Recent change of artic tundra ecosystems from a net carbon dioxide sink to a source

Abstract

Arctic tundra has been a net sink for carbon dioxide during historic and recent geological times^1-4, and large amounts of carbon are stored in the soils of northern ecosystems. Many regions of the Arctic are warmer now than they have been in the past^5-10, and this warming may cause the soil to change from a carbon dioxide sink to a source by lowering the water table^11,12, thereby accelerating the rate of soil decomposition (CO₂ source)^3,13-15 so that this dominates over photosynthesis (CO₂ sink). Here we present data indicating that the tundra on the North Slope of Alaska has indeed become a source of carbon dioxide to the atmosphere. This change coincides with recent warming in the Arctic, whether this is due to increases in greenhouse gas concentrations in the atmosphere or to some other cause. Our results suggest that tundra ecosystems may exert a positive feedback on atmospheric carbon dioxide and greenhouse warming.

Citation

Oechel, Walter C.; Hastings, Steven J.; Vourlitis, George; Jenkins, Mitchell; Riechers, George; Grulke, Nancy. 1993. Recent change of artic tundra ecosystems from a net carbon dioxide sink to a source. Nature. 361: 520-523.