkin (Harvard Forest); Stephen DeStefano (U. S. Geological Survey, Cooperative Research Unit Program, University of Massachusetts)
  • Abstract:

    One of the important ways in which ungulate browsers influence plant communities is by altering competitive interactions among plants. By reducing plant height, intensive foraging tends to reduce size discrepancies in the plant community and therefore reduce the competitive advantage of larger statured species over smaller ones. In a similar way, forest canopy disturbances create new growing space and reduce competition by removing large trees.

    In 2017 we resampled the herbaceous and low shrub layer (≤1 m) in 5.5 year-old ungulate exclosure and control plots located in 8 canopy treatment plots at the Harvard Forest Hemlock Removal Experiment. We examined the extent to which ungulate foraging and canopy disturbance (simulated Hemlock Woolly adelgid and salvage logging) altered herbaceous and woody plant composition and richness.

    Preliminary results suggest that ungulate browsing had little effect on herbaceous plant species richness (no. species/1m2) or herbaceous plant cover, but had a weak negative effect on woody plant richness (P = 0.10). Canopy disturbance had a large positive effect on woody plant cover and species richness, especially in the girdled (simulated HWA) plots, and resulted in lower herbaceous species richness compared to hardwood control plots. Community compositional data in fenced and unfenced plots are currently being analyzed.

  • Research Category: Large Experiments and Permanent Plot Studies; Invasive Plants, Pests & Pathogens; Biodiversity Studies