The relationships between biomass of dwarf shrub species and nutrient gradi
ents of forest soils was studied under field conditions in boreal forests.
The biomass-response curves of Vaccinium myrtillus and V. vitis-idaea were
fitted against soil nutrient gradients using Generalized Linear Models (GLM
). Ecological niches of Vaccinium myrtillus and V. vitis-idaea were evaluat
ed, and effects of nitrogen addition (manipulation of the nutrient gradient
) on response function were tested.
The Vaccinium species showed statistically significant Gaussian responses a
long soil nitrogen, phosphorus and calcium gradients, but not along other g
radients (K and Mg). Furthermore, manipulation of the nitrogen gradient see
med to have a minor effect on response functions, i.e. addition of nitrogen
did not change ecological niches of these species. Ecological optima of V.
myrtillus and V. vitis-idaea on the nutrient gradients were about the same
. This study suggests that differences in dominance between Vaccinium myrti
llus and V. vitis-idaea in boreal forest is not determined by nutrient grad
ients, but may rather be explained by light conditions and/ or moisture ava
ilability.