Nitrogen and Lignin Control of Hardwood Leaf Litter Decomposition Dynamics

The effects of initial nitrogen and lignin contents of six species of hardwood leaves on their decomposition dynamics were studied at the Hubbard Brook Experimental Forest. Rate constants (k) for annual leaf mass loss ranged from —0.08 to —0.47. The rate constants (k) had a negative linear correlation (r2 = .89) with the ratio of initial lignin concentration to initial nitrogen concentration. Decomposition dynamics of the litter materials were described by inverse linear relationships between the percentage of original mass remaining and the nitrogen concentration in the residual material. Initial lignin concentration was highly correlated (r2 = .93) with the slope of the inverse linear relationship for each of the litter types.