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Harvard Forest Symposium Abstract 2012
- Title: Interacting effects of ungulate browsing and forest disturbance on tree recruitment and forest dynamics
- 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:
The year 2012 marks the fourth year of the ungulate-forest dynamics project. Six new experimental exclosure sites (blocks with 3 treatment levels of ungulate browsing: moose x deer, deer, and ungulate exclusion) were constructed in unharvested oak and hemlock forests and partially harvested oak-pine sites at the Harvard Forest and in Massachusetts watershed and wildlife management areas in 2011. Fifteen exclosure sites have now been constructed across a gradient of moose and deer densities, forest types, and timber harvest intensities in central Massachusetts and northern Connecticut. In addition, new ungulate exclosures were constructed at the Hemlock Removal Experiment at the Harvard Forest to examine the response and influence of moose and deer in forests disturbed by (simulated) hemlock woolly adelgid outbreak and associated salvage logging. Data from our five oldest exclosure sites (3-4 years) in patch cut harvests show that moose x deer browsing has significantly reduced the rate of tree recruitment above 1.5-2 m in height and above 2.5 cm DBH, relative to both deer browsing alone and ungulate exclusion. Although deer browsing alone had an early effect on tree recruitment relative to herbivore exclusion, much of the vegetation has now grown out of the reach of deer (>1.5m), causing the deer-only plots to converge in structure with the ungulate exclusion plots. The tendency of moose to exploit foraging patches intensively before moving on to new ones and the ability of moose to browse up to 3 m in height contributes directly to reductions in tree recruitment in the control plots. Moose browsing also functions synergistically with deer browsing by keeping the vegetation within the reach of deer, and thus extending the period of browsing influence by the smaller herbivore.
- Research Category: Conservation and Management
Large Experiments and Permanent Plot Studies
