| Table 1 The productivity of forest types and other forms of vegetation. | ||
| Net primary production (grams of carbon per square meter per year) |
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| Vegetation | Range | Mean |
| Forests | ||
| Tropical (wet) | 450-1600 | 990 |
| Temperate | 270-1125 | 560 |
| Boreal | 180-900 | 360 |
| Savannahs | 90-900 | 400 |
| Grasslands | 90-675 | 270 |
| Cultivated land | 45-2800 | 290 |