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Progress, problems and prospects of palynology in reconstructing environmental change in inland arid areas of Asia

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Research in Cold and Arid Regions 2021年第4期13卷 271-291页

作者： YongTao Zhao YunFa Miao Yan Lei xianyong cao MingXing Xiang Key Laboratory of Desert and Desertification Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhouGansu 730000China University of Chinese Academy of Sciences Beijing 100049China Key Laboratory of Alpine Ecology Institute of Tibetan Plateau ResearchChinese Academy of SciencesBeijing 100101China

Studying the climatic and environmental changes on different time scales in inland arid regions of Asia can greatly im‐prove our understanding of climatic influences for the Qinghai-Tibet Plateau in the context of global change. Pollen, as a remnant of seed plants, is sensitive to environmental factors including precipitation, temperature and altitude, and is a clas‐sic proxy in environmental reconstruction. In the last two decades, great progress in the application of palynology to in‐land areas of Asia has highlighted the role of palynology in paleoclimatic and paleoenvironmental research. The main progress is as follows. (1) On the tectonic time scale of the late Cenozoic, the palaeoclimatological sequence has been es‐tablished on the basis of pollen percentage, concentration and taxon. Pollen data have revealed a continuous enhancement of drought in the inland arid region of Asia, in contrast to evidence acquired based on other proxies. (2) In the late Quater‐nary, an increase in herbaceous plants further supports the intensification of drought associated with global cooling. In more detail, the palynological record shows a glacial-interglacial pattern consistent with changes in global ice volume. (3) The Holocene pollen record has been established at a high resolution and across a wide range of inland areas. In general, it presents an arid grassland environment in the early Holocene, followed by the development of woody plants in the mid- to late-Holocene climate optimum. This pattern is related to moisture changes in areas dominated by the westerlies. There are also significant regional differences in the pattern and amplitude of vegetation response to the Holocene environment. (4) Modern pollen studies based on vegetation surveys, meteorological data and statistics show that topsoil palynology can better reflect regional vegetation types (e. g., grassland, meadow, desert). Drier climates yield higher pollen contents of drought-tolerant plants such as Chenopod

关键词： Palynology inland arid areas Late Cenozoic Quaternary Holocene modern environmental processes

Spatial homogenization of soil-surface pollen assemblages improves the reliability of pollen-climate calibration-set

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Science China Earth Sciences 2020年第11期63卷 1758-1766页

作者： Fang TIAN xianyong cao Ran ZHANG Qinghai XU Wei DING Xingqi LIU Baolin PAN Jianhui CHEN College of Resource Environment and Tourism Capital Normal UniversityBeijing 100048China Alpine Paleoecology and Human Adaptation Group(ALPHA) Key Laboratory of Alpine EcologyInstitute of Tibetan Plateau ResearchChinese Academy of SciencesBeijing 100101China CAS Center for Excellence in Tibetan Plateau Earth Sciences Chinese Academy of SciencesBeijing 100101China College of Resources and Environment Sciences Hebei Normal UniversityShijiazhuang 050024China Institute of Geological Sciences PalaeontologyFree University of BerlinBerlin 12249Germany Key Laboratory of Western China's Environmental Systems(Ministry of Education) College of Earth and Environmental SciencesLanzhou UniversityLanzhou 730000China

To make a reliable reconstruction of past climate from soil-surface modern pollen,it is necessary to reduce the sources of *** this paper,pollen percentages of the sub-continental scale modern pollen-climate dataset from China and Mongolia(with 68%soil-surface samples)are homogenized at various spatial scales.A tailored calibration-set is then applied to lake sediment-surface pollen assemblages from north-central China to evaluate their predictive *** indicate that spatial homogenization of modern pollen percentages can increase the proportion of inertia explained by climatic variables in CCA and improve the model performance of leave-one-out cross-validation using ***-surface pollen assemblages can thus be employed into a calibration-set for reliable climate estimation and they perform better when the calibration-set has been locally ***-scale(e.g.,radii 2,5,or 10 km)homogenization reduces the local noise in soil-surface pollen assemblages and improves the cross-validated performance,while broader scale homogenization(more than 20 km radius)blurs the pollen-climate *** sediment-surface pollen assemblages from close to the shore could contain pollen grains transported by rivers or from the shore vegetation and thus fail to represent regional climate well like the assemblages from the central part and deep-water area of lake.

关键词： North-central China Soil-surface pollen Climate reconstruction WA-PLS

Holocene thermal maximum mode versus the continuous warming mode:Problems of data-model comparisons and future research prospects

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Science China Earth Sciences 2023年第8期66卷 1683-1701页

作者： Fahu CHEN Yanwu DUAN Shuo HAO Jie CHEN Xiaoping FENG Juzhi HOU xianyong cao Xu ZHANG Tianjun ZHOU Group of Alpine Paleoecology and Human Adaptation(ALPHA) Institute of Tibetan Plateau ResearchChinese Academy of SciencesBeijing 100101China State Key Laboratory of Tibetan Plateau Earth System Resources and Environment(TPESRE)Institute of Tibetan Plateau ResearchChinese Academy of SciencesBeijing 100101China College of Earth and Environmental Sciences Lanzhou UniversityLanzhou 730000China College of Resources and Environment University of Chinese Academy of SciencesBeijing 100049China College of Atmospheric Sciences Lanzhou UniversityLanzhou 730000China Institute of Atmospheric Physics Chinese Academy of SciencesBeijing 100029China

The Holocene,the most recent interglacial,provides an important time window for evaluating current global warming and predicting future temperature *** the development of new temperature proxies and improvements in climate models,significant progress has been made in understanding Holocene temperature ***,a major debate persists about whether global temperatures during the Holocene followed a pattern of gradual warming from the end of the Last Glacial Maximum,which culminated in a temperature maximum in the early to middle Holocene,followed by gradual cooling in the late Holocene(the thermal maximum mode);or whether there was a continuous warming trend that continued to the present day(the continuous warming mode).Significant discrepancies exist between different proxy records as well as between proxy records and models,which have resulted in the “Holocene temperature conundrum” that has challenged paleoclimatologists for the past ***,we summarize the progress made to date in the study of Holocene temperature change via proxy reconstructions,climate model simulations,and paleoclimate data *** emphasize that the current research has limitations in terms of the multiplicity and seasonality of proxy records,the spatial heterogeneity of temperature records,and the incorporation of feedback processes(e.g.,vegetation,cloudradiation feedback) in climate *** limitations have hindered a comprehensive understanding of the processes and mechanisms of Holocene temperature *** solve the “Holocene temperature conundrum”,it is necessary to strengthen theoretical research on climate proxies from the perspective of the underlying processes and mechanisms,elucidate the seasonal response of various temperature proxies,emphasize regional differences in temperature changes,and expand quantitative temperature reconstructions to areas with limited ***,it is also necessary to improve the simulation performance of complex

关键词： Holocene temperature change Thermal maximum mode Continuous warming mode Seasonality of proxies Climate simulations

Influence of plant coverage and environmental variables on pollen productivities:evidence from northern China

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Frontiers of Earth Science 2020年第4期14卷 789-802页

作者： Kaixiu Zhang Wen Qin Fang Tian xianyong cao Yuecong Li Jule Xiao Wei Ding Ulrike Herzschuh Qinghai Xu College of Resource Environment and Tourism Beijing Key Laboratory of Resource Environment and GISCapital Normal UniversityBeijing100048China Key Laboratory of Alpine Ecology Institute of Tibetan Plateau ResearchChinese Academy of SciencesBeijing100101China Alpine Paleoecology and Human Adaptation Group(ALPHA) Key Laboratory of Alpine EcologyInstitute of Tibetan Plateau ResearchChinese Academy of Sciences(CAS)Beijing100101China College of Resources and Environment Sciences Hebei Normal UniversityShijiazhuang050024China Key Laboratory of Cenozoic Geology and Environment Institute of Geology and GeophysicsChinese Academy of SciencesBeijing100029China Institute of Geological Sciences PalaeontologyFree University of BerlinBerlin12249Germany Alfred Wegener Institute Helmholtz Center for Polarand Marine Research Research Unit PotsdamPotsdam14473Germany Institute of Earth and Environmental Sciences University of PotsdamPotsdam14476Germany

Pollen productivity is a critical parameter in the interpretation of pollen-vegetation relationships,and in the quantitative reconstructions of past vegetation from fossil pollen ***-year monitoring records were collected for 143 pollen traps in various parts of northern China,together with modern vegetation *** Pollen Productivity Estimates(APPE)were calculated for 11 taxa using the ratio of pollen influx to plant coverage at each applicable sampling site,in which the plants of the target taxon were *** Pollen Productivity Estimates(RPPE)were calculated for the 11 taxa(taking Poaceae as the reference taxon)at those sites in which each taxon occurred together with *** and Chenopodiaceae were found to have the highest RPPEs and the largest RPPEs ranges,while Pinus and Quercus also had higher RPPEs than Poaceae;Abies,Betula,Larix,Picea and Cyperaceae had relatively low *** in RPPE between different areas may be explained by variations in climatic conditions,plant coverage and land use practices which might influence plant growing *** effect that variations in pollen productivity can have on vegetation reconstructions was demonstrated by applying these distinct RPPEs to reconstructions of Holocene vegetation in the Lake Daihai area(northern China),such as a large range of RPPE produces a large range of plant *** in RPPEs within a single taxon,related to vegetation coverage and climatic conditions,therefore need to be considered in future vegetation reconstructions.

关键词： pollen influx pollen productivity vegetation reconstruction REVEALS model northern China

Relative pollen productivities of typical steppe species in northern China and their potential in past vegetation reconstruction

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Science China Earth Sciences 2014年第12期57卷 1254-1266页

作者： XU QingHai cao xianyong TIAN Fang ZHANG ShengRui LI YueCong LI ManYue LI Jie LIU YaoLiang LIANG Jian Institute of Nihewan Archaeology Hebei Normal University College of Resources and Environment Science Hebei Normal University Hebei Key Laboratory of Environmental Change andEcological Construction Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research Research Unit Potsdam Potsdam 14473 Germany Institute of Earth and Environmental Sciences University of Potsdam

The Relative Pollen Productivities(RPPs)of common steppe species are estimated using Extended R-value(ERV)model based on pollen analysis and vegetation survey of 30 surface soil samples from typical steppe area of northern ***,Chenopodiaceae,Poaceae,Cyperaceae,and Asteraceae are the dominant pollen types in pollen assemblages,reflecting the typical steppe communities *** five dominant pollen types and six common types(Thalictrum,Iridaceae,Potentilla,Ephedra,Brassicaceae,and Ulmus)have strong wind transport abilities;the estimated Relevant Source Area of Pollen(RSAP)is ca.1000 m when the sediment basin radius is set at 0.5 ***,Artemisia,Brassicaceae,Chenopodiaceae,and Thalictrum have relative high RPPs;Poaceae,Cyperaceae,Potentilla,and Ephedra pollen have moderate RPPs;Asteraceae and Iridaceae have low *** reliability test of RPPs revealed that most of the RPPs are reliable in past vegetation ***,the RPPs of Asteraceae and Iridaceae are obviously underestimated,and those of Poaceae,Chenopodiaceae,and Ephedra are either slightly underestimated or slightly overestimated,suggesting that those RPPs should be considered with *** RPPs were applied to estimating plant abundances for two fossil pollen spectra(from the Lake Bayanchagan and Lake Haoluku)covering the Holocene in typical steppe area,using the"Regional Estimates of Vegetation Abundance from Large Sites"(REVEALS)*** RPPs-based vegetation reconstruction revealed that meadow-steppe dominated by Poaceae,Cyperaceae,and Artemisia plants flourished in this area before 6500–5600 cal yr BP,and then was replaced by present typical steppe.

关键词： typical steppe modern surface pollen relative pollen productivity relevant pollen source area paleovegetation

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Reconciling East Asia’s mid-Holocene temperature discrepancy through vegetation-climate feedback

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Science Bulletin 2024年第15期69卷 2420-2429页

作者： Jie Chen Qiong Zhang Zhengyao Lu Yanwu Duan xianyong cao Jianping Huang Fahu Chen Key Laboratory of Western China’s Environmental Systems(Ministry of Education) College of Earth and Environmental SciencesLanzhou UniversityLanzhou 730000China Department of Physical Geography and Bolin Centre for Climate Research Stockholm UniversityStockholm 10691Sweden Department of Physical Geography and Ecosystem Science Lund UniversityLund 22100Sweden Group of Alpine Paleoecology and Human Adaptation(ALPHA) State Key Laboratory of Tibetan Plateau Earth SystemEnvironment and Resources(TPESER)Institute of Tibetan Plateau Research(ITPCAS)Chinese Academy of Sciences(CAS)Beijing 100101China Collaborative Innovation Center for Western Ecological Safety Lanzhou UniversityLanzhou 730000China

The term“Holocene temperature conundrum”refers to the inconsistencies between proxy-based reconstructions and transient model simulations,and it challenges our understanding of global temperature evolution during the *** reconstructions indicate a cooling trend following the Holocene Thermal Maximum,while model simulations indicate a consistent warming trend due to icesheet retreat and rising greenhouse gas *** factors,such as seasonal biases and overlooked feedback processes,have been proposed as potential causes for this *** this study,we examined the impact of vegetation-climate feedback on the temperature anomaly patterns in East Asia during the mid-Holocene(~6 ka).By utilizing the fully coupled Earth system model EC-Earth and performing simulations with and without coupled dynamic vegetation,our objective was to isolate the influence of vegetation changes on regional temperature *** findings reveal that vegetation-climate feedback contributed to warming across most of East Asia,resulting in spatially diverse temperature changes during the mid-Holocene and significantly improved model-data *** results high-light the crucial role of vegetation-climate feedback in addressing the Holocene temperature conundrum and emphasize its importance for simulating accurate climate scenarios.

关键词： Holocene temperature conundrum Holocene Thermal Maximum Vegetation-climate feedback East Asia Paleoclimate simulations

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碱性环境对油松花粉保存影响实验研究

第四纪研究 2006年第6期26卷 1007-1011页

作者：曹现勇许清海河北师范大学资源与环境科学学院石家庄050016

孢粉是恢复古植被、古气候的重要代用指标。然而,即使是同一时代的地层,不同地点、不同岩性提取出的花粉量差异很大,造成这些差异的原因很多,其中花粉在不同沉积环境中的保存差异是重要原因之一。本研究是在实验室内模拟自然条件下碱性... 详细信息

孢粉是恢复古植被、古气候的重要代用指标。然而,即使是同一时代的地层,不同地点、不同岩性提取出的花粉量差异很大,造成这些差异的原因很多,其中花粉在不同沉积环境中的保存差异是重要原因之一。本研究是在实验室内模拟自然条件下碱性环境对油松花粉(Pinus tabulaeform is)的破坏情况:煮水5小时,泡10%NaOH溶液10天,煮10%NaOH溶液5小时对油松花粉破坏都很小;煮20%和30%NaOH溶液1小时对油松花粉影响也不明显;煮40%NaOH溶液1小时,油松花粉壁出现蚀变,加热时间增至5小时,蚀变现象进一步加深。表明油松花粉具有很强的耐碱,耐高温能力。更强碱或更长时间情况下花粉蚀变情况,有待进一步研究。

关键词：油松花粉花粉保存花粉蚀变碱性环境

EB病毒BNLF-1基因的分子生物学研究进展

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生物化学与生物物理进展 1997年第5期24卷 409-414页

作者：马先勇曹亚姚开泰湖南医科大学肿瘤研究所长沙410078

位于EB病毒基因组U5 TR区内的BNLF 1基因 ,其转译产物为潜伏膜蛋白 (latentmembraneprotein1 ,LMP 1 ) ,由于LMP 1可以导致细胞转化并在EB病毒致癌过程中具有重要作用 ,因而成为近年来EB病毒分子生物学及相关肿瘤如人鼻咽癌、伯基特淋... 详细信息

位于EB病毒基因组U5 TR区内的BNLF 1基因 ,其转译产物为潜伏膜蛋白 (latentmembraneprotein1 ,LMP 1 ) ,由于LMP 1可以导致细胞转化并在EB病毒致癌过程中具有重要作用 ,因而成为近年来EB病毒分子生物学及相关肿瘤如人鼻咽癌、伯基特淋巴瘤、何杰金氏病等疾病病因发病学研究的热点 ,并取得了一批有重要意义的成果 ,文章从BNLF 1的基因结构及表达调控 ,LMP蛋白的结构及生化功能 ,LMP 1的生物学功能和LMP 1研究进行评述 .

关键词： EB病毒 BNLF-1基因疱疹病毒分子生物学

神经网络算法在生物群区重建中的可靠性及应用

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地理科学 2023年第5期43卷 889-898页

作者：王怡璇田芳倪健曹现勇中国科学院青藏高原研究所古生态与人类适应团队北京100101 首都师范大学资源环境与旅游学院北京100048 中国科学院大学北京100049 浙江师范大学生命科学学院浙江金华321004 青藏高原地球系统与资源环境全国重点实验室北京100101

基于中国现代孢粉数据库(2324个样点)和现代生物群区空间分布数据构建神经网络算法模型,对比样点现代生物群区特征值和模型拟合结果,发现神经网络算法模型在生物群区重建中准确度为86.6%,高于生物群区化方法的68.8%。将神经网络算法模... 详细信息

基于中国现代孢粉数据库(2324个样点)和现代生物群区空间分布数据构建神经网络算法模型,对比样点现代生物群区特征值和模型拟合结果,发现神经网络算法模型在生物群区重建中准确度为86.6%,高于生物群区化方法的68.8%。将神经网络算法模型应用于中国晚第四纪孢粉数据,重建末次冰期盛冰期以来中国陆地生物群区空间格局。结果表明:在气候寒冷干燥的末次冰期盛冰期,生物群区整体南迁;末次冰消期以来,生物群区整体呈向北、向西扩张趋势,并在温暖湿润的全新世中期森林的空间分布达到最大规模;生物群区变化过程反映全球气候变化总体特征。晚全新世人类活动强烈时期,局部地区生物群区的变化特征暗示该时期生物群区可能受到人类活动的干扰。

关键词：机器学习植被重建孢粉末次冰期盛冰期全新世

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