Interactive effects of provenance and soil lithology on root dynamics of a young subtropical plantation in China

AimsIt is essential to explore tree root development, dynamics and its control factors to improve the productivity of plantations. Tree provenance and soil lithology may jointly regulate root growth in subtropical plantations, but this relationship has not yet been quantified.MethodsWe used a split-plot design with tree provenances (DY, GP, CY, SG, TM) and soil lithology (basalt, quartz sandstone, feldspathic quartz sandstone, blastopsammite) to determine the root growth of 4-year-old Masson pine seedlings in combination.ResultsOur results showed an interaction effect between tree provenances and soil lithology on root surface area (RSA), root length (RL), root volume (RV), root biomass (RB), specific root surface area (SRA) and specific root length (SRL). The RV, RSA, RL, RB, and SRL of the DY provenance were higher than those of the other provenances due to site conditions similar to the planting site (e.g., climate, altitude, and latitude); the RSA, RV, SRL, SRA and RB of DY provenance on the soil with lithology of blastopsammite were significantly lower than those of feldspar quartz sandstone and quartz sandstone, which indicates that the root growth is also affected by soil lithology. Furthermore, soil bulk density, total soil potassium, soil organic carbon and soil particle composition were the main factors affecting root growth in basalt, quartz sandstone, feldspathic quartz sandstone and blastopsammite soil, respectively, indicating that the required soil properties by plants changes with changes in the soil environment.ConclusionsWe conclude that provenance and soil lithology jointly drive the root growth of young subtropical plantations.