Ecosystem carbon cycle under changing atmosphere, climate and land use in Dryland East Asia

Dryland ecosystems cover a large area of the earth's land surface and contain a huge amount of soil organic and inorganic carbon (C). Because of the rapid climate change and various land use types in Dryland East Asia (DEA), it is important to study the responses of ecosystem C cycling to both climate and land use changes in this region. In this chapter, we first used a process-oriented terrestrial biosphere (Organizing Carbon and Hydrology in Dynamic Ecosystems, ORCHIDEE) to simulate the carbon and water cycles in DEA. Then, we synthesized the response patterns and mechanisms of ecosystem C cycling to changes in atmospheric (CO₂ and nitrogen) and climatic (precipitation and temperature) conditions as well as land use. Both the current simulation and previous findings show the environmental changes in this area have greatly impacted ecosystem C cycling and will play an important role in the future regional C budgets. This chapter highlights the urgent needs of improving ecosystem management to enhance the contribution of DEA in mitigating the regional and global climate change.