陕西定边地区2400cal.aB.P.以来高分辨率的花粉记录及环境变化

通过对位于黄土/沙漠过渡带定边地区苟池剖面的高分辨率的花粉分析,基于9个 14C年代数据重建了2400cal.aB.P.以来定边的植被与气候变化,结果表明 2400～1740cal.aB.P.地带性植被为以栎为主的森林草原,气候较温暖湿润; 1740～1610cal.aB.P.森林退化,草原发育,气候变干; 1610～1240cal.aB.P.乔木成分增加,植被类型为疏林草原,气候较温和湿润; 1240～1010cal.aB.P.森林退缩,草原发育,气候变干; 1010～690cal.aB.P.草原进一步发育,气候干旱; 690～500cal.aB.P.阔叶树成分增加,气候略温湿; 500～190cal.aB.P.草原发育,气候干旱; 190～0cal.aB.P.乔木成分增加,气候变湿。本区花粉记录的植被和气候变化可与区域的世纪初前后(秦汉)暖期、隋唐暖期、中世纪暖期和小冰期等事件对比。     

殷墟文化发生的环境背景及人类活动的影响

不同农业单元122个表土样品花粉分析结果表明,安阳地区表土花粉组合中草本植物花粉含量最高,以禾本科、蒿属、藜科和十字花科为主,乔木植物花粉百分含量较低,以松属、桦属、胡桃属、黄栌属、栎属为主,应为西部太行山区传播而来。汪家店和茶店陂两个全新世地层自然剖面孢粉分析表明,约 10000cal.aB.P.以前,安阳地区分布着以松属、栎属、桦属等为主的落叶阔叶林;  约 10000～8200cal.aB.P.,气候变暖,降水量增加,森林植被中夹杂着常绿栎等亚热带树种;  约 8200～3400cal.aB.P.,安阳地区进入全新世大暖期,森林植被演变为亚热带落叶阔叶和常绿阔叶混交林;  商王朝在安阳地区建都后（3400cal.aB.P.后）,乔木植物花粉急剧减少,草本植物花粉和中华卷柏百分含量升高,表明森林被大量砍伐,砍伐后的林地开垦为农田,主要种植禾本科等农作物;  两条剖面上部的冲积层中出现大量中华卷柏孢子,表明森林植被破坏后水土流失加剧。古地貌面孢粉分析也证明殷商时期安阳地区生长有亚热带落叶阔叶和常绿阔叶混交林,气候和植被条件适于野象生存;  殷墟附近为禾本科农作物花粉高含量区,表明殷商时期农业已具一定规模。     

殷墟地区土壤剖面孢粉组合特征及环境意义*

安阳地区3个土壤剖面孢粉分析揭示了殷墟文化前后的环境背景。取自安阳市区的茶店陂剖面灰黑色古土壤层(3400cal.aB.P.之前)孢粉组合是以乔木植物花粉为主,推测当时茶店陂剖面所在的安阳市附近是含常绿树的落叶阔叶林植被;取自安阳市东南20余公里广润陂的"广1"和"广2"两剖面孢粉组合特征相近,都以中湿生草本植物花粉为主,表明广润陂地区是以中湿生草本植物为主的草地和湿地景观,显示了与安阳市区不同的植被特征。古土壤层上部出现较高含量的禾本科花粉和中华卷柏孢子,反映当时安阳市附近已有人类定居并从事农业生产活动,森林植被已遭受人类砍伐破坏。黑色古土壤面以上地层(3400cal.aB.P.以后)是殷墟建都,殷商文化空前发展时期的沉积,孢粉组合中乔木花粉显著减少,表明殷商先人为了满足都城建设和生活需要,对安阳市周边的森林进行了大规模地砍伐和破坏。此后,乔木植物花粉含量进一步减少,中华卷柏孢子含量不断增加,可能反映了人类活动对安阳市及周边森林植被不断加剧的破坏过程。     

南海北部深海花粉记录的环境演变

本文报道了南海北部深海沉积物中花粉的研究结果。所研究的17940孔长13．30m,包括最近4万年的沉积物。共鉴定统计103个样品,样品间距10cm,分辨率约为360a,自下而上分为3个花粉带和8个亚带。P1带(13．06～8．70m,约37000～15000aB．P．)以山地针叶树(Picea,Abies,Tsuga)花粉高含量组合与蒿属花粉占优势组合交替出现为特征,指示冷湿及温干频繁交替的气候。根据氧同位素资料该带相当于3期及本次盛冰期。P2带前期(P2-a亚带,8．70～7．23m,约15000～11300aB．P．)热带-亚热带常绿阔叶乔木花粉增加指示气候变暖,其中14000aB．P．前后红树林的高峰可能是海平面一度上升的结果;P2带后期P2-b亚带(7．23～660m,约11300～10000aB．p．)高山雨林及山地针叶树花粉增加指示气候变冷。根据氧同位素资料P2－a亚带与Bφlling－Allerφd升温期相当,而P2－b亚带属新仙女木期。P3带(660～0m,10000aB．P．至现在)为全新世,花粉组合以松属花粉占绝对优势,与现代南海北部表层沉积物中花粉组合相似,说明近万年以来南海北部气候与现代气候相近。近1400年来芒其孢子突然增加说明人类活动加剧。     

更新世末期西辽河上游地区古代环境研究

西辽河地区史前和历史时期文化发达,分别发育了小河西文化－兴隆洼文化－赵宝沟文化－红山文化－小河沿文化－夏家店下层文化－夏家店上层文化,这些文化的兴衰同环境的演变密不可分,旱作农业的起源有可能在西辽河地区。西辽河地区古代环境、与人类文明发生以及演变关系一直是研究的热点,本研究将采自赤峰地区红山水库厚度为155cm的自然剖面进行了测年、孢粉和粒度分析,得到晚更新世末期西辽河地区古植被以及古环境资料。粒度分析说明沉积环境可能为河漫滩。孢粉分析结果显示： 晚更新世末期进入全新世前,西辽河地区较现代温暖湿润,植被是草原植被,主要的植物是蒿属以及菊科的其他植物,河漫滩中生长有香蒲属植物,不远的山地分布有疏林,针叶树主要是松、云杉和铁杉,而阔叶树主要是桦木科、胡桃属、栎属和榆属。自下而上,将剖面分为4个孢粉组合带(Zone 1～4)。Zone 1(15280～14680cal. aB.P.)和 Zone 2(14680～14090cal.aB.P.),针叶树主要是云杉和铁杉,而阔叶树主要是桦木科和胡桃属植物; Zone 2,盘星藻大量增加; Zone 3(14090～13890cal.aB.P.),除了云杉和铁杉,松属也是主要的针叶树种类,此时香蒲的数量急剧增加; Zone 4分为2个亚带,即 Zone 4­1(13890～13670cal. aB.P.)和 Zone 4­2(13670～13110cal. aB.P.),Zone 4主要的针叶树为松－云杉,此时的阔叶树也变为落叶栎－榆属。在Zone 4­2,伴随着C/A值的增大,铁杉花粉消失。铁杉花粉消失在约13610cal. aB.P.,可能是由气候的干旱引起。相对温暖湿润的气候环境为农业的发生提供了丰富的野生资源,而后期环境趋于干旱,这可能是促使农业发生的一个因素。     

长江三角洲地区全新世环境变化与人类活动的影响

长江三角洲地区全新世气候和环境曾发生过大的变迁,新石器时代文化伴随着全新世气候最暖期的到来,以及三角洲的形成和发展而出现,并由此向前推衍,奠定了以稻作农业为基础的经济形态。通过研究本区与农作物相关的现代植物花粉形态和代表性表土花粉,揭示出部分用于指示人类活动的综合指标、不同植被带表土花粉的组合特征和用于半定量界定不同植被类型的比值区间。研究区自然区域全新世孢粉反映当时植被3个主要发展阶段,即亚热带常绿-落叶阔叶混交林（11000～9500cal.aB.P.）、中亚热带常绿阔叶林（9500～3900cal.aB.P.）和次生性质的亚热带针阔叶混交林（3900cal.aB.P.以来）,其中8000～3900cal.aB.P.为全新世大暖期的鼎盛期,3900cal.aB.P.以来人类活动明显增强。人类活动区绰墩遗址孢粉植物群,反映新石器各主要文化期都以亚热带含针叶植物的常绿-落叶阔叶混交林为地带性植被,遗址周围一般都有较大面积的水域分布;  人类对植被的干预只是在后期才开始明显增强。区内人类文化几经兴衰,主要受制于环境的变迁,包括气候和地理状况的变化,以及由此产生的海平面升降和植被变化等。与此同时,人类活动的影响随着时间的推移而日趋加重,成为一种新的环境影响因素。     

河北阳原侯家窑遗址孢粉组合特征及揭示的古环境与古气候演变

结合前人测年资料和本研究孢粉分析结果表明遗址形成于晚更新世,依据花粉组合变化将其划分为6个带:带Ⅰ,以喜冷的针叶树等乔木花粉为主,表明遗址附近为针阔混交林,此带还出土喜冷的披毛犀等动物化石,都表明气候寒冷而湿润;带Ⅱ,乔木花粉减少,草本植物花粉明显增加,遗址附近演变为森林草原植被,气候温暖而干燥;带Ⅲ,乔木花粉骤升,仍...     

陕西富平全新世古气候的初步研究

为了了解黄土高原中部全新世古气候演化特征,通过对陕西富平剖面的地质调查、密集采样和31个样品的孢粉分析,将孢粉图式划分为Ⅰ、Ⅱ、Ⅲ3个带,分别代表早、中、晚3个时期的孢粉带:Ⅰ带为松-菊-香蒲组合带,以草本植物花粉占优势、针叶树植物花粉含量较高为特征;Ⅱ带为松-栎-蒿-环纹藻组合带,以乔木花粉增加、草本植物花粉减少为特征;Ⅲ带为栎-松-蒿组合带,以草本植物花粉增加、乔木花粉减少为特征.结果表明,早全新世植被为森林草原-干草原,气候干凉-干冷;中全新世植被为森林草原与针阔叶混交林草原,气候温暖半湿润;晚全新世植被为森林草原或疏林草原,气候干旱偏暖-温凉干旱.     

若尔盖风成砂-古土壤序列的古气候与古环境记录研究

通过对若尔盖盆地中部辖曼地区风成砂-古土壤沉积序列的粒度分析、孢粉鉴定、磁化率测定以及AMS 14C年代测定,探讨了该地区末次冰消期以来古气候与古环境的演化过程。研究结果表明,若尔盖地区的土地沙化现象至少在距今16 ka余年的末次冰消期就已经出现。地层结构、粒度、磁化率皆指示该区古气候在末次冰消期以来经历了多次冷暖交替变化,沙地也经历了多次的固定与活化过程,其中16130~6460 aB.P.、3445 aB.P.前后以及700 aB.P.前后气候较为温暖湿润,在8170~6460 aB.P.期间有一次极暖事件。自11.3 kaB.P.开始,古土壤中的喜暖型乔木花粉含量明显降低,草本植物、尤其是狐尾藻属和莎草科等沼泽植物孢粉含量明显增多,指示该区古环境发生明显变化,开始发育沼泽泥炭。      

POLLEN-BASED RECONSTRUCTION OF VEGETATION IN XINJIANG DURING THE HOLOCENE

本文选择我国干旱的新疆地区为研究区域,运用全球植物功能型分类系统(PFTS)、生物群区化定量技术(Biomisation)和600个地层孢粉样品,重建全新世14个时段的生物群区.以20世纪80年代以来采集的地层孢粉原始记录进行收集、归并和统计分析(主要包括孢粉类群、样品百分比数据、测年记录和与地理坐标有关的信息等),同时利用Digitizer图像数字化软件恢复少数已发表的孢粉学文献的孢粉图式,获得建立孢粉数据库需要的相关数据信息,最终建立起新疆全新世孢粉数据库,共获取29个地层孢粉样点的600个样品,设计了54种新疆植物功能型和13种新疆生物群区类型.共重建出7种生物群区类型:荒漠草原(DEST)、灌木荒漠(DSDE)、平原草甸(PLME)、草原(STEP)、针阔混合林(NBMX)、山地草甸(MOME)和常绿针叶林(EVNF).从重建结果看,整个全新世,新疆平原地区一直处于温带干旱、半干旱气候条件控制之下,植被以荒漠、荒漠草原和草原为主,在相对湿润时期,如1000aB.P.,1500aB.P.,2500aB.P.,5000aB.P.,6000aB.P.和10000aB.P.等时段,植被多以荒漠草原或草原类型出现;在更加干旱时期,如500aB.P.,2000aB.P.,3000aB.P.,4000aB.P.,7000aB.P.,8000aB.P.,9000aB.P.和11000aB.P.等时段,植被多以荒漠类型出现.新疆的山地植被随气候波动及冰期、间冰期的交替,森林界线上下移动.在冷期(1000aB.P.,1500aB.P.,2500aB.P.,5000aB.P.,6000aB.P.和10000aB.P.),由于山地冰川扩大,气温降低,森林线下移,而海拔太低处又缺乏森林生长的足够湿度,因此森林带变窄,原来森林带的一部分被寒冷类型的草原代替;在暖期(500aB.P.,2000aB.P.,3000aB.P.,4000aB.P.,7000aB.P.,8000aB.P.,9000aB.P.和11000aB.P.),气温升高,森林线上移,森林扩展.植被对应于气候变化最敏感的是在平原区,尤其是以荒漠、荒漠草原以及草原的演替更为明显.在平原区荒漠广泛发育的干旱期,如500aB.P.,2000aB.P.,3000aB.P.,4000aB.P.,7000aB.P.,8000aB.P.,9000aB.P.和11000aB.P.等时段基本上气候相对温暖;在平原区荒漠草原和草原广泛发育的相对湿润期,如1000aB.P.,1500aB.P.,2500aB.P.,5000aB.P.,6000aB.P.和10000aB.P.等时段,则基本上处于相对较冷的气候条件下.     

A record of late Quaternary vegetation from Davis Lake,southern Puget Lowland,Washington

Pollen and macrofossil analyses of a core spanning 26,000 yr from Davis Lake reveal late Pleistocene and Holocene vegetational patterns in the Puget Lowland. The core ranges lithologically from a basal inorganic clay to a detritus gyttja to an upper fibrous peat and includes eight tephra units. The late Pleistocene pollen sequence records two intervals of tundra-parkland vegetation. The earlier of these has high percentages of Picea, Gramineae, and Artemisia pollen and represents the vegetation during the Evans Creek Stade (Fraser Glaciation) (ca. 25,000–17,000 yr B.P.). The later parkland interval is dominated by Picea, Tsuga mertensiana, and Gramineae. It corresponds to the maximum ice advance in the Puget Lowland during the Vashon Stade (Fraser Glaciation) (ca. 14,000 yr B.P.). An increase in Pinus ontorta pollen between the two tundra-parkland intervals suggests a temporary rise in treeline during an unnamed interstade. After 13,500 yr B.P., a mixed woodland of subalpine and lowland conifers grew at Davis Lake during a period of rapid climatic amelioration. In the early Holocene, the prolonged expansion of Pseudotsuga and Alnus woodland suggests dry, temperate conditions similar to those of present rainshadow sites in the Puget Lowland. More-mesic forests of Tsuga eterophylla, Thuja plicata, and Pseudotsuga, similar to present lowland vegetation, appeared in the late Holocene (ca. 5500 yr B.P.).     

23,000 yr of vegetation history of the Upper Lerma, a tropical high-altitude basin in Central Mexico

Pollen analysis on a 9.54-m sediment core from lake Chignahuapan in the upper Lerma basin, the highest intermontane basin in Central Mexico (2570 m asl), documents vegetation and limnological changes over the past ∼23,000 ¹⁴C yr. The core was drilled near the archaeological site of Santa Cruz Atizapán, a site with a long history of human occupation, abandoned at the end of the Epiclassic period (ca. 900 AD). Six radiocarbon AMS dates and two well-dated volcanic events, the Upper Toluca Pumice with an age of 11,600 ¹⁴C yr B.P. and the Tres Cruces Tephra of 8500 ¹⁴C yr B.P., provide the chronological framework for the lacustrine sequence. From ca. 23,000 ¹⁴C yr B.P. to ca. 11,600 ¹⁴C yr B.P. the plant communities were woodlands and grasslands based on the pollen data. The glacial advances MII-1 and MII-2 correlate with abundant non-arboreal pollen, mainly grasses, from ca. 21,000 to 16,000 ¹⁴C yr B.P., and at ca. 12,600 ¹⁴C yr B.P. During the late Pleistocene, lake Chignahuapan was a shallow freshwater lake with a phase of lower level between 19,000 and 16,000 ¹⁴C yr B.P. After 10,000 ¹⁴C yr B.P., tree cover in the area increased, and a more variable lake level is documented. Late Holocene (ca. 3100 ¹⁴C yr B.P.) deforestation was concurrent with human population expansion at the beginning of the Formative period (1500 B.C.). Agriculture and manipulation of the lacustrine environment by human lakeshore populations appear at 1200 ¹⁴C yr B.P. (550 A.D.) with the appearance of Zea mays pollen and abundant charcoal particles.     

Vegetation, Climate, and Sea Level in the Past 55,000 Years, Hanjiang Delta, Southeastern China

Pollen in Quaternary deposits from the subtropical Hanjiang Delta records three major phases in the local vegetation and climate history during the last 55,000 yr: (1) a prevalent cool-to-temperate and humid climate at ca. 24,000 ¹⁴C yr B.P. is indicated by abundant pollen of temperate trees including conifers; (2) between 20,000 and 15,000 ¹⁴C yr B.P., a cold, dry environment was associated with low sea level during the last glaciation, leading to subaerial exposure, weathering, and interruption of sedimentation, as well as departure from the region of Dacrydium and Sonneratia; (3) a short-term expansion of grassland at ca. 10,300 ¹⁴C yr B.P. reduced the predominant Lauraceae-Fagaceae evergreen forest, possibly corresponding to the Younger Dryas cooling. The combined data indicate a maximum sea-level rise in the mid-Holocene (7500–4000 ¹⁴C yr B.P.) and a marine influence in the late Pleistocene at 45,000–20,000 ¹⁴C yr B.P. The Holocene warming, however, did not bring back moisture-sensitive taxa, indicating high seasonal aridity probably caused by renewed monsoon conditions.     

A late Wisconsin and Holocene vegetation history from the central brooks range: Implications for Alaskan palaeoecology

Five pollen diagrams reveal late Wisconsin and Holocene vegetation changes in the Walker Lake/Alatna Valley region of the central Brooks Range, approximately 100 km west of the area studied by D. A. Livingstone (1955, Ecology36, 587–600). New insights into the vegetation history of this region are provided by calculations of pollen influx and by the use of linear discriminant analysis to separate Picea glauca and P. mariana pollen. Three major pollen zones are identified: (1) a basal herb zone, characterized by high percentages of Cyperaceae, Gramineae, Salix, and Artemisia, and low total pollen influx; (2) a shrub Betula zone with increased total pollen influx and very high percentages of Betula pollen, predominantly in the size range of B. nana and B. glandulosa; and (3) and Alnus zone dominated by Alnus pollen. Lakes currently within the boreal forest or near tree line show relatively high percentages of Picea pollen in the Alnus zone. Several striking vegetation changes occurred between ca. 10,000 and 7000 yr B.P. Between ca. 11,000 and 10,000 yr B.P., Populus balsamifera pollen percentages as great as 30% indicate that this species was present at low-elevation sites near Walker Lake. These populations declined abruptly ca. 10,000 yr ago and have never regained prominence. About 8500 yr B.P., Picea glauca pollen reached 10–15%, indicating the arrival of P. glauca in or near the study area. P. glauca populations evidently decreased ca. 8000 yr ago, when Picea pollen percentages and influx fell to low values. About 7000 yr B.P., Alnus pollen percentages and influx rose sharply as alder shrubs became established widely. Picea once more expanded ca. 5000 yr ago, but these populations were dominated by P. mariana rather than P. glauca, which increased slowly at this time and may still be advancing northward. Some vegetation changes have been remarkably synchronous over wide areas of interior Alaska, and probably reflect responses of in situ vegetation to environmental changes, but others may reflect the lagged responses of species migrating into new areas.     

Late-Glacial Vegetation and Climate Change in Western Oregon

Pollen records from two sites in western Oregon provide information on late-glacial variations in vegetation and climate and on the extent and character of Younger Dryas cooling in the Pacific Northwest. A subalpine forest was present at Little Lake, central Coast Range, between 15,700 and 14,850 cal yr B.P. A warm period between 14,850 and 14,500 cal yr B.P. is suggested by an increase inPseudotsugapollen and charcoal. The recurrence of subalpine forest at 14,500 cal yr B.P. implies a return to cool conditions. Another warming trend is evidenced by the reestablishment ofPseudotsugaforest at 14,250 cal yr B.P. Increased haploxylonPinuspollen between 12,400 and 11,000 cal yr B.P. indicates cooler winters than before. After 11,000 cal yr B.P. warm dry conditions are implied by the expansion ofPseudotsuga.A subalpine parkland occupied Gordon Lake, western Cascade Range, until 14,500 cal yr B.P., when it was replaced during a warming trend by a montane forest. A rise inPinuspollen from 12,800 to 11,000 cal yr B.P. suggests increased summer aridity.Pseudotsugadominated the vegetation after 11,000 cal yr B.P. Other records from the Pacific Northwest show an expansion ofPinusfrom ca. 13,000 to 11,000 cal yr B.P. This expansion may be a response either to submillennial climate changes of Younger Dryas age or to millennial-scale climatic variations.     

新疆玛纳斯湖盆周围近14000年以来的古植被古环境

根据花粉资料得到新疆玛纳斯湖距今１４０００年以来植被和气候发展的历史；约在１０５００ａＢ．Ｐ．前极低的花粉沉积率及Ａ／Ｃ值(Ａｒｔｅｍｉｓｉａ与Ｃｈｅｎｏｐｏｄｉａｃｅａｅ花粉百分含量的比值)代表以藜科为主的荒漠植被，气候寒冷、干燥，特别是１１０００—１０５００ａＢ．Ｐ．阶段，更低的花粉沉积率及贫乏的花粉类型反映了更加恶劣的气候条件，有可能与欧洲的新仙女木期相当。在１０５００—９０００ａＢ·Ｐ·阶段花粉沉积率、Ａ／Ｃ值及中生、水生植物花粉的增加都指示荒漠草原植被的出现，气候较前。阶段湿润温暖。在９０００－４２００。Ｂ．ｐ．阶段花粉沉积率及Ａ／Ｃ值进一步增加，说明当时是以蒿属为主的草原植被，但是中生及水生花粉的贫乏指示草原植被仍具旱生性质。距今４２００年以来在花粉百分比基本稳定的情况下，花粉沉积率达剖面最高峰且高低变化很大，有数次大起大落。这种花粉沉积率的大起大落具有旱生、中生植物花粉同时起落、与岩性的变化不同步以及高花粉沉积率段与低Ａ／Ｃ值相对应等特点。这表明花粉沉积率高低与植被的丰富程度没有直接关系，而可能与西风环流的加强或减弱有关。     

南海深海沉积物花粉记录的快速气候波动事件

本文根据１７９４０柱状样花粉研究结果,分析了南海末次冰期以来千年尺度气候波动事件,并利用频谱分析方法得到南海深海沉积物花粉记录的气候变化的周期。本文研究认为,这种千年级准周期的气候波动可能与高纬度地区的亚米兰科维奇准周期性事件进行对比;它也可能反映了Ｅ１Ｎｉｎｏ－ＳｏｕｔｈｅｒｎＯｓｃｉｌｌａｔｉｏｎ(ＥＮＳＯ)系统较长周期的变化,其形成和演化机制仍待进一步探讨。     

A 35,000 Year Vegetation and Climate History from Potato Lake, Mogollon Rim, Arizona

A new record from Potato Lake, central Arizona, details vegetation and climate changes since the mid-Wisconsin for the southern Colorado Plateau. Recovery of a longer record, discrimination of pine pollen to species groups, and identification of macrofossil remains extend Whiteside's (1965) original study. During the mid-Wisconsin (ca. 35,000-21,000 yr B.P.) a mixed forest of Engelmann spruce (Picea engelmannii) and other conifers grew at the site, suggesting a minimum elevational vegetation depression of ca. 460 m. Summer temperatures were as much as 5°C cooler than today. During the late Wisconsin (ca. 21,000-10,400 yr B.P.), even-cooler temperatures (7°C colder than today; ca. 800 m depression) allowed Engelmann spruce alone to predominate. Warming by ca. 10,400 yr B.P. led to the establishment of the modern ponderosa pine (Pinus ponderosa) forest. Thus, the mid-Wisconsin was not warm enough to support ponderosa pine forests in regions where the species predominates today. Climatic estimates presented here are consistent with other lines of evidence suggesting a cool and/or wet mid-Wisconsin, and a cold and/or wet late-Wisconsin climate for much of the Southwest. Potato Lake was almost completely dry during the mid-Holocene, but lake levels increased to near modern conditions by ca. 3000 yr B.P.     

中国西部末次冰期以来冰川、环境及其变化

晚更新世以来,由于青藏高原及其周围山地的上升,中国西部的气候愈来愈干冷,冰川发育受到抑制。末次冰期最盛时,雪线比今日低300—1500m,古冰缘下限比今日低300—1400m,高山带的气温比今日低3—7℃,高原外围地区低8—10℃。青藏高原从13000aB.P.开始气候变暖,6000aB.P.高温期时冰川强烈退缩或消失,4000—3000aB.P.气候又再次变冷进入全新世新冰期和现代小冰期。目前气候又开始变暖,大部冰川又转入后退时期。