Moss-inhabiting diatoms from two contrasting Maritime Antarctic islands
Faculty of Sciences. Biology
Meise [Belgique] :National Botanic Garden of Belgium
Plant ecology and evolution. - Meise [Belgique], 2010, currens
, p. 67-84
University of Antwerp
Background and aims The Maritime Antarctic vegetation is a poorly developed tundra dominated by lichens and mosses, mostly present in moist environments, providing a favourable habitat for microorganisms. Although, diatoms represent one of the most common algal groups in the Antarctic region, moss-inhabiting diatoms are rarely studied. The moss vegetation on islands in the Maritime Antarctic region forms a favorable habitat for non-marine diatoms. These moss-inhabiting diatom communities are of particular interest as little is known about their species composition, ecological preferences and habitats. The present paper discusses the diversity of moss inhabiting diatoms from Byers Peninsula (Livingston Island) and Ulu Peninsula (James Ross Island), Maritime Antarctic region. Methods The composition of the moss inhabiting diatom flora of 84 samples collected from Byers Peninsula, Livingston Island and Lagoons Mesa area, James Ross Island has been studied using light microscopy. Key results A total of 130 taxa, belonging to 39 genera has been recorded. Detrended Correspondence Analysis using the entire sample set clearly separates the James Ross Island (JRI) communities from the Livingston Island (LI) communities showing mostly the dominance of taxa preferring terrestrial (JRI) instead of more moist and aquatic conditions (LI). A Principal Component Analysis of only the Livingston Island samples formed three groups clearly separated by their diatom species composition. Although some taxa seem to occur in high abundances in several assemblages, a number of taxa showed a distinct preference for a particular assemblage. Biotic stress caused by marine birds and mammals, expressed in higher nutrient and salinity levels, seems to play a key role in determining the species composition. Conclusions Our results showed clearly the presence of a well developed moss-inhabiting diatom flora on both studied localities. The composition of the studied communities is determined by the type of habitat, moisture and biotic influences (salinity and nutrients).