关键词: 荒漠化, 干旱土壤, 土壤碳固存, 碳循环, 全球变化

Abstract: Desertification has aroused very severely ecological degradation issues in arid zone, its cause and development play a significant role in soil carbon cycling of dryland. Soils are major reservoir of carbon and important sink in terrestrial ecosystem. Global climatic changes correlate directly with the sequestration and emission of carbon by soil. Dryland does most in global carbon cycling because it occupies 40% of the earth's surface. The main influences on carbon cycling of soil degradation and desertification in drylands include two aspects: (1) the promoted mineralization of SOC (soil organic carbon) and SIC (soil inorganic carbon) leads to emission of CO₂ to the atmosphere, increasing greenhouse effect; (2) the increase of dust content in atmosphere mitigates indirectly the lose of soil carbon to some extend through limiting radiation. In this paper, the recent advances of related researches were reviewed, the potential ability of carbon sequestration by soils and role of dryland in mitigating greenhouse effect were discussed. Finally, strategies of promoting sequestration of soil carbon in dryland were suggested based on the contribution of dryland to global carbon balance.

Key words: desertification, soil degradation, Carbon sequestration by soils, Carbon cycling, global climatic changes