Variations in mineral nutrient and C distribution in the soil and vegetation compartments of five temperate tree species in NE Sweden

Abstract

The influence of five tree species on soil acidity and the distribution of carbon and nutrients between biomass and soil were studied in an experiment with 27-year-old stands in three replicates on set-aside farmland in NE Sweden. The five tree species were: Picea abies L. Karst., Pinus sylvestris L., Pinus contorta Dougl., Betula pendula Roth, and Larix sibirica Ledeb. Total tree biomass was 11 kg dw m −2 in B. pendula and L. sibirica, 10 kg dw m −2 in P. abies, and 8 kg dw m −2 in the pines. The foliage of P. abies had a more than eight times higher quantity of Ca, and a more than twice as high quantity of dry weight, Mg, K, P and N, as the foliage of any of the other species. Concentrations of Ca in foliage, branches and stems generally decreased in the order P. abies> B. pendula> L. sibirica, P. sylvestris, P. contorta. The highest amounts of Mg, K, P and N in the stems were found in B. pendula and L. sibirica. The results suggest that the choice of tree species may have a pronounced influence on the rate of nutrient removal both in case of whole-tree harvest and stem-wood harvest, also at similar rates of stem-wood biomass production. However, compared to the large differences found between the species in Ca and K contents of the above-ground part of the trees, the corresponding differences in depletions that were detected in the `non-harvestable' pools of these elements were smaller. (Non-harvestable pool: total element amounts in coarse tree roots and field vegetation and litter/organic layer, plus exchangeable element amounts in the A horizon). No significant species-related differences in soil pools of C or acidity were found. In the combined litter and organic layer, a significant difference in pH was found; about half a unit higher for B. pendula and P. abies than for P. contorta and L. sibirica.