Effects of vegetation rehabilitation on soil inorganic carbon in deserts: A meta-analysis

Abstract

Over past decades, vast areas of shifting sand lands have been controlled and restored by vegetation rehabilitation. However, a quantitative and comprehensive understanding of the variation in soil inorganic carbon (SIC) following vegetation rehabilitation is lacking. Based on 422 observations derived from 31 studies in the deserts of Asia and North America, we carried out a meta-analysis to quantify the changes in SIC following vegetation rehabilitation on shifting sand lands and analyzed the relationships of the variation in SIC with environmental factors. Overall, vegetation rehabilitation on shifting sand lands significantly increased the SIC content by 43.4% in Asian and North American deserts. The conversions of shifting sand lands to forestlands, shrublands, grasslands and croplands increased the SIC contents by 77.0%, 36.2%, 54.1% and 18.9%, respectively. The response ratio of SIC (RR-SIC) to vegetation rehabilitation was significantly and positively correlated with the rehabilitation age, the response ratio of soil organic carbon and the soil pH, respectively. A quadratic relationship was observed between the RR-SIC and the mean annual precipitation. The results of meta-analysis for the changes in SIC demonstrated that vegetation rehabilitation on shifting sand lands has a high potential to sequester SIC. The relationships of RR-SIC with the environmental factors suggested that the formation of pedogenic inorganic carbon plays an important role in SIC sequestration following vegetation rehabilitation on shifting sand lands. Our findings highlight the importance of SIC in regional carbon budget, and neglecting SIC could underestimate the carbon sequestration capacity of vegetation rehabilitation in deserts.