The ecology of snow-covered systems: a brief overview of nutrient cycling and life in the cold

The general role of snow in the ecology of snow-covered systems is presente d. A brief review on the interactions between snow and climate, and between snow and microorganisms, vegetation and animals is followed by a discussio n on some of the processes which mediate nutrient cycling when snow lies on the ground. The influence of snow on nutrient cycling and its importance i n the overall biological productivity of snow-covered ecosystems is illustr ated by the study of the dynamics of nitrogen (N). The topics include the a ssimilation of N by algae within snow cover, the gaseous emissions of CO2 a nd N2O from soil under snow cover and the hydrologic export of N during sno wmelt. Copyright (C) 1999 John Wiley & Sons, Ltd.