Paleoclimate-induced stress on polar forested ecosystems prior to the Permian–Triassic mass extinction

Abstract

The end Permian extinction (EPE) has been considered to be contemporaneous on land and in the oceans. However, re-examined floristic records and new radiometric ages from Gondwana indicate a nuanced terrestrial ecosystem response to EPE global change. Paleosol geochemistry and climate simulations indicate paleoclimate change likely caused the demise of the widespread glossopterid ecosystems on Gondwana. Here, we evaluate the climate response of plants to the EPE via dendrochronology to produce annual-resolution records of tree ring growth for a succession of Late Permian and early Middle Triassic fossil forests from Antarctica. Paleosol geochemistry provides a broader context paleoclimate history. The plant responses to this paleoclimate change were accompanied by enhanced stress during the latest Permian. These results suggest that paleoclimate change during the Late Permian exerted significant stress on high-latitude forests, consistent with the hypothesis that climate change was likely the primary driver of the extinction of the glossopterid ecosystems.