Tropical forests are experiencing compounding stressors with the changing climate. Recent evidence in the Amazon has included a record-breaking drought, heat waves, floods, and increased storm activity. However, not all of these events have shown a clear impact on the total function of forests. In fact, the vulnerability of tropical forests and the variation of this vulnerability over space and time remain unclear in spite of the clear potential for disruption. Studies at different scales, focusing on different forest processes or using different approaches tend to give different answers. Integration of these varied perspectives over long-term and landscape-wide ecological research sites can provide a stronger basis to evaluate this vulnerability. Reserva Ducke in central Amazonia (10 x 10 km, 25 years of monitoring) is one of such sites, where a huge biodiversity (e.g. >1200 tree species) and landscape diversity (varied topography and soils) congregate a diverse set of scientists, from field ecologists, physiologists, remote-sensing scientists to ecosystem modelers. In this symposium we will present a selection of studies – from the ground to towers and drones, from individual plants and species to ecosystems – that integrate to provide our response to the vulnerability of this forest so far. 

The Brazilian Long-Term Ecological Research (LTER) program has been monitoring plant and animal communities turnover over 25 y, providing the baselines to understand changes due to climate changes. This effort has been combined to the Gigante project, quantifying when, where and why giant trees die; specifically, monthly high-resolution drone imagery at landscape scale (15 km2) provides detailed information on tree damage and death, which then guides field teams to rapidly perform forensic assessments of damaged and dying trees. The Other Side of Drought project also takes advantage of the LTER baseline, adding fine-resolution monthly monitoring of tree growth and mortality, litterfall, canopy phenology, soil moisture and water-table levels that integrate to understand ecosystem-level productivity responses. Detailed physiological studies of SIF, fluorescence, photosynthesis and plant water-relations are evaluating leaf-to-individual level vulnerability to climatic stress, then combined with remote sensing to scale up tree physiology, providing estimates of how tropical forests interact with carbon and water cycles at larger spatial scales.

This suite of interdisciplinary research is allowing us to quantify the vulnerability of critical tropical forests to global change, and the breadth of this research opens the door for new collaborations asking questions that are not possible in isolation