Topographic factors and physical traits jointly shape the mechanical properties of Phyllostachys edulis

Understanding the drivers of variations in bamboo mechanical properties is essential for both sustainable resource utilization and material performance optimization. However, the relative contributions of bamboo physical traits and topographic factors to intraspecific mechanical variations remain largely unknown. In our study, we investigated the physical traits and mechanical properties of Phyllostachys edulis (Moso bamboo) culms, including parallel to grain compressive resistance (UC), tensile resistance (UT), shear resistance (US), and bending resistance (B). Additionally, variation partitioning analysis (VPA) and redundancy analysis (RDA) were applied to quantify the relative contributions of physical traits and topographic factors (slope gradient, slope aspect, and elevation) to the variations in mechanical properties. The results showed that bamboo physical traits significantly varied among different Moso bamboo specimens, except for fiber volume fraction (FVF). The mechanical properties of Moso bamboo, including UC (62.74–69.85 MPa), UT (147.07–179.86 MPa), US (7.93–10.67 MPa), and B (136.91–150.28 MPa) also showed significant intraspecific variability ( P < 0.05). The Pearson’s analysis showed that diameter at breast height (DBH) was positively correlated with UC, UT, and B, while FVF was positively correlated with UT ( P < 0.05). The results of VPA and RDA indicated that approximately 68.6% of the variations in mechanical properties could be jointly explained by bamboo physical traits and topographic factors, with physical traits (particularly DBH) playing a predominant role. Topographic factors exhibited a smaller but detectable influence, with slope gradient accounting for the largest contribution to the variations in mechanical properties. Overall, our study elucidates the structure-property relationships governing intraspecific mechanical variability in Moso bamboo. Although the environmental scope was limited to topography, the established framework provides a robust foundation for future research to integrate soil and climatic variables, further decoding the ecological mechanisms that influence bamboo mechanical performance.