Oceanic climate variability influences radial growth of Pentaclethra macroloba in the Amazon estuary through local climatic pathways

Understanding how large-scale ocean–atmosphere interactions influence tropical tree growth is essential for predicting the impacts of climate change on Amazonian forests. Here, we investigated the climatic sensitivity and annual rings formation of Pentaclethra macroloba in the Amazon estuary, a poorly studied region in tropical dendroclimatology. Tree-ring chronologies were developed from floodplain forests located in the eastern Amazon estuary and correlated with local climate variables and Sea Surface Temperature (SST) anomalies from the Equatorial Pacific and Tropical Atlantic Oceans. Ring periodicity was validated using the Mariaux window method, confirming annual growth-ring formation in the species. Correlation and spatial analyses revealed significant associations between radial growth and SST anomalies, particularly in the Niño 3.4 region and the North Tropical Atlantic. Structural equation modeling suggested that the influence of large-scale oceanic climate variability on tree growth was primarily mediated through local climatic conditions. Dry-season maximum temperature was the main positive predictor of radial growth, whereas Equatorial Pacific warming was associated with reduced rainfall during the wet season. The results indicate that P. macroloba is sensitive to interannual climatic variability and exhibits growth patterns associated with ocean–atmosphere teleconnections. These findings expand the dendroclimatological potential of estuarine Amazonian forests and highlight the importance of tropical floodplain ecosystems as natural archives of climate variability and environmental change.