Ecological Strategies of Trees Across Diverse Riparian Forests Along the Tropical Rio Doce, Brazil

ABSTRACT Understanding how plant functional traits reflect adaptations to different environmental contexts is crucial for predicting vegetation responses to selection pressures imposed by environmental filters. This study examines the functional strategies of woody plants in riparian forests along the Rio Doce, Brazil, particularly focusing on how these strategies vary between saplings and mature trees in response to soil condition, temperature and precipitation. Using Grime's CSR (Competitor, Stress‐tolerant, Ruderal) model, we analysed functional traits and their relationship with environmental parameters across 15 reference riparian sites spanning 473 km of the river. We found a large variation in species functional traits and ecological strategies in both strata, with significant inter‐site differences reflecting regional environmental gradients. Based on community weighted mean values, there were clear differences in ecological strategies displayed by the multiple riparian forests found along the Rio Doce watershed in both strata. Trait‐environment relationship analyses highlighted how trait syndromes shift with environmental gradients. In general, we found for both strata a clear association between climatic variables and species functional traits, with higher C‐selection and leaf size positively related to higher precipitation and lower temperature. On the other hand, edaphic characteristics related differently to species' functional dimensions in each stratum. Soil chemical quality was fundamental for the tree stratum, reflecting the access of deeper root systems to nutrients in lower soil horizons, while soil texture was the main filter for the juvenile stratum, as it directly regulates the availability of water and oxygen for its more superficial roots. By linking functional traits and ecological strategies to environmental factors, our findings indicate that restoration initiatives in the Doce River watershed should abandon the one‐size‐fits‐all approach. Instead, they require the implementation of multiple region‐specific reference ecosystems, according to different ecological strategies shaped by different climatic and edaphic filters along the river.