Dead bole mass and nutrients remaining 23 years after clear-felling of a northern hardwood forest

Dead bole mass and nutrients were measured in a northern hardwood forest watershed at the Hubbard Brook Experimental Forest, New Hampshire, 23 yr after all of the trees were felled and left in place. Mass of dead boles (excluding stumps) declined by c90%, from 116.5 to 12.7 Mg.ha^-1, and had an exponential decay rate constant, k, of 0.096 yr^-1. Density of hardwood species declined 50% by decay class 1, and softwood density declined 17% by decay class 1. Rates of decay appeared to be different among species, with maple and beech decomposing more quickly than birch and ash. Differences in concentrations of some nutrients were highly significant among decay classes (P and Ca) and among species (K, P, and Mg). Net release of nutrients ranged from 31% (N) to 93% (K). Root proliferation was highly correlated with decay class of dead boles. Highly decayed boles had much higher root biomass, but the total fine-root mass associated with deadwood was very low (2.1 g.m^-2) compared with fine-root mass measured in forest floor (314 g.m^-2). -from Authors