Baseline of carbon stocks in pinus radiata and eucalyptus spp. plantations of Chile

Abstract

Forest plantations have a large potential for carbon sequestration, playing an important role in the global carbon cycle. However, despite the large amount of research carried out worldwide, the absolute contribution of forest plantations is still incomplete for some parts of the world. To help bridge this gap, we calculated the amount of C stock in three fast growing forest species in Chile. Carbon pools in above-ground and below-ground biomass, forest floor, and soil were considered for this analysis. Across the plantation forests of Chile, carbon accumulated in the above-ground biomass was 181-212 Mg . ha(-1) for Pinus radiata, 147-180 Mg . ha(-1) for Eucalyptus nitens, and 95-117 Mg . ha(-1) for Eucalyptus globulus (age 20-24 years for P. radiata and 10-14 years for Eucalyptus). Total C stocks were for 343 Mg . ha(-1) for P. radiata, 352 Mg . ha(-1) for E. nitens, and 254 Mg . ha(-1) for E. globulus, also at the end of a typical rotation. The carbon pool in the forest floor was found to be significantly lower (less than 4% of the total) when compared to the other pools and showed large spatial variability. Our results agree with other studies showing that 30-50% of the total C stock is stored in the soil. The baseline data will be valuable for modelling C storage changes under different management regimes (changes in species, rotation length and stocking) and for different future climates. Given the contribution of soils to total carbon stocks, special attention should be paid to forest management activities that affect the soil organic carbon pool.