Genetic material significantly influences carbon storage in Eucalyptus plantations in Cerrado

In Brazil, Eucalyptus species are the predominant commercial forest crop, estimated to store 1.79 billion Mg ha⁻¹ CO₂ eq. Clonal hybrids are widely used in these plantations. The carbon (C) stock within Eucalyptus stands represents a significant environmental contribution by these crops, potentially mitigating global warming through C sequestration. Considering that genetic factors and silvicultural management practices are known to influence Eucalyptus C accumulation, this study aimed to evaluate the effect of genetic material on C storage in Eucalyptus stands. The research was conducted in the rural area, Federal District, Brazil, on two six-year-old Eucalyptus stands (hybrid Eucalyptus urophylla × Eucalyptus grandis): a 19 ha stand of clone GG100 and a 4 ha stand of clone I224, both planted at a spacing of 3 × 2 m. Each stand was delimited by twenty 20 × 30 m plots for the inventory. Diameter at breast height (DBH) was measured for all trees within the plots to determine average DBH. Total height (Ht) was measured using an electronic clinometer and hypsometer. Five trees of average diameter, representative of the population in each stand, were selected for destructive sampling using rigor cubing to estimate biomass. To determine C content, 3 g of material retained on a 120-mesh sieve was analyzed using a CHNS Macro Vario Cube elemental analyzer. The data revealed statistically significant variations in shoot, root, and total C stocks between the two Eucalyptus clones (p < 0.05). Clone I224 exhibited statistically significant differences in C content between different tree compartments and between the two study areas. Wood consistently showed the highest C content and stock compared to other compartments (p < 0.05). Comparing the genetic materials, clone I224 demonstrated a significantly higher total C stock, with an average of 82.58 kg per tree. This clone consistently exhibited higher C levels and stocks in all three compartments. This clone also had greater representation and stored 38% more C compared to the clone GG100 area. This study highlights the importance of genetic material selection as a relevant strategy for enhancing C accumulation in planted forests. The quantification of C stock by compartment provides valuable insights into the C storage capacity of different clones, facilitating informed decision-making for material selection, such as the promising performance of clone I224 helping in C storage, CO₂ emission mitigation and achieving the change in the production pattern, one of the goals in the 2030 Agenda for Sustainable Development.