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1.
重建中国北方泥河湾盆地中更新世(~603–587 ka)植被与气候 中国北方泥河湾盆地发育了一套含有东方人类活动证据的晚新生代地层,既发现有早更新世(距今~1.66Ma–78ka)直立人使用的石制品,也有中更新世晚期(~370–260ka)早期智人的头盖骨、牙齿等直接证据。该系列地层中孢粉学的研究为我们探索早期人类生存环境提供了可能。本文研究的虎头梁剖面地质年代距今约603–587ka,介于直立人向早期智人演化的过渡时期。基于地层孢粉学组合分析,我们重建了当时的植被从温带针阔混交林-草原(以云杉属、冷杉属、桦木属、胡桃属、蒿属和藜科为主)逐渐向以松、云冷杉为主的针叶林转变的动态过程。通过对比同时期全球其他人类遗址,揭示了早期人类以洞穴生活为主,同时伴随比较开阔的草原或森林-草原植被,以及丰富的哺乳动物。据此,推测本研究揭示的~603–587ka前泥河湾盆地茂密针叶林的出现和开阔草原的消失可能是人类追逐着大多数哺乳动物向草原或森林-草原等开阔地迁移,而离开了泥河湾的新证据。这些新发现有助于增进和丰富我们对早期人类饮食、迁徙和定居等行为方面的认知,同时也填补了泥河湾盆地中更新世(780–400ka)时期古植被与古环境研究的空白。  相似文献   

2.
末次冰盛期以来,地球系统经历了一次从冷到暖完整的气候旋回,是过去全球变化研究的一个重要时段。本文基于陇中黄土高原会宁硝沟剖面河湖相-水下黄土沉积序列的高分辨率地层孢粉记录,探讨该区末次冰盛期以来的植被演替及其气候响应模式,旨在为黄土高原生态环境建设的战略部署提供科学依据,且对进一步探讨区域气候演化机制、预测未来气候环境变化趋势具有重要意义。硝沟剖面的孢粉记录揭示,末次冰盛期以来该区的植被演替过程为:荒漠草原(寒冷的盛冰期)→针叶疏林/森林草原(逐渐增温的冰消期)→针阔叶混交林为主的森林草原→针阔叶混交林(温暖的盛间冰期)→针叶疏林草原→干草原/荒漠草原;相应的气候变化模式为:冷干→较温湿→较暖湿→暖湿→温凉偏干→较冷干。总体来看,末次冰盛期以来,研究区植被对气候环境变化的响应非常敏感,随着气候的冷暖干湿变化,森林/疏林草原带自东南-西北发生多次进退;区域顶极植物群落为中全新世气候最适宜期发育的针阔叶混交林,研究区早中全新世较长时期都有较大面积的针阔叶混交林发育;晚全新世植被退化为干草原/荒漠草原,一方面可能是气候持续变干的自然响应,另一方面可能也与此时强烈的人类活动对自然森林/草原植被的破坏导致的恶性循环有关。  相似文献   

3.
泥河湾盆地是中国北方旧石器时代古人类遗存数量最多、分布最密集、年代序列最为完整的区域。本文根据已公开发表的泥河湾盆地阳原和蔚县地区65处旧石器遗址的相关数据和信息,探讨了更新世不同时期泥河湾盆地古人类活动与环境变化之间的关系。研究结果显示:1)早更新世时期遗址主要分布在岑家湾台地北部边缘区,年代在1.8-1.0 MaBP;中更新世之后,遗址分布范围明显扩大,晚更新世时期,遗址分布模式改为集中分布于河流两岸阶地。2)在早-中更新世,80%以上遗址处在低地球轨道偏心率期,70%以上处在温暖的间冰期。3)遗址的植被多为以蒿属、藜科占优的草原或森林草原。4)晚更新世时期,随着古人类环境适应能力的提高、石器技术的进步和火的使用,在寒冷的冰期时段,古人类也可以在泥河湾盆地很好地生存。  相似文献   

4.
大珠山遗址是青岛市首个具有地层依据的旧石器遗址。该遗址的发掘不仅丰富了我国沿海地区的旧石器考古材料,更对探讨早期人类的生存适应和迁移扩散等问题具有深远意义。解译遗址中的环境背景信息,可以帮助我们更准确地理解当时人类的生存状态。本文通过花粉和磁化率等指标,重建了该遗址所在区域的环境演变过程。研究结果显示:1)大珠山遗址的光释光年龄为65.7-52.9ka,对应MIS4-MIS3c;2)从MIS5b到MIS3b(86.0-45.0ka),区域植被经历4个演替阶段,依次为落叶林草原、落叶阔叶林草原、温带草原和疏林草原,其反映的气候趋势与区域背景下的环境变化过程基本一致;3)MIS4-MIS3c期间迅速回暖的气候,稳定适宜的生存环境,均为早期人类的活动提供良好的生态背景。随后气候转冷,海岸线后退,该地区的人类遗存明显减少,可能指示人类活动减弱或者迁出。这种不同时期内的人类活动强度的变化,表明气候主控下的生存环境变化深刻影响着近海地区早期人类的适应策略。  相似文献   

5.
黄土高原西部4万多年以来植被与环境变化的孢粉记录   总被引:1,自引:0,他引:1  
采集甘肃静宁、定西、秦安等地晚更新世晚期以来几个黄土剖面的孢粉样品,分别以晚更新世每个样品分辨率200—300年,全新世20—200年,揭示了黄土高原西部4万多年以来古植被曾经历过草原、森林草原(或疏林草原)、针叶林以及荒漠草原或荒漠几种植被的多次快速变化。在44.2—11kaBP期间,静宁地区植被主要表现为森林和草原成分的相互消长,其中44—29kaBP期间(MIS3)气候以湿润为主,发育针叶林,温度低于现在;23kaBP之后,气候冷干,以稀疏草原为主,在末次盛冰期植被甚至演化为荒漠草原。全新世大部分时间内是以草原或森林草原(或疏林草原)植被为主。在全新世中期,约7.6—5.8kaBP有近1700年时间发育有森林植被,在这个时期当地自然植被覆盖度较高,而草原或疏林草原发育时期植被往往较稀疏,反映气候相对干冷。根据出现的不同类型植物的孢粉浓度及其生态环境特性,研究区早、中全新世,约8.8—5.8kaBP沉积环境较湿润;自3.8kaBP以后气候环境总的变化趋势是逐渐变干,植被开始向草原荒漠化演变。然而,研究区整个全新世气候环境存在多次干湿交替现象,据孢粉记录,其中可能存在11次气候干寒事件。  相似文献   

6.
泥河湾盆地上新世生物地层序列与环境   总被引:4,自引:2,他引:2  
总结了泥河湾盆地晚上新世生物地层,讨论了12个剖面含哺乳动物化石层位的相互关系,以稻地老窝沟剖面的地层顺序为基础排列出约3.7~2.6Ma时段内的9个代表性的生物地层单位。哺乳动物以Paenelimnoecus chinensis、Lunanosorex cf.L.lii、Trischizolagus、Pliopentalagus nihewanicus、Ungaromys、Mimomys sp.、Chardina truncatus、Mesosiphneus praetingi、M, paratingi、Plio- siphneus lyratus、Pseudomeriones complicidens、Castor anderssoni、Huaxiamys downsi、Chardinomys yusheensis、C.nihowanicus、Hipparion houfenense和Gazella blacki组合为特征。动物群在时代上与榆社麻则沟动物组合、静乐红土动物群、灵台雷家河剖面V带及任家沟静乐红粘土动物组合、宁县水磨沟动物组合、游河动物群及沂南棋盘山洞穴动物组合相当。动物群所反映的是温带草原为主、间有树林和干草原的稀树草原环境。  相似文献   

7.
水洞沟12号地点的古环境研究   总被引:1,自引:0,他引:1  
水洞沟遗址12号地点(SDG12)是一处以细石叶技术为主的旧石器时代末期文化,其文化层埋藏于边沟河Ⅱ级阶地中上部。地层时代从距今4.7万年至1.1万年左右,文化层时代为距今约1.1万年,处于更新世与全新世的过渡时期,略经流水改造,为原地埋藏。孢粉组合特征显示在整个地层发育期内该地区是以麻黄属+藜科+霸王属+蒿属+禾本科组合为主的植被类型,为气候比较干旱-半干旱荒漠草原植被景观。在SDG12地点文化层堆积时期,气候相对暖湿,附近尚生长着沼生植物和榆、栎、桦等温带落叶阔叶乔木,为稀树荒漠草原环境。SDG12地点的古人类活动及古环境特征的分析对了解水洞沟文化的发展与传承有着重要的意义,同时也为中国北方细石叶文化研究提供了确切的地层和材料。  相似文献   

8.
桦甸仙人洞旧石器遗址的上、下文化层出土了大量动物化石, 本文通过动物化石的分布状况、出土状态分析, 复原了上、下文化层沉积时期古人类的狩猎和处置猎物的行为, 总体来看, 远古人类生计方式以狩猎为主, 晚期古人类比早期对猎物资源开发得更彻底。另外, 从洞穴内大量碎骨片和石制品来看, 该洞穴可能为临时的营地或者屠宰场。通过对动物群组成、年代和孢粉分析的综合研究, 认为该遗址所处环境经历了剧烈的变化, 总体处于寒冷干燥的气候环境中, 植被以草原为主, 伴有少量森林。这一研究为探讨中国东北地区晚更新世人类的生存行为和演化特征提供了重要的研究材料和数据。  相似文献   

9.
中国境内古人类活动遗迹的研究对于揭示人类演化进程和史前人类文化具有重要意义。三峡及周边地区发现有一批遗存丰富的早更新世早期的古人类活动遗迹,包括年代由2.48 MaBP到1.54 MaBP间的龙骨坡遗址、建始人遗址、人字洞遗址、元谋人遗址、马圈沟遗址第Ⅰ-Ⅲ文化层等。这些丰富的古人类遗迹,是中国目前所知时代较早的人类活动的证据,蕴含着早期古人类在东亚演化的重要信息。通过分析发现,这些遗址主要分布在中国第二级阶梯,个别地点在第三级阶梯丘陵地带;均位于东部季风区,区域古地貌特征为山地、丘陵环绕的盆地,并濒临河湖,具有与大型水源环境位置相近的特点;植被特征为温暖湿润的亚热带森林或温带针叶阔叶混交林——草原过渡地带。各遗址均出土有丰富的伴生哺乳动物化石,说明当时生态环境良好,可供人类狩猎、采集的动植物资源丰富。在远古原始生境下,人类主动进入洞穴、开发利用洞穴资源,反映了人类对生存空间的开拓和对生活条件的改变。  相似文献   

10.
西北干旱区石羊河流域全新世早期植被与环境演化   总被引:3,自引:0,他引:3  
西北干旱区石羊河流域终闾湖泊边缘三角城剖面湖相沉积物(10.0-6.3ka.B.P.)高分辨率(每样平均40-50a左右)孢粉分析揭示该流域全新世早期植被与气候环境变化过程是:全新世初期(10-9.8ka.B.P.),温度、湿度开始上升,山上针叶林发育,该期持续较短时间后,温度、湿度下降(9.8-9.2ka.B.P.),山上森林萎缩,山下荒漠范围扩大;此后是一个持续时间较长、波动的温度、湿度上升、植被发育状况逐步好转的过程(9.2-7.75ka.B.P.);随后又是短暂的气候冷干、植被亚化阶段(7.75-7.25ka.B.P.)和一个相对持续时间较长,植被发育较好的暖湿期(7.25-6.3ka.B.P.)。石河流域全新世早期气候环境变化具有较强的不稳定性,每个相对暧湿期和冷干期中都有多个次一级的冷干、暖湿波动,植被也相应地随之变化。  相似文献   

11.
The Palearctic forest-steppe biome is a narrow vegetation zone between the temperate forest and steppe biomes, which provides important habitats for many endangered species and represents an important hotspot of biodiversity. Although the number of studies on forest–grassland mosaics is increasing, information currently available about the general compositional and structural patterns of Eurasian forest-steppes is scarce. Our study aimed to compare the habitat structure, species composition and diversity patterns of two distant sandy forest-steppes of Eurasia. We compared 72 relevés made in the main habitat components (forest, forest edge and grassland) of sandy forest-steppes in three Hungarian and three Kazakh sites. The size of the plots was 25 m2. Species number, Shannon diversity and species evenness values were calculated for each plot. Fidelity calculations and linear mixed effects models were used for the analyses. We found that the vegetation and diversity patterns of the two forest-steppes are similar and their components play important roles in maintaining landscape-scale diversity. Despite the higher species richness in Hungary, Shannon diversity was higher in Kazakhstan. The deciduous forest edges of both areas had significantly higher species richness than the neighbouring habitats (forests and grasslands); therefore they can be considered local biodiversity hotspots. Due to the special characteristics of this vegetation complex, we emphasize the high conservation value of all landscape components as a coherent system throughout the entire range of the Eurasian forest-steppe biome.  相似文献   

12.
为便于了解青藏高原植被特殊物种组成、群落特征及分布格局, 该文利用2018-2021年在青藏高原不同区域内调查的338个样地、共758个样方的数据, 分析了高原植物群落的物种组成、区系特征和植被分类, 整合形成青藏高原植物群落样方数据集。结果表明: 青藏高原高寒和温性植物群落758个样方中, 共有植物65科279属837种; 其中, 物种数最多的5个科依次是菊科(134种)、禾本科(88种)、豆科(75种)、蔷薇科(43种)和莎草科(40种), 物种数最多的5个属依次是蒿属(Artemisia, 29种)、马先蒿属(Pedicularis, 27种)、风毛菊属(Saussurea, 25种)、黄耆属(Astragalus, 23种)和早熟禾属(Poa, 23种)。植物区系主要由温带(145属)和世界广布(36属)的成分所组成。物种的生长型以草本(83.51%)和灌木(10.87%)为主, 草本和木本的生活型分别以多年生草本(88.23%)和落叶灌木(83.67%)为主。338个样地可以划分为4个植被型组, 10个植被型, 20个植被亚型, 78个群系组和117个群系, 其中草原群系34个, 草甸群系33个, 荒漠群系33个, 灌丛群系14个和针叶林群系3个。该数据集覆盖青藏高原绝大部分高寒灌丛、高寒草原、高寒草甸、高寒荒漠、温性草原和温性荒漠植被区域, 可为研究高原植被特征和地带性分异规律, 气候变化和人类活动对高原植被的影响及其生态恢复提供坚实的数据基础, 同时为下一代中国植被图的更新提供参考。  相似文献   

13.
本文依据内蒙古自治区四个考古地点的孢粉分析资料,指出呼伦贝尔盟东部地区,在11400±230年前,不仅湖沼棋布,而且生长着由松、榆、椴、胡桃等组成的繁茂的温带针叶—阔叶混交林。公元前1700年,昭乌达盟敖汗旗一带,分布着暖温带针叶—阔叶混交林,从花粉分析说明那时的人类已摆脱了单纯狩猎,开始种植作物、饲养动物。自晚更新世以来,内蒙古植被由混交林向草原迅速的发展。  相似文献   

14.
松嫩平原晚更新世以来古植被演替的初步研究   总被引:3,自引:0,他引:3  
根据松嫩平原不同地点六个剖面的孢粉分析资料及测年数据, 恢复该区晚更新世晚期以来的六种植被类型, 并且对晚更新世晚期在冰缘气候控制下的三种模式孢粉组合所代表向三种典型植被类型进行讨论。  相似文献   

15.
Carabid diversity has been studied in the forest-steppe in southern West Siberia along a continuous 180-m transect from the center of a small birch forest outlier through steppe and mesophytic meadows to a single tree. Carabid communities characteristic of open and forest habitats are different. Communities of open habitats are more differentiated than forest ones. The former can be further subdivided into steppe and meadow variants. Some species are generalists, exhibiting no preferences to particular open habitats.  相似文献   

16.
A pollen record from the Taishizhuang site (40°21.5′N, 115°49.5′E) located in the transitional forest-steppe zone near the present-day limit of the summer monsoon is used to reconstruct vegetation and climate. Quantitative biome reconstruction suggests that between ca. 5700 and 4400 cal. years B.P. temperate deciduous forest dominated the vegetation cover around the Taishizhuang site. After that time the landscape became more open and the scores of the steppe biome were always higher than those of the temperate deciduous forest except for two oscillations dated to ca. 4000 cal. years B.P. and ca. 3500 cal. years B.P. However, ca. 3400-2100 cal. years B.P. the common vegetation became steppe and the landscape was more open in comparison with the previous time interval. The results of the pollen-based precipitation reconstruction suggest that annual precipitation was ca. 550-750 mm (ca. 100-300 mm higher than present) during the mid-Holocene ‘forest phase’, and ca. 450-650 mm during the following ‘forest-steppe phase’. From ca. 3400 cal. years B.P. during the ‘steppe phase’ annual precipitation was similar to modern values (ca. 300-500 mm). Archaeological records from 100 sites prove the habitation of northeastern China during the prehistoric and early historic periods from ca. 8200 cal. years B.P., but do not provide evidence of the use of wood resources intensive enough to influence the regional vegetation development and to leave traces in the pollen assemblages. Both archaeological and palaeoenvironmental data support the conclusion that changes in pollen composition in northeastern China between 5700 and 2100 cal. years B.P. reflect natural variations in precipitation and not major deforestation caused by humans.  相似文献   

17.
青海湖地区植被及其分布规律   总被引:8,自引:0,他引:8       下载免费PDF全文
青海湖地区位于青藏高原东北部。境内复杂的地貌类型及青海湖的存在对植被有重要影响。本区植物种类贫乏,现有种子植物52科、174属、445种。主要植被类型有寒温性针叶林、高原河谷灌丛、高寒灌丛、沙生灌丛、温性草原、高寒草原、高寒草甸、沼泽草甸、高寒流石坡植被等。植被分布表现出明显的规律性变化。草原分布于湖盆及河谷地带,由东而西植被类型有更加适应寒旱趋势。温性草原以青海湖为中心;呈环带状分布,而高寒草原的分布则与生境寒冷干旱相一致。山地垂直带谱表现为草原带、高寒灌丛与高寒草甸带以及高寒流石坡植被带。本区植被水平地带性分异受到青海湖的影响,其植被组合及特征表现出与青藏高原植被的明显相似性。作为祁连山南麓中部地区的一个大型山间盆地,其东西方向界于青海省东部地区和柴达木盆地之间,植被东西方向的水平地带性并未表现出明显的过渡特征。根据植被特点及分布规律分析,本区植被有其自身的特殊性,并与青藏高原隆升之后气候寒冷干旱相一致。因此,青海湖地区就整体而言应属祁连山地区植被一个相对独立的组成部分。  相似文献   

18.
《植物生态学报》2017,41(7):779
Aims Our main purposes were to analyze the relationship between vegetation and pollen in the surface soil of the Turpan region, which is located in the southern slope of the eastern Tianshan Mountains, and to compare different pollen assemblages between the Turpan region and the northern slope of the Tianshan Mountains.Methods We collected 36 modern pollen samples and carried out modern vegetation survey in the Turpan region along an altitudinal gradient from 2 000 m to -154 m. Detrended correspondence analysis and Redundancy analysis were applied to analyze the distribution pattern of pollen in surface soils. Important findings We divided the pollen spectra into four pollen assemblage zones (mountain desert-steppe and desert, Gobi gravel, typical desert and salt mash vegetation), corresponding to the major vegetation types in the Turpan region. When compared with the northern slope, the characteristics of pollen assemblages in the mountain desert-steppe and desert were similar to those in the forest-steppe on the northern slope of the Tianshan Mountains; the pollen assemblages in the Gobi gravel and the typical desert seemed to be more consistent with those in the typical desert on the northern slope; however, no analogue was found in the salt mash vegetation. Obviously, the vertical pollen spectra in Turpan region were incomplete, lacking typical forest and Artemisia desert pollen zones. Besides, similar pollen zones in the Turpan region were found at an elevation of about 300 m higher than those in the northern slope. It is remarkable that the typical tree pollen, such as Picea and Pinus, showed their extra representation in the Turpan region. On one hand, the valley forest on the southern slope of the Tianshan mountains played an important role in pollen dispersal. On the other hand, with the cold air on the northern slope over the Tianshan Mountains, pollen may be carried and deposited in the Turpan region. The rivers feeding into Aiding Lake in the Turpan region may also contribute to the distribution of Picea and Pinuspollen. Lots of pollen studies have shown that the ratio of Artemisia to Chenopodiaceae (A/C) can be used as a good indicator of the degree of humidity in the semi-arid and arid areas. Our study revealed that A/C can roughly reflect the characteristics of the desert zone in the study area. The results of Redundancy Analysis ordination on pollen assemblages and environmental factors (mean annual temperature (MAT), mean annual precipitation (MAP) and altitude (ALT)) revealed that MAP was the main environmental factor affecting the pollen assemblages in the surface soil in the Turpan region and had more significant effects on the distribution of Nitraria pollen than on the distribution of Artemisia and Chenopodiaceae.  相似文献   

19.
Global change during the late Pliocene was manifested in declining temperatures, increased amplitude of climate cycles, and shifts in the periodicity of orbital climate forcing. Linking these changes to the evolution of African continental faunas and to hominin evolution requires well-documented fossil evidence that can be examined through substantial periods of time. The Omo sequence of southern Ethiopia provides such a database, and we use it to analyze change in the abundances of mammal taxa at different levels of temporal and taxonomic resolution between 4 and 2 Ma. This study provides new evidence for shifts through time in the ecological dominance of suids, cercopithecids, and bovids, and for a trend from more forested to more open woodland habitats. Superimposed on these long-term trends are two episodes of faunal change, one involving a marked shift in the abundances of different taxa at about 2.8+/-0.1 Ma, and the second the transition at 2.5 Ma from a 200-ka interval of faunal stability to marked variability over intervals of about 100 ka. The first appearance of Homo, the earliest artefacts, and the extinction of non-robust Australopithecus in the Omo sequence coincide in time with the beginning of this period of high variability. We conclude that climate change caused significant shifts in vegetation in the Omo paleo-ecosystem and is a plausible explanation for the gradual ecological change from forest to open woodland between 3.4 and 2.0 Ma, the faunal shift at 2.8 +/-0.1 Ma, and the change in the tempo of faunal variability of 2.5 Ma. Climate forcing in the late Pliocene is more clearly indicated by population shifts within the Omo mammal community than by marked turnover at the species level.  相似文献   

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