The quaternary climo-environment changes in Chaiwopu basin of Xinjiang region

This paper describes the paleoclimatic changesoccurring in the Chaiwopu Basin since 730,000 yr.B.P., together with theformation and evolution of Chaiwopu Lake based on the chronology and characteristics of a core drilled in the basin. Analysis of the drilling core provides information on the climate and environment of the area. It would appear that the paleoclimatic changes that occurred in the basin during the Pleistocene was controlled by the relationship between the sun and the earth and by Long-term (10,000 yr.) climatic cycles. The climate tended to cold-dry during the glacial period (ice age) and warm-moist during the interglacial. Following the warm period of the Holocene, short-term (1,000 yr.) climatic cycles occurred in cool-moist periods, similar to the “Little Ice Age”, alternated with warm-dry periods.     

THE QUATERNARY CLIMO-ENVIRONMENT CHANGES IN CHAIWQPU BASIN OF XINJIANG REGION

This paper describes the paleoclimatic changesoccurring in the Chaiwopu Basin since 730,000 yr.B.P., together with theformation and evolution of Chaiwopu Lake based on the chronology and characteristics of a core drilled in the basin. Analysis of the drilling core provides information on the climate and environment of the area. It would appear that the paleoclimatic changes that occurred in the basin during the Pleistocene was controlled by the relationship between the sun and the earth and by Long-term (10,000 yr.) climatic cycles. The climate tended to cold-dry during the glacial period (ice age) and warm-moist during the interglacial. Following the warm period of the Holocene, short-term (1,000 yr.) climatic cycles occurred in cool-moist periods, similar to the "Little Ice Age", alternated with warm-dry periods.     

Potential distribution of a montane rodent(Cricetidae,Handleyomys chapmani) through time in Mexico: the importance of occurrence data

Ecological Niche Modeling uses the geographic coordinates of species presence records as the primary input to estimate potential geographic distributions. It is little known whether carrying out rigorous data pre-processing is necessary before building niche models to be transferred to different time period. Here we compared the current, past, and future potential distributions projected by niche models built from two different databases, an openaccess database and a database compiled ad hoc, for Handleyomys chapmani, a rodent closely associated with montane cloud forests in Mexico. The models predicted different spatial patterns of climatic suitability for the three periods examined. Based on our current knowledge of cloud forest species in Mexico, the distributions predicted by the model built from the ad hoc database are more ecologically realistic than those obtained from the open-access database. The models built using the open-access database were particularly inaccurate at the limits of the geographic range, predicting larger, more diffuse distributions for the three periods. We conclude that pre-processing occurrence data is crucial for mountain species, as the number of localities and even minor inaccuracies in the geographic coordinates can translate into very different climatic conditions due to abrupt altitudinal changes. Finally, the predicted shifts in the potential distribution of H. chapmani over time indicate that this species is highly susceptible to climate change.     

Studies on quaternary sporo-pollen assemblage and paleoclimate based on Bohai Sea core Bc−1

Analysis of 13 spore-pollen assemblage zones reflecting environmental changes since the later middle Pleistocene showed the seccession of paleovegetation and the paleogeographic changes in the Bohai Basin and circumjacent area. Paleoclimatic variations here can obviously be divided into 5 cold and 5 warm periods: 2 cold and 1 warm periods in 200,000–100,000 a B.P.(late middle Pleistocene) 3 cold and 3 warm periods in 100,000–12,000 a B.P.(late Pleistocene), and 1 warm period since 12,000 a B.P. Late Pleistocene climate tended to become colder and colder. The coldest period was in the later stage of late Pleistocene, when the study area was a periglacial zone. The mean annual temperature then was about 10°C lower than it is now. In the middle stage of late Pleistocene, climate became warm; the mean annual temperature then was about 3–4°C higher than it is now. By applying principles of climatic stratigraphy, the authors deduced through sporo-pollen analysis, that the boundary between middle and late Pleistocene should be at 178–181 m, and that between Pleistocene and Holocene should be at 12.8 m. The results of climatic stratigraphy are consistent with those of magnetic stratigraphy. This paper was published in Chinese inOceanologica et Limnologia Sinica.18 (3): 253–266, 1987.     

VULNERABILITY AND ADAPTATION OF CHINESE AGRICULTURE TO GLOBAL CLIMATE CHANGE

Globalclimatechangeanditspotentialinlliactsonhumanaffairshavebeenthesubjectofconsiderablediscussionwithintheaca相似文献   

Alpine taxa exhibit differing responses to climate warming in the Snowy Mountains of Australia

The phenologies of plants and animals in snow-covered landscapes are expected to accelerate with global warming. However, there are few studies that have examined a range of unrelated taxa in alpine environments to determine whether there is commonality in the proximate causes, synchrony in timing, or the direction of any changes. Records for five alpine animal species and two alpine plant species, chosen primarily for their visibility, were examined to determine their temporal response to regional climate warming. Over the 30-year period studied, they showed an array of different phenological responses. Plant flowering appeared linked to date of snow melt, whereas animal responses varied. Although having accelerated phenologies, two migratory bird species exhibited contrary changes; one to low-altitude warming regardless of snow conditions in the alpine zone (flame robin) and the other to state of the snowpack regardless of low-altitude temperatures (Richard’s pipit). By contrast, the migratory bogong moth arrived significantly later over the years with no apparent explanatory climatic cause. Although bogong moths are not responding to earlier snow melt, insectivorous predators on the ground are. This could lead to a serious mismatch in timing at different trophic levels, putting pressure on endangered vertebrates. Emergence of locally wintering insect species, March flies and Macleay’s swallowtails, were not significantly related to measured climatic parameters over the study period. A consequence of the disparate responses to climate warming recorded here is the questionable value of ‘indicator species’ to examine the impact of climate warming on alpine ecosystems.     

A METHOD TO ESTIMATE PALEOTEMPERATURE FROM ENVIRONMENTAL PROXIES IN LAKE SEDIMENTS——A STUDY ON ZOIGE BASIN IN EASTERN TIBETAN PLATEAU, CHINA

Seeking for an effective method to probe further the relation among Tibetan Plateau, climatic events, and natural environmental changes in the Zoige Basin, we proposed a physical model for the reconstruction of climate and environment and a preliminary application was conducted on the 45 m (about 200 ka BP), upper part of Core RM (310 m long) drilled in the Zoige Basin (33°57’N, 102°21’E), on the eastern Tibetan Plateau. The results showed that: a) in the Zoige region, the maximum temperature in the period equivalent to Stage 7 in the deep-sea stable oxygen record was 2.7°C higher than that at present; b) Stage 6 temperature was 4.3°C lower than that at present; c) Stage 5 peak temperature was 5.2°C higher that that at present; d) Stage 4 average temperature should have been 2–3°C lower than that at present; and e) Stage 3 temperature differences within the period were more than 4°C. It was found that during Stage 6 (140–160 ka BP) the environment in the Zoige Basin was extraordinary, representing a transition period from warm-dry and cold-wet to warm-wet and cold-dry environmental conditions due to the uplift that occurred on the Tibetan Plateau at this period. Project 49803001 supported by NSFC and also funded by National and CAS Tibet Research Project (G1998040800).     

A singular spectrum analysis on Holocene climatic oscillation from lake sedimentary record in Minqin Basin, China

The total organic carbon (TOC) content series from the lake sediment of Minqin Basin (100°57′–104°57′E, 37°48′–39°17′N) in northwestern China, which has a 10 000-year-long paleo-climatic proxy record, was used to analyze the Holocene climate changes in the local region. The proxy record was established in the Sanjiaocheng (SJC), Triangle Town in Chinese, Section (103°20′25″E, 39°00′38″N), which is located at the northwestern boundary of the present Asian summer monsoon in China, and is sensitive to global environmental and climate changes. Applying singular spectrum analysis (SSA) to the TOC series, principal climatic oscillations and periodical changes were studied. The results reveal 3 major patterns of climate change regulated by reconstructed components (RCs). The first pattern is natural long-term trend of climatic change in the local area (Minqin Basin), indicating a relatively wetter stage in early Holocene (starting at 9.5 kaBP), and a relatively dryer stage with a strong lake desiccation and a declined vegetation cover in mid-Holocene (during 7–6 kaBP). From 4.0 kaBP to the present, there has been a gradually decreasing trend in the third reconstructed component (RC3) showing that the local climate changed again into a dryer stage. The second pattern shows millennial-centennial scale oscillations containing cycles of 1 600 and 800 years that have been present throughout almost the entire Holocene period of the last 10 000 years. The third pattern is a millennial-centennial scale variation with a relatively smaller amplitude and unclear cycles showing a nonlinear interaction within the earth’s climate systems.     

RELATIVE BRIGHTNESS INDEX AND IT‘S CLIMATIC SIGNIFICANCE FROM LACUSTRINE SEDIMENT OF NAPAHAI LAKE，NORTHWESTERN YUNNAN PLATEAU，CHINA

Information on the palaeoenvironment from Late Pleistocene to Holocene in northwestern Yannan Plateau has been deduced from a study of a 28.81m-long core taken from Napahai Lake.The results from Relative Brightness In-dex(RBI) as well as those from the lithological analyses of bulk sediments,total organic carbon and granulometric analy-ses have been used to reconstruct the environmental and climatic evolution of the area.The ages were provided by three ^14C datings.The record suggested a climate fluctuation between warm-dry and cool-wet from ca.57 to 32ka B.P.which led a shallowing and swamping of the lake.The water level again increased quickly at ca.32ka B.P.,reached itˊs peak during LGM(Last Glacial Maximum,ca.18-20kaB.P.)and remained relative high until ca.15kaB.P.The high wa-ter level at LGM is attributed to cold-wet conditions.The area experienced an abrupt and unstable climatic changes dur-ing the transition period form 15 to 10ka B.P.with a dominated littoral environment.Awarm-dry climate led to the contrac-tion of the lake during the Holocene and reed-swamps became dominant..After a minor wet-cool pulse during the Late Holocene,the modern climate became to be established.     

Pulling Vs. Pushing:Effect of Climatic Factors on Periodical Fluctuation of Russian and South Korean Tourist Demand in Hainan Island,China

While climate is an important factor attracting tourists to certain destinations,it can also motivate people residing in a country with a harsh climate to move to another location.By applying X-12 decompositions and a panel data regression analysis,this study analyzes the pull and push effects of climatic seasonal factors between destination(Hainan Island,China) and source countries(Russia and South Korea).The findings show that climatic seasonal factors have significant pulling and pushing effects on seasonal patterns of tourism demand,with temperature being the main factor.Furthermore,the number of paid vacation days in the source country affects that country's sensitivity to climatic seasonal factors;countries with a higher numbers of paid vacation days are more sensitive to climatic conditions.Lastly,future global warming may causes the aforementioned pull and push effects to abate,which will have an unavoidable influence on tourism industries.     

Contemporary climatic change over the qinghai-xizang plateau and its response to the green-house effect

The knowledge of contemporary climatic change over the Qinghai-Xizang (Tibet) Plateau (QXP) has been inadequate for a long time due to lack of enough observational data. In this paper, on the basis of monthly temperature and precipitation data in 1961–1990 from 48 stations on the QXP, the temperature data are extended backward to 1901 with an empirical orthogonal function (EOF) method, microscopic characteristics of contemporary climatic change over the QXP are analyzed, and the response of the plateau climate to global warming is discussed in combination with atmospheric general circulation model (GCM) outputs. The results show that the plateau climate, as a whole, has been warming since the early part of this century, that the precipitation has generally been increasing during the recent 30 years, and that these climatic trends seem to be related to the enhanced green-house effect induced by increasing CO₂ concentration in the atmosphere. This work is supported by the National and CAS (the Chinese Academy of Sciences) Tibet Research Project.     

Desertification hazard and farming-grazing sustainable development in Lingwu-Yanchi region of Ningxia

１ＰＲＯＣＥＳＳＯＦＤＥＳＥＲＴＩＦＩＣＡＴＩＯＮＡＮＤＩＮＦＬＵＥＮＣＥＯＦＰＨＹＳＩＣＡＬＥＮＶＩＲＯＮＭＥＮＴＡＮＤＨＵＭＡＮＡＣＴＩＶＩＴＹＩＮＬＩＮＧＷＵＹＡＮＣＨＩＲＥＧＩＯＮＴｈｅｄｅｓｅｒｔｉｆｉｃａｔｉｏｎｈａｚａｒｄｉｎＬｉ...     

Pulling vs. pushing: effect of climate factors on periodical fluctuation of Russian and South Korean tourist demand in Hainan Island,China

While climate is an important factor attracting tourists to certain destinations, it can also motivate people residing in a country with a harsh climate to move to another location. By applying X-12 decompositions and a panel data regression analysis, this study analyzes the pull and push effects of climatic seasonal factors between destination (Hainan Island, China) and source countries (Russia and South Korea). The findings show that climatic seasonal factors have significant pulling and pushing effects on seasonal patterns of tourism demand, with temperature being the main factor. Furthermore, the number of paid vacation days in the source country affects that country’s sensitivity to climatic seasonal factors; countries with a higher numbers of paid vacation days are more sensitive to climatic conditions. Lastly, future global warming may causes the aforementioned pull and push effects to abate, which will have an unavoidable influence on tourism industries.     

EVIDENCE FOR ABRUPT CLIMATIC CHANGES ONNORTHWESTERN MARGIN OF EAST ASIAN MONSOON REGION DURING LAST DEGLACIATION

Based on investigations of the Zhongwei Nanshan aeolian section situated in the southeastern margin of Tengger Dcsert, carbon-14 and TL (thermoluminescence) dating results and paleoclimatic proxies such as magnetic susceptibility and grain size, we inferred that the northwestern margin of East Asian monsoon region experienced abrupt climatic changes during the last deglaciation. Six oscillation events were identified: Oldest Dryas, Belling, Older Dryas, AllerФd, lntra-AllerФd Cold Period (1ACP) and Younger Dryas (YD). The summer monsoon was weaker during Oldest Dryas and Younger Dryas when the winter monsoon was stronger. However, during the B/A (BФlling/AllerФd) period, the summer monsoon strengthened, reflected by magnetic susceptibility, when the winter monsoon also became strong, which is different from the paleoclimatic pattern established in the East Asian monsoon region. Furthermore,the summer monsoon was nearly in phase with the climate changes inferred from the oxygen isotopic records of Greenland ice cores. It could be speculated that the variations of the sea ice cover in the high latitudes of the North Hemisphere affected the high pressure of Asian continent and the changes of the winter monsoon inland. On the other hand,the sea ice cover variations might have indirectly caused the occurrence of ENSO events that has tightly been related to the summer monsoon in northwest margin of East Asian monsoon region.     

Luminescence chronology and age model application for the upper part of the Chumbur-Kosa loess sequence in the Sea of Azov,Russia

A reliable chronology is essentially critical for correlating loess records with other paleoenvironmental time series, as well as for continuing improvements in the reconstruction of paleoenvironment and paleoclimate changes. It is exactly that the scarcity of chronologies across the Sea of Azov has limited the interpretation of climatic and environmental information in the East European Plain. In view of this, this paper conducted an exploratory study to investigate whether the optically stimulated luminescence (OSL) dating of mediumgrained quartz could be used to obtain a set of chronologies and the age models could be used to establish an independent time scale since the Late Pleistocene for the Sea of Azov loess. The results showed that an internally consistent set of optical ages for the Azov loess deposited up to ~76 ka. In addition, the ages developed based on magnetic susceptibility and grain size ages models showed good comparability with independent OSL ages at an acceptable range, suggesting that it might be practicable to establish an independent time scale using age models at the Sea of Azov loess, at least for the uppermost part of the Chumbur-Kosa section. Comparison with the ages based on two age models, the grain size ages using fine-grain fractions may provide a more reliable chronological sequence at the Azov loess since the Late Pleistocene. With the help of absolute ages and climate proxies (magnetic susceptibility and grain size), paleoclimatic change in the Sea of Azov have been traced for the Late Pleistocene.     

京津冀地区NDVI变化及气候因子驱动分析

植被覆盖动态监测及与气候变化的响应,是陆地生态系统研究的重要内容。本文以2001-2013年间京津冀地区MOD13A 3月合成NDVI数据,结合生长季的降水和气温资料,运用偏相关和复相关分析、趋势分析方法,研究了该区域NDVI的变化特征和空间分布,以及其区域植被覆盖变化的气候驱动力。结果表明,该区域NDVI最大值在13a间缓慢增加,植被覆盖呈现改善趋势;NDVI和生长季降雨量及平均气温的平均偏相关系数分别为0.20和-0.14,表明在年际变化水平上,京津冀地区NDVI总体与降水量呈正相关,与平均气温呈负相关,且降水对NDVI的影响大于温度对NDVI的影响。对植被覆盖驱动分区得出,降水和气温驱动型占区域面积的5.68%;单独降水驱动型和气温驱动型分别占4.51%、0.18%;区域内植被覆盖变化主要受非气候因子驱动型为主,所占比例为89.63%,表明人类活动对植被变化的影响巨大。     

简单随机模式进一步分析(Ⅰ)——非线性外通函数项处理

本文利用等效线性化法和Fokker-planck方程,对一个简单的非线性随机模式非线性项在不同气候时期的参数化进行了讨论,得到了冰期、间冰期和现代气候的概率分布密度及输出响应特征。     

DRY/WET CLIMATE CHANGE SINCE 960 A.D.IN TAIHU DRAINAGE BASIN OF CHINA

IINTRODUCTION climate chang巳 divided d叮／wet penodS and discussed itsrelationships with cold／warm vanatlon and solar activityRecords ofellmate dlsasterhave been abundantly（CHEN198飞 1989）．IOund In Chinese historical literature．Previous works The present study tends to establish the dry／wethave collected such records to study the historical elf－series since 960 A．D．ofTal…     

ENVIRONMENTAL EVOLUTION OF ORDOS DESERT IN CHINA SINCE 1.1MA B. P. AS INDICATED BY YULIN STRATIGRAPHICAL SECTION AND ITS GRAIN-SIZE ANALYSIS RESULTS

1INTRODUCTIONOrdosDesertisageneral appellationof Qubqi Desert onthe north, Hedong Sandy Landonthesouthwest and MuUs Desert on the southeast (Fig. 1). It is situated on atransitional zone from arid desert steppe to semi-aridsteppe between ariddesertinNorth…     

ORGANIC GEOCHEMISTRY MARKERSOF CLIMATIC EVOLUTION IN LOESSREGION OF CHINA

Two hundred and thirty-five samples collected from Weinan loess section (L₂ – S₀) have been analyzed by TOC (total organic carbon) and pyrolysis hydrocarbons. The curve of TOC with depth has been set up and compared well with other climatic markers. The main periods of TOC variation of the last 0.14 Ma are 67.08 ka and 18.29 ka, which is near with the periods of the variation of sunshine, showing that the TOC variation may be controlled by the variation of 65°N sun-shine. The distribution of pyrolysis hydrocarbon and its parameters shows that there are two kinds of hydrocarbon associated with climatic change. One is called hydrocarbon pyrolysted directly from organism (pHC_2–1) which is in the range of T _max350°C – 500°C, and associated with atmospheric water. The other is called carbonate inclusion hydrocarbon (pHC_2–2) which is in the range of T _max 500°C – 600°C and formed by evaporation and associated with dry climate. The formula calculating humidity has been deduced Og=pHC_2–1/(pHC_2–1 + pHC_2–2). The range of humidity of the section is 47% – 77% and the reducing order is S_1–3, S_1–2, S₀, S_1–1, S_1–4, S_1–1, L_1–1, L_1–3, and L_1–5. And the trend of the humidity is still increasing today.