Land-use/cover conversion affects soil organic carbon stocks

Soil organic carbon (SOC) constitutes a large pool within the global carbon cycle. Sequestering carbon in SOC is seen as one way to mitigate climate change by reducing atmospheric carbon dioxide.

Changes in land-use/cover conversion strongly drive variation of SOC stocks. A recent study by scientists from the Xinjiang Institute of Ecology and Geography (XIEG) of the Chinese Academy of Sciences showed that area and structure of land-use/cover conversion along the main channel of the Tarim River in China have changed, and therefore affected SOC stocks in this area.

The study, based on data from Landsat Thematic Mapper images for 2000-2010, analyzed the changes in four types of land use and cover, as well as their influence on SOC content, density, and regional stocks along the main channel of the Tarim River.

"Specifically, the areas of cultivated, industrial and residential, and shrub land increased, particularly cultivated and shrub land. The areas of forestland, grassland, water bodies, and unused land decreased", said YANG Yuhai, leading researcher of the study from XIEG.

SOC stocks in forestland, grassland and unused land decreased between 2000 and 2010. The total SOC stock for the forestland, shrub land, grassland and unused land was lower in 2010 than 2000, the study found.

"Conversions from forestland to shrub land, forestland to grassland, forestland to unused land, grassland to shrub land, grassland to unused land, and shrub land to unused land decreased the SOC stocks," YANG said.

As the largest inland river basin with more than one million square kilometers, and a major production area of grain and cotton in China, Tarim River Basin is rich in natural resources but fragile in ecology. This study provides a scientific basis for management of land use and eco-environmental protection in arid areas.

Results of the study were published on Plos One, entitled “Land-use/cover conversion affects soil organic-carbon stocks: A case study along the main channel of the Tarim River, China”.

Contact: LIU Jie, Xinjiang Institute of Ecology and Geography

E-mail: liujie@ms.xjb.ac.cn