DECOMPOSITION OF ORGANIC MATTER ON THE FOREST FLOOR OF PINUS RADIATA PLANTATIONS

Laboratory experiments were carried out on the relative decomposition of litters collected from stands with contrasting accumulations of organic matter on the forest floor. Decomposition was measured by the weight loss of sterile litters inoculated with Pholiota and Lenzites, and by the microbial respiration in non sterile litters. Some differences were measured in litters from stands with dissimilar ages and productivities. The most striking differences in decomposition were those observed in litters from older stands (assumed to be in a steady state condition) of the same age and productivity class but on different soil types. These differences matched the patterns of relative litter accumulations in these stands in the field. The variations found in P. radiata litter decomposition were attributed to nutritionally induced differences in polyphenol complexing of litter materials.