Growth responses of precious tree species with different plant characteristics to three lithological soil types and...

Based on specific nutrient requirements, precise tree species-site matching is the cornerstone of effective silviculture. To explore plant-soil interactions, this study investigated the nutrient utilization strategies of three tree species with distinct traits (Ormosia hosiei Hemsl. et Wils, Ormosia henryi Prain, and Phoebe bournei (Hemsl.) Yen C. Yang) cultivated in soils derived from slate, sandstone, and coal-bearing sandy shale. We further analyzed the interactive effects between plant characteristics and lithological substrates. Results indicated that cultivation significantly altered soil physicochemical properties. Notably, O. hosiei significantly increased soil organic matter in slate and sandstone (p < 0.05) while minimizing AN consumption in these two soil types. Lithological soils significantly influenced seedling growth, nutrient utilization, and biomass accumulation. Although all species performed optimally in coal-bearing sandy shale, their driving soil factors varied. Redundancy and correlation analyses revealed that soil AK and BD drove O. hosiei growth by regulating leaf-root resource allocation and nutrient uptake. For O. henryi, growth was co-limited by AK, BD, and AP. It adapted to the soil environment by optimizing an "aboveground nitrogen (SNR) and underground phosphorus (RPR)" allocation pattern to achieve trait differentiation. In contrast, the growth of P. bournei was primarily driven by soil pH. It regulated inter-organ phosphorus partitioning and whole-plant NUE, and PUE via pH-mediated nutrient availability, thereby maintaining growth homeostasis across different environments. This study systematically elucidates the adaptive strategies and nutrient allocation mechanisms of different species across varied lithological soils. These findings provide a robust theoretical framework for precise species-site matching and efficient plantation management during the structural adjustment of degraded coniferous forests in southern China.