The following table shows six tropical forests, arranged from least to most fertile soils, estimated from total soil nitrogen.
Parameter | Lower montane rainforest, Puerto Rico | Amazon caatinga, Venezuela | Oxisol forest, Venezuela | Evergreen forest, Ivory Coast | Dipterocarp forest, Malaysia | Lowland rainforest, Costa Rica |
Above-ground biomass (metric tons/ha) | 228 | 268 | 264 | 513 | 475 | 382 |
Root biomass (metric tons/ha) | 72.3 | 132 | 56 | 49 | 20.5 | 14.4 |
Total soil nitrogen (kg/ha) | –– | 785 | 1697 | 6500 | 6752 | 20 000 |
Turnover time of leaves (years) | 2 | 2.2 | 1.7 | –– | 1.3 | –– |
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