Distribution of Organic Carbon in the Soils of Antarctica

Abstract

Antarctica can be divided into nine ice-free regions. Only 0.35 % of the continent is ice-free, amounting to 49,500 km(2). Profile quantities of soil organic carbon (SOC) determined on a mass per area basis are greatest along the Antarctic Peninsula, intermediate in East Antarctica, and lowest in the Transantarctic Mountains (TAMs). Sea-birds input very large quantities of manure in terrestrial environments and are the dominant factor influencing SOC levels in Antarctic soils. In the McMurdo Dry Valleys, profile quantities of SOC are related to proximity to water sources. From chronosequence studies, the amounts of SOC in the TAMs peak in about 2 kyr and decline thereafter but SOC storage in soils of the Antarctic Peninsula continue to rise after 8 kyr. Because of a dramatically warming climate, the ice-free area of Antarctica is increasing and there is evidence that the soils may be acting as a sink rather than a source for atmospheric carbon dioxide.