FOREST-FLOOR NUTRIENT DYNAMICS 599 FOREST-FLOOR NUTRIENT DYNAMICS IN SOUTHERN APPALACHIAN HARDWOOD

Nutrient content and detrital biomass in the forest floor of a mature deciduous hardwood watershed and a 15-year-old white pine plantation at Coweeta Hydrologic Laboratory, N. C., were followed through one complete annual cycle, May 1970 to May 1971. Total carbon storage is significantly greater in the white pine than in the deciduous hardwood forest floor. Forest-floor biomass is probably approaching a steady state in the pine plantation, as indicated by computed turnover times. Calcium content, which is on the order of 100 kg/ha in both forest floors, is higher in the hardwood forest floor than in the pine; this reflects a considerably higher concentration of calcium in hardwood litter.'. Magnesium content is an order of magnitude lower than calcium. Potassium and sodium levels are very similar in both forest floors. Nitrogen and phosphorus storage is considerably higher in the white pine than in the hardwood forest floor. Summer loss rates were computed for forest-floor components. In temperate forest eeosystems the forest floor, or aboveground detritus, is one of the major reservoirs of the elements required for ecosystem metabolism an