Table 1.

Areas and ecosystem C densities (area weighted mean ± SD) at the beginning (PR-B) and in the year 2010 (PR-2010) and the reference sites (RS-2010) for six key ecological restoration projects in China

National key ecological projects
Properties, C densities and sequestrations of the projectsForest ProtectionGrassland ConservationNorth Shelter Forest fourthSand ControlGGPRiver Shelter Forest second
Area, 106 ha72.9605.23.39.22.3
Duration1998–20102003–20102001–20102001–20102000–20102001–2010
C densities, Mg C per ha
 Biomass
  PR-B43.7 ± 19.32.6 ± 1.137.3 ± 16.93.1 ± 2.90*5.9 ± 3.5
  PR-201050.3 ± 17.43.7 ± 1.6256.6 ± 15.616.2 ± 4.519.7 ± 5.927.9 ± 8.8
  Increment6.61.119.313.119.722.0
  RS-20102.6 ± 1.841.6 ± 18.33.5 ± 2.20*7.7 ± 2.8
 Soil
  PR-B144.8 ± 42.782.5 ± 50.244.8 ± 16.335.9 ± 7.344.0 ± 29.363.5 ± 12.2
  PR-2010150.5 ± 25.883.5 ± 50.549.3 ± 20.138.7 ± 10.453.7 ± 26.366.7 ± 18.9
  Increment5.61.03.22.99.73.2
  RS-201082.6 ± 50.041.4 ± 20.730.3 ± 8.951.3 ± 41.8
 Total
  PR-B188.5 ± 53.985.1 ± 51.382.1 ± 28.339.0 ± 10.344.0 ± 29.369.4 ± 13.0
  PR-2010200.7 ± 49.087.2 ± 52.2105.9 ± 31.654.8 ± 14.273.4 ± 28.094.6 ± 19.0
  Increment12.22.123.815.829.425.3
  RS-201085.2 ± 51.183.0 ± 33.033.8 ± 9.959.0 ± 42.9
Total C sequestration rate, Mg C per ha per y0.940.262.381.582.672.53
  • * The GGP is implemented in hilly cropland; therefore, the biomass C density in the project area in 2000 (beginning of GGP) and at reference sites in 2010 were set as 0.

  • The contribution of the Forest Protection project to C sequestration was estimated based on the C storage in the newly planted forest vegetation (CPVN), the C retention (CR) resulting from harvest volume reduction, and soil organic C retention (SCR); see Eqs. 1014. No reference sites were set for estimation.

  • The contribution of GGP to C sequestration in soil is considered to be the soil organic C retention (SCR), that is, the reduced C loss due to the control of soil erosion attributed to GGP, which was estimated using the results of Deng et al. (38), as in Eqs. 15 and 16.