Latitudinal gradient in climate warming impacts on Pinus massoniana

Understanding the spatiotemporal variability of climate–growth relationships is critical for predicting forest responses to environmental change and guiding sustainable forest management. However, research on this subject in subtropical conifer species remains limited. We quantified spatiotemporal growth patterns and climatic drivers of Pinus massoniana Lamb. across 32 sites spanning the climate gradient of subtropical China. Across the study area, the overall growth of P. massoniana exhibited an increasing trend, with growth declines observed only at a few sites in the central region. Temperature was positively correlated with growth in colder northern regions but negatively correlated with growth in warmer southern regions, whereas growth in the central region showed a significant positive correlation with relative humidity. This indicates that tree growth is primarily constrained by region-specific climatic factors, including high temperatures in the south, drought in the central region, and low temperatures in the north. Furthermore, drought stress has increasingly limited the growth of central and southern P. massoniana populations over time. Simulations based on the VS-Lite model further revealed divergent growth phenological patterns: Northern trees display a unimodal growth pattern, while central and southern populations exhibit a bimodal pattern. Under three projected future climate change scenarios, tree growth in the central and southern regions is projected to exhibit more pronounced declines. This study highlights the importance of accounting for the spatiotemporal variability of climate–growth relationships when developing forest management plans, including those for future plantations. Effective management should prioritize region-specific strategies to mitigate the impacts of climate change, ensuring the resilience of P. massoniana subtropical forests.