Long-term performance and ecological adaptability of Populus clones on reclaimed tidelands

Reclaimed tidelands present challenging soil conditions that constrain plantation establishment and long-term ecosystem services, highlighting the need to identify tree genotypes with high productivity and stability under such environments. Poplars ( Populus spp.) are widely used in reclamation and short rotation coppice systems; however, long term evaluations of clonal performance on reclaimed land remain limited. Accordingly, this study aimed to identify poplar clones suitable for reclaimed tidelands by evaluating the survival and growth performance of 30 experimental clones grown for 9 years in the Saemangeum area of South Korea. The clones included intraspecific Populus deltoides × P. deltoides (DD) and interspecific P. deltoides × P. nigra (DN) hybrids representing distinct bioecological characteristics. Significant differences were detected among clones and between crossing combinations in tree volume index, survival rate, tree vitality, and pest and disease resistance. DD clones, particularly 79-1-01 and 79-IL-16, consistently exhibited the highest values across all evaluated parameters, whereas DN clones, especially I-476 and I-154, generally showed the lowest performance. The ecological adaptability of the clones was assessed and ranked based on results from principal component analysis (PCA). Among all clones evaluated, 12 poplar clones exhibited positive comprehensive F (CF) values, with the DD clones 79-21-01 and 79-IL-16 showing C F values greater than 2. These findings reveal substantial clonal variation under reclaimed land conditions and confirm, through PCA-based clone ranking, the high suitability of selected DD clones for afforestation and biomass production in reclaimed tidelands. Overall, the study provides a scientific basis for clone selection strategies in reclaimed tideland afforestation and bioenergy-oriented plantations.