Species composition in low mountain beech (Fagus sylvatica L.) stands in the Bieszczady National Park under the global warming

Abstract

The author analyzes the changes in the tree species composition of Dentario glandulosae-Fagetum Klika 1927 em. Mat. 1964 in the mountain stands of Bieszczady National Park in 1993-2003. The analysis takes into account the changes over a ten-year period in the number and volume structure of each tree species in each stand layer: young natural regeneration, undergrowth, and mature stand. Additionally, after comparing the results with the natural Carpathian forests' structure, the adaptation level of the present tree species composition to the current climate and soil conditions, as well as probable directions of future changes have been assessed. A ten-year period is too short to find significant changes in stand species structure but it is possible to see some trends: beech share in stands is increasing and fir is decreasing.