STANDING CROP AND NET PRODUCTION OF SEDGE MEADOWS OF AN UNGRAZED POLAR DESERT OASIS

Standing crop and net production were measured in sedge meadow communities of a coastal lowland at Alexandra Fiord, Ellesmere Island (79-degrees-N), a high arctic oasis. The meadows are dominated by Carex aquatilis stans, Carex membranacea, and Eriophorum angustifolium triste. Dwarf shrubs (Dryas integrifolia and Salix arctica) are also important constituents. Total standing crop ranged from 1400 to 3200 g/m2 and was largely (50-80%) composed of attached dead matter. The accumulation of litter and dead roots and rhizomes is attributed to low rates of decomposition, and to a lack of grazing by large herbivores such as muskox. Net production (100-200 g/m2) was similar to more southerly tundra meadows, emphasizing the oasis-like nature of this high arctic location. Furthermore, net production did not vary significantly among sites or years. The consistent net production was due to similar edaphic and climatic conditions, the concentration of biomass belowground, and the apparently fixed growth period of arctic sedges.