Soil-forming effect of Douglas fir at lower altitudes - a case study.

Forest ecosystem and in particular forest soil biodiversity and stability could be jeopardised by the im - propriate tree species composition. Douglas fir is a species which has a high potential in Europe both from economic and biodiversity aspects of forest management. A more detailed analysis of Douglas fir effects on the humus forms and forest soil under different conditions is needed to evaluate the future use of this species in central European forests. The study plots cover acid sites with natural hardwood, spruce monoculture and Douglas fir stands. The soil analysis proved favourable effects of this species on soil chemistry, organic matter as well as nutrient dynamics. When compared with domestic coniferous species, Douglas fir proved to have lower acidifying effects on upper soil layers and contributes to better humus forms, recycling nutrients more effectively and producing litter which could be easily decomposed.