The Once and Future Amazon Forest? Climate and Landscape Change May Drive the Expansion of Nutrient‐Poor Amazonian Ecosystems

ABSTRACT Poor‐soil Amazonian ecosystems, such as white‐sand ecosystems (WSE, sensu lato), were widespread in the past, reflecting a diverse origin, and have a history of repeated expansion and contraction in response to climate fluctuations and landscape reconfiguration. Although modern climate change outpaces natural processes, we hypothesize that soil nutrient degradation will trigger a cascade of ecosystem reconfigurations, favoring the eventual expansion of WSE‐like habitats long into the future. This expansion may be a nuanced aspect of the broader process of Amazon degradation. Long‐term monitoring and field experiments remain necessary to test these predictions regarding the “once and future” Amazon Forest.