Vegetation restoration in dryland with shrub serves as a carbon sink: evidence from a 13-year observation at the Tengger Desert of Northern China

Dryland area accounts for about 40% of land area, which play a significance role on regulating the carbon sequestration variability of land. Vegetation restoration in dryland, which is a widely adopted to prevent land degradation, could potential serve as a carbon sink based on the short-term observation. However, the sustainability of the carbon sink for the revegetated ecosystem in dryland is still unknown due to the lack of the long term of the observation data. Thus, we are aiming to investigate the carbon sequestration ability of the planted vegetation in dryland area in long run. Based on the observation of the long established revegetation, we found the revegetation area serves as a carbon sink in all of the year as net ecosystem production (NEP) is positive and demonstrate a significant increasing trend by 5.65 gC m −2 yr −2 . The increase in spring temperature, the earlier start of carbon earlier onset of carbon uptake and longer duration of carbon uptake may contribute to the emergence of a gradual trend in NEP, but the amount of annual NEP was more determined by summer precipitation. Meanwhile, our results revealed that the increasing of carbon sequestration by the revegetation is not over-consuming water resources as there is no soil water depletion. This highlights that revegetation in dryland area could serves a carbon sink in long run.