Productivity and Wood Quality Traits of Corymbia and Eucalyptus Species in Two Soil Water Deficit Sites

Climate change and the advancement of forestry in areas with greater water scarcity represent major challenges for Eucalyptus cultivation in Brazil. This study aimed to evaluate the productivity and wood quality of non-traditional Corymbia and Eucalyptus species in two Brazilian climatic conditions, to expand the genetic base available for breeding programs. Mean annual increment, wood density, stem biomass, heartwood and bark percentage, tangential vessel diameter, vessel frequency, fiber length, and fiber wall thickness were assessed. Four Corymbia species (Corymbia citriodora subsp. citriodora, Corymbia henryi, Corymbia torelliana, Corymbia citriodora subsp. variegata) and three Eucalyptus species (Eucalyptus amplifolia, Eucalyptus longirostrata, Eucalyptus major) were evaluated. Monthly evaluations were conducted on the mean air temperature, precipitation, and soil water deficit. Soil water deficit had a negative impact on mean annual increment, biomass, and heartwood percentage, while also resulting in higher bark percentages. However, it did not affect wood density or vessel diameter. The species showed different behaviors in response to the increase in water deficit. Eucalyptus longirostrata had the lowest impact on the environment, the highest mean annual increment (48.40 m³ ha−1 and 26.94 m³ ha−1) and heartwood percentage values (19.23 % and 16.27 %). Corymbia henryi had the most similar mean annual increment values in both locations (25.33 m³ ha−1 and 20.18 m³ ha−1), but there was a significant decrease in heartwood formation in the location with the lower soil water deficit (18.20 %). Corymbia citriodora subsp. citriodora, Corymbia henryi, Corymbia citriodora subsp. variegata, Eucalyptus major, and Corymbia torelliana displayed strong growth and wood characteristics, indicating great potential for cultivation in both locations.