ZLV Online

Abstrakt

The paper evaluates the nutritional status of young Norway spruce stands on five forest sites that were chosen for introduction of admixture consisting of broadleaves and silver fir. Since no broadleaves and firs were present in the pure spruce stands to be diversified, Norway spruce was used as an indicator of nutritional potential (trophy) of forest sites. The concentrations of nitrogen (N), phosphorus (P), potassium (K), magnesium (Mg), calcium (Ca) and sulphur (S) were determined in the dry mass of spruce needles. The achieved macroelement concentrations were confronted with the nutritional criteria used for evaluating the nutrition of spruce to elicit the information on nutritional status of spruce on the forest sites. Authors suggest that this information could be generalized and the potential of the forest sites to supply also another native species (including broadleaves and silver fir) with nutrients could be derived from nutritional status of spruce. The obtained results suggest that the nutrition of young Norway spruce is sufficient on all five forest sites at present time; nonetheless, the uptake of nutrients from soil will probably rise to considerably higher levels than now whilst the young forest will form its crown and foliage biomass. Phosphorus and potassium seem to be the most limiting components in tree nutrition during the future development of young forest stand on the evaluated sites. Therefore, the initial fertilization of the broadleaves and silver fir introduced to the coniferous stands with slow-release PK fertilizers was recommended. To help the young plantations of broadleaves and silver fir to surmount the post-planting shock, the addition of slow-release N is also desirable in the amendment intended for the initial fertilization.