The structural mosaic of secondary xylem in a continuum of Atlantic Forest phytophysiognomies

Summary The Atlantic Forest encompasses different phytophysiognomies that act as ecological filters, shaping plant species distribution. This study aimed to evaluate how the variation of secondary xylem traits varies among species in different phytophysiognomies. By analyzing 16 representative species across a continuum of five phytophysiognomies (Montane Dense Ombrophilous Forest, Submontane Dense Ombrophilous Forest, Restinga, Mangrove, and Floodplain Wetland). We identified distinct adaptive strategies in xylem anatomy that reflect both environmental heterogeneity and the evolutionary history of the taxa. Vessel wall thickness was the most variable functional trait among phytophysiognomies, highlighting its role in acclimatization. Additionally, a coordinated relationship among anatomical traits ensures a balance between safe and efficient water transport. These findings provide critical insights into the adaptive mechanisms of woody plants in tropical forests, offering perspectives on their resilience to the challenges posed by global climate change.