Relationship between phytolith morphology and physical and mechanical properties in bamboo Ferrocalamus strictus

Ferrocalamus strictus is a rare bamboo species native to Yunnan, China, and is notable for its favorable mechanical properties. However, the relationship between phytolith morphology and these properties remains unclear. This study measured nine physical and mechanical traits and 26 phytolith parameters in culms from five provenances aged 1–3 years. Linear mixed models showed that outer hardness was positively associated with phytolith content but negatively associated with phytolith weight, suggesting that phytolith content may be more closely associated with surface hardness than phytolith weight. Partial least squares regression identified phytolith morphotypes showing relatively high variable importance for specific properties; elongate hollow forms showed relatively high importance for modulus of elasticity, while elongate finely porous forms showed relatively high importance for compressive strength and shrinkage traits. These findings provide quantitative evidence of associations between phytolith morphology and the physical and mechanical properties of F. strictus , providing a reference for understanding phytolith-related variation in this rare bamboo and for future comparative studies of high-silicon bamboos.