Spatial Distribution of Fine-Root Growth, Mortality and Decomposition in a Young Scots Pine Stand in Central Sweden

Abstract

The spatial distribution of fine-root growth, mortality and decomposition, in a 15-20 yr old Scots pine Pinus sylvestris, stand at Ivantjarnsheden in Central Sweden was investigated by core sampling during an entire growth period. Since both the fine-root biomass and necromass (diameter < 2 mm) of the most important species P. sylvestris, Calluna vulgaris and Vaccinium vitis-idaea varied considerably during the season, pooled averages of 26, 50 and 49 g m2 and 68, 18 and 40 g m respectively were calculated for the total period of study. Both the fine-root and coarse-root (diameter 2 -< 10 mm) biomass and necromass of P. sylvestris decreased slowly with increased distance from the nearest tree. The annual turnover of the fine roots of P. sylvestris, C. vulgaris and V. vitis-idaea was estimated to 35, 34 and 135 g m7' respectively in the F/H layer and to 183, 42 and 57 g mi2 respectively in the mineral soil. The largest supply of dead P. sylvestris fine roots went to the mineral soil, whereas that of the superficially distributed dwarf shrubs ended up in the F/H layer.