Different xylogenesis responses to atmospheric water demand contribute to species coexistence in a mixed pine–oak forest

Abstract Seasonal patterns of wood formation (xylogenesis) remain understudied in mixed pine–oak forests despite their contribution to tree coexistence through temporal niche complementarity. Xylogenesis was assessed three pine species ( Pinus cembroides , leiophylla engelmannii ) and one oak Quercus grisea coexisting a semi-arid Mexican forest. The main xylogenesis phases (production cambium cells, radial enlargement, cell-wall thickening maturation) were related climate data considering 5–15-day windows. In pines, activity maximized from mid-March April as temperature evaporation increased, whereas cell enlargement peaked May constrained by high low precipitation. Cell-wall June July August–September maximum vapour pressure deficit (VPD) increased. Maturation earlywood latewood tracheids occurred May–June June–July, enhanced minimum temperatures VPD P. . oak, cambial onset started March, temperatures, vessel increment vessels matured Overall, 15-day wet conditions P early-summer drove Warm night rates during spring summer growth. An earlier growth peak higher responsiveness spring–summer water demand pines contributed coexistence.