Miocene fire intensification linked to continuous aridification on the Tibetan Plateau

作者：Yunfa Miao, Fuli Wu, Sophie Warny, Xiaomin Fang, Haijian Lu, Bihong Fu, Chunhui Song, Xiaoli Yan, Gilles Escarguel, Yibo Yang, Qingquan Meng, Pilong Shi · 发表于：Geology · 年份：2019 · DOI：10.1130/g45720.1 · 被引用次数：54 · 研究领域：Fire effects on ecosystems、Landslides and related hazards、Geology and Paleoclimatology Research

Although fire is considered an important factor in global vegetation evolution and climate change, few high-resolution Miocene fire records have been obtained worldwide. Here, two independent micro-charcoal-based fire records from the northern Tibetan Plateau were analyzed; both show similar trends in micro-charcoal concentrations through time, with low abundances in the warmer Middle Miocene Climate Optimum (18-14 Ma) followed by a continuous increase throughout the late Miocene (14-5 Ma) cooling. Our detailed statistical analyses show that the micro-charcoal concentration trend is highly positively correlated to the trend in oxygen isotopes (δ<sup>18</sup>O, r = 0.94) and xerophytic species (%<inf>Xero</inf>, r = 0.95). We propose that the intensified fire frequency on the Tibetan Plateau mainly originated from the forest-steppe ecotone as a result of the continuous aridification in winter driven by the global cooling and decreased atmospheric pCO<inf>2</inf> that occurred during 18-5 Ma, with a secondary control by the tectonic activity of the northern Tibetan Plateau.<br/> © 2019 Geological Society of America.