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Harvard Forest Symposium Abstract 2013

• Title: Moose at their southern range limit alter temperate forest development
• Primary Author: Edward Faison (Highstead, Inc.)
• Additional Authors: Stephen DeStefano (U. S. Geological Survey, Cooperative Research Unit Program, University of Massachusetts); David Foster (Harvard University)
• Abstract:

  Extirpations of large herbivores have left most eastern temperate forest regions as single ungulate systems dominated by white-tailed deer (Odocoileus virginianus). In the Northeastern United States, moose (Alces alces) have recently recolonized their former southern range, joining deer in this landscape for the first time in almost 200 years. We used a randomized block design with three ungulate treatments (moose + deer, deer, and no ungulates) in 4-5 year old patch cut timber harvests to undertake the first study of the ecological effects of combined moose and deer browsing in the temperate forests of North America. In this landscape where both deer and moose are at relatively low densities we tested the following hypotheses: (i) the herbivores have no effect on woody vegetation; (ii) both herbivore treatments influence the vegetation with no significant difference between them; (iii) both herbivore treatments influence the vegetation and differ significantly; and (iv) moose + deer influences the vegetation but deer do not. Tree density and species richness in the larger size classes (above 3 m and at least 2.5 cm DBH) were reduced by moose + deer browsing, and density of small stems (0.5-1.5 m) were increased by moose + deer. Species richness of small and medium stems (1.51-3.0 m) were unaffected by herbivory. Moose + deer reduced the proportion of Prunus pensylvanica, Betula papyrifera and Betula lenta >3 m in height, altering community composition. Prunus serotina and Pinus strobus were browsed in lower proportion to their availability by moose + deer; and both trees increased in relative abundance, although not significantly. Deer reduced the density of stems that recruited into the 2.5 cm DBH size class but did not otherwise alter forest dynamics. Relatively low densities of moose + deer altered forest dynamics, but did not prevent regeneration or eliminate tree species from these developing stands.

• Research Category: Conservation and Management
  Large Experiments and Permanent Plot Studies
  Physiological Ecology, Population Dynamics, and Species Interactions
  Regional Studies