Subindo a montanha: o que a anatomia foliar pode revelar sobre as estratégias das árvores que ocorrem em gradientes

Abstract

Altitudinal gradients constitute important environmental axes that integrate climatic, edaphic, and microclimatic variations, directly influencing plant structure and functioning. In this context, this study aimed to evaluate leaf anatomical variation and phenotypic plasticity in Myrceugenia rufescens, Drimys brasiliensis, and Solanum asperum along an altitudinal gradient in Montane Dense Ombrophilous Forest areas of the Atlantic Forest. Anatomical analyses were conducted on fully expanded leaves, including epidermal, stomatal, mesophyll, and vascular traits, in association with the characterization of edaphoclimatic variables and species occurrence within the sampling plots. The results showed that altitude exerts a significant influence on leaf anatomy, promoting structural adjustments associated with thermal, hydric, and edaphic conditions along the gradient. Drimys brasiliensis exhibited more robust anatomical modifications related to conservative resource-use strategies. Myrceugenia rufescens displayed subtle but consistent variations, reflecting an intermediate strategy compatible with humid environments and high cloud cover. Solanum asperum stood out due to its greater anatomical plasticity, particularly the high density of trichomes and the structural flexibility of the mesophyll, which favors its occurrence across different altitudinal ranges. Overall, the results demonstrate that leaf anatomy responds plastically to variations imposed by the altitudinal gradient, reflecting distinct ecological strategies among species. This study contributes to the understanding of structural plant responses in Atlantic Forest montane ecosystems and provides insights into the resilience of species under scenarios of environmental change.