This Project Grant from the National Science Foundation Division of Earth Sciences provides $436,560 to Brown University from June 2021 through May 2024 to conduct collaborative research titled "Are Amazonian and Andean Ecosystems Close to a Tipping Point?". The research is being conducted under the Biological Sciences program (CFDA 47.074), which aims to promote progress in the biological sciences and strengthen the Nation's scientific enterprise through increasing scientific knowledge and enhancing understanding of major problems confronting the Nation. Most of the research supported through this program is basic. The funding will support Brown University in conducting collaborative research over a three year period to analyze whether ecosystems in the Amazon and Andes regions in South America are approaching critical thresholds or "tipping points" due to changing environmental conditions.