Rethinking the Wood Economics Spectrum: From a Static Trade-Off to a Dynamic and Multidimensional Framework of Wood Functional Traits

Secondary xylem (wood) is a multifunctional tissue that reflects the evolutionary history of woody plants and shapes their ecological strategies. Variation in wood functional traits has often been interpreted through the Wood Economics Spectrum (WES), which describes trade-offs between resource acquisition and conservation and links wood traits to ecological strategies. Here, we synthesize structure–function relationships in secondary xylem across gymnosperms and angiosperms, focusing on the ecological significance of wood functional traits, including conduit size, pit membrane architecture, parenchyma abundance, and wood density. We consider their roles in water transport, biomechanical support, storage, and stress tolerance, and examine how seasonal patterns of xylogenesis relate to longer-term adaptive strategies and mechanisms that modify the expression of classical functional trade-offs, including hydraulic capacitance, parenchyma functions, reaction wood formation, and intraspecific plasticity. We propose a holistic perspective that builds on the classical WES by considering wood as a dynamic, multidimensional system shaped by interactions among anatomical traits, physiology, development, and environmental variability. Integrating seasonal xylogenesis and intraspecific plasticity with dendrochronological and microcoring approaches may provide a more comprehensive understanding of tree responses to climate change and improve forecasts of forest resilience.