叶缘—年均温中国模型在定量重建中国新生代植物群古年均温中的应用

叶缘分析法是一种利用现代植被木本双子叶植物全缘叶物种百分比与年均温的函数关系,定量重建化石植物群古年均温的方法。该方法在新生代植物群的古年均温定量重建研究中得到了广泛的应用。目前基于世界不同地区现代植被的研究表明,尽管全缘叶物种百分比与年均温存在很好的相关性,但其相关性具有地区差异性。本文旨在总结叶缘分析法的研究进展,并介绍基于中国植被建立的叶缘—年均温中国模型;同时,采用该模型重建了中国新生代不同时期植物群的古年均温,且与前人采用其它模型得到的年均温重建值相比较。结果表明,叶缘—年均温中国模型能够有效地重建中国新生代植物群的古年均温值。

Quantitative Reconstructions of Mean Annual Temperatures for Cenozoic Paleofloras in China Based on the Chinese Leaf Margin Analysis Model

Leaf Margin Analysis (LMA) is a method which bases on the relationship between the proportion of woody dicotyledonous species with untoothed leaves (P) and mean annual temperature (MAT) to quantitatively estimate paleotemperatures from fossil leaf floras. In recent years, LMA is widely used for paleoclimatic reconstructions of Cenozoic leaf floras. Even with the high correlation between P and MAT, studies from different regions indicate that this method shows regional constraints. In recent work, a new Chinese LMA model was proposed based on 50 samples from humid to mesic forests in China. This new Chinese LMA model was applied to reconstruct paleoclimates of Chinese Cenozoic leaf floras in this paper. Estimated MATs from this new model are similar to these from other different methods in former studies. Therefore, this new LMA model from China, other than the widely used East Asian LMA model, is more properly applied to paleoclimatic reconstructions of Chinese Cenozoic leaf floras. In order to improve the accuracy of paleoclimatic reconstructions, more work is need by the following aspects: i.e., regional constraints of LMA, accurate definition of entire leaves, available climate data, taphonomic process, and the mechanisms of leaf physiognomy in response to the surrounding environment.