NSFDEB-NERC: Gigante: Quantifying and upscaling the causes and drivers of death for giant tropical trees

Cary Institute Of Ecosystem Studies, Inc., Millbrook NY

Investigators

Abstract

This project – named Gigante - aims to understand when, where, and why the largest trees in tropical forests die. The research is important because the largest 1% of trees contain enormous amounts of carbon: about half of all carbon stored in plants of these forests. However, we do not know what kills these trees and therefore can’t predict how they might fare in the future or their impact on climate. Gigante will use drones to guide field teams to locate and describe thousands of giant tree deaths in tropical forests around the world. These data will then be used to predict when and where other giant trees will likely die in the future and to improve our understanding of how carbon cycles on our planet today. Gigante’s outcomes are crucial to a better understanding of how vulnerable tropical forests are to environmental change. The project will train new and aspiring scientists across an international network in the use of modern technology for studying giant trees, generate publicly accessible data on all giant tree deaths to help satellite experts and others monitor forests, and generate new software and training materials to help scientists and land managers monitor the health of forests worldwide. Gigante will locate giant tree mortality events using multi-platform, high-frequency remote sensing of 7,500 hectares of tropical forest across five “super sites.” These data will facilitate targeted field surveys using detailed state-of-the art protocols to assign proximate agents of mortality to recently dead trees in an unprecedentedly large field study. The researchers will integrate these data with information about climate, topography, canopy structure, and tree traits to validate mechanistic models of tree mortality risk. Finally, combining these risk models with forest plots and satellite LiDAR, they will evaluate how drivers of giant tree death predict spatial variation in forest dynamics, structure, and carbon storage. In the course of this project, Gigante will produce software and videos to facilitate the use of these methods elsewhere, and provide training and capacity building to scientists across this collaborative network. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.