Estimating the global potential of forest and agroforest management practices to sequester carbon

Forests play a prominent role in the global C cycle. Occupying one-third of the earth's land area, forest vegetation and soils contain about 60% of the total terrestrial C. Forest biomass productivity can be enhanced by management practices, which suggests that, by this means, forests could store more C globally and thereby slow the increase in atmospheric CO₂. The question is how much C can be sequestered by forest and agroforest management practices. To address the question, a global database of information was compiled to assess quantitatively the potential of forestry practices to sequester C. The database presently has information for 94 forested nations that represent the boreal, temperate and tropical latitudes. Results indicate that the most promising management practices are reforestation in the temperate and tropical latitudes, afforestation in the temperate regions, and agroforestry and natural reforestation in the tropics. Across all practices, the median of the mean C storage values for the boreal latitudes is 16 tCha^?1 (n=46) while in the temperate and tropical latitudes the median values are 71 tCha^?1 (n=401) and 66 tCha^?1 (n=170), respectively. Preliminary projections are that if these practices were implemented on 0.6 to 1.2×10⁹ ha of available land over a 50-yr period, approximately 50 to 100 GtC could be sequestered.