Trade-off between soil water maintenance and carbon sequestration during
the implementation of ecological restoration programs in semi-arid Loess
Plateau
Abstract
Converting degraded ecosystems into perennial vegetation in
water-limited regions creates potentially conflicting demands for soil
water maintenance and carbon sequestration. Current understanding of
these competing demands remains still limited. In this study, to
quantify the trade-off between them resulting from land-use conversion
(converting cropland into forest, shrub and grassland usually) in the
Loess Plateau, 2775 observations for soil organic carbon (SOC) stocks
(to a depth of 100 cm) and 2654 observations for soil water storage
(SWS) (to a depth of 500 cm) from peer-reviewed papers and measured data
were synthesized. Results showed that (1) Land-use conversion influenced
the trade-off greatly, and in general, converting cropland into natural
grassland and evergreen trees performed relatively better in carbon
sequestration and soil water maintenance; (2) In rainfall zone less than
550 mm, natural grassland exhibited higher capability in increasing SOC
stock but maintaining a lower SWS depletion while forest was a better
choice in rainfall greater than 550 mm; (3) With restoration age
increasing, SOC stock and SWS depletion both increased significantly,
and nevertheless natural grassland appeared to be sustainable and stable
to achieve a win-win result. Moreover, with ages increasing, an
accumulation of 0.7 Mg ha-1 SOC stock in the upper 100 cm was associated
with an approximately 5.14 mm SWS decrease in the 0-500 cm soil layers.
Overall, this study provides practical insights for land and water
managers on how to achieve the win-win results between soil- and water-
related ecosystem services during ecological restoration in
water-limited regions.