Data from: Disentangling the roles of phylogeny and environment in shaping functional diversity of terrestrial ferns in the southern Brazilian Atlantic Forest

Questions: 1) Do climatic and edaphic conditions influence the functional diversity of terrestrial ferns in the southern Atlantic Forest? 2) Which morphological functional traits are most relevant to climatic and edaphic variation? 3) What adaptive eco-evolutionary mechanisms can be inferred from them? Location: States of Rio Grande do Sul, Santa Catarina, and Paraná, southern Brazil. Methods: We analyzed ten morphological traits related to environmental resistance, competitive ability, and reproductive strategy. To assess functional diversity and trait-environment relationships, we evaluated traits both with and without phylogenetic correction. Subsequently, linear models were used to identify the most influential climatic or edaphic drivers, a permutational framework was applied to test the significance of these relationships. Results: Functional diversity of terrestrial ferns correlated with rainfall and temperature, showing subtle shifts after phylogenetic correction. Competitive and reproductive traits were associated with annual rainfall and rainfall seasonality. However, most morphological traits varied independently of the evaluated drivers, regardless of whether phylogenetic relatedness was considered. A few traits, specifically those related to resistance and competitive ability, were dispersed across the phylogeny and showed no association with the measured factors. This suggests that such traits may be shaped by unmeasured microenvironmental factors or neutral evolutionary processes. Conclusions: Our analyses demonstrate that climatic rather than edaphic factors are the primary drivers of trait diversity in terrestrial ferns within the Subtropical Atlantic Forest, influencing most evaluated traits. These findings help project how terrestrial fern assemblages may respond in the face of increasing land-use and land-cover changes across the Atlantic Forest domain.