The effect of soil conditions on submountain site suitability for Norway spruce (Picea abies Karst.) in Central Europe

Norway spruce ( Picea abies [L.] Karst.) occurred rarely at submountain altitudes before reaching its present position as the most important economic tree species in Central Europe. Spruce cultivation outside of natural sites is under constant threat from harmful agents. In this study, we focused on the indication of potentially suitable planting sites for Norway spruce in areas of protected submountain (< 700 m a.s.l) populations using linear discriminant analysis (LDA) of soil properties in oak-beech, mixed and spruce stands in the territory of the Czech Republic. The soil A-horizon properties in mixed stands were more similar to those in spruce than in broadleaved stands; stand mixtures resulted in lower soil property separability than the localization of individual populations (57% and 85%, respectively). The suitable sites were defined by acid phosphomonoesterase > 151 µg hour -1 , soil porosity > 63%, aeration > 53%, bulk density < 0.86 g cm -3 , cation exchange capacity < 18 cmol + kg -1 , C org < 9% and N tot < 0.5% in clusters comprising the Bohemian highlands, North Bohemian rock cities and the Outer Western Carpathians. The LDA of soil properties offered a useful tool for assessing both naturalness and forest threats to support sustainable management.