关键词: 南极,雪藻,分类,分布,环境因子

Abstract:

Species composition and distribution of snow algae were studied at King George Island,Antarctica with reference to physical and chemical characters of colored snow such as snow condition,pH,conductivity and nutrient concentration of meltwater to assess the environmental factors influencing the distribution of snow algae. Most snow algae were members of Chlorophyta. Cyanophyceae and Bacillariophyceae were poorly represented compared with other freshwater habitats. Ecological studies were carried out on coastal communities of Fildes Peninsula and Ardley Island using three types of snow:red snow dominated by red resting cells of green alga,green snow dominated by a filamentous green alga, Klebsormidium sp. and brown snow dominated by a coccoid chrysophycean alga. Red and brown snow tended to occur on coarsely granulated,while,green snow tended to occur on waterlogged snow. Although pH was the same in all colored snow ( 5-6) , both conductivity and NH 4 N concentration in meltwater of green snow were higher than those of red and brown snow. Chlorophyll a contents of green snow were much higher than those of red snow. Relationship between Chlorophyll a content and nutrient concentrations of NH 4 N,PO 4 P were not clear in both red and green snow. Among studied environmental factors,snow condition,and both conductivity and NH 4J N in snow meltwater were considered to influence the distribution of snow algae.