SEASONAL INVESTIGATIONS OF SOLUBLE CARBOHYDRATES AND PIGMENT LEVELS IN ANTARCTIC BRYOPHYTES AND LICHENS

Levels of soluble carbohydrates, moisture, and pigments in the major b ryophytes and lichens from the Windmill Islands, continental Antarctic a, were monitored over a 14- month period. Gas-liquid chromatography r evealed little seasonal change in soluble carbohydrate levels. Water c ontent of vegetation varied throughout the season with maximum hydrati on occurring over the summer months. Pigment levels also varied season ally with a decrease in total chlorophyll and chlorophyll a/b ratios d uring winter. Levels of total carotenoids increased over summer in res ponse to high ambient irradiation. In contrast with the seasonality of soluble carbohydrates reported in some cryptogams from subpolar regio ns, the lack of any significant seasonal changes in the Antarctic bryo phytes and lichens may be due to the extreme climate and rapid tempera ture fluctuations in the continental Antarctic environment.