Ecological and Physiological Investigations in Continental Antarctic Cryptogams: I. Vegetation Pattern and its Relation to Snow Cover on a Hill Near Casey Station, Wilkes Land

Abstract

Summary The vegetation of the summit region of a small ice:free hill in the inner part of the east-Antarctic Bailey Peninsula, Windmill Islands, was recorded by 105 releves along various transects. It was analysed by the Braun-Blanquet phytosociological method, by a divisive polythetic procedure and tested by an ordination analysis. An epipetric Usnea sphacelata- and a Rinodina olivaceobrunnea -moss turf community were described as distinct communities and additionally a transient community. The vegetation is highly dependent on the extension and duration of a shallow snow cover, because snow is the main water source for the poikilohydrous cryptogams. This was shown by recording regularly the changes of snow cover in 5 quadrats of the summit region. The photophilous, wind- exposed vegetation of this hill resembles ecologically that of high arctic and alpine regions. The dominance of Neuropogon species is characteristic of the Antarctic and also the Andine region, in equivalent arctic-alpine communities Umbilicaria species are the most prominent element. The epibryic and epigeic Rinodina olivaceobrunnea -moss turf community has no identical counterpart in the arctic and alpine region.