福建漳浦中中新世佛昙群植物化石及植物-昆虫相互作用研究

The middle Miocene Fotan flora has been considered likely a Miocene tropical rain forest based on occurrence of several extant tropical plant taxa, including Dipterocarpus, Shorea, Calophyllum among others. Previous studies of this flora indicate that these plant lineages that are today mostly restricted to the tropical region of Southeast Asia, might have first migrated to South China during the Mid-Miocene Climatic Maximum, some of them had survived Quaternary glaciation and become important components of modern floras in South China. In this project we propose to conduct fieldwork in Zhangpu to collect new and abundant fossil material, and study the plant fossils as well as insect feeding damages on fossil leaves from the middle Miocene Fotan Group. The primary goal of the proposed research is to reconstruct the fossil plants, palaeovegetation and palaeoclimate of Zhangpu during the middle Miocene. Furthermore the Fotan fossil flora will be compared with several different types of tropical and subtropical forests in South China and Southeast Asia in terms of its floristic composition, plant diversity, leaf physiognomy, types and diversity of insect feeding damages, as well as climatic conditions, in order to elucidate quantitatively the vegetation type of the Fotan fossil flora. This research will greatly contribute to understanding the origin and evolution of plant diversity and floristic composition in South China. The study of insect feeding damage on fossil leaves of Fotan flora will help to predict the developing trend of insect damages in modern forest with the current global warming.

福建漳浦中中新世佛昙植物群包括龙脑香属、娑罗双属、红厚壳属等多种现代热带雨林植物，被认为很可能代表一个中新世热带雨林。前期研究暗示，这些现今主要分布于东南亚热带的植物很有可能在中中新世气候适宜期首次到达华南，部分类群在第四纪冰期后幸存至今，成为华南植物区系的重要组成部分。本项目计划在大量采集化石材料的基础上，系统研究佛昙群植物化石和叶化石昆虫取食遗迹，重建漳浦地区中中新世的古植物、古植被和古气候。通过与我国华南及东南亚不同类型的现代热带和亚热带森林对比，从植物群类群组成、多样性水平、叶相组成、昆虫取食遗迹类型组成及多样性程度、和植物群生境气候指数等多个方面，定量探讨中中新世佛昙植物群的植被类型。本项研究对认识华南植物多样性和植物区系的起源和演化具有重要意义。对佛昙植物群叶化石昆虫取食遗迹的研究还将有助于认识未来气候变暖趋势下农林业病虫害的发展。

福建漳浦县中中新世佛昙植物群是我国保存最精美、多样性最丰富的新生代植物群之一。本项目计划在大量采集化石材料的基础上，系统研究漳浦中中新世植物化石，重建漳浦地区中中新世的古植被、古生态和古气候。项目执行期间课题组在漳浦组织了多次野外考察和采样，采集植物化石近5000块。区系组成和叶相组成都显示漳浦中中新世佛昙植物群代表一个热带季雨林植被，其叶相组成最类似于现今泰国中部，印度中部和恒河三角洲的植被。古植物群中多样性最高、化石标本最丰富的类群包括龙脑香科、豆科、樟科和藤黄科。植物化石中其它泛热带分布的科还有番荔枝科、漆树科、橄榄科、大戟科、野牡丹科、桑科、肉豆蔻科和桃金娘科等。这些科的植物现今都是东南亚热带雨林和季雨林的优势类群。植物化石叶相古气候分析显示，漳浦地区中中新世处于热带北缘，年均温22.5 ± 2.4 °C，夏季均温27.1 ± 2.9 °C，冬季均温17.2 ± 3.6 °C，生长季长约12个月，生长季降水1929 ± 643 mm，春季是最干旱的季节。与现今漳浦的气候相比，中中新世漳浦气候最显著的不同是冬季更温暖，全年温度季节性差异较小。中中新世漳浦地区温暖的冬季使得泛热带分布的植物向北扩散至我国福建东南沿海地区，并强烈影响了华南的植物多样性格局。这项研究对认识华南植物多样性的起源和演化，以及全球变暖对植物多样性的影响都具有重要意义。