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

Abstract

Abstract The finely‐ground woods and barks of 9 species of pine were allowed to decompose in soils in the presence and absence of additional nitrogen for periods of 63 to 800 days. Carbon dioxide evolution was measured at frequent intervals. The pine species studied were white, shortleaf, loblolly, slash, longleaf, ponderosa, western white, lodgepole, and sugar. An average of 16.2% of the wood carbon was oxidized in 60 days in the absence of extra nitrogen and 16.9% in its presence. The corresponding values for the barks were 8.7 and 8.6. The wood species showed variations in CO 2 evolution during the 60‐day period, ranging from 8% for sugar pine to 51% for shortleaf pine. The variations for the barks were between 3.0% for white pine and 23.3% for lodgepole pine. Most of the pine woods decomposed somewhat more rapidly than did the other softwoods previously studied, but not nearly so rapidly as did the hardwoods. The pine barks are oxidized at about the same slow rate as are the other softwood barks.