Effects of Forest Disturbance and Soil Depth on Digestible Energy for Moose and White-tailed Deer

Spruce budworm defoliation, clearcutting for salvage, and prescribed burning of clearcut areas on deep and shallow soils influenced deer and moose foraging in eastern Maine spruce-fir forests from 1980 to 1984. Plant standing crop biomass, seasonal plant selection by tractable moose and white-tailed deer, and digestible energy for deer and moose were determined for each treatment. Early successional plant species were most abundant on burned areas, and were common on clearcut areas. Increase in biomass after defoliation was substantial. Deer and moose ate many of the same plant species, but in different proportions. Deer found more desirable foods on deep than on shallow soils and were more selective of plant parts than moose. Deer digested their diets slightly better than moose from late spring through fall. Deer obtained more digestible energy than moose during fall and early winter on all treatments. Moose obtained more digestible energy than deer during spring and summer on burned areas where forage was abundant. Available energy by treatment was significantly different for moose year round and for deer during spring and fall: clearcut and burn clearcut >defoliated >undefoliated (control).