中新世山旺盆地植被演替与环境变迁

THE MIOCENE VEGETATION SUCCESSION AND ENVIRONMENTAL CHANGES IN SHANWANG BASIN,SHANDONG PROVINCE,CHINA

山东省临朐县山旺盆地中新世植物群及其研究成果闻名遐迩 ,但是在植物群的研究上依然有以下问题 :(1)在植物分类鉴定方面 ,缺乏解剖学特征研究 ;(2 )在植被演替的研究上 ,缺乏高分辨率的时间尺度 ;(3)在古环境和古气候的分析上 ,缺乏定量化标准 ;(4 )在时间和空间范围上 ,需要拓展性研究。针对上述问题 ,我们首先将山旺组富含化石的硅藻土沉积划分为 19层 ,然后以厘米级间距逐层采集标本和孢粉样品 ,目的是进行高分辨率研究和保证多种材料、多种方法研究结果的可比性。在植物类群研究方面 ,我们已经报道了中国可靠的、国际公认的化石杜仲新记录 ,建立了一个新属(Chaneya) ,而且开展了山旺古果实学的研究。在古植被演替的研究上 ,孢粉学研究表明山旺中新世植被经历了 5个发展阶段。应用特有种气候分析法、共存分析法、叶相分析对山旺中新世的古气候进行定量重建 ,获得诸如年均温、降水量、相对湿度等气象数值。根据国际学术界的最新动向 ,今后有必要在全球变化和亚洲古环境的宏观背景下加强和拓展山旺植物群的研究 ,如 :深入研究植物演化过程和植被演替的规律 ,从地层沉积物和植物化石上提取全球气候变化的信息 ,搜寻东亚季风形成和兴盛的新证据 ,探讨植物对洋流改变和新生代第

Although the Miocene\|aged Shanwang flora from Linqu County, Shandong Province is well\|known in the world, there are some critical problems about the flora, which are described as follows: (1) the paucity of anatomical characters for the identification of taxa; (2) the low resolution of time\|scale regarding the studies of the vegetation succession;(3)the lack of standards for quantitative reconstruction of palaeoenvironment and palaeoclimate;and (4)much need of further studies of Shanwang flora in terms of large temporal and spatial scales. According to these problems we divided the diatomaceous earth with abundant fossils in the Shanwang Formation into 19 units, and collected megafossils and samples layer by layer (in centimeter scale) in order to conduct the high\|resolution and comparable studies using different materials and approaches. Some great progresses have been made pertaining to the studies on Shanwang fossil plants in the following aspects:(1)the discovery of reliable and internationally\|recognized fossil specimens of Eucommia cf. ulmoides ; (2)the establishment of a new genus ( Chaneya ); and (3)the initiation of carpological studies, e. g. research on the fruits of Quercus . Novel palynological studies have been conducted to understand the vegetation succession, indicating that the vegetation of Shanwang during the Miocene experienced 5 stages. New methods, such as Climate Analysis of Endemic Species (CASE), Co\|existence Approach (CA)and Climate Leaf Analysis Multivariate Program (CLAMP), have been applied to the quantitative reconstruction of the palaeoclimate of Shanwang during the Miocene. A series of meteorological factors, e.g. Mean Annual Temperature (MAT), Mean Annual Precipitation (MAP) and Relative Humidity (RH) have been obtained. According to the latest situation in the world academic community, it is necessary to make further studies of Shanwang flora in the context of global change and Asian palaeoenvironment, and aiming at the following problems: (1) further study the process of plant evolution and vegetation succession; (2) extract the information of global climate in the high\|resolution stratigraphic sequence; (3) search new evidence for the formation and rise of eastern Asian monsoon;and (4) explore the response of plants to the changing ocean current and the third bolide\|impact event in the Cenozoic. It is no doubt that these further studies will bring about the brilliant future for the research on the Shanwang flora.