Performance of Eucalyptus clones in growth and wood quality under contrasting climatic conditions for kraft pulp production

This study evaluated how contrasting climatic conditions across three sites in Brazil affect growth, basic density, and wood chemical composition of five young Eucalyptus clones. Analyses included mean annual increment, biomass production, basic density, extractives content, total lignin, hemicellulose, alpha-cellulose, ash content, and the syringyl-to-guaiacyl (S/G) lignin ratio. Higher water availability at the SP site (lowest water deficit) and the BA site (intermediate water availability) promoted greater wood biomass accumulation, whereas the environment with the highest water deficit (MA) resulted in increased basic density. The responses of chemical traits were dependent on the genetic material, with extractives content being the most unstable variable across environments. Among climatic variables, only temperature was positively correlated with basic density, which influenced the specific wood consumption (SWC), showing an inverse relationship with basic density. The results indicate that genetic improvement programs may help reduce variability in the most sensitive properties (particularly extractives), thereby decreasing environmental heterogeneity that can compromise the predictability of kraft pulping performance.