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Impacts of permafrost changes on alpine ecosystem in Qinghai-Tibet Plateau

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Science china Earth Sciences 2006年第11期49卷 1156-1169页

作者： WANG Genxu1,3., LI Yuanshou2 , WU Qingbai2 & WANG Yibo3.1. institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu 610041, china 2. Cold and Arid Regions Environmental and Engineering research institute, Chinese Academy of Sciences, lanzhou 73.000, china 3. Resource and Environment School, lanzhou University, lanzhou 73.000, china 1. institute of Mountain Hazards and Environment Chinese Academy of Sciences Chengdu 610041 China 3. Resource and Environment School Lanzhou University Lanzhou 730000 China 2. Cold and Arid Regions Environmental and Engineering research institute Chinese Academy of Sciences Lanzhou 730000 China

Alpine cold ecosystem with permafrost environment is quite sensitive to climatic changes and the changes in permafrost can significantly affect the alpine ecosystem. The vegetation coverage, grassland biomass and soil nutrient and texture are selected to indicate the regime of alpine cold ecosystems in the Qinghai-Tibet Plateau. The interactions between alpine ecosystem and permafrost were investigated with the depth of active layer, permafrost thickness and mean annual ground temperature (MAGTs). Based on the statistics model of GPTR for MAGTs and annual air temperatures, an analysis method was developed to analyze the impacts of permafrost changes on the alpine ecosystems. Under the climate change and human engineering activities, the permafrost change and its impacts on alpine ecosystems in the permafrost region between the Kunlun Mountains and the Tanggula Range of Qinghai-Tibet Plateau are studied in this paper. The results showed that the per- mafrost changes have a different influence on different alpine ecosystems. With the increase in the thickness of active layer, the vegetation cover and biomass of the alpine cold meadow exhibit a significant conic reduction, the soil organic matter content of the alpine cold meadow ecosystem shows an exponential decrease, and the surface soil materials become coarse and gravelly. The alpine cold steppe ecosystem, however, seems to have a relatively weak relation to the permafrost environment. Those relationships resulted in the fact that the distribution area of alpine cold meadow decreased by 7.98% and alpine cold swamp decreased by 28.11% under the permafrost environment degradation during recent 15 years. In the future 50 years the alpine cold meadow ecosystems in different geomorphologic units may have different responses to the changes of the permafrost under different climate warming conditions, among them the alpine cold meadow and swamp ecosystem located in the low mountain and plateau area will have a relatively

关键词： permafrost environment, alpine cold ecosystem, statistics relationship, climate change, impacts, Qinghai-Tibet Plateau.

Impact of land-use change on hydrological processes in the Maying River basin, china

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Science china Earth Sciences 2006年第10期49卷 1098-1110页

作者： WANG Genxu1,3. ZHANG Yu2, LIU Guimin2 & CHEN Lin3.1. institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu 610041, china 2. Cold and Arid Regions Environmental and Engineering research institute, Chinese Academy of Sciences, lanzhou 73.000, china 3. Resource and Environment School, lanzhou University, lanzhou 73.000, china 1. institute of Mountain Hazards and Environment Chinese Academy of Sciences Chengdu 610041 China 3. Resource and Environment School Lanzhou University Lanzhou 730000 China 2. Cold and Arid Regions Environmental and Engineering research institute Chinese Academy of Sciences Lanzhou 730000 China

Since the 1960s, dramatic changes have taken place in land-use patterns characterized by the persistent expansion of cultivated land and a continuous decrease in natural woodland and grassland in the arid inland river basins of china. It is very important to assess the effects of such land-use changes on the hydrological processes so vital for water resource management and sustainable development on the catchment scale. The Maying River catchment, a typical arid inland watershed located in the middle of the Hexi Corridor in northwest china, was the site chosen to investigate the hydrological responses to land-use changes. The annual runoff, base flow, maximum peak flow, and typical seasonal runoff in both spring and autumn flood periods were selected as the variables in the hydrological processes. Statistical-trend analysis and curvilinear regression were utilized to detect the trends in hydrological variables while eliminating the climatic influence. The relationship between cultivated land-use and hydrological variables was analyzed based on four periods of land-use variation data collected since 1965. A runoff model was established composed of two factors, i.e., cultivated land use and precipitation. The impact of land use changes, especially in the large ar- eas of upstream woodland and grassland turned into cultivated lands since 1967, has resulted in a mean annual runoff decrease of 28.12%, a base flow decline of 3..3.%, a drop in the maximum peak discharge of 3..77%, and mean discharge decreases in spring and autumn of 3..05% and 24.87% respectively, of which the contribution of cultivated land expansion to the influence of annual runoff amounts to 77%-80%, with the contribution to the influence of spring discharge being 73.-81%, and that to the influence of base flow reaching 62%-65%. Thus, a rational regulation policy of land use patterns is vitally important to the sustainable use of water resources and the proper development of the entire catchment.

关键词： land-use change, arid inland river catchment, hydrological process, impact, Maying River.

Organic geochemical studies of sinking particulate material in china sea area Ⅱ——Geochemical significance of compositional features of ketone, aldehyde and alcohol compounds

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Chinese Science Bulletin 1997年第22期42卷 1894-1898页

作者： DUAN Yi,CUl Mingzhong, MA Lanhua, SONG Jinming, ZHOU Shixin and LUO Binjie1. lanzhou institute of Geology, Chinese Academy of Sciences, lanzhou 73.000,{3. 2. Earthquake research institute of lanzhou, SSB, lanzhou 73.000,{3. 3. institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071,{3. lanzhou institute of Geology Chinese Academy of Sciences Lanzhou China Earthquake research institute of lanzhou SSB Lanzhou China institute of Oceanology Chinese Academy of Sciences Qingdao China

SINKING particulate organic matter of the sea plays an important role in marine environment. Itnot only provides food for marine organisms and takes part in chemical cycling, but also pro-vides sedimentary organic matter for marine sediments. Therefore, researchers always payclose attention to the source and processes of transport and transformation of marine sinkingparticulate organic matter. Its transport process can be understood by measuring the

关键词： marine sinking paniculate material composition of lipid compounds organic matter source and biochemical pro-cesses.

Vertical quantitative and dominant population distribution of the bacteria isolated from the Muztagata ice core

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Science china Earth Sciences 2005年第10期48卷 1728-1739页

作者： XIANG Shurong1, YAO Tandong1, 2, AN Lizhe1, 3. WU Guangjian2, XU Baiqing2, MA Xiaojun 3. LI Zhen1, WANG Junxia1 & YU Wusheng1 1. Key Laboratory of Ice Core and Cold Regions Environment, Cold and Arid Regions Environmental and Engineering research institute, Chinese Academy of Sciences, lanzhou 73.000,{3. 2. institute of Tibetan Plateau research, Chinese Academy of Sciences, Beijing 100085,{3. 3. College of Life Science, lanzhou University, lanzhou 73.000,{3. Key Laboratory of Ice Core and Cold Regions Environment Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences Lanzhou China institute of Tibetan Plateau research Chinese Academy of Sciences Beijing china College of Life Science lanzhou University lanzhou china

Vertical distribution of the main bacteria isolated from the Muztagata ice core (about 22.4 m) was investigated by means of cultivation and 16S rRNA sequence analysis. The results showed that the amount of culturable bacteria fluctuated with ice core depth, and was more in dirty layer than in clean ice, which suggested the close corresponding relationship between high input of the bacteria deposited by wind and snowflow and dirty layer. Most of the bacteria were psychrophiles and psychrotolerants, including α- and γ-proteobacteria, Cryobacterium psychro-philum, CFB (Cytophaga-Flavobacterium-Bacteroides) group, high-G+C gram-positive bacteria (HGC). Acinetobacter sp. and HGC repeatly occurred in different ice depths, and their quantita-tive distribution was consistent with the change of the total amount of culturable bacteria with depth, which suggested the main bio-indicator; while Flavobacterium, Cryobacterium psychro-philum, and α-proteobacteria, also functioned as a secondary indicator of climatic and environ-mental changes. This study is the first report concerning continuous quantitative variation and pattern of the main culturable bacteria in ice core section.

关键词： Pamirs Plateau, ice core, pattern of bacteria, bio-indicator.

Theory of truth degrees of propositions in the logic system Ln^＊

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Science in china(Series F) 2006年第4期49卷 471-483页

作者： LI Jun1,2 & WANG Guojun1,3.1. institute of Mathematics, Shaanxi Normal University, Xi’an 710062, china 2. School of Sciences, lanzhou University of Technology, lanzhou 73.050, china 3. research Center for Science, Xi’an Jiaotong University, Xi’an 710049, china 1. institute of Mathematics Shaanxi Normal University Xi’an 710062 China 2. School of Sciences Lanzhou University of Technology Lanzhou 730050 China 3. research Center for Science Xi’an Jiaotong University Xi’an 710049 China

By means of infinite product of uniformly distributed probability spaces of cardinal n the concept of truth degrees of propositions in the n-valued generalized Lu- kasiewicz propositional logic system Ln^＊ is introduced in the present paper. It is proved that the set consisting of truth degrees of all formulas is dense in [0,1], and a general expres- sion of truth degrees of formulas as well as a deduction rule of truth degrees is then obtained. Moreover, similarity degrees among formulas are proposed and a pseudo-metric is defined therefrom on the set of formulas, and hence a possible framework suitable for developing approximate reasoning theory in n-valued generalized Lukasiewicz propositional logic is established.

关键词： truth degree similarity degree approximate reasoning.

Climate instability in the Yili region, Xinjiang during the last glaciation

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Chinese Science Bulletin 2000年第17期45卷 1604-1609页

作者： YE Wei, DONG Guangrong, YUAN Yujiang & MA Yingjie1. Xinjiang institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 83.011, china 2. Department of Geography, Zhejiang Normal University, Jinhua 3.1004, china {3., Chinese Academy of Sciences, lanzhou 73.000, china 4. Xinjiang institute of Meteorological research, Urumqi 83.002, china Xinjiang institute of Ecology and Geography Chinese Academy of Sciences Urumqi China Department of Geography Zhejiang Normal University Jinhua China institute of desert research Chinese Academy of Sciences Lanzhou China Xinjiang institute of Meteorological research Urumqi China

The climate is influenced by westerlies year in year out and the aeolian loess is widespread in the Yili region, the Xinjiang Uygur Autonomous Region. Through the study of the loess section with a thickness of 21.5 m, much useful information about climatic change in this region during the last glaciation was gotten. Grain size analysis of loess samples in the section showed that the climatic change in the Yili region was of instability during the last glaciation and similar to those of the North Atlantic Ocean and Greenland. In correspondence with the Heinrich events, the percentage of the size fraction of loess with grain size less than 10 μm decreased in cold stadials in the Yili region. This result suggests that the westerly wind be strengthened during the cold periods. Compared with the stadials, the content of the loess with grain size less than 10 μm was increased in interstadials, which indicated that the strength of the westerly wind was weakened. It is obvious that the climate was instable

关键词： Yili region last glaciation climate instability.

Timing and history of marine hydrocarbon accumulation in Tarim craton

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Chinese Science Bulletin 2002年第S1期47卷 120-127页

作者： ZHAO Jingzhou~(1,2) & LI Qiming~3.1. Department of Petroleum Geology, Xi’an Petroleum institute, Xi’an 710065, china 2. research institute of Petroleum Exploration and Development, Petrochina, Beijing 100083. china 3. Tarim Oilfield Company, Kuerle, Xinjiang 841000, china Xian Petr Inst Dept Petr Geol Xian 710065 Peoples R China Petrochina Res Inst Petr Explorat & Dev Beijing 100083 Peoples R China Tarim Oilfield Co Xinjiang 841000 Peoples R China

Based on the analyses of hydrocarbon inclu-sions, K-Ar dating of authigenic illites and oil/gas-watercontact retrospection as well as other methods, the marineprimary reservoirs in the cratonic region of the Tarim Basinare found to have been formed in the late Caledonian toearly Hercynian, late Hercynian, and Himalayan, and oil andgas adjusted and redistributed in the Yanshanian (Jurassic toCretaceous) and Himalayan (Tertiary). The analyses alsoshow that the remaining primary oil accumulations aremostly formed in the late Hercynian, and the secondary oilreservoirs resulted from the adjustment and redistribution ofthe earlier accumulations during the Yanshanian and Hima-layan (especially late Himalayan), of which the Himalayan isalso the major stage of gas accumulation. The primary oilreservoirs formed in the late Hercynian mostly occur withinthe Paleozoic formation, whereas the secondary reservoirsformed in the Himalayan in the Mesozoic. The late adjust-ment and redistribution of reservoirs in the craton region ofthe Tarim Basin is ubiquitous because of the intensified tec-tonic movements since the Mesozoic, especially Cenozoic andintrusion of the high- to over-mature gas. Furthermore, thelower amplitude of reservoirs in the craton region also makesthem easier to be adjusted and redistributed. Therefore, theremaining paleo-uplift and palaeo-slope developed in rela-tively stable tectonic regions are the main potential areas forthe middle-large marine reservoirs in the Tarim Basin.

关键词： Tarim Basin craton geochronology of hydrocarbon accumulation history of hydrocarbon accumulation marine reservoir primary reservoir secondary reservoir.

Temperature and precipitation trends in Minqin desert during the period of 1961-2007

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Journal of Arid Land 2011年第3期3卷 214-219页

作者： ShuJuan ZHU1,2,3.ZhaoFeng CHANG1,2,3.1 Gansu Minqin National Field Observation & research Station on Ecosystem of desertified Rangeland,Minqin 73.3.0,china 2 Key Laboratory of desertification Combating of Gansu Province,lanzhou 73.070,china 3.Gansu desert Control research institute,lanzhou 73.070,china Gansu Minqin National Field Observation and research Station on Ecosystem of desertified Rangeland Minqin 733300 China Key Laboratory of desertification Combating of Gansu Province Lanzhou 733070 China Gansu desert Control research institute Lanzhou 733070 China

This paper analyzed the data of temperature and precipitation in Minqin,typical desert area in north-west china,during the period of 1961 2007 by linear *** result indicated that the increasing rate of the mean annual temperature in Minqin was higher than that of the average of china;and the temperature in February increased by 3.01oC averagely in the past 47 *** climate in Minqin displayed an evident warming ***,there was no evidently increasing trend of precipitation in the past 47 years,and drought occurred during the whole growing season.

关键词： temperature precipitation global climate Minqin

Carbon and hydrogen isotopic characteristics of natural gases from the Luliang and Baoshan basins in Yunnan Province, china

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Science china Earth Sciences 2006年第9期49卷 938-946页

作者： XU Yongchang1, LIU Wenhui2, SHEN Ping1, WANG Wanchun1, WANG Xiaofeng1, Tenger1, YAN Yaomin3.& LIU Ruobin3.1. lanzhou Center of Oil & Gas Resources, institute of Geology and Geophsics, Chinese Academy of Sciences, lanzhou 73.000,{3. 2. research institute of Petroleum Exploration and Production, SINOPEC, Beijing 100083.{3. 3. South Branch of Petroleum Exploration and Production Company, SINOPEC, Kuming 650000,{3. 1. lanzhou Center of Oil & Gas Resources Institute of Geology and Geophsics Chinese Academy of Sciences Lanzhou 730000 China 2. research institute of Petroleum Exploration and Production SINOPEC Beijing 100083 China 3. South Branch of Petroleum Exploration and Production Company SINOPEC Kuming 650000 China

The Luliang and Baoshan basins of Yunnan Province are two small-sizedcontinental oil/gas-bearing sedimentary basins, which were developed at the bases of theCarboniferous and Devonian systems during the Late Tertiary, covering an area of 3.5 km^2 and 254km^2, respectively. Since the 1990s, there have been discovered small-sized natural gas pools inthese two basins. The natural gases are composed mainly of hydrocarbon gases, with nonhydrocarbonsaccounting for less than 2%. Of the hydrocarbon gases, methane accounts for more than 99%, and thecomponents above C_2 account for less than 0.2%. On the basis of previous studies of geologicalbackground, the composition of natural gases and their carbon isotopic composition, it has beendefined that these two gas pools are of bacterial origin. In this work we have comprehensivelymeasured the carbon and hydrogen isotopic composition of natural gases from these two basins andhave gone into the details of the mechanism of gas generation. The δ^(13.C_1 values of naturalgases from the Luliang Basin are within the range of -72.1 per thousand - -73.3.per thousand, andthe δD_(CH_4) values, -242 per thousand - -23. per thousand, indicating that the bacterial gasgeneration is dominated by the way of CO_2 reduction. It has been evidenced that undercontinental-facies fresh water conditions there did occur the CO_2 reduction as a process ofbacterial gas generation. The δ^(13.C_1 values of natural gases from the Baoshan Basin are withinthe range of - 62.5 per thousand - -63.5 per thousand, and the δD_(CH_4) values, -252 per thousand- -260 per thousand. These isotopic characteristics are fallen into transitional phase of acetatefermentation and CO_2 reduction as defined by Whiticar et al. (1986). An important discovery in theLuliang Basin is the carbon isotopic composition of ethane of purely biogenetic origin, i.e., itsδ^(13.C_2 values are within the range of - 61.2 per thousand - - 66.0 per thousand. These carbonisotopic values have been r

关键词： bacterial gas, carbon and hydrogen isotope, CO2 reduction, acetate fermentation.