Changes in soil organic carbon of terrestrial ecosystems in China: a mini-review.

The present study provides an overview of existing literature on changes in soil organic carbon (SOC) of various terrestrial ecosystems in China. Datasets from the literature suggest that SOC stocks in forest, grassland, shrubland and cropland increased between the early 1980s and the early 2000s, amounting to (71+/-19) Tg x a(-1). Conversion of marshland to cropland in the Sanjiang Plain of northeast China resulted in SOC loss of (6+/-2) Tg x a(-1) during the same period. Nevertheless, large uncertainties exist in these estimates, especially for the SOC changes in the forest, shrubland and grassland. To reduce uncertainty, we suggest that future research should focus on: (i) identifying land use changes throughout China with high spatiotemporal resolution, and measuring the SOC loss and sequestration due to land use change; (ii) estimating the changes in SOC of shrubland and non-forest trees (i.e., cash, shelter and landscape trees); (iii) quantifying the impacts of grassland management on the SOC pool; (iv) evaluating carbon changes in deep soil layers; (v) projecting SOC sequestration potential; and (vi) developing carbon budget models for better estimating the changes in SOC of terrestrial ecosystems in China.