SEASONAL NUTRIENT DYNAMICS OF FOLIAGE AND LITTERFALL ON WALKER BRANCH WATERSHED, A DECIDUOUS FOREST ECOSYSTEM

摘要

A detailed twelve-month study of litterfall, live foliage biomass, and seasonal nutrient (nitrogen, phosphorus, potassium, calcium, sodium, and magnesium) dynamics in tree components was performed for forest types on Walker Branch Watershed, Oak Ridge, Tennessee. Biomass and nutrient content of foliage, reproductive parts and branches were examined for ten dominant trees in order to assess the relative importance of litterfall in returning nutrients to the forest floor in four different forest types. Litterfall, measured in pine, pine-oak-hickory, oak-hickory, and mesophytic hardwood forests, was separated into three com¬ponents (leaves, reproductive parts, and branches). Seasonal compari¬sons of those forest types were made for biomass and nutrient inputs for each component and for total litterfall. Each forest type was characterized by total annual input to the forest floor of biomass and individual nutrients for each component as well as total litterfall. Canonical analysis was performed on the yearly totals to test for signifi¬cant differences among the forest types.