Resumo

Background: Contrasting edaphoclimatic differences will influence the development of Eucalyptus forests, resulting in varying responses according to the clone. This study aimed to evaluate the impact of clone x site interaction on the wood density (WD) of Eucalyptus planted in tropical environments in Brazil. Eucalyptus clones (R9: E. urophylla, B2: E. urophylla x E. grandis, H8, and D4: E. grandis x E. urophylla) were analyzed 4 years after planting at 10 sites. A total of 120 trees were sampled, and the WD was determined. The relationship between WD, mean annual increment, and climate variables (temperature, precipitation, vapor pressure deficit and soil water deficit) was assessed for each clone.

Results: The site effect and clone x site interaction were significant. Clones H8 and R9 showed the most consistent WD across sites, with density differences of 18 % and 14 %, respectively, and H8 exhibited a similar mean in 80 % of the sites. B2 and D4 were the most influenced by local growth with density variations of 28 and 22 %, respectively, indicating that WD is affected by the interaction of genotype and growth environment. Only B2 showed significant correlations between density and all environmental variables, while density in R9 did not correlate with any variable.

Conclusion: Clones are similarly affected by climate across the tropical gradient of Brazil. However, the magnitude of responses differs among clones at a single site. The effects of climate conditions on density are more evident when contrasting situations are compared.