Comparative Rates of Decomposition in Soil of Wood and Bark Particles of Several Hardwood Species

Abstract

Abstract The decomposition rates of the finely‐ground woods and barks of 9 species of hardwoods were determined in the laboratory at two nitrogen levels. Carbon dioxide was measured at frequent intervals during periods varying from 72 to 580 days. The following species were studied: black oak, white oak, red oak, post oak, hickory, red gum, yellow poplar, chestnut, and black walnut. During the first 60 days an average of 30.3% of the wood carbon was released as CO 2 in the absence of fertilizer nitrogen, and 45.1% was released in its presence; the corresponding values for the barks were 22.4 and 24.5%. The variations in the rates of CO 2 release from the woods were not great, but hickory and black walnut barks decomposed much slower than the other barks. The hardwoods were attacked much more readily than most of the softwoods used in an earlier study, and consequently more nitrogen was required by the microorganisms that decomposed them. There were no indications that any of these wood products was toxic to the decay organisms.