Adjustments of hydraulic, leaf and stem traits in tree species in environmental gradients in the Amazon

succession, flooding, drought, functional traits

 

Habitat heterogeneity is an important cause of tree species diversity in Amazonian forests. However, the high turnover of tree species in local environmental gradients suggests that species specialize in specific habitat conditions, thus, through the functional trait’s measurements, we can assess the adaptive strategies of plants along environmental gradients. The main objective of this study is to evaluate whether congeneric tree species from successional and flooding gradients differ in their morphological, structural, and hydraulic (leaf and stem) characteristics. Functional traits were collected in six permanent plots (0.25ha) along a succession gradient, in the municipality of Bragança, Pará and in five permanent plots (50x50m) in a flood gradient in the Mamirauá Sustainable Development Reserve (MSDR). Co-occurring species with greater abundance among the studied areas were selected. A set of functional traits belonging to different plant organs were measured, such as: total height, specific leaf area, leaf dry matter content, wood density, minimum water potential, water potential in which the plant loses 50% (P50) and 88% (P88) of its conductivity and hydraulic safety margin. We will evaluate the strategy of the plantspecies and if there is trait variation among the areas through analyzes of variance. Descriptive analyzes of each trait will be carried out, as well as a correlation matrix to verify the pair-to-pair relationships between all characteristics, we will also use network analysis, to demonstrate the connectivity and distance of the functional trait related to each part of the plant. Therefore, we intend to increase the evaluation spectrum of intraspecific variation in environmental gradients of succession and flooding, because knowing the variability of multiple traits within individuals is crucial to accurately predict species distribution limits and functional trends during natural regeneration and in the face of climate change intensification.