Biogeochemical processes in high-latitude lakes and rivers

Polar aquatic ecosystems are excellent laboratories for biogeochemical research. The polar regions are among the least modified by human activities, so there are opportunities to study biogeochemical processes in the absence of overwhelming anthropogenic influences. In addition, there are abundant freshwater ecosystems in which comparative or experimental work can be conducted, and increasing evidence for environmental change is driving a rapid expansion in polar research. This chapter draws upon extensive surveys of lake chemistry to summarize the biogeochemical composition of polar lakes, and to illustrate the growing potential for crosssystem comparisons. It describes the general features of biogeochemical cycles in polar aquatic environments, and the important and sometimes unique controls over biogeochemical processes.