Mass and nutrient content of dead wood in a central Illinois floodplain forest

Abstract

The quantity and quality of dead wood in a central Illinois floodplain forest was measured to determine its role in organic matter and nutrient budgets. Dead wood (downed wood and standing dead trees) was inventoried using plots and the line intersect method for mass, and samples were analyzed for density and concentration of ash. N, and P. Total dead wood was estimated at 15.9 Mg ha⁻¹ and was comprised of 9.3 Mg ha⁻¹ as standing dead (59%) and 6.6 Mg ha⁻¹ as downed wood (41%). Most of the downed wood (82% of the total) was in the intermediate decomposition class. Density of downed wood (0.19–0.47 g cm⁻³) decreased and concentrations of N (0.18–1.29%), P (0.12–0.56 mg g⁻¹, and ash (1–23%) increased with increasing state of decomposition. Mean N, P, and ash pools in dead wood were 47 kg ha⁻¹, 3.1 kg ha⁻¹, and 481 kg ha⁻¹, respectively. Downed wood contained 56%, 54%, and 69% of the total N, P, and ash pools, respectively. During periods of rapid decomposition of leaves and reproductive parts, downed dead wood is the dominant and often sole component of the floor litter mass.