Table 1.
Estimated late twentieth-century net carbon sink in different components of biomass and different geographical regions, across the world's major tropical forests. (We take the net gain in above-ground coarse biomass (trees of 10 cm dbh and above) recorded in Amazonia (0.62±0.22 t C ha−1 yr−1), and scale by the estimated ratio of trees of up to 10 cm dbh and lianas of 1 cm dbh and above to trees of 10 cm dbh and above in Amazonia (equal to 0.099, Phillips et al. 1998), by the most comprehensive estimate of coarse necromass:above-ground coarse biomass ratio available for Amazonia (equal to 0.127, K.-J. Chao, O. L. Phillips, T. R. Baker 2002–2006, unpublished data), and by the latest estimate of below-ground:above-ground biomass ratio (equal to 0.370, unpublished central Amazonian estimate: N. Higuchi 2000–2006, unpublished data). The values for each region are estimated by assuming the same allometry and behaviour as Amazonian forests. Forest area estimates are adapted from Mayaux et al. (2005). GLC, Global Land Cover; FRA CS, FAO Forest Resource Assessment (2000) country statistics; FRA RS, FAO Forest Resource Assessment (2000) remotely sensed values. Scaled-up estimates based on FRA RS highlighted in italics are mentioned in the text. Units for biomass stock increases are 106 t C yr−1.)
| land cover class | forest area | coarse above-ground biomass increase (trees of 10 cm dbh and above) | above-ground biomass increase (trees of up to 10 cm and lianas of 1 cm and above) | coarse necromass increase | total above-ground biomass and necromass increase | below-ground biomass increase | total biomass and necromass increase | ||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| ha 106 | mean | CI | mean | mean | mean | CI | mean | mean | CI | ||
| South America | |||||||||||
| GLC2000 | humid tropical forest | 630.5 | 392.2 | 142.4 | 38.8 | 49.8 | 480.9 | 174.6 | 159.4 | 640.3 | 232.4 |
| dry tropical forest | 146.7 | 91.3 | 33.1 | 9.0 | 11.6 | 111.9 | 40.6 | 37.1 | 149.0 | 54.1 | |
| flooded tropical forests | 25.3 | 15.7 | 5.7 | 1.6 | 2.0 | 19.3 | 7.0 | 6.4 | 25.7 | 9.3 | |
| total | 802.5 | 499.2 | 181.2 | 49.4 | 63.4 | 612.1 | 222.2 | 202.9 | 815.0 | 295.8 | |
| FRA CS | closed forest | 858.3 | 533.9 | 193.8 | 52.9 | 67.8 | 654.6 | 237.6 | 217.0 | 871.7 | 316.4 |
| open forest | 68.9 | 42.9 | 15.6 | 4.2 | 5.4 | 52.5 | 19.1 | 17.4 | 70.0 | 25.4 | |
| total | 927.2 | 576.8 | 209.4 | 57.1 | 73.3 | 707.2 | 256.7 | 234.5 | 941.6 | 341.8 | |
| FRA RS | forest total | 780.2 | 485.4 | 176.2 | 48.1 | 61.6 | 595.1 | 216.0 | 197.3 | 792.3 | 287.6 |
| Africa | |||||||||||
| GLC2000 | humid tropical forest | 232.7 | 144.8 | 52.5 | 14.3 | 18.4 | 177.5 | 64.4 | 58.8 | 236.3 | 85.8 |
| dry tropical forest | 415.1 | 258.2 | 93.7 | 25.6 | 32.8 | 316.6 | 114.9 | 105.0 | 421.6 | 153.0 | |
| flooded tropical forests | 13.1 | 8.1 | 3.0 | 0.8 | 1.0 | 10.0 | 3.6 | 3.3 | 13.3 | 4.8 | |
| total | 660.9 | 411.1 | 149.2 | 40.7 | 52.2 | 504.1 | 183.0 | 167.1 | 671.2 | 243.6 | |
| FRA CS | closed forest | 352.7 | 219.4 | 79.6 | 21.7 | 27.9 | 269.0 | 97.6 | 89.2 | 358.2 | 130.0 |
| open forest | 288.9 | 179.7 | 65.2 | 17.8 | 22.8 | 220.3 | 80.0 | 73.1 | 293.4 | 106.5 | |
| total | 641.6 | 399.1 | 144.9 | 39.5 | 50.7 | 489.3 | 177.6 | 162.2 | 651.6 | 236.5 | |
| FRA RS | forest total | 518.5 | 322.6 | 117.1 | 31.9 | 41.0 | 395.5 | 143.6 | 131.1 | 526.6 | 191.1 |
| Asia | |||||||||||
| GLC2000 | humid tropical forest | 230.6 | 143.5 | 52.1 | 14.2 | 18.2 | 175.9 | 63.8 | 58.3 | 234.2 | 85.0 |
| dry tropical forest | 144.8 | 90.1 | 32.7 | 8.9 | 11.4 | 110.4 | 40.1 | 36.6 | 147.1 | 53.4 | |
| flooded tropical forests | 13.5 | 8.4 | 3.0 | 0.8 | 1.1 | 10.3 | 3.7 | 3.4 | 13.7 | 5.0 | |
| total | 388.9 | 241.9 | 87.8 | 24.0 | 30.7 | 296.6 | 107.7 | 98.3 | 395.0 | 143.4 | |
| FRA CS | closed forest | 416.2 | 258.9 | 94.0 | 25.6 | 32.9 | 317.4 | 115.2 | 105.2 | 422.7 | 153.4 |
| open forest | 58.3 | 36.3 | 13.2 | 3.6 | 4.6 | 44.5 | 16.1 | 14.7 | 59.2 | 21.5 | |
| total | 474.5 | 295.2 | 107.2 | 29.2 | 37.5 | 361.9 | 131.4 | 120.0 | 481.9 | 174.9 | |
| FRA RS | forest total | 272.0 | 169.2 | 61.4 | 16.8 | 21.5 | 207.5 | 75.3 | 68.8 | 276.2 | 100.3 |
| global | |||||||||||
| GLC2000 | humid tropical forest | 1093.8 | 680.5 | 247.0 | 67.4 | 86.4 | 834.2 | 302.8 | 276.6 | 1110.8 | 403.2 |
| dry tropical forest | 706.6 | 439.6 | 159.6 | 43.5 | 55.8 | 538.9 | 195.6 | 178.7 | 717.6 | 260.5 | |
| flooded tropical forests | 51.9 | 32.3 | 11.7 | 3.2 | 4.1 | 39.6 | 14.4 | 13.1 | 52.7 | 19.1 | |
| total | 1852.3 | 1152.3 | 418.3 | 114.1 | 146.3 | 1412.7 | 512.8 | 468.4 | 1881.1 | 682.9 | |
| FRA CS | closed forest | 1627.2 | 1012.3 | 367.5 | 100.2 | 128.6 | 1241.1 | 450.5 | 411.5 | 1652.5 | 599.9 |
| open forest | 416.1 | 258.9 | 94.0 | 25.6 | 32.9 | 317.4 | 115.2 | 105.2 | 422.6 | 153.4 | |
| total | 2043.3 | 1271.1 | 461.4 | 125.8 | 161.4 | 1558.4 | 565.7 | 516.7 | 2075.1 | 753.3 | |
| FRA RS | forest total | 1570.7 | 977.1 | 354.7 | 96.7 | 124.1 | 1198.0 | 434.9 | 397.2 | 1595.1 | 579.1 |