Litterfall: An overlooked food source for wintering white-tailed deer

Litterfall in mature forest stands may be a significant food resource for white-tailed deer (Odocoileus virginianus) wintering in northern regions, but has received little study. To determine forage production, we measured biomass of litterfall in unharvested stands of 3 wintering areas, and biomass of browse from deciduous trees and shrubs in unharvested stands and harvested patches of the same wintering areas during January-March 1994. Mean biomass of northern white-cedar (Thuja occidentalis), eastern hemlock (Tsuga canadensis), arboreal lichens (Usnea a spp. and Evernia spp.), and hardwood leaves in unharvested stands was 18.4 kg/ha (SE = 4.80). At mean digestible energy (DE) level of 1.5 and 1.7 kcal/g dry matter (DM), biomass of hardwood browse and litter biomass did not differ (P > 0.15) between harvested patches and unharvested stands. At greater mean levels of digestible energy (1.9 and 2.1 kcal/g DM), biomass was greater (P < 0.05) in unharvested stands than harvested patches because of the relatively high DE content of litterfall. We concluded that litterfall in unharvested stands was high relative to the availability of more commonly measured browses (e.g., understory trees and shrubs), and may be more palatable and of greater nutritional value. However, availability of hardwood browse during winter may be more predictable than litterfall.