We studied species richness, composition and coverage of the bryophyte layer in young deciduous forest plantations on abandoned agricultural lands in relation to overstory tree species (hybrid aspen or silver birch), land use history (crop field or grassland), site preparation method (whole-area ploughing or strip tillage), and soil properties (moisture, pH, concentrations of N, P and K). The aim of these plantations is to produce pulpwood and energy-wood under the principles of short-rotation forestry. The area under forest plantations is increasing in the region; however their impact on biodiversity is still scantily studied. Previous studies on understory vegetation have focused more often on vascular plants and less frequently on bryophytes. For this experiment, a total of 248 vegetation plots (2 m × 2 m) were established within 62 long-term experimental plots (size 0.1 ha). Thirty eight bryophyte species were found in total, with an average of 1.86 ± 0.11 species per vegetation plot and 4.02 ± 0.26 per experimental plot. The mean coverage of the bryophyte layer was 11.54 ± 2.14%. As expected, typical bryophytes were light-demanding perennials. According to substrate preference the majority of species were either epigeic or generalist. Positive correlation was observed between soil pH and coverage of the bryophyte layer. The impact of land use history and site preparation method on species composition was still evident, since the number of short-living bryophytes was higher in former fields and whole-area ploughed sites. Bryophyte species richness was not affected by overstory tree species in young plantations. Obviously during the further management of plantations the emergence of new substrata e.g. stem bark of bigger trees, leaning stems, branch litter and cutting residues should add diversity to the bryophyte vegetation.

Keywords: abandoned agricultural lands, bryophytes, floristic diversity, hybrid aspen, plantation forestry, silver birch