Late Miocene Xianfeng palaeoflora and palaeoclimate of Yunnan Province, southwestern China

Three available quantitative climate reconstruction methods from fossil plants, i.e. Leaf Margin Analysis (LMA), the Climate Leaf Analysis Multivariate Program (CLAMP), and the Coexistence Approach (CA) were used in this study. MATs (mean annual temperatures) resulting from these three approaches (i.e., LMA: 17.2 ± 2.38 °C; CLAMP: 15.43 ± 1.25 °C; CA: 17.2-21.7 °C) appear to have been higher than the present (14.9 °C), suggesting a much warmer climate in the late Miocene.

Both the growing season precipitation (GSP) from CLAMP (1908.7 ± 217.7 mm) and mean annual precipitation (MAP) from CA (1206.0-1613.0 mm) estimates are higher than modern values (1003.2 mm (GSP) and 1038 mm (MAP) respectively) indicating a more humid climate during the late Miocene. By comparing these with climates reconstructed from neighboring late Miocene floras, we conclude that the general late Miocene climate appears warmer and more humid than present conditions in southwestern China.