中国北方典型生态区表土孢粉组合特征及其与现代植被和气候的关系

Surface pollen assemblages and their relationhips with the modern vegetation and climate provide a foundation for investigating palaeo-environment conditions by fossil pollen analysis. A promising trend of palynology is to link pollen data more closely with ecology. In this study, I summarized the characteristics of surface pollen assemblages and their quantitative relation with the vegetation and climate of the typical ecological regions in northern China, based on surface pollen analysis of 205 sites and investigating of modern vegetation and climate. The primary conclusions are as follows:The differences in surface pollen assemblages for different vegetation regions are obvious. In the forest communities, the arboreal pollen percentages are more than 30%, herbs less than 50% and shrubs less than 10%; total pollen concentrations are more than 106 grains/g. In the steppe communities, arboreal pollen percentages are generally less than 5%; herb pollen percentages are more than 90%, and Artemisia and Chenopodiaceae are dominant in the pollen assemblages; total pollen concentrations range from 103 to 106 grains/g. In the desert communities, arboreal pollen percentages are less than 5%. Although Chenopodiaceae and Artemisia still dominate the pollen assemblages, Ephedra, Tamaricaceae and Nitraria are also significant important in the pollen assemblages; total pollen concentrations are mostly less than 104grains/g. In the sub-alpine or high and cold meadow communities, arboreal pollen percentages are less than 30%. and Cyperaceae is one of the most significant-taxa in the pollen assemblages. In the shrub communities, the pollen assemblages are consistent with the zonal vegetation; shrub pollen percentages are mostly less than 20%, except for Artemisia and Hippophae rhamnoides communities.There are obvious trends for the pollen percentage ratios of Artemisia to Chenopodiaceae (A/C), Pinus to Artemisia (P/A) and arbor to non-arbor (AP/NAP) in the different ecological regions. In the temperate deciduous broad-leaved forest region, the P/A ratios are generally higher than 0.1, the A/C ratios higher than 2 and the AP/NAP ratios higher than 0.3. In the temperate steppe regions, the P/A ratios are generally less than 0.1, the A/C ratios higher than 1 and the AP/NAP ratios less than 0.1. In the temperate desert regions, the P/A ratios are generally less than 0.1, the A/C ratios less than 1, and the AP/NAP ratios less than 0.1.The study on the representation and indication of pollen to vegetation shows that Pinus, Artemisia, Betula, Chenopodiaceae, Ephedra, Selaginella sinensis etc. are over-representative in the pollen assemblages and can only indicate the regional vegetation. Some pollen types, such as Quercus, Carpinus, Picea, Abies, Elaeagus, Larix, Salix, Pterocelis, Juglans, Ulmus, Gleditsia, Cotinus, Oleaceae, Spiraea, Corylus, Ostryopsis, Vites, Tetraena, Caragana, Tamaricaceae, Zygophyllum, Nitraria, Cyperaceae, Sanguisorba etc. are under-representative in the pollen assemblages, and can indicate the plant communities well. Populus, Rosaceae, Saxifranaceae, Gramineae, Leguminosae, Compositae, Caprifoliaceae etc. can not be used as significant indicators to the plants.The study on the relation of pollen percentages with plant covers shows that Pinus pollen percentages are more than 30% where pine trees exist in the surrounding region. The Picea+Abies pollen percentages are higher than 20% where the Picea+Abies trees are dominant in the communities, but less than 5% where the parent plants are sparse or absent. Larix pollen percentages vary from 5% to 20% where the Larix trees are dominant in the communities, but less than 5% where the parent plants are sparse or absent. Betula pollen percentages are higher than 40% where the Betula trees are dominant in the communities" but less than 5% where the parent plants are sparse or absent. Quercus pollen percentages are higher than 10% where the Quercus trees are dominant in the communities, but less than 1% where the parent plants sparse or absent. Carpinus pollen percentages vary from 5% to 15% where the Carpinus trees are dominant in the communities, but less than 1% where the parent plants are sparse or absent. Populus pollen percentages are about 0-5% at pure Populus communities, but cannot be recorded easily where the Populus plants mixed with other trees in the communities. Juglans pollen accounts for 25% to 35% in the forest of Juglans mandshurica, but less than 1% where the parent plants are sparse or absent. Pterocelis pollen percentages are less than 15% where the Pterocelis trees are dominant in the communities, but cannot be recorded easily where the parent plants are sparse or absent. Ulmus pollen percentages are more than 8% at Ulmus communities, but less than 1% where the Ulmus plants mixed with other trees in the communities. Vitex pollen percentages increase along with increasing of parent plant covers, but the maximum values are less than 10 %. Caragana pollen percentages are less than 20 % where the Caragana plant are dominant in the communities, and cannot be recorded easily where the parent plants are sparse or absent. Spiraea pollen percentages are less than 16 % where the Spiraea plant are dominant in the communities, and cannot be recorded easily where the parent plants are sparse or absent.The study on the relation of surface pollen assemblages with the modern climate shows that, in the axis 1 of DCA, surface samples scores have significant correlation with the average annual precipitations, and the highest determination coefficient (R2) is 0.8 for the fitting result of the third degree polynomial functions. In the axis 2 of DCA, the samples scores have significant correlation with the average annual temperatures, average July temperatures and average January temperatures, and the determination coefficient falls in 0.13-0.29 for the fitting result of the third degree polynomial functions with the highest determination coefficient for the average July temperature.The sensitivity of the different pollen taxa to climate change shows that some pollen taxa such as Pinus, Quercus, Carpinus, Juglans, Spiraea, Oleaceae, Gramineae, Tamariaceae and Ephedra are only sensitive to the change in precipitation.

Análise botânica, química e biológica comparativa entre flores das espécies sambucus nigra L. e sambucus australis cham. & Schltdt. e avaliação preliminar da estabilidade

Flores das espécies Sambucus nigra, de origem européia, e Sambucus australis, nativa da América do Sul (Caprifoliaceae), denominadas sabugueiro e sabugueirodo- brasil, respectivamente, são utilizadas popularmente sob forma de infusão, como antiinflamatórias, laxativas e para condições febris resultantes de afecções do trato respiratório. Estudos prévios para S. nigra indicam compostos fenólicos como principais constituintes químicos, sendo estes relacionados às principais atividades biológicas avaliadas. Objetivando comparar esta espécie com Sambucus australis, foram realizadas análises botânicas macro e microscópicas das flores, identificando as principais diferenças entre as espécies, tais como o número de lóculos no ovário e presença de idioblastos cristalíferos em algumas estruturas, e observando os possíveis contaminantes (pedicelos). Também foram determinados os parâmetros farmacopéicos: cinzas totais e perda por dessecação. Após a análise química, foi escolhido o flavonóide rutina como marcador das espécies, para realizar análises quantitativas nas 31 amostras adquiridas e / ou coletadas, utilizando método de CLAE previamente validado. Soluções hidroetanólicas apresentaram maior capacidade de extração do produto alvo. Os limites mínimos de rutina observados para ambas as espécies foram de aproximadamente 0,65%. Também foram quantificados, por método espectrofotométrico, os flavonóides totais expressos em quercetina, sendo 0,93% e 1,46% os teores mínimos determinados para S.nigra e S. australis, respectivamente. O estudo da estabilidade acelerada (50°C ± 90% U.R.), avaliando a degradação dos constituintes químicos presentes permitiu sugerir a cinética de degradação de segunda ordem para da rutina nas duas espécies. Comparações de atividades biológicas das espécies foram realizadas pelos ensaios das atividades antiinflamatória (inibição do edema em pata de rato induzido por carragenina) e antioxidante (DPPH). Os resultados para o primeiro ensaio demonstraram ação equivalente em ambas as espécies para extratos hidroetanólicos a 80% (86% de inibição) e aquosos (81%), com atividade semelhante ao padrão indometacina (~83%); para a atividade antioxidante os extratos hidroetanólicos a 80% foram mais ativos (CE50 = 16 μg/ml) que os aquosos (CE50 = 27 μg/ml) em S. australis, e ambos extratos, superiores ao 28 extrato padronizado Gingko biloba (CE50 = 40 μg/ml) e aos extratos de S. nigra (CE50= 50 μg/ml – hidroetanólico e CE50= 32 μg/ml – aquoso).

Pollen record from Golkow, Poland

Janczyk-Kopikowa (1966): The series of the organic deposits, developed in the vicinity of Golkow near Warsaw as oil shales and peats, was laid down in a grough valley and now rests on the deposits of the Middle Polish Glaciation (Riss). The organic deposits are overlain by the fluviale deposits of the North Polish Glaciation (Würm). The locality Golkow occurs beyond the extent of the continental glacier of this glaciation. Polen analysis completed by microfloristic examinations allows to determine the age of the organic series that is thought to be Eemian. The pollen diagram from Golkow does not call in question the stratigraphical position of the deposits investigated mainly due to its characteristic features such as minimum content of coniferous trees in the climatic optimum - about 5%, high percentage of Corylus - 77.5% and well developed phase of hornbeam. It may be well compared with other Eemian diagrams from the area of Poland and reveals much similar features. The development of vegetation at Golkow has depended upon the prevailing climate. At first, the cool climate brings about the development of plants having small thermal requirements. Here belong thin, park-like forests with pine and birch (Pinus, Betula) accompanied by the heliophilic plants such as Hippohäe and Ephedra. Improvement of climate that becomes warm and humid provides for development of deciduous forests prevailing in the climatic optimum, of the interglacial. Decrease of temperature causes a repeated change in the type of forest. This latter changes into coniferous forest with prevailing spruce (Picea) and fir (Abies) at the beginning, and then with pine (Pinus) and birch (Betula). During the Eemian Interglacial, the development of plants at Golkow terminates with a new and long-lasting predominance of pine-birch forests. However, such a longevity may be apparent only. Apparent character of this phenomenon is proved by a fact that the pollen spectra of the warm climatic periods have found their reflex in the oil shale that increased considerably slower than the layers off feebly decomposed peat evidencing the existence of cool pine-birch forests from the decline of the Interglacial. The water basin, in which the polen grains were laid down from surrounding plants is characterized by a calm sedimentation as proved by the occurrence of the oil shale. An insignificant water flow left behind some thin sand laminae. The not too deep basin becomes shallower owing to the growing water vegetation, and marshy vegetation. The growing of the plants causes a complete shallowing of the basin and formation of peat bog in situ, as proved by the peat beds occurring in the section. ---- Gadomska (1966): In the vicinity of Golków a series of organic deposits occurs amounting to 6.5-9.3 m in thickness, and consisting of oil shales, lacustrine silts and sands, as well as peats and peaty silts. The organic deposits fill up an old, small, but fairly deep lake basin, probably of finger-lake origin. It may be seen to-day as a slight lowering of the relief, filled up with soaked ground, stretching from north to south. On the basis of palaeobotanical examinations the organic deposits considered are of Eemian Interglacial age (Z. Janczyk-Kopikowa, 1063). The lower part of the organic series consists of a compact oil shale horizon, the maximum thickness of which may attain up to 8 m. The oil shales contain particularly in their upper part, numerous intercalations of arenaceous silts, dark grey or black in colour, or of sands mainly of lacustrine provenance. At the top of the oil shales are found peats, up to 2.5 m in thickness, covered by black, humus silts with numerous plant remains. The Eemian Interglacial deposits are covered by a series of fluviatile sands belonging partly to the Baltic Glaciation (bottom part of the series), partly to the Holocene (top part of the series). The thickness of the sands is 0.5-3.7 m. Higher up, there are found the Holocene and present-day deposits developed as clayey alluvion, or arenaceous slide rocks, or arenaceous-silty soil.

Pollen and macrofossils profiles and age determination from three cores in Northeastern Kansas, U.S.A.

Two marshes near Muscotah and Arrington, Atchison County, northeastern Kansas, yielded a pollen sequence covering the last 25,000 yrs of vegetation development. The earliest pollen spectra are comparable with surface pollen spectra from southern Saskatchewan and southeastern Manitoba and might indicate a rather open vegetation but with some pine, spruce, and birch as the most important tree species, with local stands of alder and willow. This type of vegetation changed about 23,000 yrs ago to a spruce forest, which prevailed in the region until at least 15,000 yrs ago. Because of a hiatus, the vegetation changes resulting in the spread of a mixed deciduous forest and prairie, which was present in the region from 11,000 to 9,000 yrs ago, remain unknown. Prairie vegetation, with perhaps a few trees along the valleys, covered the region until about 5,000 yrs ago, when a re-expansion of deciduous trees began in the lowlands.

Early - Late Miocene palaeoclimate data and palaefloras of 48 samples from Southern China

Southern China, especially Yunnan, has undergone high tectonic activity caused by the uplift of Himalayan Mountains during the Neogene, which led to a fast changing palaeogeography. Previous study shows that Southern China has been influenced by the Asian Monsoon since at least the Early Miocene. However, it is yet not well understood how intense the Miocene monsoon system was. In the present study, 63 fossil floras of 16 localities from Southern China are compiled and evaluated for obtaining available information concerning floristic composition, stratigraphic age, sedimentology, etc. Based on such reliable information, selected mega- and micro-floras have been analysed with the coexistence approach to obtain quantitative palaeoclimate data. Visualization of climate results in maps shows a distinct spatial differentiation in Southern China during the Miocene. Higher seasonalities of temperature and precipitation occur in the north and south parts of Southern China, respectively. During the Miocene, most regions of Southern China and Europe were both warm and humid. Central Eurasia was likely to be an arid center, which gradually spread westward and eastward. Our data provide information about Miocene climate patterns in Southern China and about the evolution of these patterns throughout the Miocene, and is also crucial to unravel and understand the climatic signals of global cooling and tectonic uplift.