Sujetovienė, G. 2006. Understorey Vegetation of Scots Pine Stands along a Pollution Gradient Near the Nitrogen Fertilizer Plant. Baltic Forestry, 12 (1): 51-58

Species composition of the understorey of Scots pine (Pinus sylvestris L.) forests was studied along a 9 km transect running east from a nitrogen fertilizers producer plant J/V “Achema”, situated in central Lithuania. Long-term accumulation of nitrogen and sulphur in the forest ecosystems has changed plant communities. Species typical of Vaccinio–myrtillosa site type (e.g., Vaccinium myrtillus, V.vitis-idaea) were those that increased in cover with the distance from “Achema”. Many non–typical species (Calamagrostis epigejos, Chameriom angustifolium, Galeopsis tetrahit, Rubus idaeus, Stellaria graminea) preferring nutrient–rich sites increased in frequency in the vicinity of “Achema”. The cover of species which were indifferent to low soil pH (Deschampsia cespitosa, Chelidonium majus, Rumex acetosella, Athyrium filix–femina) was negatively correlated with the distance from “Achema”. According to the comparison of average Ellenberg indicator values between the sample plots and reference level, the sample plots had become more acid and nitrogen rich.

Key words: Ellenberg indicator values, forest vegetation, nitrogen deposition, Scots pine stands, species abundance