Dynamics of macronutrients during the first stages of litter decomposition from forest species in a temperate area (Galicia,NW Spain)

The decomposition and dynamics of nutrient elements was studied for leaves and twigs from Quercus robur, Pinus radiata and Eucalyptus nitens in soils developed from granodiorite, slate and limestone in Galicia, NW Spain. Two 1-ha plots were selected for each material-vegetation combination, making a total of 18 plots. Litter decomposition and nutrient dynamics during the first six months were investigated using litterbags. Mass loss was higher for leaves than twigs and not significantly different for different tree species. Mass loss correlated significantly with carbon loss (r = 0.96 for leaves, r = 0.90 for twigs). As a general trend, nutrient release from leaves and twigs was greater for the broadleaved species (eucalyptus and oak). K and S were rapidly released from all litters, while Ca and Mg showed the highest tendency to be immobilised. N and P behave similarly, with a final balance of net release. Soil parent material did not significantly influence decomposition or nutrient dynamics.