FORAGE ENERGY FOR WHITE-TAILED DEER IN LOBLOLLY PINE PLANTATIONS

Standing crop of forage and forage-based energy for white-tailed deer (Odocoileus virginianus) was determined during the spring and fall seasons in 2-, 5-, 11-, and 17-year-old loblolly pine (Pinus taeda) plantations and 60-75-year-old 2nd growth hardwood forests in the central Virginia Piedmont. Forage (dry wt) availability was highest in 2-year-old plantations (132 kg/ha), declined slightly in 5-year-old plantations (105 kg/ha), then decreased more sharply through plantation ages 11 (66 kg/ha) and 17 (26 kg/ha). Digest- ible energy also was highest in 2-year-old plantations (4.5 x 105 kcal/ha) and showed a trend similar to forage with increasing stand age. Quality energy (digestible energy weighted by an index of preferred deer forage abundance) decreased from relatively high levels in 2- and 5-year-old plantations (1.8 x 105 and 1.6 x 105 kcal/ha, respectively) to very low levels (<0.1 x 105 kcal/ha) as the forest crown approached closure (around stand age 11). Quality energy dropped off more quickly in the fall than did digestible energy, and it was virtually absent in all plantations by October. Forage and energy availability in 2nd growth hardwood forests, exclusive of mast, was comparable to the low levels in 17-year-old plantations.