Decomposition of Pinus sylvestris litter in litter bags: Influence of underlying native litter layer

Pinus sylvestris (L.) litter confined in 1-mm mesh litter bags was incubated on layers of either P. sylvestris or Picea abies (Dietra.) litter of different origins (native litters) under standard conditions in the laboratory. The decomposition rate of the confined litter was measured both as evolution of CO2 and as mass loss. The native litter played an important part in governing the rate of decomposition of the confined litter, with the native litters richest in N and Ca resulting in greater decomposition rates (up to 15% more) of the confined litter than the nutrient poor native litters. Both inter- and intra-species effects were observed and these are discussed in terms of chemical and physical interactions between the confined and native litters.