Extinction Pattern and Recovery of the Permian–Triassic Flora in South China

Abstract

AbstractThe end-Permian mass extinction affected not only the marine realm but also the terrestrial ecosystem. Data on terrestrial floral changes across the Permian–Triassic boundary are presented separately from megaplant fossils and palynomorphs across several non-marine PTB sections in South China. The changing trend in higher plant vegetation across the Paleozoic–Mesozoic transition is characterized by a change from fern-dominated vegetation in the Upper Permian to pteridosperm and gymnosperm-dominated vegetation in the Lower Triassic. Temporarily, the decline of land vegetation in southwest China began in the early Late Permian (Wuchiapingian) and persisted through to the Early Triassic, and the rate of decline in both species and generic diversity was accelerated at the Permian–Triassic transitional interval. Overall, the temporal trend in the change of plants in the study area indicates a long, protracted extinction process that may have commenced well before the Permian–Triassic boundary. It is related to a protracted global climate change that may have been initiated by the Pangea formation and then exacerbated by the volcanism at the end-Permian. Some of prosperous plants during the Permian survived the mass extinction as the residual elements and continued to the Early Triassic. The vegetation recovery depends on the new group including the crisis progenitors in the surviving interval rather than the Paleozoic surviving flora. Specifically, Lepacyclotes (= Annalepis) may be mainly responsible for the recovery.