Desmids of Gorce Mts. Geobotanical studies

Abstract

The presented work is the first comprehensive study on the desmids of mountainous areas of the Gorce region in Poland. The Gorce Mts flora of the order Desmidiales comprises 20 genera and 247 species. The most diverse genera in the Gorce Mts are Cosmarium with 99 taxa, Closterium with 39 taxa, Staurastrum with 38 taxa and Euastrum with 17 taxa. All reported taxa are described and documented by original hand drawings and microphotographs. Environmental data with geographical coordinates are included for all studied sites. Among the recorded taxa, eight (Actinotaenium borgeanum, Actinotaenium gelidum, Actinotaenium perminutum, Cosmarium alpestre, Cosmarium dispersum, Cosmarium paragranatoides, Closterium sublaterale, Staurastrum pyramidatum) are new for the Polish flora. An important factor affecting the biodiversity of desmids in the Gorce area is human activity. In typically anthropogenic habitats, which in the study area include roads and paths, 157 species were found (63.7% of the Gorce desmid flora). Many montane species, such as Closterium pusillum and Cosmarium decedens, associated with wet moss on rocks, had secondary habitats there. A group of 21 species found only in anthropogenic habitats can be considered anthropophytes of the studied area. There are also semi-natural habitats in the form of meadows that persist only due to human activity. The situation is similar to that of vascular plants. Clearings used until the 1980s showed significantly higher species richness than clearings where grazing has been abandoned for a long time. Overall, human activity has contributed to an increase of desmid species diversity in the Gorce region.