Analysis of Allometric Relations of Picea schrenkiana in Different Development Stages in the Western Tianshan Mountains of China

During the growth process of a tree population, the characteristics of biomass allocation vary with individual size or development stages, which typically reflect the life-history strategies of plant populations. However, differences in allometric strategies across different development stages and the underlying factors influencing these differences have not yet been fully studied. This study investigated the differences in the allometric relations among tree height (H), diameter at breast height (DBH), and crown width (CW) of Picea schrenkiana growing in the western Tianshan Mountains of China, across different development stages and slope aspects. The results revealed that allometric relations exist among H, DBH, and CW of P. schrenkiana at all development stages. The differences in allometric relations among different development stages were significant. Moreover, the allometric patterns varied with development stages, with seedlings prioritizing DBH growth and saplings prioritizing CW growth. The allometric relations of P. schrenkiana at different development stages did not change significantly with different slope aspects. In summary, P. schrenkiana adopts an allometric strategy at all development stages, with significant differences in the allometric relations at each stage, and these differences remain unchanged across different slope aspects. Our findings can provide crucial theoretical support for the management and ecological conservation of this tree species.