Chinese researchers have figured out the main factors affecting carbon and nitrogen cycling on the Qinghai-Tibet Plateau, according to a research article published recently in the journal Nature Reviews Earth and Environment.

Sustainable grassland management, ecological engineering and green technology development on the plateau can curb greenhouse emissions and help maintain the carbon sink, which absorbs carbon dioxide from the atmosphere and stores carbon-containing chemical compounds, said researchers from the Chinese Academy of Sciences (CAS), China's Hohai University and Hunan Normal University.

The researchers found that the soil on the plateau contained substantial carbon stocks, with over 90 percent of carbon stocked in the soil, and 1.72 billion tonnes of nitrogen stored in the upper 2 meters of the permafrost region.

Net ecosystem productivity – the net change in carbon storage in the ecosystem – has increased as a result of climate change and restoration, according to the research.

"The plateau acts as a net carbon sink at a rate of 44 million tonnes of carbon annually, and the Qinghai-Tibet Plateau is greening as seen by remote sensing satellites," said Chen Huai, a researcher at the Chengdu Institute of Biology under CAS and first author of the research article.

"But greenhouse gas emissions, such as methane emissions, have also increased," said Chen.

The researchers deemed that factors such as temperature, nitrogen, carbon and water have an important influence on the regional biogeochemical cycles.

The Qinghai-Tibet Plateau ecosystem plays an important role in soil and water conservation, global biodiversity protection, regional climate regulation and carbon sink, and restoration efforts have driven regional increases in soil carbon and nitrogen stocks, the article said.

The researchers predicted that the Qinghai-Tibet Plateau will continue to function as a net carbon sink, and nitrogen stocks are expected to remain relatively stable there.

(With input from Xinhua)