Effects of Thinning and Nitrogen Fertilization on Sugars and Terpenes in Douglas-Fir Vascular Tissues: Implications for Black Bear Foraging

摘要: The chemical constituents of coniferous vascular tissues play a role in bear forage selection. In particular, foraging preferences are related to the concentrations simple sugars (nonstructural carbohydrates) and terpenes forage. Analyses tissue samples from trees collected test plots indicated that both thinning fertilization caused sugar concentra- tion lower bole increase. However, these treatments had no effect on hydrocarbon monoterpenes, oxygenated or sesquiterpenes. These results may explain observations black bears prefer thinned fertilized stands.