Betula pubescens Ehrh. subsp. carpatica (Willd.) Ascherson & Graebner, a new taxon in the flora of the Julian Alps and Slovenia and its new association Rhododendro hirsuti-Betuletum carpaticae ass. nov.

Abstract

Based on most of its morphological characters the downy birch that grows in cold cirques in the altimontane-subalpine belt of the eastern Julian Alps (Pod Špikom, Za Akom, Beli potok and Smrajka) can be classified into the taxon Betula pubescens subsp. carpatica, which is new to the flora of Slovenia. The stands with Pinus mugo, Rhododendron hirsutum and Alnus viridis where it dominates in the tree layer were described as a new association Rhododendro hirsuti-Betuletum carpaticae ass. nov. (alliance Pinion mugo, class Vaccinio-Piceetea), which is a novelty among Alpine dwarf pine communities. Although they occupy small areas its stands have a significant protective and biotope role, also as the site of rare and protected species such as Cypripedium calceolus and Listera cordata.