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