The Carnian Pluvial Event is the most important global environmental event during the Late Triassic. The geological record of this event mostly occurs in marine strata, while relatively few studies have been conducted based on high-resolution sporopollen stratigraphy. The Middle-Upper Triassic terrestrial strata in the Ordos Basin are continuously developed and rich in plant and animal fossils, which are important for in-depth research on the changes in terrestrial vegetation and climate shifts during the Middle-Late Triassic.

The Paleobotanical Research Group of the Northeast Asia International Research and Teaching Center of Geosciences of Jilin University and Research Center of Paleontology and Stratigraphy (RCPS) Jilin University has been researching on the high-resolution sporopollen stratigraphy, the reconstruction of paleovegetation and paleoclimate in the Middle-Upper Triassic strata of the Ordos Basin since 2018, relying on the State Key Laboratory of Shale Oil and Gas Enrichment Mechanisms and Effective Development and National Natural Science Foundation of China. Dr. Li Xiang conducted a detailed analysis and identification of 87 sporopollen samples, which were collected from the Yanchang Formation, which spans from the YC8-1 sub-member to the YC7-3 sub-member, at Yunmeng Town, Yijun County, Tongchuan City, Shaanxi Province, North China, and compared the data to the bottom boundary of Carnian sporopollen on the GSSP section in Italy and the Middle and Late Triassic sporopollen biostratigraphic sequences in other parts of the world. The coexistence of Cyathidites minor、Dictyophyllidites harrisii、Apiculatisporis bulliensis、Aratrisporites xiangxiensis、Piceaepollenites omoriciformis、Podocarpidites ornatus、Discisporites granulus and Classopollis, is equivalent to the Carnian palynostratigraphy criterion reported in the North China palynofloristic realm for the first time.

The vegetation changes are obvious, especially at the Ladinian to Carnian boundary, about 70% ferns and over 30% gymnosperms species are lost, and the vegetation changes might be triggered by the strong seasonal arid climate indicated by the emergency of the xerophytes represented by the Cheirolepidiaceae. By analyzing the abundance of species and pollen content of different ecological types, three major pluvial pulse were identified during the late Ladinian and the early Carnian periods. From this perspective, short-term pluvial pulses during the Triassic may not be limited solely to the Carnian period.

The above-mentioned research findings, titled "Vegetation changes and climate shift during the latest Ladinian to the early Carnian: Palynological evidence from the Yanchang Formation, Ordos Basin, China," have been published in the journal "Frontiers in Earth Science". DOI:10.3389/feart.2022.1008707.