前言

青藏高原是世界上最高的高原,它的隆升是新生代一个极其重要的地质事件。青藏高原不但是理解陆陆碰撞理论的天然实验室,而且它的隆升对全球新生代气候和环境变化起着极其重要的影响,尤其是对亚洲地区气候变化、环境变化、自然格局形成演化,以及中东亚文明演进和社会发展均产生了重大影响。青藏高原隆升及其环境效应研究已成为国际多学科关注的研究热点,也是中国科学家发挥作用的理想天然实验场。李吉均院士在青藏高原隆升及其环境效应、中国大江大河水系和地貌格局演化、青藏高原现代冰川发育和东部第四纪古冰川,以及西部地区地理建设和地理学人才培养方面做出了卓越贡献。在恰逢李吉均院士八十华诞之际,由兰州大学西部环境教育部重点实验室、西部环境与气候变化研究院、资源环境学院和南京师范大学地理科学学院发起组织的     

三峡及邻区第四纪沉积物地球化学特征及其对古气候的指示

讨论三峡和宜昌地区第四纪古气候的演化过程及青藏高原隆升对古气候演化的影响。以三峡及宜昌地区第四纪沉积物为主要研究对象,在沉积剖面研究的基础上,对低夷平面、阶地及冲积扇和湖相沉积物进行地球化学元素分析,依据地球化学元素的变化曲线及沉积特征,认为三峡及宜昌地区第四纪古气候的演化趋势相似,经历了早更新世晚期及中更新世暖湿气候到晚更新世干冷气候的转变。结合全球气候背景、青藏高原隆升过程对气候影响等方面的资料,认为150 ka B.P.之后青藏高原隆升至4 km时,青藏高原对三峡及宜昌地区的古气候产生了较大影响。     

特殊气候条件对多年冻土地区路基的影响

为了揭示多年冻土地区路基病害发生的根源，基于青藏高原五道梁、沱沱河和安多等地的气象资料，研究了特殊气候条件对青藏公路路基的影响。从青藏高原年平均气温变化曲线及年降水变化曲线入手，考虑路基周期冻结和融化过程中水分迁移及相变作用，结合SWS-3型连续面波仪的路基强度测试结果，分析了青藏公路纵向裂缝、波浪扭曲变形和不均匀沉陷等典型病害的发生机理。研究发现：青藏高原的低温特征使得路基常年处于冻结和融化的交替状态；雨季集中、固态降水特征致使路侧积水严重；在特殊的气候夺件下路基土体的动弹性模量由最初的均匀分布逐渐过渡到不均匀状态；路基两侧的积水及土体的冻融疏松是造成路基强度不均匀分布、产生病害的直接原因。     

东亚季风区气候和生态系统相互作用的诊断和模拟研究

大气圈和生物圈的相互作用是连接地球系统中生命世界和无生命世界的重要过程之一，也是地球环境变化中一个最基本的过程。通过卫星遥感植被和地表覆盖信息与气候要素关系的诊断分析以及生态和气候模式的数值模拟，揭示了东亚季风区气候和生态系统相互作用的基本特征，包括季节、年际和长期的季风气候变化对生态系统的影响和大范围植被覆盖状况的变化对季风气候的影响。结果表明，东亚季风区与气候与生态系统相互作用最为强烈的地区之一，这里陆地生态系统的时空变率表现出明显的对季风气候的响应特征；另一方面，人类活动引起的大范围植被覆盖状况的变化可以对季风气候产生显的反馈影响，它们是叠加在季风系统自然变率之上的一种重要变化。同时，虚拟试验表明，通过有序的人类活动，因地制宜，合理利用土地资源，保护和恢复自然植被，可以产生明显的气候和环境效应。     

中国北方新近纪红黏土记录的古气候意义——与动物群化石序列对比

目的研究中国北方新近纪红黏土序列的古气候演化特征。方法对中国北方4个新近纪红黏土剖面沉积物的粒度、磁化率和化石动物群时间序列进行区域对比。结果黄土高原新近纪红黏土沉积以来发生了5次大的气候事件,气候事件的分界线在粒度、磁化率年龄曲线上特征明显,反映的气候特点与化石动物群演替性质完全一致。结论中国北方新近纪红黏土序列古气候演化过程的气候事件均与青藏高原隆升和东亚季风的发展相联系。时间上,南北气候演化事件基本同步;空间上,北部较南部地区变化剧烈。5次气候事件从下到上表现为半湿润、半干旱、湿润、干旱与湿润交替、干旱的气候演化特征;相应动物群生态类型表现为草原-疏林草原、草原为主的疏林草原、森林、草原荒漠与森林交替到草原的演化特点。     

昼夜情境转换下旅游者行为特征及影响因素探索

昼夜情境转换是一种非人为营造的自然情境,旅游地昼夜环境存在明显差异,造成旅游者景观感知的差异,进而对旅游者行为产生影响。以广州塔为中心的夜游区域到访游客为研究对象,利用访谈法、参与观察法探索昼夜情境转换下游客的行为特征及影响因素,并采用关键事件法对获取的访谈资料进行内容分析。气候因素与灯光景观是城市夜间旅游发展的驱动因素,同时也是游客与居民"昼伏夜出"与"室内转向室外"等行为特征的诱导因素。休闲氛围""心理安全感"与"环境安全感"方面的感知是游客出现情绪变化、行为趋向本真的重要影响因素。     

青藏高原对亚洲和太平洋地区天气气候的影响

在大气运动的过程中,经常受到地球表面特性的影响,除海洋以外。高原是影响大气运动和气候变化的重要因素之一。我国的青藏高原.平均海拔在四千米以上,是我国、也是世界上又高又大地形复杂的高原,天气变化剧烈,具有独特的天气气候特征。影响我国天气气候的天气系统,不少产生于青藏高原。东亚和世界各地的天气气候,也要受到青藏高原的制约。国内外气象科学工作者对青藏高原的研究已在多方面取得可喜的成果。本文的目的是把     

青藏高原植物抗寒性研究进展

植物生长发育过程受到多种环境因子的影响,比如光照、温度、水分等,其中温度的高低对植物分布情况起着主导作用。生长在青藏高原高山环境中的植物,长期经受着高寒缺氧、强烈的太阳辐射等生态因素以及气候急剧变化的严重胁迫。文章主要分析了近年来青藏高原植物抗寒性与生物膜系统、抗氧化酶、渗透调节物质等方面的研究进展,并对该领域的研究前景进行了展望。     

全球气候变化下高山植物生理特性的研究进展

青藏高原因其独特的地理区位和气候环境特征,成为全球气候变化的敏感区域.研究气候变化对青藏高原植被生理特性的影响,对于保护高原自然生态系统有着积极的意义.分析了气候变暖对植物光合作用、生物量以及水分利用效率的影响,并对全球气候变化下高山植物生理特性的研究做了展望.     

全球气候变化与塔里木盆地古城绿洲演变关系

我国西部地区地形复杂,气候的地域差异性大.特别是青藏高原的突起给塔里木盆地的环境带来了巨大的变化,导致盆地气温降水的突变.从而使塔里木盆地水流分布状态发生改变,导致盆地中原有的古绿洲的蜕变,进而直接影响到整个人类的发展历史.历史研究表明,塔里木盆地气候服从于全球气候变化,并且与某些人文事件,特别是古城绿洲兴盛与消亡有着十分一致的耦合关系.所以,全球环境变化对古城绿洲发展影响重大.     

Placing late Neanderthals in a climatic context

Attempts to place Palaeolithic finds within a precise climatic framework are complicated by both uncertainty over the radiocarbon calibration beyond about 21,500 14C years bp and the absence of a master calendar chronology for climate events from reference archives such as Greenland ice cores or speleothems. Here we present an alternative approach, in which 14C dates of interest are mapped directly onto the palaeoclimate record of the Cariaco Basin by means of its 14C series, circumventing calendar age model and correlation uncertainties, and placing dated events in the millennial-scale climate context of the last glacial period. This is applied to different sets of dates from levels with Mousterian artefacts, presumably produced by late Neanderthals, from Gorham's Cave in Gibraltar: first, generally accepted estimates of about 32,000 14C years bp for the uppermost Mousterian levels; second, a possible extended Middle Palaeolithic occupation until about 28,000 14C years bp; and third, more contentious evidence for persistence until about 24,000 14C years bp. This study shows that the three sets translate to different scenarios on the role of climate in Neanderthal extinction. The first two correspond to intervals of general climatic instability between stadials and interstadials that characterized most of the Middle Pleniglacial and are not coeval with Heinrich Events. In contrast, if accepted, the youngest date indicates that late Neanderthals may have persisted up to the onset of a major environmental shift, which included an expansion in global ice volume and an increased latitudinal temperature gradient. More generally, our radiocarbon climatostratigraphic approach can be applied to any 'snapshot' date from discontinuous records in a variety of deposits and can become a powerful tool in evaluating the climatic signature of critical intervals in Late Pleistocene human evolution.     

近300年来岱海流域气候干湿变化与人类活动的湖泊响应

根据岱海60cm柱状岩芯的磁化率、孢粉、粒度等环境指标的分析结果,对历史时期岱海气候干湿变化和人类活动的湖泊记录进行探讨,岱海湖泊沉积记录近300年来的气候干湿变化可划分七个阶段,与历史记载有较好的一致性;频率磁化率高值段对应气候偏湿阶段,低值对应气候偏干阶段,人类活动特别是人口增加和土地开垦,加剧流域水土流失,导致湖泊沉积物中细颗粒组分增加,频率磁化率升高;孢粉Ulmus的变化受流域人口增加的影响。频率磁化率和孢粉是反映岱海历史时期干湿变化和人类活动的重要环境指标。     

New focuses of polar ice-core study: NEEM and Dome A

Ice core records from polar regions are of great value to study long-term climate and environmental change. Greenland ice-core records are celebrated for their high resolution and have provided very important knowledge for understanding the late Quaternary palaeoclimate, especially in reference to millennial-scale abrupt climatic flips during the last glaciation. Recently, a new project to retrieve a deep ice-core from Greenland known as NEEM for North Greenland Eemian Ice Drilling, has been launched with the main target being the last interglacial period. The new core will help us understand further details of climate changes during a period of warmth as the present. Antarctic ice cores have a unique advantage in providing recovery of longer time-scale paleclimate information and hence are regarded as a crucial pillar to examine climatic cycles on the time-scale of Earth-orbital phenomena. Since the bottom ice in Dome A is estimated to be older than a million years, a deep drilling there becomes a new focus for ice core studies. Supported by Knowledge Innovation Project of the Chinese Academy of Sciences (Grant No. KZCX2-SW-354) and National Key Technology Research and Development Program (Grant No. 2006BAB18B01)     

The paleoclimatic events and cause in the Okinawa Trough during 50 kaBP

Planktonic foraminiferal δ ¹⁸O record for core DGKS9603 from the Okinawa Trough shows a series of climatic fluctuations and sudden cooling events in short time scale during 50 kaBP, which appear to correlate closely to the Younger Dryas and Heinrich events H1-5 recorded in Chinese loess, the South China Sea, the North Atlantic cores and the Greenland ice cores. Three polarity reversal events, correlating to Gothenburg, Mungo and Laschamp events, approximately correspond to Heinrich events H1, H3 and H5 respectively, which could be a cause of global climate changes. The δ ¹⁸O curve of the Okinawa Trough is well associated with the grain size record of the Lijiayuan loess profile in northwestern China and is somewhat different from the climate fluctuations documented in the Greenland ice cores. These correlation results indicate that regional factors play an important role in controlling the climate changes in the East Asia, and the East Asian Monsoon could be the prominent regional controlling factor.     

舟山海域哺乳动物化石研究

记述了舟山海域发现的120余件哺乳动物化石并对其中4件带有人工痕迹的鹿角进行了观察和描述;结合台湾澎湖海沟、福建东山等海域的发现以及海洋地质学、冰川学、第四纪孢粉学资料,对末次冰期时舟山地区的古气候和古生态环境进行了探讨;通过对河姆渡遗址以及国内外考古资料的分析,说明宁绍平原可能是冰后期一个人类生产活动和文化传播的中心.     

Retrospect and prospect: advances and future strategies in climate research

A brief review of the progress in climate research and a prospect on its further development in the 21st century is presented. Some key findings including the concept of climate system, the discovery of climatic multi-equilibrium and abrupt climate changes, and the recognition of human activities as an important force of climate change made breakthroughs in climatology possible during last few decades. The adaptation to climatic and global change emerged as a new aspect of climatic research during the 1990s. Climate research will break through in the observation of the global system, in the analysis of mass data, in the deepening of research on the mechanism of climatic change, and in the improvement of models. In the applied fields of climate research, there will be substantial progress in the research on adaptation to global change and sustainable development, on orderly human activities, and climate modification.     

广州地区晚第四纪孢粉气候研究

 利用广州地区南北2个不同沉积地貌区的钻孔进行孢粉分析,结合测年和沉积信息,分析了广州所代表的珠江三角洲地区晚更新世以来的沉积环境和气候变化。孢粉分析结果显示：在晚更新世珠江三角洲地区气候经历了偏冷干-偏凉干-暖湿-热湿-偏凉干-冷干的变化过程,末次冰期对本区具有明显影响,使全新世和晚更新世孢粉组合表现出一定的差异;全新世气候明显转暖湿,整体上以暖湿为主,但出现了一些小的气候波动事件,最明显的是在2 250 a BP 前后偏凉干的变化;该区在晚更新世和全新世各经历过一次海侵,两孔反映的气候期和海平面变化较为一致,气候和海平面变化也有很好的对应。两孔在地层、沉积相和孢粉特征上的差异是地理位置、沉积环境和基座地貌等差异造成的。     

武都黄土堆积及晚更新世以来环境变迁研究

武都黄土剖面的研究结果表明：它完整且高分辩率地记录了晚更新以来气候环境变化的历史，清晰易辨的黄土－古土壤系列和稳定的磁化率特征反映了这种变化的全过程；系统的元素地球化学分析证明了武都黄土物质构成主体部分与黄土高原一致；大旋回，大幅度的粒度变化特点说明受控于远距离，大尺度搬运过程及风力强弱的交替。     

One-to-one coupling of glacial climate variability in Greenland and Antarctica

Precise knowledge of the phase relationship between climate changes in the two hemispheres is a key for understanding the Earth's climate dynamics. For the last glacial period, ice core studies have revealed strong coupling of the largest millennial-scale warm events in Antarctica with the longest Dansgaard-Oeschger events in Greenland through the Atlantic meridional overturning circulation. It has been unclear, however, whether the shorter Dansgaard-Oeschger events have counterparts in the shorter and less prominent Antarctic temperature variations, and whether these events are linked by the same mechanism. Here we present a glacial climate record derived from an ice core from Dronning Maud Land, Antarctica, which represents South Atlantic climate at a resolution comparable with the Greenland ice core records. After methane synchronization with an ice core from North Greenland, the oxygen isotope record from the Dronning Maud Land ice core shows a one-to-one coupling between all Antarctic warm events and Greenland Dansgaard-Oeschger events by the bipolar seesaw6. The amplitude of the Antarctic warm events is found to be linearly dependent on the duration of the concurrent stadial in the North, suggesting that they all result from a similar reduction in the meridional overturning circulation.     

Change of bacterial community in the Malan Ice Core and its relation to climate and environment

In order to understand the relationship between the community structure of bacteria in ice core and the past climate and environment, we initiated the study on the microorganisms in the three selected ice samples from the Malan ice core drilled from the Tibetan Plateau. The 16S ribosomal DNA (rDNA) molecules were directly amplified from the melt water samples, and three 16S rDNA clone libraries were established. Among 94 positive clones, eleven clones with unique restriction pattern were used for partial sequence and compared with eight reported sequences from the same ice core. The phylotypes were divided into 5 groups: alpha, beta, gamma proteobacteria; CFB, and other eubacteria group. Among them, there were many “typical Malan glacial bacteria“ pertaining to psychrophilies and new bacteria found in the ice core. At a longer time scale, the concentration distribution of “typical Malan glacial bacteria“ with depth showed negative correlation with temperature variations and was coincident with dirty layer. It implied the influence of temperature on the microbial record through impact on the concentrations of the “typical Malan glacial bacteria“. In addition, the nutrition contained in ice was another important factor controlling the distribution of microbial population in ice core section. Moreover, the result displayed an apparent layer distribution of bacterial community in the ice core section, which reflected the microbial response to the past climatic and environmental conditions at the time of deposition.