Mechanisms and controlling factors of grassland ecosystem greenhouse gas emissions

Grassland ecosystems are the main terrestrial ecosystems, and are intensively affected by human activities. Greenhouse gas emissions from grassland ecosystems have severely impacted on the global climate changes. This study gave a brief review of the mechanisms and controlling factors of CO2, CH4 and N2O emissions from grassland ecosystems and indivated that the conjunction of environmental, biological and management factors played a key role in variations of greenhouse gas emissions from grassland ecosystems. The key issues and further tasks were discussed, which included mechanisms and the overall process of greenhouse gas emissions, and the comparative study of greenhouse gas emissions of grassland ecosystems in different regions. Developing and improving greenhouse gas emission inventories under different grassland types and utilization patterns, according to the methods recommended by IPCC, will also be the further study objectives.