48 resultados para Taxodiaceae


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本文以杉科(Taxodiaceae)五属六种植物--杉木属(Cunninghamia)的杉木(C. lanceolata)、水松属(Glyptostrobus)的水松(G. pensilis)、落羽杉属(Taxodium)的池杉(T. ascendens)、水杉属(Metasequoia)的水杉(M. glyptostroboides)、柳杉属(Cryptomeria)的柳杉(C. fortunei)及日本柳杉(C. japonica)为材料,进行了以下研究: 1、用气相色谱-质谱-计算机联用法,在统一条件下测定了上述植物叶的精油成分及各成分百分含量。共检测到七十余种成分,包括α-蒎稀(α-pinene)、龙脑(borneol)、乙酸松油酯(terpinyl acetate)、杜松烯(cadinene)等十六种共有成分和其它分布各异的成分。 2、用柱层析和薄层层析法从杉木中提取、分离、纯化了5个双黄酮成分,鉴定为一类3'-8"联接的化合物,分别为穗花杉双黄酮(amentoflavone)、长叶世界爷双黄酮(sequoiaflavone)、银杏双黄酮(gingetin)、榧黄素(kayaflavone)和金松双黄酮(sciadopitysin)。 3、用薄层层析法检测上述5个双黄酮成分在6种植物中的分布,发现每一植物均含有这五个已知化合物。 4、根据以上结果并结合文献资料,讨论了以下问题: 1)、杉科植物精油成分及其组成特点; 2)、杉科植物双黄酮成分及其分布规律; 3)有关柳杉与日本柳杉关系的化学证据; 4)有关水杉归属的化学证据。

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我国古新世植物化石发现较少,因而目前对古新世的植被面貌;生态环境等植物学;植物地理学和地质学方面的认识尚感不足。抚顺古新过木化石群的研究提供了这方面的新资料无疑在植物学;质植物地理学和地质学等方面都有一定意义。 本研究表明,抚顺古新世木化石群皆由松柏目Pinales裸子植物组成,共有三科七属七种和三个未定种。其中杉科Taxodiaceae三属三种和一个未定种,松科Pinaceae和柏科Cupressaceae各二属二种和一个未定种。共有四个新种。本化石群的地质时代被确定为古新世。通过对此化石植物群的研究,作者认为右新世时抚顺地区存在着以杉和柏科植物为主体的北亚热带一北温暖带边缘地带暖性针叶林。根据孢粉资料(木化石未见)同时还有繁盛的被子植物存在。当时当地的生态环境类似我国现今长江流域南部偏北地带,如川鄂;江浙一带的山地,系属亚热带山区气候。 此外,根据新的化石资料,本文还对扁柏型木属Chamaecyparioxylon做了补充修正,报导了木化石中真菌菌丝的发现。它被初步鉴定为藻状菌纲毛霉目 Mucorales真菌。

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本文对杉科植物的分类系统作了回顾。以形态学为依据,参考其他学科的研究成果,用分支分析和表征分析两种方法探讨了杉科植物的系统演化关系.提出了新的分类系统。对杉科植物的系统分类作了修订.通过对各属现代分布和地史分布的研究,结合古地理和古气候资料,讨论了杉科植物的分布中心、起源时间、起源地、散布途径及现代分布格局的成因.主要结论如下: 1.属间关系:柳杉属是现存杉科植物中最原始的类群.水松属和落羽杉属关系密切,二者与柳杉属近缘.巨杉属和北美红杉属关系密切,是中级进化水平的类群.水杉属的系统位置比较孤立,与巨杉属和北美红杉属的关缘关系相对较近.杉木属、密叶杉属和台湾杉属关系密切,是杉科植物中的高级进化类群,其中台湾杉属最为进化. 2.系统排列:支持金松科的成立.将杉科分成5族,即柳杉族(仅含柳杉属)、落羽杉族(含水松属、落羽杉属)、北美红杉族(含巨杉属、北美红杉属)、水杉族(仅含水杉属)和杉木族(含杉木属、密叶杉属及台湾杉属). 3.分类:经修订,杉科植物共9属12种4变种.将德昌杉木、米德杉木和厚皮杉木归并,作为杉木的变种,支持柳杉作为日本柳杉的变种、台湾杉木作为杉木的变种、秃杉和台湾杉归并的观点。 4.地理分布:我国长江、秦岭以南至华南一带是杉科的现代分布中心,我国华北北部及东北、朝鲜、日本和前苏联西伯利亚东南部等地可能为起源中心和早期分化中心,起源时间可追溯至早侏罗纪或晚三叠纪.杉科的现存各属均为古老的孑遗类群.

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本论文研究了我国云南龙陵大坝和镇安、昌宁红星晚上新世以及楚雄洲吕合晚中新世191个化石木标本,鉴定出7种化石木类型,其中越桔型木属为新属,越桔型木、常绿杜鹃型木和龙陵杜鹃型木为新种。并利用化石木的现存种或现存亲缘种的生态环境对化石产地的气候和环境进行了讨论。 木材种类的特征如下: 华山松(Pinus armandii Franchet):生长轮明显,早材至晚材渐变。交叉场纹孔主为窗格型。木射线具单列射线和纺锤状射线。射线管胞内壁平滑或微锯齿状。具正常轴向和径向树脂道,由薄壁泌脂细胞组成。 云南铁杉(Tsuga dumosa Eicher):生长轮明显,早材至晚材略急变至渐变。管胞径壁具缘纹孔单列;具缘纹孔膜上明显具棒状延伸;纹孔膜下具缘纹孔外表面具明显的瘤状层,瘤状突起大小相近。交叉场纹孔式柏木型。木射线主为单列;由射线薄壁细胞和射线管胞组成;射线细胞水平壁厚,纹孔明显,数多;端壁节状加厚明显。轴向木薄壁组织细胞数少,轮界状;其端壁节状加厚明显。 柳杉型木(Taxodioxylon cryptomeripsoides Schonfeld):生长轮明显,早材至晚材略急变。管胞径壁纹孔1列,偶尔成疏松排列的2列;晚材弦壁纹孔明显可见。交叉场具1-4枚杉木型纹孔。轴向木薄壁组织细胞数多,星散状或有时成短弦线状;端壁节状不明显或略现。木射线单列,全由射线薄壁细胞组成;射线细胞水平壁薄,纹孔缺乏,端壁平滑。 杉木型木(Taxodioxylon cunninghamioides Watari):生长轮明显,早材至晚材渐变。管胞径壁纹孔1-2列;晚材弦壁纹孔明显可见。交叉场1-4枚杉木型纹孔。轴向木薄壁组织丰富,星散状或有时成短弦线状;端壁节状不明显或略现。木射线单列全由射线薄壁细胞组成;射线细胞水平壁薄;端壁薄,平滑。 龙陵杜鹃型木(新种)(Ericaceoxylon longlingense sp. nov.):生长轮明显,散孔材。导管横切面为多角形,单管孔,散生。螺纹加厚仅出现导管分子尾端。梯状穿孔为主。管间纹孔式为对列或梯状对列。轴向薄壁组织量少,疏环管状。纤维分子细胞壁厚度中等。射线宽1-6细胞。多列射线的中部多为横卧细胞,边缘有1-4(6)行直立和/或方形细胞。射线导管间纹孔式梯状对列,类似导管间纹孔式。 常绿杜鹃型木(新种)(Ericaceoxylon hymenanthesoides sp. nov.):生长轮明显,半环孔材。导管横切面为多角形,单管孔,散生。螺纹加厚出现整个导管分子壁上。复穿孔,梯状穿孔为主。管间纹孔式为互列。轴向薄壁组织量少,疏环管状;端壁节状加厚不明显。纤维分子细胞壁厚度中等;径壁和弦壁均具有具缘纹孔。射线宽1-4细胞;多列射线的中部多为横卧细胞,边缘有1-9行直立和/或方形细胞。射线导管间纹孔式互列,类似导管间纹孔式。 常绿杜鹃型木(相似种)(Ericaceoxylon cf. hymenanthesoides):生长轮明显,半环孔材。单管孔;导管散生。梯状穿孔板;管间纹孔式为互列;射线导管间纹孔式多对列,类似导管间纹孔式。螺纹加厚出现在导管分子壁上。木纤维细胞壁中等厚度。射线宽1-3细胞。 越桔型木(新种)(Vacciniaceoxylon vacciniumoides sp. nov.):生长轮略明显,散孔材。单管孔,散生;整个导管分子上具螺纹加厚。网状和梯状穿孔。轴向薄壁组织量少,星散状或疏环管状。纤维分子径壁和弦壁都具有具缘纹孔。射线多列和单列射线组成,两种大小,1-4细胞宽。射线导管间纹孔式互列,纹孔有明显的纹孔缘。 化石木植物群及其所反映的古植被和古气候如下: 楚雄吕合化石木植物群4个标本中鉴定出两种木材类型—柳杉型木和杉木型木。由于化石标本少,不足以反映植被面貌,两种杉科植物的出现反映其生长地为亚热带温暖湿润环境。 龙陵大坝和镇安化石木植物群95个标本中鉴定出四种木材类型:华山松、常绿杜鹃型木、越桔型木和龙陵杜鹃型木。他们反映的古植被为针阔混交林,生长于亚热带温凉湿润的山地气候环境中,当时当地的海拔高度在1800-3000米之间。 昌宁红星化石木植物群92个标本中鉴定出三种木材类型:华山松、云南铁杉、常绿杜鹃型木(相似种)。他们反映的古植被为针阔混交林,生长于亚热带温凉湿润的山地气候环境中,当时当地的海拔在2200-3000米之间。

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全球古近纪和新近纪气候波动明显,很多科学家对古近纪和新近纪生物演化和气候演变规律的定量研究给予了相当的重视。杉科植物有长期发展的历史、少数的现存种和丰富的化石记录,成为指示古环境的理想植物之一。利用杉科植物重建古环境,首先要对化石植物进行正确的分类鉴定。杉科各属枝叶形态特征变异幅度较大,且枝叶排列和形态特征近似,有时各属之间存在交叉特征。杉科化石标本通常仅保存枝叶形式,且多个属的化石标本经常发现于同一地层,因而分类鉴定比较困难。植物的叶表皮结构是压型植物化石细胞信息的重要来源,是属种分类鉴定重要依据之一。本文在以往研究的基础上,完整分析了杉科9属现生植物的表皮特征,建立了杉科化石植物分类鉴定的现生植物的表皮特征参照系。 杉科植物的叶多为条形、钻形、鳞形或披针形,同种植物有1种、2种甚至3种叶型。其中水杉属的叶交互对生,其它属的叶螺旋状互生。水杉属的多数表皮细胞垂周壁明显弯曲,落羽杉属和杉木属有时微呈波状,其他属的表皮细胞垂周壁直。多数植物的叶片近轴面和远轴面的气孔数量和分布不同。一般来说,条形叶和披针形叶的远轴面气孔分布状况和气孔数量稳定,远轴面的中部最稳定。条形叶远轴面的气孔分布于中脉两侧,形成纵向的气孔带。条形叶近轴面气孔分布状况和气孔数量变化大,近轴面的气孔数量有时与远轴面近似,但多数情况下比远轴面少,有时整个叶片的近轴面仅少数几个气孔或没有气孔分布。钻形叶的近轴面和远轴面的气孔数量近似,或叶片近轴面的气孔数量比远轴面的气孔数量多,气孔分布范围也比远轴面气孔分布范围广。气孔椭圆形,落羽杉属植物和水松鳞形叶的气孔长轴方向与叶片长轴垂直或斜向排列,柳杉属植物的气孔多斜向排列,水松的条形叶和条状钻形叶的气孔多平行向排列。落羽杉属和柳杉属以外的杉科植物的气孔长轴多数与叶片长轴平行。在扫描电子显微镜下的密叶杉属植物叶片角质层的内表面,副卫细胞和表皮细胞的垂周壁与叶表面的角度一致,且副卫细胞的形态与表皮细胞类似,这种特殊气孔器被称为A-型气孔器。杉科植物中水杉属、落羽杉属和杉木属的气孔器近似密叶杉的这种A-型气孔器。台湾杉属、柳杉属、水松属、红杉属和巨杉属植物的气孔器与这种A-型气孔器不同,这几属的副卫细胞垂周壁表皮细胞的垂周壁方向不同,且副卫细胞的形态与表皮细胞的形态明显不同。因而气孔所有副卫细胞组成呈明显的圆盘状,保卫细胞在盘子的中央。综合分析植物的枝叶形态和表皮特征可以区分杉科各属。 本文研究了采自抚顺始新世的杉科植物标本,经枝叶特征、表皮结构和球果鳞片等特征分析为水松属的欧洲水松。论文分析了中国东北地区古温度定量研究结果与杉科植物的相关性。抚顺植物群发现有化石水杉M. occidentalis、中华红杉和欧洲水松,根据这三种化石植物的年均温度和年降水量,通过共存分析,推测抚顺始新世的年均温为12.1-17℃,年降水量为1199.6-2231mm。

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This paper concentrates on the Early Oligocene palaeoclimate of the southern part of Eastern and Central Europe and gives a detailed climatological analysis, combined with leaf-morphological studies and modelling of the palaeoatmospheric CO2 level using stomatal and d13 C data. Climate data are calculated using the Coexistence Approach for Kiscellian floras of the Palaeogene Basin (Hungary and Slovenia) and coeval assemblages from Central and Southeastern Europe. Potential microclimatic or habitat variations are considered using morphometric analysis of fossil leaves from Hungarian, Slovenian and Italian floras. Reconstruction of CO2 is performed by applying a recently introduced mechanistic model. Results of climate analysis indicate distinct latitudinal and longitudinal climate patterns for various variables which agree well with reconstructed palaeogeography and vegetation. Calculated climate variables in general suggest a warm and frost-free climate with low seasonal variation of temperature. A difference in temperature parameters is recorded between localities from Central and Southeastern Europe, manifested mainly in the mean temperature of the coldest month. Results of morphometric analysis suggest microclimatic or habitat difference among studied floras. Extending the scarce information available on atmospheric CO2 levels during the Oligocene, we provide data for a well-defined time-interval. Reconstructed atmospheric CO2 levels agree well with threshold values for Antarctic ice sheet growth suggested by recent modelling studies. The successful application of the mechanistic model for the reconstruction of atmospheric CO2 levels raises new possibitities for future climate inference from macro-flora studies.

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This study presents a newly compiled dataset of modern pollen and climate data from 798 sites across Japan and the Russian Far East. This comprehensive reference dataset combined with the modern analogue technique (MAT) provides a powerful tool for pollen-based reconstruction of the Quaternary Northwest Pacific climate. Pollen-derived reconstruction of the modern climate at the reference pollen-sampling sites matches well with the estimated modern climate values (R2 values vary between 0.79 and 0.95, and RMSEP values vary between 5.8 and 9.7% of the modern climatic range for all nine tested variables). The successful testing of the method encourages its application to the fossil pollen records. We used a coarse-resolution pollen record from Lake Biwa to reconstruct glacial-interglacial climate dynamics in central Japan since ~438 kyr and compared it to the earlier reconstruction based on a less representative reference dataset. The current and earlier results consistently demonstrate that the coldest glacial intervals experienced pronounced cooling in winter and moderate cooling in summer, supporting the growth of cool mixed forest (COMX) where warm mixed forest (WAMX) predominates today. During the last glacial, maximum (~24 kyr BP) mean temperatures of the coldest (MTCO) and warmest (MTWA) month were about -13 °C (RMSEP = 2.34 °C) and 21 °C (RMSEP = 1.66 °C) respectively, and annual precipitation (PANN) was about 800 mm (RMSEP = 158.06 mm). During the thermal optimums of the interglacial intervals, the temperatures of the coldest and warmest month were above 0 °C and 25 °C respectively, leading to the reconstruction of WAMX and temperate conifer forest (TECO). Although both these vegetation types grow in the southern part of Japan today, WAMX requires warmer space. The presence of WAMX during marine isotope stages (MIS) 11 and 1, and its absence during MIS 9 and MIS 5 contradict the marine isotope and Antarctic ice records, suggesting that the latter two interglacials were the warmest of the last 800 kyr. The apparent contradiction allows at least three different explanations including low temporal resolution of the pollen record; different trends in CO2 concentrations during 'short' and 'long' interglacials; and regional climate variability and non-linear response of different regions to the global forcing. More definitive conclusions will be possible on the basis of forthcoming high-resolution pollen records from central Japan.

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This study reconstructs middle and late Holocene vegetation and climate dynamics in the Oshima Peninsula, SW Hokkaido, using the published method of biome reconstruction and modern analogue technique applied to the Yakumo pollen record (42°17'03''N, 140°15'34''E) spanning the last 5500 years. Two previously published matrices assigning Japanese plant/pollen taxa to the major vegetation types (biomes) are tested using a newly compiled dataset of 78 surface pollen spectra from Hokkaido. With both matrices showing strengths and weaknesses in reconstructing cool mixed and temperate deciduous forests of Hokkaido, the results suggest the necessity to consider the whole list of identified terrestrial pollen taxa for generating robust vegetation reconstructions for northern Japan. Applied to the fossil pollen data, both biome-reconstruction approaches demonstrate consistently that oak-dominated cool mixed forest spread in the study region between 5.5 and 3.6 cal ka BP and was subsequently replaced by beech-dominated temperate deciduous forest. The pollen-based climate reconstruction suggests this change in the vegetation composition was caused by a shift from cooler and drier than present climate to warmer and wetter, similar to modern conditions about 3.6 cal ka BP. Comparing the pollen-based reconstruction results with the published marine records from the NW Pacific, the reconstructed vegetation and climate dynamics can be satisfactorily explained by the greater role played by the warm Tsushima Current in the Sea of Japan and in the Tsugaru Strait during the middle and late Holocene. An increase in sea surface temperatures west and south of the study site would favour air temperature rise and moisture uptake and cause an increase in precipitation and snow accumulation in the western part of Hokkaido during the late Holocene.