2025/01/21 by Yunfei Yan, Dongyuan Tian, Zipeng Zhang +2 · 1 voice
Environmental Science · Engineering · #Forest ecology and management #Plant Water Relations and Carbon Dynamics #Tree Root and Stability Studies
paper · doi:10.1093/forestry/cpaf001
openalex publication_date 2025/01/21 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Abstract Crown radius (CR) and crown width are fundamental indicators used to describe tree crown sizes and are widely included as predictors in growth and yield models. Crown width is the arithmetic average of two perpendicular diameters to each other, obtained from measurements of four crown radii: east, south, west, and north. Climate change and soil variations influence the physiological activities of trees, thereby impacting tree crown development. However, most CR studies do not quantify the impact of climate and soil factors on CR. In this study, we developed a nonlinear mixed-effects simultaneous CR model system to address the above problems. This study used 7188 trees from 98 plantation plots of Korean pine (Pinus koraiensis) in northeast China. The results showed that climate (extreme temperature and precipitation) and soil (total nitrogen) variables improved the model performance of the simultaneous CR model system. The CR of large-sized trees was more sensitive to climate and soil variables as compared to smaller trees. Incorporating plot-level random effects into the nonlinear mixed-effects simultaneous CR model system improved both the fitting accuracy and predictive performance of CR and crown width. Our results provide new insights into the environmental variability of crown sizes in planted forests and suggest that integrating environmental factors in CR modeling can improve CR model results. These findings may become relevant for improving forest management strategies under changing climate conditions.