Climatic reconstruction at the Miocene Shanwang basin, China, using leaf margin analysis, CLAMP, coexistence approach, and overlapping distribution analysis

Abstract

The reconstruction of the climate in the Miocene Shanwang basin is an important link in understanding past climate and environmental changes in East Asia. A recent study showed that the mean annual temperature (MAT) estimates derived from leaf margin analysis (LMA) and the Climate Leaf Analysis Multivariate Program (CLAMP) conflicted with and were remarkably lower than those estimated by the coexistence approach (CA). Overlapping distribution analysis (ODA), a new method introduced here, is used to reconstruct the Shanwang Miocene climate based explicitly on local plant distribution data and associated meteorological stations. The Shanwang flora (17-15.2 Ma) suggests a MAT of 10.9-14.5°C and a mean annual precipitation (MAP) of 1107.3-1880.0 mm. This result is closer to the values derived from CLAMP and LMA than that obtained by CA. This report is the first comprehensive intercomparison of foliar physiognomic and nearest living relative climate proxies in a Chinese context and provides important cross validation of results.