Drought Records in the Carbon Dynamics of Amazonian Forest: An Approach Using Tree Rings and Stable Isotopes

• Grant number: 25/15169-8
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: November 01, 2025
• End date: October 31, 2028
• Field of knowledge: Agronomical Sciences - Forestry Resources and Forestry Engineering
• Principal Investigator: Luiz Antonio Martinelli
• Grantee: Ana Claudia Gama Batista
• Host Institution: Centro de Energia Nuclear na Agricultura (CENA). Universidade de São Paulo (USP). Piracicaba , SP, Brazil

Abstract

This project investigates how droughts impact carbon dynamics in the Amazon rainforest. The proposal aims to combine analyses of tree-ring width with the isotopic composition of carbon (¿13C) and oxygen (¿18O) to identify variations in water-use efficiency and characterize ecophysiological responses to water stress at sub-seasonal timescales. The proposed study will be conducted along an east-west transect in the Amazon Basin, covering areas with established tree-ring chronologies and areas with three new sites. Advanced measurement methodologies such as laser ablation isotope ratio mass spectrometry (LA-IRMS) will be applied for high-resolution isotope analysis. The data obtained will contribute to 1) understanding the effects of drought on the forest at sub-seasonal frequency and over multidecadal time-scales, 2) benchmarking Earth system models, and 3) informing predictions of forest resilience to climate change.Keywords: tree rings, stable isotopes, drought, Amazon, carbon, intrinsic water use efficiency, sub-seasonal, laser-ablation mass spectrometry.