Hydraulic architecture, hydraulic efficiency, drought, functional strategies

Tropical forests provide global ecosystem services. The vulnerability of these forests, especially the Amazon, has been the subject of studies to understand how species cope with frequent climate changes, particularly drought. In environments with low water availability, plants may show hydraulic failure. Hydraulic failure due to embolism reduces water transport efficiency in the plant and potentially causing the death of the individual. In response to water scarcity, plants tend to modify their hydraulic architecture and show trade-offs between efficiency and hydraulic safety. In light of the above, this study aimed to investigate adjustments in the hydraulic architecture of three species from distinct functional groups (evergreens and deciduous) in response to drought, to understand the specific adaptive strategies of these species under adverse environmental conditions. We hypothesized that: i) there will be changes in the hydraulic architecture of the species, ii) evergreen species will undergo greater modifications than deciduous species, as deciduous species have a strategy to avoid drought by losing their leaf cover. To test our hypotheses, seedlings of Clitoria fairchildiana R.A. Howard. (Fabaceae), Manilkara elata (Allemão ex Miq.) Monach. (Sapotaceae) e Bertholletia excelsa Bonpl. (Lecythidaceae) will be distributed across 3 treatments with different water supplies (15%, 50%, and 100% field capacity) for a period of 3 months. For each species and treatment, analyses of water potential at the point of turgor loss, potential in which plants lose 50% and 88% of their hydraulic conductivity and branch anatomy will be conducted. We aim to better understand the functional and anatomical arrangements of these species in tolerating periods of water scarcity through the obtained results.