Ecological studies of the moss and lichen communities in the ice-free areas near Syowa Station, Antarctica

Ecological investigations of the terrestrial vegetation were made as a part of the studies on the ecosystem to serve as the background for an evaluation of the effects of environmental contamination by human activities in the Antarctic. Under the project of the 16th Japanese Antarctic Research Expedition (JARE-16), field investigations were carried out in certain ice-free areas near Syowa Station during January and February 1975. The present paper includes some noteworthy results obtained in this field work. (1) It became clear from floristic and taxonomical investigation that one lichen (Physica dubia (HOFFM.) LETT.) and two mosses (Bryum antarcticum HOOK. f. & WILS. and Grimmia lawiana WILLIS) could be added to the flora of the areas, and also that there were some species which previously had been treated under wrong scientific names. (2) The moss communities were classified into six sociations on the basis of species composition. The distribution of the moss sociations was analyzed in relation to the pattern of water supply. From this investigation, it was ascertained that the distribution of some sociations was closely correlated with this pattern. (3) A remarkable relationship between lichen communities and bird nests was observed in the central region of Skarvsnes. It seems that the species composition and the distribution of the lichen communities are influenced decidedly by the organic nutrients supplied from the excrement of sea birds. (4) The direction of the habitat of each terrestrial community was examined in all ice-free areas. Most of the communities grew in habitats on the leeward side of wind-barriers facing from west-northwest to southwest, although the direction was somewhat determined by the pattern of water supply in their habitat. Further examination in detail, however, revealed that each ice-free area had the most frequent direction slightly different from that of the others. This seems to suggest that the direction of the prevailing wind may be different in each ice-free area