###### Abstract  
Long-term meteorological analyzes suggest an increase in air temperature and a decrease in rainfall over the Amazon biome. The effect of these climate changes on the forest remains unresolved, because field observations on functional traits are sparse in time and space, and the results from remote sensing analyses are divergent. Then, we analyzed the drought response in a 'terra firme' forest fragment in the southwestern Amazonia, during an extreme drought event influenced by ENSO episode (2015/2017), focusing on stem growth, litter production, functional traits and forest canopy dynamics. We use the Moderate Resolution Imaging Spectroradiometer (MODIS), corrected by Multi-Angle Implementation of Atmospheric Correction (MAIAC) to generate the enhanced vegetation index (EVI) and green chromatic coordinate (Gcc) vegetation indices. We monitor stem growth and measure the functional traits of trees in situ, such as the potential at which the plant loses 50% of hydraulic conductivity (P\({}_{50}\)), turgor loss point (\(\tau\)TLP), hydraulic safety margin (HSM) and isohydricity. Our results suggest that: (a) during the dry season, there is a smooth reduction in EVI values (browning) and an increase in the wet season (greening); (b) in the dry season, leaf flush occurs, when the water table still has a quota at the limit of the root zone; (c) the forest showed moderate resistance to drought, with water as the primary limiting factor, and the thickest trees were the most resistant; and (d) a decline in stem growth post-El-Nino 2015/2016 was observed, suggesting that the persistence of negative rainfall anomalies may be as critical to the forest as the drought episode itself. g 2022 14 2022 202  
Given the prospects of a drier and warmer climate in the Amazon [4; 5; 13; 14], it is necessary to understand the response of the forest to these changes, given that conclusions of the research are divergent. For example, the forest can be replaced by vegetation that is more resistant to drought, such as the savannah, as a result of changes in the rainfall regime, increase in temperature and deforestation [13; 15]; or some regions of the Amazon experience an increase or decline in evapotranspiration in the dry season (drought that has well-defined months), and the forest increase, decline or maintain the gross ecosystem productivity (GPP) [16; 17; 18; 19]. Extreme drought events, such as those that occurred in 2005, 2010 and recently in 2015/2016, have acted as natural laboratories to understand forest dynamics during these climatic episodes. However, a number of questions still remain, because the conclusions resulting from in situ and remote sensing analysis are divergent. While remote sensing analyses have identified a potential resilience of the Amazon rainforest to drought with apparent greening during the dry season [20; 21], others have shown that this is due to satellite artifacts and solar sensor geometry [22; 23; 24]. On the other hand, in situ studies have shown decreased gross primary productivity [25], increased mortality [26; 27; 28], decline in photosynthesis [29] and stem diameter growth, and leaf litterfall and leaf flushing increase [30; 31]. These variations reinforce the complexity of the Amazon biome, and increase scientific efforts to investigate ecological issues, such as the response of organisms and the functional composition of trees, as a function of environmental and climatic changes [32; 33]. These functional traits are morphological, physiological and phenological attributes that allow one to analyze the potential of communities to adapt to climate change [34; 35]. The ecophysiological responses of the trees to drought using functional traits such as isohydricity, turgor loss point potential (\(\pi\)TLP), potential in which the plant loses 50% of hydraulic conductivity (P\({}_{50}\)) and hydraulic safety margin (HSM), have been analyzed as measurements of drought tolerance [36; 37].