Fuel load, humus consumption and humus moisture dynamics in Central European Scots pine stands.

摘要

Samples of Scots pine (Pinus sylvestris) humus were burned under different moisture and fuel load scenarios to model humus consumption. For moisture levels below 120% on a dry mass basis, a parabolic increase of humus remaining with increasing moisture content was observed while, for higher moisture levels up to 300%, humus was reduced by a constant 10-15% on a dry mass basis. Both fuel load and humus moisture had a highly significant influence on humus consumption. Humus gross calorific value of Scots pine (19 509 KJ kg-1) is lower than that of other pine species. We found a desorption time lag for humus moisture of 85 h in this study. Field data show a steady accumulation of humus in Central European Scots pine stands (up to 45 tonnes ha-1 in 120-year-old stands). Amounts of litter remain constant over the different stand ages (~15 tonnes ha-1). This study provides important information to predict humus consumption in Scots pine stands. The results can be used to build a fire severity and post-fire succession model for Scots pine stands in Central Europe..