Wood decomposition over a first-order watershed: mass loss as a function of lignocellulase activity.

TLDR: In this paper, the authors investigated the role of extracellular enzymes in plant litter decomposition by placing arrays of white birch ice-cream sticks at eight upland, riparian and lotie sites on a forested watershed in northern New York.

Abstract: Because plant litter decomposition is directly mediated by extracellular enzymes, analyses of the dynamics of their activity may clarify the mechanisms that link decomposition rates to substrate quality and to temperature, moisture and nutrient availability patterns. We investigated this possibility by placing arrays of white birch ice-cream sticks at eight upland, riparian and lotie sites on a forested watershed in northern New York. For 3 yr, samples were analyzed for mass loss, protein, nitrogen and phosphorus accumulation and the activity of 11 classes of extracellular enzymes involved in lignocellulose degradation and nutrient cycling. Despite considerable heterogeneity both within and between sites, decomposition rates were closely related to the activity of lignocellulose-degrading enzymes. A statistical model was developed that accounted for 94% of the variance in mass loss rates as a function of the temporally-integrated activity of these enzymes. Models of this type contribute to our understanding of scale integration and may facilitate the estimation of decomposition rates among landscape units.