The variability of Gentiana pneumonanthe L. subpopulations in different habitat conditions

Abstract

The impact of habitat conditions on the spatio-temporal variability of abundance and structure of subpopulations of Gentiana pneumonanthe L. was investigated in the years 2013-2015 in patches of abandoned Molinion caeruleae meadows in different stages of successional overgrowing (Patches I-III), as well as in a patch of willow thickets (Patch IV). The height of the standing vegetation and soil humidity increased in successive patches, while the light intensity at ground level diminished gradually. Performed observations showed that abundance of subpopulations decreased from Patch I to Patch IV. Seedlings, juvenile and dormant individuals were not found in all subpopulations, whereas the share of vegetative and generative adults differed significantly. The total number of above-ground units per individual, as well as the height of vegetative stems, increased in consecutive years; moreover, it augmented from Patch I to Patch III and it diminished in Patch IV. The height of flowering stalks rose in consecutive years and in successive patches. The numbers of flowers and fruits in consecutive years were rather constant, whilst in successive study sites they augmented gradually. In light of the performed studies, it might be concluded that the subpopulation occurring in Patch I presents the best state, whereas the subpopulation occurring in Patch IV shows the worst condition and, in the near future, might be eliminated from the colonised site.