Nursery light environments shape planting‐stock phenotype in Copaifera langsdorffii for forest restoration

Abstract Introduction Scaling ecological restoration in the Amazon requires a reliable supply of native planting stock, yet nursery environments can strongly shape seedling phenotypes and species‐specific guidance remains limited. For late‐successional tropical trees, understanding how manageable nursery conditions coordinate growth and biomass allocation can improve planting‐stock production without assuming field performance. Objectives We tested whether shade‐net environments generate coordinated, nonlinear changes in growth, biomass allocation, and morphometric quality of Copaíba ( Copaifera langsdorffii Desf.). Methods Seedlings were grown for 10 months under nominal 0, 20, 30, 50, and 75% shade. Height, stem and canopy diameter, shoot, root, and total dry mass (TDM), biomass allocation, root:shoot ratio, and Dickson Quality Index (DQI) were evaluated using analysis of variance, polynomial regression, multivariate analysis of variance, response‐surface modeling, and principal component analysis. Results Growth and biomass responded nonlinearly. Height, stem diameter, and TDM were maximized near 47% shade, root dry mass near 41%, and DQI near 44%. Seedlings under 30–50% shade had the most favorable multivariate growth profile, whereas full sun and intense shade reduced nursery performance. Root allocation was proportionally greater under full sun and 20% shade. Conclusions Moderate shade‐net environments produced a distinct nursery phenotype combining greater biomass accumulation and morphometric balance. A nominal 50% shade net is therefore a practical nursery target under comparable western Amazon conditions, but nursery‐stage quality alone does not demonstrate superior post‐planting performance.