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CH_4 uptake flux of Leymus chinensis steppe during rapid growth season in Inner Mongolia,china

Science china Earth sciences 2010年第7期53卷 977-983页

作者： geng yuanbo1, luo guangqiang1,{2. yuan guofu1 1 institute of geographic sciences and Natural resources research, chinese academy of sciences, beijing 100101,{12. 2.Graduate University of chinese academy of sciences, beijing 100049,{12. institute of geographic {2. and Natural resources research Chinese Academy of Sciences Beijing China Graduate University of chinese academy of sciences Beijing China

The influence of near ground atmosphere CH4 concentration, soil water content, soil Eh, plants, soil temperature, and pH on CH4 uptake flux of Leymus chinensis steppe during rapid growth season was studied using field in-situ measurement in Xilin River basin of Inner Mongolia, china. The results showed that CH4 uptake flux was positively correlated with near ground atmosphere CH4 concentration and soil Eh but negatively correlated with soil water content. Precipitation may decrease the CH4 flux by increasing the soil water content. The average fluxes of three treatments during the observation period were 1.52.(natural conditions, 1.51 (aboveground plants were excluded), and 2.00 mg m?2.d?1 (all plants were removed), respectively. The difference between the CH4 flux of natural condition treatment and that of removing aboveground plants treatment is small, whereas the flux of removing all plants treatment is larger than the other two treatments. This means that the contribution of aboveground plants to CH4 uptake flux is smaller than that of roots or roots-removing process. CH4 uptake flux is not sensitive to soil temperature and the narrow-ranged soil pH (6.36–7.86). The Leymus chinensis steppe acts as a sink for CH4, and thus more studies should be focused on its affecting factors and related mechanisms.

关键词： CH4 uptake flux Leymus chinensis steppe affecting factors static opaque chamber/gas chromatography method

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Study on the processing method of nighttime CO_2.eddy covariance flux data in chinaFLUX

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Science china Earth sciences 2006年第S2期49卷 36-46页

作者： ZHU Zhilin, SUN Xiaomin, WEN Xuefa, ZHOU Yanlian, TIAN Jing & yuan guofu Key Laboratory of Ecosystem Network Observation and Model, {2. of geographic sciences and Natural resources research, chinese academy of sciences, beijing 100101, china Graduate University of the chinese academy of sciences, beijing 100049, china Key Laboratory of Ecosystem Network Observation and Model Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing China Graduate University of the chinese academy of sciences Beijing China

At present, using Eddy Covariance (EC) method to estimate the "true value" of carbon sequestration in terrestrial ecosystem arrests more attention. However, one issue is how to solve the uncertainty of observations (especially the nighttime CO2.flux data) appearing in post-processing CO2.flux data. The ratio of effective and reliable nighttime EC CO2.flux data to all nighttime data is relatively low (commonly, less than 50%) for all the long-term and continuous observation stations in the world. Thus, the processing method of nighttime CO2.flux data and its effect analysis on estimating CO2.flux annual sums are very important. In this paper, the authors analyze and discuss the reasons for underestimating nighttime CO2.flux using EC method, and introduce the general theory and method for processing nighttime CO2.flux data. By analyzing the relationship between nighttime CO2.flux and air fraction velocity u., we present an alternate method, Average Values Test (AVT), to determine the thresholds of fraction velocity (u.c) for screening the effective nighttime CO2.flux data. Meanwhile, taking the data observed in Yucheng and Changbai Mountains stations for an example, we analyze and discuss the effects of different methods or parameters on nighttime CO2.flux estimations. Finally, based on the data of part chinaFLUX stations and related literatures, empirical models of nighttime respiration at different sites in chinaFLUX are summarized.

关键词： eddy covariance nighttime CO2 flux data correction chinaFLUX.

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Variation properties of ionospheric eclipse factor and ionospheric influence factor

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Progress in Natural Science:Materials International 2005年第6期15卷 573-576页

作者： ZHAO Chunmei 1,2.*, yuan Yunbin1, OU Jikun1 and CHEN Jinping3(1. institute of Geodesy and Geophysics,{2., Wuhan 430077, china 2. Graduate School of{2., beijing 100039, china 3. Department of Precision Instrument and Mechanology, Tsinghua University, beijing 100084, china) institute of Geodesy and Geophysics Chinese Academy of Sciences Wuhan 430077 China Graduate School Chinese Academy of Sciences Beijing 100039 China Department of Precision Instrument and Mechanology Tsinghua University Beijing 100084 China

The concepts and calculation methods of ionospheric eclipse factor (IEF) and ionospheric influence factor (IFF) are further illustrated. The temporal and spacial variation properties of IEF and IFF are studied, which shows that the properties are influenced by the geographic position and season. The possibility of improving the precision of using GPS data to determine ionospheric delay based on the above variation properties is also analysed.

关键词： GPS Ionospheric eclipse factor Ionospheric influence factor

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Confirmation of a natural hybrid species in Petrocosmea(Gesneriaceae) based on molecular and morphological evidence

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Journal of Systematics and Evolution 2011年第5期49卷 449-463页

作者： 1,3~Zhi-Jing QIU 2.Zu-Li yuan 1~Zhen-Yu LI 1~Yin-Zheng WANG 1(State Key Laboratory of Systematic and Evolutionary Botany,institute of Botany,{2. academy of sciences,beijing 100093,china) 2.Henan Agricultural University,Zhengzhou 45002.china) 3(Graduate School of the chinese academy of sciences,beijing 100049,china) (State Key Laboratory of Systematic and Evolutionary Botany Institute of Botany Chinese Academy of Sciences Beijing 100093 China) (Graduate School of the chinese academy of sciences Beijing 100049 China) (Henan Agricultural University Zhengzhou 45002 China)

A natural hybrid species in Petrocosmea named Longianthera in Yanshan County,Yunnan Province is confirmed for the first time based on molecular and morphological *** character count procedure of the variable characters show that Longianthera populations are characteristic of the intermediate morphological traits between its putative parents Yanshan and Petrocosmea *** nuclear ribosomal internal transcribed spacer region and three chloroplast regions of matK,trnL-F,and trnT-L are sequenced in the putative hybrid and the related *** alignment of DNA sequences and the phylogenetic trees could exclude all the other species in Petrocosmea as the parental species except for Yanshan and *** haplotypes in the 31 internal transcribed spacer sequences and six haplotypes in 42.cpDNA sequences were found from 14 individuals of Longianthera *** analyses of DNA sequences,haplotypes,and phylogenetic trees indicate that Longianthera is likely a hybrid species between its putative parents Yanshan and ***,in which Yanshan might be the most possible maternal *** factors may contribute to the natural hybridization between these two parental species in Petrocosmea,such as the overlapped geographic distribution,habitats,flowering periods,and shared ***,the new species of Yanshan and the natural hybrid species of Longianthera are described.

关键词： chloroplast DNA Gesneriaceae ITS morphology natural hybridization Petrocosmea.

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Surface roughness length dynamic over several different surfaces and its effects on modeling fluxes

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Science china Earth sciences 2006年第S2期49卷 262-272页

作者： ZHOU Yanlian, SUN Xiaomin, ZHU Zhilin, ZHANG Renhua, TIAN Jing, LIU Yunfen, GUAN Dexin & yuan guofu Key Laboratory of Ecosystem Network Observation and Modeling, {2. of geographic sciences and Natural resources research, chinese academy of sciences, beijing 100101, china Graduate University of the chinese academy of sciences, beijing 100049, china {2. of Applied Ecology, chinese academy of sciences, Shenyang 110016, china Key Laboratory of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing China Graduate University of the chinese academy of sciences Beijing China institute of Applied Ecology Chinese Academy of Sciences Shenyang China

Roughness length and zero-plane displacement over three typical surfaces were calculated iteratively by least-square method, which are Yucheng Experimental Station for agriculture surfaces, Qianyanzhou Experimental Station for complex and undulant surfaces, and Changbai Mountains Experimental Station for forest surfaces. On the basis of roughness length dynamic, the effects of roughness length dynamic on fluxes were analyzed with SEBS model. The results indicate that, aerodynamic roughness length changes with vegetation conditions (such as vegetation height, LAI), wind speed, friction velocity and some other factors. In Yucheng and Changbai Mountains Experimental Station, aerodynamic roughness length over the fetch of flux tower changes with vegetation height and LAI obviously, that is, with the increase of LAI, roughness length increases to the peak value firstly, and then decreases. In Qianyanzhou Experimental Station, LAI changes slightly, so the relationship between roughness length and LAI is not obvious. The aerodynamic roughness length of Yucheng and Changbai Mountains Experimental Station changes slightly with wind direction, while aerodynamic roughness length of Qianyanzhou Experimental Station changes obviously with wind direction. The reason for that is the terrain in Yucheng and Changbai Mountains Experimental Station is relatively flat, while in Qianyanzhou Experimental Station the terrain is very undulant and heterogeneous. With the increase of wind speed, aerodynamic roughness length of Yucheng Experimental Station changes slightly, while it decreases obviously in Qianyanzhou Experimental Station and Changbai Mountains Experimental Station. Roughness length dynamic takes great effects on fluxes calculation, and the effects are analyzed by SEBS model. By comparing 1 day averaged roughness length in Yucheng Experimental Station and 5 day averaged roughness length of Qianyanzhou and Changbai Mountains Experimental Station with roughness length parameter

关键词： chinaFLUX surface roughness length dynamic spatial heterogeneity Yucheng Experimental Station Qianyanzhou Experimental Station Changbai Mountains Experimental Station.

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Spatial-Temporal Changes of Soil Organic Carbon During Vegetation Recovery at Ziwuling, china

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Pedosphere 2005年第5期15卷 601-610页

作者： LI Yu-yuan SHAO Ming-An ZHENG Ji-Yong ZHANG Xing-Chang Key Laboratory of Water Cycle and Related Land Surface Processes Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 （China） State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau Institute of Soil and Water Conservation Chinese Academy of Sciences and Ministry of Water Resources Yangling 712100 （China）

To probe the processes and mechanisms of soil organic carbon (SOC) changes during forest recovery, a 150-yearchronosequence study on SOC was conducted for various vegetation succession stages at the Ziwuling area, in the centralpart of the Loess Plateau, china. Results showed that during the 150 years of local vegetation rehabilitation SOC increasedsignificantly (P 2.before the shrubland stage and became a source in the later period. This change resulted from the spatially variedcomposition and structure of the vegetation. Vegetation recovery had a maximum effect on the surface (0-2. cm) SOCpool. It. was concluded that vegetation recovery on the Loess Plateau could result in significantly increased sequestrationof atmospheric CO2.in soil and vegetation, which was ecologically important for mitigating the increase of atmosphericconcentration of CO2.and for ameliorating the local eco-environment.

关键词： soil organic carbon density spatial-temporal change vegetation recovery vegetation succession

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Spatial distribution of wind erosion and its driving factors in china

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Journal of geographical sciences 2001年第2期11卷 127-139页

作者： ZHANG Guo-ping~1, ZHANG Zeng-xiang~1, LIU Ji-yuan~2.(1. institute of Remote Sensing Application, CAS,{2., china 2. institute of geographic sciences and Natural resources research, CAS,{2., china) institute of Remote Sensing Application CAS Beijing China institute of geographic {2. and Natural resources research CAS Beijing China

Based on remote sensing and geographic information system, the spatial distribution of nation-wide wind erosion is studied, and the 1∶100 000 national map of soil erosion by wind in china is made. Wind speed, soil dryness,NDVI, soil texture and the slope of land surface are the key factors to wind erosion. The relations between wind erosion and each factor are discussed. The method of principal component is used to pick up the information included in the five factors, and the wind erosion dynamic index (WEDI) is established. Its comparison with theRS/GIS derived data shows thatWEDI can reflect the potential capacity of soil erosion by wind. The dynamic process of the wind erosion is studied to reveal the distribution of the most intense wind erosion regions and the dominant factors in these regions. All these studies may greatly help the mitigation of wind erosion of soil.

关键词： remote sensing geographic information system wind erosion of soil desertification control in china WEDI

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Eco-Environmental Vulnerability Evaluation in the Yellow River Basin,china

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Pedosphere 2008年第2期18卷 171-182页

作者： WANG Si-yuan LIU Jing-Shi YANG Cun-Jian institute of Tibetan Plateau research Chinese Academy of Sciences Beijing 100085 （China） institute of Electronics Chinese Academy of Sciences Beijing 100080 （China） Centre of RS and GIS Applications Sichuan Normal University Chengdu 610066 （China）

Using remote sensing(RS)data and geographical information system(GIS),eco-environmental vulnerability and its changes were analyzed for the Yellow River Basin,*** objective of this study was to improve our understanding of eco-environmental changes so that a strategy of sustainable land use could be *** environmental numerical model was developed using spatial principal component analysis(SPCA)*** model contains twelve factors that include variables of land use,soil erosion,topography,climate,and *** this model,synthetic eco- environmental vulnerability index(SEVI)was computed for 1990 and 2.00 for the Yellow River *** SEVI was classified into six levels,potential,slight,light,medium,heavy,and very heavy,following the natural breaks classification. The eco-environmental vulnerability distribution and its changes over the ten years from 1990 to 2.00 were analyzed and the driving factors of eco-environmental changes were *** results show that the eco-environmental vulnerability in the study area was at medium level,and the eco-environmental quality had been gradually improved on the ***,the eco-environmental quality had become worse over the ten years in some *** the study area,population growth,vegetation degradation,and governmental policies for eco-environmental protection were found to be the major factors that caused the eco-environmental changes over the ten years.

关键词： eco-environmental vulnerability geographic information system (GIS) remote sensing (RS) spatial principal component analysis Yellow River Basin

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Wetland vegetation biomass estimation and mapping from Landsat ETM data: a case study of Poyang Lake

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Journal of geographical sciences 2002年第1期12卷 35-41页

作者： LI Ren-dong1, 2. LIU Ji-yuan2.(1. institute of Geodesy and Geophysics, CAS, Wuhan 430077,{2. 2. institute of geographic sciences and Natural resources research, CAS, beijing 100101 china) institute of Geodesy and Geophysics CAS Wuhan China institute of geographic {2. and Natural resources research CAS Beijing China

Poyang Lake is the largest freshwater lake in china. This paper conducted a digital and rapid investigation of the lake’s wetland vegetation biomass using Landsat ETM data acquired on April 16, 2.00. First, utilizing the false color composite derived from the ETM data as one of the main references, the authors designed a reasonable sampling route for field measurement of the biomass, and carried it out on April 18–2., 2.00. Then after both the sampling data and the ETM data were geometrically corrected to an equal-area projection of Albers, linear relationships among the sampling data and some transformed data derived from the ETM data and the ETM 4 were calculated. The results show that the sampling data is best relative to the band 4 data with a high correlation coefficient of 0.86, followed by the DVI and NDVI data with 0.83 and 0.80 respectively. Therefore, a linear regression model, which was based on the field data and band 4 data, was used to estimate the total biomass of entire Poyang Lake, and then the map of the biomass distribution was compiled.

关键词： Poyang Lake biomass wetland vegetation Landsat ETM data

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“Greatest lake period” and its palaeo-environment on the Tibetan Plateau

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Journal of geographical sciences 2001年第1期11卷 34-42页

作者： LI Bing-yuan, ZHU Li-ping (institute of {2. sciences and Natural resources research, CAS, beijing 100101, china) institute of geographic {2. and Natural resources research CAS Beijing China

The “greatest lake period” means that the lakes are in the stage of their maximum areas. As the paleo lake shorelines are widely distributed in the lake basins on the Tibetan Plateau, the lake areas during the “greatest lake period” may be inferred by the last highest lake shorelines. They are several, even tens times larger than that at present. According to the analyses of tens of lakes on the Plateau, most dating data fell into the range of 40-2. ka BP, some lasted to 2. ka BP. It was corresponded to the stage 3 of marine isotope and interstitial of last glaciation. The occurrence of maximum areas of lakes marked the very humid period on the Plateau and was also related to the stronger summer monsoon during that period.

关键词： Tibetan Plateau greatest lake period highest lake levels interstitial of last glaciation paleo-monsoon

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