DECOMPOSITION DYNAMICS OF LITTERS OF VARIOUS PINE SPECIES IN A CORSICAN PINE FOREST

The decomposition dynamics of the litters of Corsican pine (Pinus lari cio Poiret), Stone pine (P. pinea L.) and Scots pine (P. sylvestris L. ) exposed in a Corsican pine forest in the South Italy Apennines were followed for 2.5 y. Litter decomposition was very slow for all three s pecies and appeared to be limited mainly by the low water availability throughout the study. The microbial activity expressed as respiration , and the fungal biomass were also low due to the low moisture content of the litters, as suggested by the high increase of the potential re spiration, after their hydration. A highly significant and positive re lationship between potential CO2 evolution rates and litter moisture c ontent was found. The decomposition dynamics were also affected by the initial chemical composition of the three litter types. A delay in st arting decomposition and the lowest initial rate were observed in Ston e pine litter, that had the highest initial N, but also the highest li gnin content and the lowest initial Mn content. (C) 1998 Elsevier Scie nce Ltd. All rights reserved.