The Pliocene is a key period for the global climate change with a transition from the warmer Miocene to the cooler Pleistocene. However, the understanding of the Pliocene climate in the Qinghai-Tibetan Plateau is poor. The Tuantian flora, being on the western side of Mt. Gaoligong and Mt. Nu, is the only Pliocene fossil flora in western Yunnan with paleoclimate reconstructions based on leaf physiognomy.
Prof. Zhou Zhekun and his team of Xishuangbanna Tropical Botanical Garden (XTBG) examined the late Pliocene Longmen flora on the eastern side of Mt. Gaoligong and Mt. Nu in western Yunnan. Their study was aimed (1) to reconstruct quantitatively the paleoclimate by using leaf-physiognomy-based methods and recently developed calibration datasets, (2) to compare their results with previous results calculated by taxa based coexistence approach in late Pliocene floras of western Yunnan, and (3) to discuss the evolution of the Asian monsoonal climate of Yunnan.
The fossil site was located in Longmen Village, Yongping County, western Yunnan Province (25°30′48″N, 99°31′11″ E), at the southeastern boundary of the Qinghai-Tibet Plateau. The paleoclimate of the late Pliocene Longmen flora from Yongping County was reconstructed using two leaf-physiognomy-based methods, i.e., leaf margin analysis (LMA) and Climate Leaf Analysis Multivariate Program (CLAMP), to understand the paleoclimate condition and geographical pattern of monsoonal climate in southwestern China during the late Pliocene.
In combination with results of previous paleoclimatic studies, the researchers concluded that both temperature and precipitation in the late Miocene and the Pliocene of Yunnan were higher than at the present day. The significant change of the monsoonal climate might have been resulted from the continuous uplift of mountains in western Yunnan, as well as the intensification of the eastern Asian winter monsoon, both occurring concurrently in the post-Pliocene period.
The study entitled “Post-Pliocene establishment of the present monsoonal climate in SW China: evidence from the late Pliocene Longmen megaflora” has been published in Climate of the Past.
