Abstract

In a common garden experiment planted in Virginia (VA), North Carolina (NC), and Brazil (BR), we quantified above- and belowground biomass accumulation and examined above- versus belowground biomass partitioning and light use efficiency (LUE) (total biomass increment per unit of absorbed photosynthetically active radiation) as possible explanations for why Pinus taeda L. can grow much better in Brazil than in the southeastern United States (SEUS). Management selections for genotype, planting density, and silvicultural treatments had a tremendous effect on accumulated biomass. The BR site (48.3 Mg ha?1 yr?1) produced more biomass than the VA (26.8 Mg ha?1 yr?1) and NC (25.4 Mg ha?1 yr?1) sites. Trees at the BR site partitioned 23 % of total biomass increment to coarse roots, whereas trees at the VA and NC sites partitioned 10 % and 11 %, respectively. Increased aboveground growth at the BR site was not related to changes in above- and belowground partitioning. The LUE differed by site, with BR (3.7 g MJ?1) > VA (3.2 g MJ?1) > NC (1.6 g MJ?1). The low LUE and growth at the NC site may be associated with higher vapor pressure deficits and more extreme temperatures compared to the other sites. LUE partially explained the observed differences in growth between the SEUS and Brazil, but there were likely other factors that contributed to these differences. Our findings determined that above- versus belowground biomass accumulation did not explain why P. taeda may grow better in Brazil, but LUE was identified as contributing to this phenomenon. © 2025 Elsevier B.V.