PARENT SESSION
Poster Session 2: Forest Ecology
Monday, August 8, 5:00 PM - 6:30 PM, Exhibit Hall 220 A-E, Level 2, Palais des congrès de Montréal

A case of white-tailed deer controlling the woody vegetation in a powerline right-of-way located in a winter yard.

Doucet, Jean^*,1, ¹ TransEnergie, Montreal, Quebec, Canada

ABSTRACT- The Rigaud white-tailed deer (Odocoileus virginianus) yard is located approximately 100 km west of Montreal, Quebec. The yard is bisected in a north-south axis by a 120 kV transmission powerline built in 1972. The powerline collapsed during a major ice storm in January 1998 and was rebuilt in the summer and fall 1998. In the summer 1998 a brush cutter treatment was done and the vegetation was further damaged by construction activities. By October 2002 several woody stems were higher than 2 m and a mechanical treatment of the vegetation was done with hand-held cutters. During the winter 2003 the right-of-way provided very little browse, but on several occasions, we observed deer browsing in the right-of-way for long periods. We formulated the hypothesis that deer browsing pressure controlled the residual woody vegetation in the right-of-way. The April 2003 and 2004 browse surveys targeted the stems of 3 species sought by deer : red-osier dogwood (Cornus stolonifera), American ash (Fraxinus americana) and willows (Salix spp.). We sampled over 200 stems of each species each spring. All these residual stems were short and most were missed during the October 2002 treatment. Browsing rates on C. stolonifera, Salix spp. and F. americana were respectively 97,3%, 97,3% et 84,9% in 2003, and 96.3 %, 97.3 % 89.2% in 2004. These very high browsing rates indicate that when stems are short and deer density is high, deer can exert a certain control of the woody vegetation in a right-of-way in a deer yard, at least during the first winters following a vegetation control treatment.

Key words: browse, white-tailed deer, right-of-way, winter yard