This widespread ecological system is composed of unvegetated landscapes of annual/perennial ice and snow in the North American arctic, and south into the highest elevations of the Rocky Mountains, Pacific coastal ranges, and the Sierra Madre of Mexico. They occur where snowfall accumulation exceeds melting. The primary ecological processes include snow/ice retention, wind desiccation, and permafrost. The snowpack/ice field never melts or, if so, then for only a few weeks. In places the ice fields are extensive, covering huge areas, while in the alpine, ice fields are part of the alpine mosaic consisting of alpine bedrock and scree, tundra dry meadow, wet meadow, fell-fields, and dwarf-shrubland. There are no vascular plants occurring in this system; biotic composition may include algal blooms, insect communities, and birds or mammals foraging on the insects.
Information Source: http://www.natureserve.org/explorer/