Table 1

Global terrestrial and African carbon stocks and fluxes representative of the 1990s.


Global Total
Africa Total
Africa/Global
Global Citations
Africa Citations

Land Area [1012m2]
148.8
30.2
0.20
--
--
Human Population [109]
6.38
0.87
0.14
[15]
[15]
Soil Carbon
1600 ± 220 (2060, 1395)
200 ± 50 (240, 170)
0.13
[77–81]
[22, 81]
Live Plant Carbon
610 ± 47 (654, 559)
80 ± 28 (105, 50)
0.13
[77, 80, 82, 83]
[22, 84, 85]
Net Primary Production
-56 ± 10 (-72, -37)
-10 ± 3 (-13, -7)
0.19
[24-26, 80, 83, 86-89]
[22, 24–26, 89]
Heterotrophic Respiration
57 ± 17 (81, 34)
11 ± 5 (-18, -7)
0.19
[24, 87, 90, 91]
[24, 91]
Fossil Emissions
6.2 ± 0.2 (6.4, 6.0)
0.2 (--)
0.03
[16, 77, 92]
[16]
Net Land Use Emissions
1.7 ± 0.71 (2.8, 0.8)
0.36 ± 0.05 (0.4, 0.3)
0.21
[32, 77, 92, 93]
[31, 32, 94]
     Deforestation
1.42 ± 0.64 (2.2, 0.5)
0.24 ± 0.12 (0.37, 0.08)
0.17
[29, 32, 33, 95, 96]
[32, 33]
     Conversion to Crops
0.83 ± 0.17 (1.0, 0.6)
0.10 ± 0.01 (0.11, 0.08)
0.12
[24]
[24, 31]
Biomass Burning
2.9 ± 0.9 (4.7, 1.5)
1.1 ± 0.5 (1.8, 0.3)
0.37
[27, 28, 40, 76, 97–100]
[40, 76, 98, 100, 101]
     Deforestation
0.36 ± 0.26 (0.89, 0.13)
0.07 (--)
0.19
[27, 76, 97–100]
[76]
     Shifting Cultivation
0.60 ± 0.30 (1.13, 0.34)
0.24 (--)
0.41
[27, 28, 76, 97–99]
[76]
     Savanna Fires
1.45 ± 1.14 (4.1, 0.22)
1.47 ± 0.33 (1.67, 1.09)
1.02
[27, 28, 41, 76, 97–99]
[41, 76, 98, 102]
     Fuel wood
0.51 ± 0.36 (1.26, 0.28)
0.16 ± 0.08 (0.24, 0.08)
0.32
[27, 28, 76, 97–99]
[76]
     Agricultural Residues
0.41 ± 0.24 (0.80, 0.13)
0.01 (--)
0.03
[27, 28, 76, 97–99]
[76]
Riverine C Discharge
0.71 ± 0.13 (0.8, 0.62)
0.055 ± 0.021 (0.07, 0.04)
0.08
[35, 70]
This study
     DIC
0.41 ± 0.03 (0.44, 0.38)
0.040 ± 0.014 (0.05, 0.03)
0.10
[35, 70]
This study
     DOC
0.29 ± 0.16 (0.40, 0.18)
0.017 ± 0.006 (0.021, 0.013)
0.06
[35, 70]
This study
Precipitation C Flux
-0.51 ± 0.17 (0.68, 0.34)
-0.036 ± 0.025 (-0.054, -0.018)
0.07
[71]
This study
     DIC
-0.08 ± 0.02 (-0.10, -0.06)
-0.009 ± 0.006 (-0.013, -0.004)
0.11
[71]
This study
     DOC
-0.43 ± 0.15 (-0.58, -0.28)
-0.028 ± 0.019 (-0.041, -0.014)
0.06
[71]
This study
CH4Emissions
0.33 ± 0.11 (0.40, 0.25)
0.007 (--)
0.02
[77, 103]
This study
     CH4 from fires
0.02 ± 0.01 (0.03, 0.01)
0.005 ± 0.001 (0.007, 0.004)
0.33
[40, 41]
[40, 41]
CO Emissions
0.30 ± 0.09 (0.36, 0.24)
0.07 (--)
0.24
[77, 105]
[105]
     CO from fires
0.27 ± 0.14 (0.51, 0.12)
0.09 ± 0.02 (0.11, 0.07)
0.32
[40] [27, 28]
[40]
NMHC Emissions
0.15 (--)
0.05 ± 0.04 (0.08, 0.02)
0.33
[105]
[46, 105]
Net Biomass Trade
0.023 (--)
0.038 (--)
NA
[47]
[47]
     Gross Import
-0.345 (--)
-0.023 (--)
0.07
[47]
[47]
     Gross Export
0.370 (--)
0.061 (--)
0.16
[47]
[47]

NA is not applicable, DIC is dissolved inorganic carbon, DOC is dissolved organic carbon, NMHC is non-methane hydrocarbon, biomass import and export are the sum of cereal, paper, and wood products.

Shown are means and standard deviations of published estimates with maximum and minimum values in parentheses. Positive fluxes refer to a terrestrial source from Africa to the atmosphere, ocean, or other land masses as appropriate. Carbon stocks and fluxes have units of Pg C and Pg C y-1, respectively. See Appendices 1 for methods of calculation. Inconsistencies among tabular values arise in part due to inclusion of studies that report only some of the terms and between study variation in methods of estimation (e.g. through use of reports containing global but not African deforestation rates).

Williams et al. Carbon Balance and Management 2007 2:3   doi:10.1186/1750-0680-2-3