Decomposition and element release from confined jack pine needle litter on and in the feathermoss layer

An experiment was conducted in a mature boreal jack pine (Pinus banksiana Lamb.) stand comparing decomposition and element release rates of jack pine needle litter in mesh bags placed on the surface versus inserted into the feathermoss layer. There was a small but significant increase in decomposition rate of litter inserted into the feathermoss layer compared with litter placed on the surface, which persisted until at least the end of the fourth growing season of exposure. There were significantly lower N and P masses (reflecting more the loss of organic matter than change in element concentration) associated with inserted litter residues compared with residues of surface-placed litters. This result suggests a more rapid release of these elements. As feathermoss layers occupy the ground surface of many upland boreal conifer sites and most needle fall is quickly enveloped by this layer, insertion of litterbags into the feathermoss layer is a realistic representation of litterfall dynamics with implications for element cycling.