Long-Term Decomposition Plots at Harvard Forest 1990-2009

Mass loss (estimated by decreases in density) and total nitrogen content (TKN) is measured in decaying logs (1.2 m long and diameter range: 6-50 cm) and sticks (10-30 cm long and diameter less than 5 cm) of red pine (Pinus resinosa Ait.) and red maple (Acer rubrum L.) Logs and sticks were collected from freshly cut trees and placed on the forest floor in a red pine plantation (pine only) or a nearby red maple dominated deciduous forest (maple only) in the Prospect Hill tract. Maple logs and sticks lost density faster than did pine. Total Kjeldahl Nitrogen is measured as a percent of organic matter in red pine and red maple logs. N content differed significantly according to state of decay (p=0.002) but not between species. Total organic phosphorus in Kjeldahl digests is measured as a percent of organic matter in red pine and red maple logs. P content differed significantly according to state of decay (p=0.0008) but not between species.