【作者】 程业明；

【导师】 李承森； 王宇飞； 姜笑梅；

【作者基本信息】 中国科学院研究生院（植物研究所） ， 植物学， 2004， 博士

【摘要】 首次报道了云南元谋盆地(虎跳滩土林、湾堡土林和新华土林)晚上新世的硅化木材植物群和山西太谷盆地晚上新世的炭屑木材植物群,分析了这两个盆地当时的植被、环境和气候,为认识我国西南地区和北方中部地区晚上新世气候变化提供了生物学证据。1. 云南元谋盆地晚上新世沙沟组(相当于钱方等1991元谋组下部一、二段)化石木植物群包括:裸子植物1种,归属于三尖杉科(Cephalotaxaceae)三尖杉属(Cephalotaxus)或红豆杉科(Taxaceae)穗花杉属(Amentotaxus);被子植物11种,分别归属于楝科(Meliaceae)香椿属(Toona)、大戟科(Euphorbiaceae)秋枫属(Bischofia)、榆科(Ulmaceae)榉属(Zelkova)、豆科(Fabaceae)黄檀属(Dalbergia)、壳斗科(Fagaceae)锥属(Castanopsis)、青冈属(Cyclobalanopsis)、千屈菜科(Lythraceae)紫薇属(Lagerstroemia)、桑科(Moraceae)桑属(Morus)、胡桃科(Juglandaceae)、豆科和壳斗科。其中三尖杉属或穗花杉属、楝科香椿属、豆科黄檀属、壳斗科锥属、青冈属、千屈菜科紫薇属、桑科桑属、胡桃科和壳斗科的化石木在我国为首次报道。依据植物群的组成,当时该盆地周围山地上的森林是以锥属、青冈属和三尖杉属或穗花杉属为主要分子的常绿针阔混交林,盆地内的树木包括楝科香椿属、大戟科秋枫属、豆科和千屈菜科紫薇属等植物;当时的气候为亚热带气候,温暖湿润。与印度同时代植物群相比,元谋植物群不具有典型的热带雨林分子如龙脑香科植物,而在印度晚第三纪则常见热带雨林分子。这种差异可能是因为中印植物区系起源不同,以及地质历史时期青藏高原的隆升造成区域气候分异,从而导致中印古植物区系不同。2. 山西太谷盆地晚上新世小白组化石木植物群包括榆科(Ulmaceae)榆属(Ulmus)、蔷薇科(Rosaceae)李属(Prunus)和桑科柘属(Cudrania),它们的标本保存为炭屑木材。该化石木群的发现,以及综合通过孢粉学研究得出的古气候研究结果,表明当时当地属于典型的温带气候。化石木清晰的生长轮表明当时气候具明显的季节性。现代生态木材解剖学研究发现温带干旱地区植物群中导管分子壁的螺纹加厚比例较高、且明显。化石木标本导管分子壁具明显的螺纹加厚也表明盆地内为温带的气候类型。孢粉学研究和地层中丰富的石膏层也表明当时气候具有明显的干湿波动,地层中多层炭屑的存在证明了当时气候条件下森林火频繁发生。这些炭屑木材的发现丰富了太谷盆地晚上新世植物群,为古植被重建和古环境恢复提供了新的证据。关键词:元谋,太谷,化石木,晚上新世,古植被,古环境,古气候刀更多还原

【Abstract】 Fossil woods, silicified and charcoal material, are investigated for the first time from the Yuanmou Basin of Yunnan Province and the Taigu Basin of Shanxi Province at the age of Pliocene in present paper. The palaeovegetation, palaeoenvironment and palaeoclimate in these localities are reconstructed based on the biological evidences obtained from the fossil wood flora.1. Yuanmou wood flora in the age of Late Pliocene (Shagou Formation) of the Yuanmou Basin, including Hutiaotan Earth Forest, Wanpu Earth Forest and Xinhua Earth Forest, Yunnan province, China, contains a gymnosperm of Cephalotaxus (Cephalotaxaceae) or Amentotaxus (Taxaceae) and 11 angiosperms of Toona (Meliaceae), Bischofia (Euphorbiaceae), Zelkova (Ulmaceae), Dalbergia (Fabaceae), Castanopsis, Cyclobalanopsis (Fagaceae), Lagerstroemia (Lythraceae), Morus (Moraceae), Juglandaceae, Fabaceae and Fagaceae. The fossil woods of Toona (Meliaceae), Dalbergia (Fabaceae), Castanopsis, Cyclobalanopsis (Fagaceae), Lagerstroemia (Lythraceae), Morns (Moraceae), Juglandaceae and Fabaceae are reported in China for the first time.Evergreen broad-leaved plants like Castanopsis and Cyclobalanopsis (Fagaceae)mixed with needle leaf plants such as Cephalotaxus (Cephalotaxaceae) or Amentotaxus (Taxaceae) grow on the high lands around the basin, while plants of Toona (Meliaceae), Bischofia (Euphorbiaceae), Lagerstroemia (Lythraceae) and Fabaceae etc. are accustomed to grow inside the basin under warm and humid subtropical climate.Compared with contemporaneous flora of India, the Yuanmou flora does not have the typical tropical rain forest elements like Dipterocarpaceae, which is very common in the Tertiary floras in India. The difference between the floras of two countries was resulted from Pliocene climate, that was formed as a result of Himalaya uplifting and flora origin.2. Taigu wood flora in the age of Late Pliocene (Xiaobai Formation) of the Taigu Basin, Shanxi Province, China, contains Ulmus (Ulmaceae), Prunus (Rosaceae) and Cudrania (Moraceae). Dicotyledonous charcoal woods of Tertiary are discovered for the first time in China. The elements of this flora demonstrate that typical temperate climate in the basin during Pliocene. Fossil woods with distinct growth ring show that the climate has seasonal change obviously during that time. The modern temperate plants possess high incidence of distinct helical thickenings on vessels. The fossil wood vessels from Taigu showed the distinct helical thickenings. It is an additional evidence for comparing the modern temperate climate with the Pliocene one in the Taigu basin. The abundant layers of charcoal and gypsum indicate that wild fire occurs under the dry climate frequently. The Taigu wood flora enriched the Pliocene flora of the Taigu Basin and provide new evidences for the reconstruction of palaeovegetation, palaeoenvironment and palaeoclimate there.更多还原