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Harvard Forest Symposium Abstract 2011

• Title: Assessing the changing effects of moose and deer browsing on forest ecosystems
• Primary Author: Edward Faison (Highstead, Inc.)
• Additional Authors: Justin Compton (University of Massachusetts at Amherst); Stephen DeStefano (U. S. Geological Survey, Cooperative Research Unit Program, University of Massachusetts); David Foster (Harvard University); David Wattles (University of Massachusetts at Amherst)
• Abstract:

  Three years ago, the Harvard Forest began collaborating with the USGS’s Massachusetts Cooperative Fish and Wildlife Unit, Massachusetts State Wildlife and Conservation Agencies, and Highstead in southern CT on a long-term study of the effects of deer and moose browsing on forest structure and composition. Between 2007 and 2010, experimental exclosures were built in recently logged stands in Massachusetts state forestlands (3), Harvard Forest (4), Yale-Myers Forest in northeastern CT (1) and Great Mountain Forest in northwestern CT (1). The design includes three treatments: full exclosure (excludes both moose and deer), partial exclosure (allows access to deer but not moose), and control. At the start of the experiment, there were no differences in seedling density or richness among the three treatments. After three growing seasons at our 5 oldest sites, a greater density and richness of tree seedlings above 1m have recruited in the full exclosure than in the other treatments. Hardwood seedlings and stump sprouts were generally browsed in proportion to their availability, but white pine (Pinus strobus) seedlings were largely avoided. At two sites where white pine occurs, we are beginning to see a greater abundance of pine above 1m in the control plots than in the full exclosures. In 2010, we also expanded our studies into mature oak-hardwood forests. We compared tree regeneration in southwestern Connecticut where deer densities are high (>12/km²) to regeneration in similar forests in central Massachusetts where deer densities are relatively low (<5.8/km²). White oak (Quercus alba) seedling density was significantly lower in southwestern Connecticut than in central Massachusetts, despite a longer growing season and a more open understory (proxy for available light) in southwestern Connecticut. In 2011, we will begin to investigate the role of deer and moose in unharvested forests experimentally by constructing new exclosure sites in mature stands.

• Research Category: Conservation and Management
  Large Experiments and Permanent Plot Studies
  Regional Studies