云南保山上新统黄背栎Quercus Pannosa Hand.-Mazz.角质层特征及古环境意义

在滇西保山上新统首次发现了黄背栎(Quercuspannosa)压型化石,并分析了角质层构造。其特征主要为:上表皮无气孔器,表皮细胞为不规则形五边形,垂周壁微弯曲,脉络为网格状,无毛基;下表皮具环列型气孔器,表皮细胞为不规则形五边形,垂周壁微弯曲,脉络为五边形的网格状,具毛基,毛的根部由多细胞组成,毛基部的细胞特化成辐射状。利用现存最近亲缘种(NLRspecies)原理,并比较化石和现生Q.pannosa角质层特征,推断上新世Q.pannosa在羊邑生长的古环境比现生Q.pannosa生存的冷湿气候相对干旱,且化石Q.pannosa为近原地埋藏。     

广西百色盆地更新世樟科两种植物角质层研究

本文描述的具角质层的两块叶化石,产自广西百色盆地更新统长蛇岭组。经与现代植物的角质层对比研究后,确定这两块叶化石分属于樟科的两属两种,即油丹(近似种)(Alseoda-phne cf.hainanensis Merr.)和紫楠(近似种)[Phoebe cf.sheareri(Hemsl.)Gamble]。研究结果表明,角质层在鉴定被子植物化石中具有可靠的价值。     

皱皮油丹(樟科)在云南东南部的发现及其生物地理学意义

该文报道了在云南省马关县古林箐省级自然保护区发现的一个云南省新记录种——皱皮油丹(Alseodaphne rugosa Merr.et Chun),并对其形态、生境及该新记录种的生物地理学意义进行了描述与讨论。此新记录种的发现对樟科油丹属植物的系统分类学、生物地理学和区域生物多样性等方面的研究具有重要意义,同时也为探讨海南岛的起源问题提供了具有价值的研究材料。     

云南樟科油丹属一新种——黄连山油丹

报道了樟科油丹属一新种,即黄连山油丹Alseodaphne huanglianshanensis H. W. Li & Y. M. Shui。它产自中国云南东南部绿春县黄连山海拔840-1300 m的热带阔叶次生林中,在体态上与同一分布区内的云南油丹A. yunnanensis Kosterm.十分相似,但叶为长圆形或倒披针状长圆形(5-13×(0.8-)1.2-2.8 cm),明显较狭,两面几无蜂窝穴,总梗及果梗无毛,密被灰白色小瘤而不同。该新种也与油丹A. hainanensis Merr. 相似,但叶长圆形至倒披针状长圆形,坚纸质,先端锐尖或渐尖,两面几无蜂窝穴,侧脉每侧7-8条,果梗长5-7 mm,密被灰白色条形的小瘤而不同。     

四川西部高原上新世植物群

本文描述的植物化石系产自四川西部高原德昌县昔格达组和松潘县红土坡。德昌昔格达组植物群计有5属7种,其中包括4新种,它们全系被子植物,以常绿阔叶植物为主兼有少量落叶植物的混生林,代表亚热带的气候环境。松潘红土坡的植物化石数量很少,均为落叶植物,显示温带的气候特点。这两个植物群代表的地质时代均属上新世或上新世晚期。     

中国植物化石角质层研究综述

总结近30年来中国大陆植物化石角质层研究的进展,介绍角质层分析的3个主要研究方向:植物化石表皮微细构造研究、植物化石气孔参数与大气CO2和气候变化研究以及植物化石角质层地球化学特征研究.举出众多典型实例,提出植物化石角质层分析的研究展望.     

希夏邦马峰高山栎化石层的发现及其在植物学和地质学上的意义

希夏邦马峰是喜马拉雅山中部的高峰之一,海拔8012米。在其北坡山脚下有一套灰黄色砂岩层,露出的厚度约为1000米。在砂岩层的下部出现一个植物化石层,保存着高山栎(Quercus semicarpifolia Sm.)、类似黄背栎(Qu.cf.pannosa Hand.-Mzt.)、灰背栎(Qu .senescens Hand.-Mzt.)、常绿乔木和莎草科的叶化石。经孢粉分析,发现砂砾岩的上、下部岩石中都含有大量的雪松属和栎属花粉,各占本部孢粉含量的59.1%及72.2%。此外,有冷杉、云杉、松、铁杉和桦等属乔木花粉和杜鹃科、唇形科、莎草科灌木和草本植物花粉及凤尾蕨、水龙骨、卷柏等属孢子。上、下部的孢粉组合大体相似,但上部成分较为复杂,冷杉属的分量有所增加,并出现云杉属和松属的花粉。灌木和草本植物花粉也多出现于上部。说明晚期植被趋向温带类型,气候趋向微凉方向发展。总的说来,当时植被以常绿栎林和雪松林为主,气候温和而多雨,酷似今日的亚热带。从植物区系上看,希夏邦马植物区系与云南西北部上新世、南欧东部上新世中晚期以及克什米尔早更新世的植物区系有较密切的关系,其发展趋势与保加利亚南部索非亚的艾奔(Ebene)上新世和法国南部康塔耳(Cantal)上新世中期的植物区系相仿。因此,含高山栎岩系的地质时代不会早于上新世中晚期。现在化石产地气候十分严寒,海拔5700—5900米。盛夏之际,草木不生,而大小植物化石皆指出在上新世中、晚期该地比较温暖,海拔不过2500米。显然希夏邦马峰在上新世以后二三百万年间,已升高了约3000米。     

云南腾冲上新统Cinnamomum cf.camphora叶形态和表皮微细构造研究

化石采自云南腾冲上新统芒棒组.通过对比叶结构和角质层微细构造特征,从宏观和微观两个角度将化石鉴定为樟科植物樟(相似种)Cinnamomum cf.camphora(L.)Presl.化石叶片为卵状椭圆形,基部宽楔形,全缘,离基三出脉;上表皮无气孔器,表皮细胞为不规则四边形或多边形;下表皮细胞为不规则多边形,脉络上可见少...     

横断山南段上新世的植被多样性与分布格局

横断山南段复杂的地形地貌和多样的气候环境造就了高度丰富的植被多样性。这种植被多样性的演化与形成是植物学、生态学等领域共同关注的科学问题, 而植物化石是回答这一科学问题的重要媒介。本文基于横断山南段的9个上新世化石植物群, 根据其植物组成和优势成分, 分析其所代表的植被类型, 总结了该地区上新世的植被多样性与空间分布, 并结合古环境研究资料, 探讨该地区植被多样性的兴起, 植被分布格局的形成, 及其与环境变迁之间的关联。结果显示, 横断山南段在上新世时期已经具有了多种植被类型, 包括亚热带常绿阔叶林、亚热带落叶阔叶林、硬叶常绿阔叶林、针阔叶混交林、灌丛草地等, 体现了丰富的植被多样性; 植被类型从南面的偏热性植被向北面的偏温性植被逐渐转变, 反映了当时随纬度变化的海拔梯度, 植被类型与分布呈现出与现在高度相似的格局。同时, 小范围内也具有适应于不同气候的植被类型, 反映了当地较大的海拔落差, 可能与高大山体的存在有着密切关联。我们推测, 横断山南段现在丰富的植被多样性和随纬度变化的植被面貌最晚在上新世就已基本形成, 但形成时间是否更早则需要更多、更老化石植物群的发现与研究。     

云南腾冲上新统芒棒组植物分散角质层研究

在云南腾冲上新统芒棒组中发现保存较好的植物分散角质层,共识别出7种:Reticutissolida,Reticutis tylotis,Fundicutis verriculis,Lusaticutis arizelis,Piliparicutis anfracta,Discrepoparicutis elongata,Enormicutis torquata,可归于6属,4亚类,4类,1个大类,表现出上叶角质层类型和下叶角质层类型的组合特征及上叶角质层类型的优先保存情况。从表皮细胞形态及气孔器等微观特征上看,具气孔的4种之间有着明显的差别,表明它们可能分别来自不同的母体植物;其中3种角质层的母体植物极有可能为被子植物,并处于优势地位。滇西当时温暖湿润的热带-亚热带、暖温带气候,为分散角质层的母体植物提供了良好的生存条件。而该区植物分散角质层的发现为分析其母体植物和重建古环境提供微体植物化石证据。     

Cuticular Studies on Two Pleistocene Species of Lauraceae in Baise Basin,Guangxi

Two fossil leaves with cuticle described here were collected from the Pleistocene Changseling Formation of Baise Basin, Guangxi. A detailed comparison of the cuticular analysis between the fossils and their living equivalents indicated that the two fossil species belong to 2 genera of Lauraceae, that is, Alseodaphne of, hainanensis Merr. and Pheobe cf. sheareri (Hemsl.) Gamble. The first report on lauraceous fossil leaves with cuticle in China showed that cuticular analysis had a reliable value in identifying the angiospermous fossil plants.     

油丹生物碱的研究

从油丹中分到6种生物碱,其中4种经理化常数及光谱测定,鉴定为：番荔枝宁,杏黄罂粟碱,多略发宁及1－（4－甲氧基苄基）,6,7－亚甲二氧基1,2,3,4－四氢异喹啉生物碱。     

Studies on the Alkaloids of Alseodaphne hainanensis Merr

Six alkaloids were isolated from the stem of Alseodaphne hainanensis Merr. (Lauraceae) collected in Hainan Island. Four of them were identified as xylopinine, armepavine, doryafranine, and 1-(4-methoxybenzyl)-6,7-methylenedioxy-l,2,3,4-tetrahydroisoquinoline by means of spectral analysis and comparison of physico-chemical constants.     

Fruit fossils of Rosoideae (Rosaceae) from the late Pliocene of northwestern Yunnan,Southwest China

The subfamily Rosoideae Focke (Rosaceae) has a good fossil record in the Northern Hemisphere, but these fossil records are confined mainly to a few genera, whereas the majority, in particular those with herbaceous members, are still under‐represented. In this study, we describe new fruit fossils of Rosoideae, including Fragaria achenes and Rubus endocarps, from the late Pliocene of northwestern Yunnan, Southwest China. These fossils add new accounts to the fossil archive of Rosoideae and provide the first fossil record of Fragaria in East Asia. The new fossil findings provide a historical backdrop for the modern diversity and distribution of the subfamily in northwestern Yunnan, a topographically complex area accommodating a high diversity for many plant groups. Our Rubus fossils, in combination with other nearby coeval occurrences of the genus, suggest that Rubus was already establishing its modern diversity in northwestern Yunnan during the late Pliocene. This finding enriches our knowledge of the post‐Neogene diversification of flowering plants in northwestern Yunnan, which is thought to be largely driven by dramatic mountain uplifts and environmental complications associated with the southeastern extension of the Tibetan Plateau.     

Late Pliocene diversity and distribution of Drynaria(Polypodiaceae) in western Yunnan explained by forest vegetation and humid climates

The palaeodiversity of flowering plants in Yunnan has been extensively interpreted from both a molecular and fossil perspective. However, for cryptogamic plants such as ferns, the palaeodiversity remains poorly known. In this study, we describe a new ferny fossil taxon, Drynaria lanpingensis sp. nov. Huang,Su et Zhou(Polypodiaceae), from the late Pliocene of northwestern Yunnan based on fragmentary frond and pinna with in situ spores. The frond is pinnatifid and the pinnae are entirely margined. The sori are arranged in one row on each side of the primary vein. The spores have a semicircular to bean-shaped equatorial view and a tuberculate surface. Taken together with previously described fossils, there are now representatives of three known fossil taxa of Drynaria from the late Pliocene of western Yunnan.These finds suggest that Drynaria diversity was considerable in the region at that time. As Drynaria is a shade-tolerant plant, growing preferably in wet conditions in the understory of forests, its extensive existence may indicate forest vegetation and humid climates in western Yunnan during the late Pliocene.This is in line with results from floristic investigations and palaeoclimatic reconstructions based on fossil floras.     

Conifer Woods of the Pliocene Age from Yunnan, China

The Tertiary floras play an integral role in understanding the biodiversity and interactions between climate and vegetation in Yunnan, China. The fossil spores, pollen grains, and leaves in this region have been investiagedintensively. In comparison, the woods have been studied relatively little. A large number of Pliocene wood specimens was collected from the opencast lignite coal mine of Hongxing situated in Changning County of Yunnan Province. Among the collection, Tsuga cf. dumosa (D. Don) Eichler and Pinus cf. armandii Franchet were identified based on wood structures. The subtle feature of tori extensions is reported in the wood of T. cf. dumosa. Considering the climatic requirements of modern T. dumosa and P.armandii, the two species of conifer described from Pliocene sediments probably grew in mountainous terrain at an elevation of approximately 2 300 m, in a cool and humid environment.