Prof. Xiujun Wang1
1Beijing Normal University, Haidian, China
Soil organic carbon (SOC) and inorganic carbon (SIC) are important reservoirs of carbon in arid, semi-arid and semi-humid regions. While SOC has attracted great attention, SIC exceeds SOC greatly in arid and semi-arid lands, thus may play an important role in carbon sequestration. However, there were not much done to evaluate the dynamics of both SOC and SIC in the terrestrial ecosystems; and limited studies showed inconsistent findings on the relationship between SIC and SOC. While both negative and positive correlations between SOC and SIC may exist, water limitation and saline/alkaline conditions in the arid and semi-arid regions would be beneficial to carbonate formation. Thus, a positive relationship would be more common, in particular, when SOC and SIC stocks in deep soils are included, which implies that increasing SOC may lead to an increase of SIC in arid and semi-arid lands. Here, we present a summary of relevant studies conducted in the northern China’s agricultural land, and provide a review on the SIC dynamics and its relationship with SOC. We explore the underlying mechanisms regulating the transformations of main soil carbon forms, and discuss the potential of carbon sequestration as SOC and SIC in arid and semi-arid lands.
Xiujun Wang is a professor and chief scientist at the College of Global Change and Earth System Science, Beijing Normal University. Her recent research interests include the dynamics of organic and inorganic carbon in soils of the arid and semi-arid regions of China. One of her main accomplishments was the first assessment of the accumulation rate of soil carbonate in the cropland of north China.