Palaeoenvironmental changes from pollen record in deep sea core PC-1 from northern Okinawa Trough, East China Sea during the past 24 ka

A pollen record of core PC-1 from the northern Okinawa Trough, East China Sea （ECS）, provides information on vegetation and climate changes since 24 cal. kaBP. A total of 103 samples were palynologically analyzed at 8 cm intervals with a time resolution of 230 a. Four pollen zones are recognized： zone Ⅰ （812-715 cm, 24.2-21.1 cah kaBP）, zone Ⅱ （715-451 cm, 21.1-15.2 cah kaBP）, zone Ⅲ （451-251 cm, 15.2-0.8 cah kaBP）, zone Ⅳ （251-0 cm, 10.8-0.3 cal. kaBP）, corresponding to Late MIS 3, Last Glacial Maximum （LGM）, deglaciation and Holocene, respectively. The LGM is characterized by the dominance of herbs, mainly Artemisia, and high pollen influx, implying an open vegetation on the ex- posed continental shelf and a cool and dry climate. The deglaciation is a climate warming stage with Pinus percentage increased and Artemisia percentage decreased and a rapid sea-level rise. The Holocene is characterized by predominance of tree pollen with rapid increase in Castanea-Castanopsis indicating the development of mixed evergreen and deciduous broad-leaved forest and a warm, humid climate. Low pollen influx during the Holocene probably implies submergence of the continental shelf and retreat of the pollen source area. The vegetation indicated by pollen assemblage found in this upper zone is consistent with the present vegetation found in Kyushu, Japan. Originating from the humid mountain area of North Luzon of the Philippines, Tasmania and New Zealand, Phyllocladus with sporadic occurrence throughout PC-1 core probably suggests the influence of Palaeo-Kuroshio Current or intense summer monsoon. The observed changes in Pinus and Herbs percentage indicate fluctuations of the sea level, and high Pinus percentage corresponds to high sea level. Spectrum analysis of the pollen percentage record reveals many millennial-scale periodicities, such as periodicities of 6.8, 3.8, 2.2, 1.6 ka.     

Relationships between vegetation and stomata, and between vegetation and pollen surface soil in Yunnan, Southwest China

Surface pollen and stomata of 61 samples collected in a study area ranging from tropical seasonal rainforest to oak forest(Quercus spinosa) in the Yulong Snow Mountain region in Yunnan,China,are used to distinguish vegetation communities.The results show that tropical seasonal rainforest(and mountain rainforest),south subtropical evergreen broad-leaved forest,and Quercus shrub are distinguished effectively from other vegetation types by analysis of surface pollen.The south subtropical evergreen broad-leaved forest,Pinus kesiya forest and evergreen broadleaf forest are distinguished effectively from other types of vegetation by pollen analysis.However,P.yunnanensis forest is not distinguished from other vegetation types,and P.armandii,P.densata forest and temperate deciduous conifer mixed forest are not distinguished.The over-representation of Pinus pollen is the main reason that these vegetation communities are not distinguished from each other.Conifer stomata analysis is an effective tool for identifying and distinguishing different types of coniferous forest,and this method performs well even with a small number of sampling points.     

6000 aBP以来洞庭湖沉积记录的环境演变及其同人类活动的关系

通过对东洞庭湖地区ZK01钻孔沉积物的粒度、磁化率、孢粉等古环境指标的分析, 初步揭示了该地区6000 aBP以来湖泊环境及气候演变的历史: 6000~4000 aBP, ZK01钻孔所在区域为水深较大的湖泊环境, 湖泊周围地区分布有亚热带常绿阔叶林植被, 代表较为湿热的气候; 4000~1000 aBP仍为深湖环境, 但后期水深有所减小, 其中4000 aBP的气候有明显变干变凉的趋势, 植被也发生了明显的变化; 1000~600 aBP湖泊演变为浅湖环境, 600 aBP之后进一步演变为浅滩与湖沼交互相环境。 该地区环境演变同史前及历史时期人类活动的相互关系研究表明, 6000~1000 aBP的水文环境及气候变化显著地影响了区域的古代人类文化与历史的进程, 其中4000 aBP的气候变凉及水文环境的变化可能是该地区史前文明迅速衰落的原因; 1000 aBP以来, 人类在长江两岸的筑堤和围垦等活动明显影响了洞庭湖地区的水沙过程及河湖环境的演变历史。     

安徽省鹞落坪自然保护区的植被类型及其分布

鹞落坪自然保护区地处大别山腹地主峰分水岭的主段，植物种类丰富，计有野生种子植物１２９８种，５７２属、１４１科。植物区系起源古老、特有现象明显。区系成分以温带为主，兼为温带和热带，亚热带的双重性质。植被类型多样，该区自然植被主要有５个植被型。８个植被亚型，２４个群系。     

The early Holocene optimum inferred from a hish-resolution pollen record of Husuansyan Maar Lake in southern China

A high-resolution pollen record of the past 13000 a from Huguangyan Maar Lake reveals the vegetation and environment changes in southern China during the Holocene. It shows that （i） pollen percentage of trees and shrubs reached 56% during the early Holocene （11600-7800 cal a BP）, of which the pollen percentage of tropical trees reached a maximum at 9500-8000 cal a BP, reflecting a hot and wet environment; （ii） during the mid-Holocene （7800-4200 cal a BP）, the pollen percentage of montane coniferous trees and herbs increased, while the percentage of tropical-subtropical trees decreased, indicating lower temperature and humidity; （iii） in the late Holocene spanning from 4200 to 350 cal a BP, the pollen percentage of herbs and montane conifer increased significantly, indicating a marked decrease of temperature and humidity. Our pollen data reveal that the time period 9500-8000 cal a BP in southern China represents a climatic optimum for the Holocene characterized by hot and wet conditions. This is consistent with the Holocene optimum found in lower latitude regions globally. We speculate that strong insolation might cause the northward migration of the ITCZ and subtropical summer monsoon front, which resulted in an early Holocene optimum in the Huguangyan area. The dry tendency and climate fluctuations of the middle and late Holocene could be associated with a decrease in solar insolation and frequent ENSO event.     

Palynological records of environmental changes in the middle part of Inner Mongolia,China

Today, the central part of Inner Mongolia has a continental climate, with cold winters, hot summers, and approximately 70% of the precipitation falling in the summer months. Vegetation is dominated by steppe vegetation with Stipa bungeana and Stipa breviflora. Scattered individuals of Quercus liaotungensis, Populus davidiana, Betula platyplylla are distributed in the mountains, with some Pinus tabluaoformis, near Miaoyu, and with fragmentary Picea above 1700—1800 m a.s.l. The Huitenglian…     

江西省三清山的植被类型及其分布

1.三清山位于江西省东北部怀玉山脉的东段,北纬28°56′,东经118°04′,面积约150平方公里,主峰玉京峰海拔1816.9米。三清山现已被列为省级风景区。 2.植物种类丰富,初步统计约有种子植物130科,480属,1100多种。植物区系起源古老,以亚热带和热带成分为主,与浙南的九龙山最为相近。 3.本地区主要有五个植被型组:Ⅰ、阔叶林;Ⅱ、山地矮林;Ⅲ、针叶林;Ⅳ、竹林;Ⅴ、沼泽.常绿阔叶林为本地区的基带植被;本地区的特色植被为华东黄杉林和猴头杜鹃林。     

江西省三清山的植被类型及其分布

1.三清山位于江西省东北部怀玉山脉的东段,北纬28°56′,东经118°04′,面积约150平方公里,主峰玉京峰海拔1816.9米。三清山现已被列为省级风景区。 2.植物种类丰富,初步统计约有种子植物130科,480属,1100多种。植物区系起源古老,以亚热带和热带成分为主,与浙南的九龙山最为相近。 3.本地区主要有五个植被型组:Ⅰ、阔叶林;Ⅱ、山地矮林;Ⅲ、针叶林;Ⅳ、竹林;Ⅴ、沼泽。常绿阔叶林为本地区的基带植被;本地区的特色植被为华东黄杉林和猴头杜鹃林。     

中国常绿阔叶林壳斗科主要种的分布与气候

Ｈｏｌｄｒｉｄｇｅ的生命地带分类系统由于其指标的计算十分简便，且与植被的对应性高而受到生态学与地理学工作者的重视和广泛采用。利用该系统的指标－生物温度ＢＴ、降水量Ｐ及可能蒸散率ＰＥＲ分析了组成中国亚热带常绿阔叶林的主要科属成分壳斗科栲属、石栎属、青冈属及栎属的３８个优势种及常见种分布与气候的关系，所得计算结果较好。利用生物温度和可能蒸散率，可将优势种及常见种划分为５个水热分布类型，与实际对应较好。     

白水江保护区植物物种多样性垂直带优先保护评价

以构建的次级自然单元植物优先保护评价指标体系及层次分析法运算的结果为依据,对白水江自然保护区植被垂直分布带进行了优先保护评价,评价结果表明植物优先保护的顺序依次为常绿落叶阔叶混交林带、落叶阔叶林带、常绿阔叶林带、针阔混交林带、亚高山针叶林带、高山灌丛草甸带,评价指标的综合值依次为78.60,57.32,57.20,38.18,14.08,3.27.常绿落叶阔叶混交林带拥有亚热带和温带的多种植物种类,同时也是国家重点保护、珍稀濒危、特有、单(寡)型类型集中分布的区域,是保护区植物保护的最优先植被带.评价指标的综合值随海拔梯度由常绿阔叶林带的57.20增至常绿落叶阔叶混交林带的78.60后持续减小,体现了物种多样性随海拔升高的单峰分布格局.这种分布格局主要是由不同海拔梯度所产生的水热状况的差异形成的,同时也与低海拔地区强烈的人为干扰和高海拔山地的面积较小等因素有关.     

浙江省珊溪水库库区森林植被类型的研究

珊溪库区森林植被类型主要有：中亚热带常绿阔叶林、中亚热带常绿-落叶阔叶混交林、中亚热带落叶阉叶林、中亚热带针叶林、中亚热带针阔混交林、竹林、灌丛和灌草丛。其中,中亚热带常绿阔叶林为地带性森林植被类型。     

Periodicity of Holocene climatic variations in the Huguangyan Maar Lake

There exist five primary periods of 2 930, 1 140, 490, 250 and 220 a in the Holocene climatic variations in the Huguangyan Maar Lake, according to the energy-spectrum and filter analyses of high-resolution time sequences (10–15 a) of the sediment dry density. The peak values of the three temperature-decreasing periods with the 2 930 a cycle occur at about 7 300, 4 250 and 1 200 Cal. aBP. There are 7–8 temperature-decreasing periods with the 1 140 a cycle, and the climate fluctuation range is largest in the early Holocene, and reduces gradually in the middle and late Holocene. The millennial-scale climatic change in the Holocene may adjust the global water cycle and the thermohaline circulation intensity through the harmonic tones of the earth’s precession cycle, which in turn influences the global climate change.     

京杭大运河沿线第四纪植被变迁分析

京杭大运河是世界上开凿最早、规模最大、里程最长的人工河流。笔者以运河区域内第四纪古植物证据为基础,对孢粉植物群的组成、区系成分和生态功能类型进行了分析,对第四纪植被进行了重建。结果显示：该区域共有陆地植物105科;植物区系以温带成分为基本骨架,具有温带和热带过渡性质,反映出干湿交替、冷暖更替和水陆镶嵌的古环境特点。点多样性指数显示,北部为22～68个科（属）,南部为65～117个科（属）。孢粉植物群划分为13个生态功能类型。运河沿线中全新世森林植被自北而南分为凉温带针阔混交林、温带落叶阔叶林、暖温带常绿落叶阔叶混交林,以及亚热带常绿阔叶林4个植被带。影响运河沿线第四纪植被变迁的主要因素有第三纪植物遗存、第四纪气候变迁和早期人类活动等。     

Sedimentation rates and provenance analysis in the Southwestern Okinawa Trough since the mid-Holocene

As a high-sedimentation rate depocenter along the path of the Kuroshio Current, the southwesternmost part of the Okinawa Trough is a key area to understand the Kuroshio history and sediments transpor-tation. A 34.17-m-long sediment core was obtained by the advanced piston corer of Marco Polo/IMAGES XII MARION DUFRESNE during the May 2005 from the Southern Okinawa Trough at site MD05-2908. The recovered sediments were analyzed by AMS ¹⁴C dating, coarse size fraction (>63 μm) extraction and moisture content determination in order to study its sedimentation flux and provenance. The depth-age relationship of core MD05-2908 was well constrained by 17 ¹⁴C dating points. The sediments span across the mid-Holocene (6.8 ka B.P.) and have remarkablely high sedimentation rates between 1.8 and 21.2 m ka^-1, which is well consistent with the modern observations from sediment traps. We identified five 70―200 a periods of abnormally rapid sedimentation events at 6790―6600 a B.P., 5690―5600 a B.P., 4820―4720 a B.P., 1090―880 a B.P., and 260―190 a B.P., during which the highest sedimentation rate is up to 21.2 m/ka. In general, the lithology of the sediments were dominated by silt and clay, associated with less than 5% coarse size fraction (>63 μm). As the most significant sediment source, the Lanyang River in northeastern Taiwan annually deliver about 10Mt materials to the coastal and offshore region of northeast Taiwan, a portion of which could be carried northward by currents toward the study area. Therefore, we concluded that the 5 abnormally rapid sedimentation events may be related to intensified rainfall in Taiwan and thus increased materials to our study area at that time. However, a few ex-treme-rapid sedimentation events cannot be explained by normal river runoff alone. The large earth-quakes or typhoons induced hyperpycnal discharge of fluvial sediment to the ocean may also act as a potential source supply to the Okinawa Trough.     

Deep sea pollen record during 12－1.6 Ma from the southern South China Sea and its response to envi-ronmental change

Based on deep-sea pollen results (512-76 m) from ODP Site 1143 in the southern South China Sea (SCS),the climate and vegetation evolution sequence on the surrounding islands and the exposed continental shelf are discussed. The pollen records show that the pollen influx was quite low before 8.15 Ma and increased dramatically afterwards. The influx changes can be ascribed,on one side,to tectonics deformations around the southern SCS resulting in rapid uplift of islands and subsequent increase of the sediment rates and pollen influx and on the other side to climate cooling and monsoon enhancement. Around 2.63 Ma was another obvious boundary,the increasing of pollen and spores influx since this time was mainly related to global climate cooling. Spectrum analysis of pollen influx values shows that 2 Ma,0.67 Ma,and 0.19-0.17 Ma cycles existed during 12-3.0 Ma,while 0.1 Ma and 46.9 ka cycles existed during 3.0-2.0 Ma.     

圩墩遗址古木研究

通过对圩墩遗址出土古木１５个树种的鉴定，确定五，六千年前圩墩存在过落叶－常绿阔叶混交林带。该林带是温带针，阔叶混交林带与亚热带常绿阔叶林带之间的过渡区，属温暖，湿润的亚热带植被类型。落叶阔叶树有壳斗科的麻栋和槲栎类，金缕梅科的枫香，漆树科的黄连木及豆的黄檀等树种。常绿阔叶树有茶科的荷木，豆科的红豆树及木犀科的蜡树等树种。     

常绿阔叶林壳斗科优势种植物地理特征数量分析

以壳斗科锥属、青冈属和柯属的22个典型常绿阔叶优势种的分布资料和11项环境因子为基础,利用对应分析和典范对应分析,对这些物种的分布类型以及同环境因子之间的关系开展数量分析.根据对应分析的结果,全部物种可分为东、西两个分布类型.其中,东部类型又分为南、北两个亚类型.对应于物种的分布类型,研究区域也分为了西部、东部偏北和东部偏南三个分布区域.典范对应分析的结果表明,不同空间梯度上影响物种分布类型的主要环境因子不同.影响物种东西方向上分布的主要因子是年平均温差、最暖月平均温度、日照时数、太阳实际总辐射和干燥指数,而影响物种在南北方向上分布的主要因子是最冷月平均温度和太阳潜在总辐射.从分布区域的划分结果来看,同以往对亚热带常绿阔叶林区域的划分方案相比,东、西两个区域的划分与之相吻合,而南、北两个区域的划分则向北略有延伸.     

大别山植物区系的特点和森林植被的研究

大别山植物种类丰富，古老，孑遗植物较多，植物区系地理成分复杂、联系广泛、特有现象明显。森林植被的主要类型有：常绿阔叶林，常绿落叶混交林，落叶阔叶林，山地矮林和针叶林。本文对大别山森林植被现状进行了生态评价，并对其合理开发利用提出了一系列建议。     

华东地区植被概况

华东地区六省一市从北向南大致属于暖温带落叶阔叶林区域、北亚热带常绿落叶阔叶混交林地带、典型的中亚热带常绿阔叶林地带、南亚热带季风常绿阔叶林地带。通过对华东地区自然地理成因、气候和土壤状况的介绍，从不同生境角度分析了华东地区原生植被类型、次生植被类型和人工栽培植被类型