ZLV Online

Afforestation of agricultural lands took place in different sites and ecological conditions, including lower and medium-elevated localities. The presented study documents the rapidity of surface humus layers accumulation and their characteristics, as well as the production in stands of Scots pine (Pinus sylvestris), Norway spruce (Picea abies), birch (Betula verrucosa) and Douglas fir (Pseudotsuga menziesii) on the territory of the School Training Forest Kostelec nad Černými lesy, at the altitude 430 m a.s.l., on the locality of forest site type 4Q1 (nutrient-poor Oak-Fir bilberry). The plots were compared with the neighbouring continuously-forested site with pine-spruce old stand and with the arable field. During the first roughly 40 years, considerable changes were documented on the afforested plots. The surface humus layers in the coniferous stands were formed, the humus forms being more favourable comparing with the old-forest-site. Acidification and loss of nutrients run in the upper mineral horizons. These processes were also responsible for the less favourable character of the forest soil in the old stand. Birch showed lesser shifts comparing to the conifers in the mineral horizon, the surface humus accumulation has not been registered there yet. The lowest degradation among conifers showed the Douglas fir, being able to uptake deficient nutrients intensively. Douglas fir is the most productive tree species with favourable soil forming effects from the studied spectrum.