Table of Content

15 March 2013, Volume 30 Issue 2 Previous Issue    Next Issue

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Soil Salinization in the Manas River Basin in Spring JI Li-Li-?A-Bu-Du-Wai-Li, A Yi-Gu-Li-?Mai-Mai-Ti, TANG Yang 2013, 30 (2):  189-195.  Abstract ( 1635 )   PDF (3025KB) ( 969 )   In this paper,the conventional statistics and redundancy analysis were used to investigate the spatial distribution of total salt content (TS),pH value,electrical conductivity (EC),sodium adsorption ratio (SAR) and ion composition of salty soil in the Manas River Basin,Xinjiang, China.Results are as follows:(1) The soil salt content varied in a range from 5.80 g•kg-1 to 9.02 g•kg-1, soil salt accumulation occurred in subsoil, slight or moderate salinization occurred in soil layer, that is the slight soil salinization occurred in topsoil (0-10 cm) and moderate one in subsoil (20-70 cm); (2) pH value, EC and SAR in whole soil profile varied in ranges of 8.2-8.4, 0.70-1.38 mS•cm-1 and 0.25-0.64 respectively, so alkalization did not occur; (3) Ca2+and SO42-、Na+ and SO 2-4 were good relationships in whole soil layer; (4) SO42-、 Na+, Ca 2+ and Mg 2+ were the main factors affecting the spatial distribution of total soil salt content throughout soil profile.Although there was a slight variation of their contents, SO42-and Na+ were still the main factors; (5) The spatial distribution of EC in the whole soil profile was restricted by SO42-and Na+ except in soil layers where Na+  and Cl- were the dominant factors; (6) Except the pH value in soil layer of 0-10 cm in depth was affected by HCO-3, the pH value in the whole profile was mainly affected by CO32-；; (7) The effect of environmental factors on SAR was slight, except SAR in soil layer of 50-70 cm in depth was affected by Cl-, there were no the dominant factors for soil layer of 0-50 cm. References | Related Articles | Metrics

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Soil Salinity in the Riparian Zone in Lower Reaches of the Main Feeding Rivers of the Ebinur Lake WANG Yong-Hui, MA Bei, HAI Mi-Ti-Yi-Mi-Ti 2013, 30 (2):  196-202.  Abstract ( 1863 )   PDF (2109KB) ( 833 )   Soil samples were collected and analyzed from the riparian zone in the lower reaches of the Bortala and Jinghe rivers, the main feeding rivers of the Ebinur Lake. The pH values and the contents of total salt and 8 ions in soil under the different conditions of vegetation coverage were measured. The correlation analysis and statistical analysis were used in the study. The results showed that, under the different conditions of vegetation coverage, the total salt and ion contents in topsoil and soil at 20 cm depth were higher than those at other soil layers in riparian zone in the lower reaches of the two rivers, and salt accumulation in topsoil was significant. The results showed that there was a significant correlation between total salt and K+、Na+、Cl－、HCO-3 contents in different soil layers in the riparian zone in lower reaches of the Bortala River, and also between total salt content and K+、Na+、Cl－、Mg 2+ in soil in the riparian zone in lower reaches of the Jinghe River. Soil salinization in the riparian zone in lower reaches of the two rivers was mainly caused by accumulation of chlorides. References | Related Articles | Metrics

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The Effect of Water Consumption on Surface Runoff in Oasis in the Aksu River Basin WANG Sheng-Xia, YE Bai-Sheng, DING Yong-Jian, ZHAO Chuan-Cheng, QIN Jia 2013, 30 (2):  203-210.  Abstract ( 1810 )   PDF (1499KB) ( 873 )   Based on the remote sensing data derived with the advanced very high resolution radiometers, the normalized difference vegetation index (NDVI) in an arid oasis is of sensitive response to surface runoff.According to the experience, a region with NDVI value > 0.2 is recognized as an oasis, so the oasis in the Aksu River Basin is also recognized based on its total accumulative NDVI.In this paper, the total accumulative NDVI was substituted for the index of human activities dominated by farming.Based on the data of surface runoff volume, the relationship between human activities and surface runoff in oasis in the Aksu River Basin during the period from 1982 to 2006 was analyzed.Results revealed that, during the period from 1982 to 2006, the mountainous runoff volume in the Aksu River Basin was increased by 21.4% compared with that at the beginning of the study, water consumption in the oasis was increased by 53.2%, total accumulative NDVI of the oasis was increased by 35.3%, and the oasis area was enlarged by 33.4%.There were the positive correlations among the runoff volume at Aral, water consumption and stream inflow in the oasis, which revealed that the increased water consumption was mainly caused by the oasis expansion in middle reaches of the Aksu River Basin.The change of total accumulative NDVI of the oasis was gradually accelerated from the central area to the marginal zone of the oasis.In the same period, the trend of total accumulative NDVI was gradually intensified from the marginal zone to the central area of the oasis.According to the correlations among the total accumulative NDVI of the oasis, stream inflow and water consumption in the oasis, precipitation in the oasis could not be ignored, which means that precipitation in the oasis was of support and maintenance function for stability of the oasis, and the contribution of precipitation in the oasis was 25.2%.Among the variation coefficients of glacier runoff and mountainous runoff volumes as well as precipitation in the basin, the contribution of glacier runoff in the oasis was 33.4%, which showed that glacier runoff was of the functions of adjusting runoff and maintaining a stable oasis scale.Moreover, under climate change in the future, the relationship between surface runoff and oasis scale in the Aksu River Basin was further analyzed.The results show that temperature is the main factor affecting surface runoff regardless at present or in the future.It is estimated that the lacier runoff volume will be decreased under climate change in the future, and oasis scale will be expanded except the scenarios that temperature will be stable and precipitation will be increased by 10%, 20% and 30%.It is also estimated that the water consumption in the oasis will be increased significantly, and it will be much higher than the mountainous runoff volume, which will cause an obvious reduction of runoff volume at Aral, so it will be very necessary to control water consumption in the Aksu River Basin so as to achieve a sustainable development in the whole Tarim River Basin. References | Related Articles | Metrics

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Dynamic Change of Wetland Landscapes in the Ertix River Basin, Xinjiang during the Period of 1990-2010 YANG Han, CHEN Xue-Gang, WANG Ya-Qi 2013, 30 (2):  211-218.  Abstract ( 1610 )   PDF (2474KB) ( 1113 )   In this paper, the changes of landscape patterns at both landscape scale and patch scale in the Ertix River Basin, Xinjiang, China were studied based on the satellite images in 1990, 2000 and 2010. The landscape analysis was accomplished using GIS and FRAGSTATS software, and the analyzed items included the various landscape indices relating to the temporal and spatial change of wetland landscape patterns during the period from 1990 to 2010. The results showed that the number of wetland patches was increased, shape of the wetland patches became more irregular, and the wetland landscapes were more fragmental. The total area of wetland patches was enlarged because of the increase of precipitation in the basin since the 1980s, and the increase of landscape fragmentation was mainly caused by the increase of human activities. To sum up, the serious fragmentation of wetland landscapes in the basin was affected by both natural and human factors, and the human adverse impact on the wetland landscapes became more and more serious. References | Related Articles | Metrics

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Temperature and Volumetric Moisture Content on  Vegetation Degeneration over the Achnatherum splendens Steppe around the Qinghai Lake, China ZHANG Fa-Wei, GUO Zhu-Jun, LI Yi-Kang, LIN Li, ZHOU Guo-Ying, CAO Guang-Min 2013, 30 (2):  219-225.  Abstract ( 1609 )   PDF (4380KB) ( 1321 )   Achnatherum splendens steppe is one of the dominated vegetation types around the Qinghai Lake in Qinghai Province, China, but it has been degenerated seriously. However, its driving effect on soil temperature and moisture content is still unclear. The continuouslymeasured data were used to analyze the soil temperature and volumetric moisture content in soil layers at 0, 5, 10, 20, 40 cm and 80 cm and 5, 10, 20, 40 cm and 80 cm in depth over the native vegetation area and the typical degenerated area of the steppe in whole 2011. The results showed that the vegetation degeneration resulted directly in a significant increase of topsoil maximum temperature at 0 and 5 cm in depth (39.04% and 13.91% respectively), the daily minimum temperature was significantly decreased, the daily range of soil temperature was increased, but there was no significant response of daily temperature of soil deeper than 10 cm to vegetation degeneration. Daily topsoil temperature was decreased obviously in plant growing season from May to September, but that at soil layers of 5 cm and 10 cm in depth was slightly increased in nongrowing season. There was a vertical diffusion of annual soil temperature under the A. splendens canopy and litters as well as in rhizosphere. Vegetation degeneration resulted indirectly in an increase of soil volumetric moisture content (35.20%) at 5 cm but a significantly decrease at 20 cm. Moreover, the temporal stability of soil moisture content was reduced. The cluster analysis revealed that the comprehensive response of soil temperature and moisture content to the degeneration of A. splendens steppe occurred mainly during the period from July to August. References | Related Articles | Metrics

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Spatial Distributions of Organic Carbon and Dissolved Ions in the Bosten Lake, Xinjiang FANG Chuan-Ling, WANG Xiu-Jun, WANG Jia-Ping 2013, 30 (2):  226-230.  Abstract ( 1516 )   PDF (845KB) ( 1008 )   In order to study the spatial distribution of organic carbon, some water and topsoil samples were collected in and around the Bosten Lake in Xinjiang, China in November 2011. Particulate organic carbon (POC), dissolved organic carbon (DOC) and dissolved ions in water samples, and organic and inorganic carbon contents in soil samples were measured. The results showed that there was a wide range of POC (0.1-1.2 mg•L-1) but a narrow one of DOC (8.5-12.3 mg•L-1) in the Bosten Lake. Concentrations of POC and DOC near the inlet and outlet of the lake were similar to those in the Kaidu River, but much lower than the average values of the lake. Our analysis suggested that there might be a transformation of CO3 2-to HCO3- in the Bosten Lake in recent 30 years. There was no significant correlation between soil carbon content and POC or DOC, which suggested that the effect of soil on carbon content in Bosten Lake water was not significant. References | Related Articles | Metrics

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Optical Stimulated Luminescence Dating of Loess Profiles in the Changchengyuan Loess Tableland MI Xiao-Jian, HUANG Chun-Chang, ZHOU Ya-Li 2013, 30 (2):  231-235.  Abstract ( 1780 )   PDF (1439KB) ( 1037 )   Based on filed survey, the very typical Holocene loess strata were found on the Changchengyuan Loess Tableland in Pengyang, Ningxia Hui Autonomous Region. Seven samples were collected from a Holocene loesspaleosol profile in the study area. The dating of these samples was tested using the optical stimulated luminescence dating. The results show that Malan loess formed around 12.58 ka BP. when it was drought; the transitional loess formed around 11.498 ka BP. when it was relatively warm; the paleosol formed during the periods of 6.731 ka BP. and 2.827 ka BP. when it was very warm; the Holocene loess formed around 1.394 ka BP. when it was drought again. The results are similar to the dating data of MJY profile and ETC profile, so they are reliable. References | Related Articles | Metrics

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Leaf Stoichiometric Properties of Garden Tree Species in Fuxin City WANG Kai, WU Xiang-Yun, LU Hui, XU Dong-Yang, LI Na 2013, 30 (2):  236-241.  Abstract ( 2394 )   PDF (885KB) ( 1160 )   The values of stoichiometric properties of leaf C, N and P contents of 55 garden tree species in Fuxin city Liaoning Province, China were derived. The results showed that the C, N and P contents varied in ranges of 496-664, 7.5-26.6 mg•g-1 and 1.0-2.2 mg•g-1, and the C/N, C/P and N/P in ranges of 22.4-74.3, 262-522 and 5.4-13.8, respectively. Moreover, there was a significant correlation between leaf N and C/N or C/P （P<0.001). The leaf N and P contents and N/P of evergreen coniferous tree species were significantly higher than those of broadleaf deciduous tree species （P<0.05), but C/N and C/P of evergreen coniferous tree species were significantly lower than those of broadleaf deciduous tree species （P<0.05). The leaf N content and N/P of tree species were significantly higher than those of shrub species （P<0.05), but the differences in P content, C/P and C/P were not significant （P>0.05). These results revealed that the C storage capability and nutrient use efficiency of garden tree species were high.The garden tree species were Nlimited in the study area. References | Related Articles | Metrics

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On the Intraspecific Competition of Picea crassifolia Populationin the Qilian Mountains ZHANG Xue-Long, MA Yu, ZHAO Wei-Jun, LIU Xian-De, JIN Ming, JING Wen-Mao 2013, 30 (2):  242-247.  Abstract ( 1569 )   PDF (1419KB) ( 1182 )   In this study,a 1 hm2 sample plot of Picea crassifolia forest was delimited to analyze the intraspecific competition of Picea crassifolia population in the subalpine zone of the Qilian Mountains using the method of gradually expanding the scope and Duan Renyan’s improved individual tree competition index model.The results were as follows:(1) In the Picea crassifolia population,the competition intensity decreased gradually with the increase of circularity radius,and the circularity radius affecting the competition of Picea crassifolia trees was 6 m; (2) The competition intensity of Picea crassifolia decreased with the increase of diameter at breast height (DBH),especially it decreased sharply in the DBH ranges of 5-10 cm and 25-30 cm,and the inflection point occurred at DBH range of 25-30 cm.With the increase of DBH,the competitive pressure of Picea crassifolia changed gently,and the competition occurred mainly in DBH range less than 25-30 cm; (3) The intraspecific competition and diameter of Picea crassifolia trees followed a power function ofCI = AD-B,and the level was significant.The experimental data showed that the model could be used to predict the intraspecific competition of [WTBX]Picea crassifolia[WTBZ] population well.The analyzed results could provide a theoretical basis and reference for tending and managing Picea crassifolia forests in the Qilian Mountains. References | Related Articles | Metrics

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Water Retention Capacity of Picea schrenkiana var. tianschanica Fallen Trees in the Tianshan Mountains, Northwest China MA Xian-Yong- , LIU Hua- , ZANG Run-Guo, BAI Zhi-Qiang, LIU Gui-Feng, GUO Zhong-Jun, HAN Yan-Liang 2013, 30 (2):  248-255.  Abstract ( 1782 )   PDF (2057KB) ( 923 )   Fallen tree has an important role in forest ecosystem, especially in hydrology of mountainous forest ecosystem with water and soil conservation functions. The samples of fallen trees of Picea schrenkiana var. tianschanica (Rupr.) Chen et Fu were collected from 5 areas (Zhaosu, Xinyuan, Hutubi, Tianchi and Qitai) across nine longitudes in the forest region in the Tianshan Mountains so as to understand the water retention capacity and its hydrological function in forest in the Tianshan Mountains. These samples were treated with soaking simulation. The results showed that, in the soaking process, the water retention capacity, specific retention and water retention capability of the P. schrenkiana fallen trees at 5 sampling sites were all increased with the increase of soaking time. The relationship between water retention capacity (Q) and soaking time ([WTBX]t[WTBZ]) could be fitted by =aln t+b. But the water absorbing rate was decreased with the increase of soaking time from the decomposition level I to V. The relationship between water absorbing rate (V) and soaking time (t)could be fitted by V=c t-d. The relationship between water retention capacity(Q′)and decomposition level (x could be fitted by Q′=ex2+fx+g. So there was a significant difference of water retention capacity among P. schrenkiana fallen trees at 5 sampling sites. The study results offered the foundational data for further study on hydrological functions in forest in the Tianshan Mountains. References | Related Articles | Metrics

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Spatial Distribution Pattern and Relevancy of Artemisia  arenaria Population along the River Course of Middle  Reaches of the Shiyang River ZHANG Ying-Hua- , LIU Shi-Zeng- , LIU Hu-Jun- , MAN Duo-Qing- , LI Yin-Ke- , HAN Fu-Gui 2013, 30 (2):  256-263.  Abstract ( 1641 )   PDF (3508KB) ( 1049 )   Artemisia arenaria is an important plant species of fixing sand in the Shiyang River Basin, Gansu Province. In this study, some sample plots with different distance away from the river course of the Shiyang River were delimited to analyze the spatial distribution pattern of Artemisia arenaria population. In the plots, the height, crown breadth and spatial relevancy of all the differentaged Artemisia arenariaplants were recorded. The point pattern analysis was used to analyze the spatial distribution pattern and relevancy of the plants in different plots. The results were as follows:(1) Artemisia arenaria population was in a decrease trend with the increase of distance away from the river course; (2)Artemisia arenaria population was in a significant aggregation distribution pattern at relatively small scale, the aggregation distribution pattern decreased gradually with the enlargement of scale, a random distribution occurred, and the aggregation degree near the river course was higher than that far away from the river course. At different distance, young plants grew in an aggregation pattern, but the adult ones in random pattern; (3) There was a positive spatial relevancy among the high plants near the river course, but a negative one among the short plants far away from the river course. References | Related Articles | Metrics

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Change and Mechanism of Vegetation in the Fenced Sandy Grassland in Horqin Sandy Land MIAO Ren-Hui, JIANG De-Ming, WANG Yong-Cui 2013, 30 (2):  264-270.  Abstract ( 1487 )   PDF (1526KB) ( 1054 )   In this paper,the change and mechanism of vegetation in sandy grassland in Horqin Sandy Land during the natural regeneration process was studied.The study was carried out at Ulan'aodu in Horqin Sandy Land.The results are as follows:(1) Vegetation density and species richness in the fenced grassland were obviously improved,and the dominant species of plant community were changed obviously.The indexes of Simpson and ShannonWiener species diversity were decreased with the increase of fenced time,whereas the Pielou evenness was increased at firstly,and then decreased with the increase of fenced period; (2) Nutrient content in topsoil (0-10 cm) in the fenced grassland was increased,but the electric conductivity was decreased at firstly,and then increased with the vegetation regeneration process.Soil moisture content was decreased with fenced time; (3) Effects of topsoil factors on the plant species diversity were different.There was a significant negative correlation (P<0.05) between total N and the pH value and Pielou diversity index,but a positive one between total N and richness index.The correlations between soil factors and diversity indices were not so significant.Therefore,fencing in sandy grassland was disadvantageous for maintaining the species diversity but advantageous for accumulating soil nutrient. References | Related Articles | Metrics

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Effects of Shrubs of Ephedra distachya and Artemisia arenaria on Algal Distribution WANG Jing-Zhu, ZHANG Bing-Chang, ZHANG Yuan-Ming, XUE Ying 2013, 30 (2):  271-276.  Abstract ( 1819 )   PDF (1290KB) ( 1145 )   The effects of shrubs of Ephedra distachya and Artemisia arenaria on the distribution, species composition, species diversity and community structure of algae were investigated within and out of the shrubs of Ephedra distachya  and Artemisia arenaria . The results showed that there was no obvious difference in species composition of algae within and out of the shrubs of E. distachya and A. arenaria. The difference was mainly represented by the change of dominant species of algae. There was a difference of species diversity for the two semishrub plants. Species diversity in the shrubs of E. distachya was lower significantly than that out of the semishrubs. However, number of algal taxa in the semishrubs of A. arenaria was higher significantly than that out of the shrubs, and there was no difference in ShannonWeaver index. In community structure, number of taxa and dominance degree of cyanobacteria and filamentous algae in the semishrubs of E. distachya were significant lower than those out of the shrubs (P<0.05). An opposite change trend was observed for unicellular and coccoid algae. However, for A. arenaria, numbers of taxa of cyanobacteria, green algae, diatom, filamentous algae, unicellular and coccoid algae in the semishrubs were higher significantly than those out of the shrubs. The dominance degree of cyanobacteria and filamentous algae increased significantly from the internal area to the external area of the shrubs (P<0.01). An opposite trend was observed for green algae, unicellular and coccoid algae. The change of dominance degree of different communities within and out of the two semishrubs was mainly caused by some key taxa. Different distribution of algae in the semishrubs of E. distachya  andA. arenaria  was possibly caused by different regulative mechanisms. References | Related Articles | Metrics

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A Taxonomic Study of Orthotrichum Hedw.in Xinjiang DI Li-Nu-尔?Ai-Ni-Wan, MAI Mai-Ti-Ming-?Su-Lai-Man, A Bu-Du-La-?Ba-尔 , RE Zi-Wan-Gu-?Ai-Ze-Zi 2013, 30 (2):  277-283.  Abstract ( 2121 )   PDF (3200KB) ( 936 )   In views of the advance of research on the genus [WTBX]Orthotrichum[WTBZ] and according to the specimens of 350 packets collected from different parts of Xinjiang,17 species are reported in this paper.Among them 1 species (O.alpestre Hornsch.ex B.S.G.) is reported for the first time in China,and 4 species (O. hookeri Wils.ex Mitt.,O.ibukiense Toy.,O.pumilum Sw.and  O.revolutum C.Muell.) are reported for the first time in Xinjiang.All species are in 5 subgenera,6 species (O.affine Schrad.ex Brid.,O.dasymitrium Lewinsky in T.Kop.,O. hookeri Wils.ex Mitt.,O.sordidum Sull.et Lesq.,O.speciosum Nees.and O.striatum Hedw.) in subg.Gymnoporus,1 species (O.obtusifolium Brid.) in subg.Orthophyllum,5 species (O.alpestre Hornsch.ex B.S.G.,O.crenulatum Mitt.,O.pallens Bruch.ex Brid.,O.pumilum Sw.and O. revolutum C.Muell.) in subg.Pulchella,1 species (O.rupestre Schleicher ex Schwaegr.) in subg.Phaneroporum,and 4 species (O. anomalum Hedw.,O. cupulatum Brid.,O.hallii Sull.et Lesq.and O. ibukiense Toy.) in subg.[WTBX]Orthotrichum.According to these specimens,the keys to the subgenera and species are made respectively.The Chinese names,Latin names and reference literatures as well as the characteristics and geographical distribution of the species are also included.The purpose is to provide the data for the compilation of Flora Bryophytarum in Xinjiang.The studied specimens are deposited in the herbarium of College of Life Science and Tecnology,Xinjiang University (XJU) and the Institue of Botany,Chinese Academy of Sciences. References | Related Articles | Metrics

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Floristic Characteristics of Seed Plant along the Great Wall and Protection of the Great Wall in Central Gansu Province DU Wei-Bo, WANG Wan-Fu, PAN Jian-Bin, WU Fa-Si, ZHANG Guo-Bin, FENG Hu-Yuan 2013, 30 (2):  284-290.  Abstract ( 1556 )   PDF (1130KB) ( 993 )   In this study,a survey on seed plants along the Great Wall built in the Warring States Period and the Qin Dynasty in the Dingxi area of Gansu Province was carried out.In the survey 444 plant species in 242 genera and 58 families were found,in which 3 species in 3 genera and 2 families belonged to Gymnosperm,and 441 species in 239 genera and 56 families belonged to Angiosperm.Among the 58 families,there were 15 monotypic genus families and 5 families with more than 10 genera at least,and they accounted for 45.5% and 52.4% of the total surveyed genera and total species respectively.Compositae with 82 species and 38 genera was the richest family.There were 4 areal types and 4 subtypes at family level,and 13 areal types and 11 subtypes at genus level,in which 2 genera belonging to Compositae and Umbelliferae were endemic in China.There were the rich plant species and complex geographical elements in the study area,the flora were dominated by the Old World Temperate and the North Temperate types.Two rare and endangered species with low protection level were found.These conclusions could contribute to the theoretical and practical proofs for protecting the Great Wall with plants. References | Related Articles | Metrics

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On the Climate Change and Fluctuation of Climate Boundaries in the Headwaters of the Yellow River Basin in Recent 50 Years DU Jia-Qiang, GUO Yang, FANG Xiao-Lei, LIU Cheng-Cheng, WANG Li-Xia, SHEN Yun, ZHANG Lin-Bo 2013, 30 (2):  291-298.  Abstract ( 1592 )   PDF (1470KB) ( 1005 )   In this paper,the temporal changes of climatic factors were analyzed using the daily meteorological data from 13 stations in the headwaters of the Yellow River Basin during the period from 1959 to 2008.The regional climate change was researched using the precipitation and evapotranspiration ratios estimated with the FAO PenmanMonteith model.The results are as follows:(1) Climate became obviously drier and warmer in the southeast part but wetter and warmer in other parts of the study area during the period of 1959-2008.The warming trend was dominant; (2) Average annual and minimum temperature was mainly in an increase trend during the periods of 1959-1988,1969-1998 and 1979-2008.The increase trend of maximum temperature occurred in recent 30 years; (3) Under the effects of increase of minimum and maximum temperature,the increase trend of average annual temperature was the most obvious during the period of 1979-2008; (4) Sunshine duration was in a significant decrease trend at the meteorological stations with lower elevation,and it was in an obvious increase trend at the Maduo and Dari stations with higher elevation; (5) Increasing trend of relative humidity was dominant at the stations with lower elevation,but the relative humidity was in a decrease trend at most stations with higher elevation; ⑥ Wind speed was in a decrease trend,especially at the stations with lower elevation and during the latter two periods.Thirtyyear time interval was feasible for analyzing climate change. References | Related Articles | Metrics

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Prediction of Climate Change Trend Based on Rescaled Range Analysis  and Nonperiodic Cycle Analysis—A Case Study in Lanzhou City LI Guo-Dong, ZHANG Jun-Hua, WANG Nai-Ang, CHENG Hong-Yi, ZHAO Li-Ping 2013, 30 (2):  299-307.  Abstract ( 1842 )   PDF (4550KB) ( 1228 )   Based on two methods of R/S and nonperiodic cycle analysis, the values of Hurst parameter H, fractal dimension D and noncycle average cycle length of temperature and precipitation at time series in Lanzhou City were calculated, and then the variation trends, longterm memory effects and memory cycles of temperature and precipitation at the time series were analyzed. The results show that the values of  H and  D of average seasonal and annual temperature varied in ranges of 0.5-1 and 1-1.5 respectively, there was a fractal structure, and average seasonal and annual temperature was in a continuous increase trend. Average cycle lengths of average annual and spring, summer, autumn and winter temperature at time series were 9 years, 4 years, 8 years, 5 years and 6 years respectively. Precipitation in spring and winter will continuously decrease but increase in summer.  H  and  D of average annual and autumn precipitation series with longterm negative correlation will vary in ranges of 0-0.5 and 1.5-2 respectively, the change process has an antipersistent character, the average annual and autumn precipitation in the future will in an increase trend, average cycle lengths of average annual, spring, summer, autumn and winter precipitation at time series will be 9 years, 7 years, 10 years, 12 years and 13 years respectively. Precipitation in the past will affect that in the future for a long time. The study revealed that the methods of R/S and nonperiodic cycle analysis are new, scientific and reliable in predicting regional climate change. References | Related Articles | Metrics

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Climate Change and Its Effect on Steppe Animal Husbandry in Northwest Tibet ZHANG He-Zhen, LU Hong-Ya, HONG Jian-Chang, MA Peng-Fei 2013, 30 (2):  308-314.  Abstract ( 1852 )   PDF (1869KB) ( 1162 )   Temperature in northwest Tibet was increased significantly, especially in dry season, precipitation was increased in most areas, but the potential evaporation was decreased during the period from 1971 to 2010. Regionally, temperature was increased significantly, precipitation was increased, potential evaporation was decreased in the central and eastern parts of northwest Tibet, and climate trended a warmingwetting pattern. However, temperature was increased, precipitation was decreased, potential evaporation was increased, and climate trended a warmingdrying pattern in the western regions including Shiquanhe. The beginning time of pasture growing and greengrass seasons became earlier, their end time was postponed, the durations were extended significantly, and the cumulative temperature and precipitation were increased significantly in these seasons. The fatten duration of livestock were extended significantly in most places 〔the tendency rate was 2.7 d•(10a) -1〕, and the fatloss duration was in a significant reduction 〔the tendency rate was 6.1 d•(10a)-1〕 in northwest Tibet in recent 35 years. Climate change was in a favorable trend for steppe animal husbandry in the northwest Tibet. It is of significance for controlling steppe degeneration to rationally regulate the livestock structure and limit the number of livestock, especially goats in northwest Tibet. References | Related Articles | Metrics

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On Extreme Precipitation Events in the Nujiang River Basin in Tibet in Recent 40 Years YANG Yong, DU Jun, LUO Su-Xuan, SHI Lei 2013, 30 (2):  315-321.  Abstract ( 1671 )   PDF (1402KB) ( 1053 )   Based on the daily precipitation datasets recorded by 9 meteorological stations in the Nujiang River Basin in Tibet during the period from 1971 to 2010, the thresholds of extreme precipitation at these stations were defined using 99 percentile values, and the spatiotemporal change of extreme precipitation events in the basin was analyzed. The results show that the thresholds of extreme precipitation varied in a range of 20.6-33.8 mm in the Nujiang River Basin, and the spatial distribution of extreme precipitation thresholds was consistent with annual precipitation. In recent 30 years (1981-2010), the maximum daily precipitation was in an increase trend in most areas including Nagqu, Baxoi and Zayu, especially in Zayu where the increase rate was 5.2 mm•(10a)-1. The frequency of extreme precipitation tended to an increase in Dengqen, Baxoi and Zayu, but it decreased at other stations with rates of -0.06--0.41 d•(10a)-1. The annual extreme precipitation increased significantly with a rate of 29.4 mm•(10a)-1 at Zayua, changed slightly at Zogang, and was in a decrease trend with rates of -1.0--27.2 mm•(10a)-1 at other stations. In addition, the extreme precipitation intensity increased with rates of 0.6-6.2 mm•d-1•(10a)-1 at Nagqu, Sog, Zogang and Zayu, it was in a decrease trend at Amdo and Dengqen, but there was no change at Biru, Lhorong and Baxoi. It was also found that there was a significant 4-5year period of frequency of extreme precipitation, maximum daily precipitation, extreme precipitation and extreme precipitation intensity before the 1990s, and a significant 2-4year period after 2000. References | Related Articles | Metrics

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Statistical Downscaling of Air Temperature Change in the Qinling Mountains ZHANG Jie, BAI Hong-Ying, YUAN Bo, MA Xin-Ping 2013, 30 (2):  322-328.  Abstract ( 1729 )   PDF (2915KB) ( 1230 )   A statistical downscaling model（SDSM）was applied to develop the quantitative statistical relationships between the predictands and the predictors based on the mean daily, maximum and minimum temperature data observed by 7 meteorological stations in the Qinling Mountains during the period of 1961-2011. The gradual linear regression method was used in the study, the optimal predictors in NCEP atmospheric circulation were selected, the applicability of air temperature change in the Qinling Mountains in the future was analyzed, and the change trends of air temperature in three periods of 2011-2040, 2041-2070 and 2071-2099 were predicted. The results showed that the air temperature results simulated with SDSM for the situation in the Qinling Mountains were significantly good. The increase of air temperature in the study area in the future would be remarkable, its difference, however, would be quite different from different time scales. The temporal change of three predictands was similar at monthly and seasonal scales. At monthly scale, the temperature increase would be the highest in August but the lowest in December. At seasonal scale, the temperature increase would be in an order of winter < spring < autumn < summer. Spatially, the increase of temperature in 2011-2040 would be higher in the northern slope of the Qinling Mountains than that in the southern slope. References | Related Articles | Metrics

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Drought Trend in Northeast China in the Future under SRES A1B Scenario MA Jian-Yong, PAN Jie, XU Yin-Long, JIANG Jiang 2013, 30 (2):  329-335.  Abstract ( 2396 )   PDF (3309KB) ( 1026 )   The values of relative humidity index were calculated using the data of mean daily temperature and precipitation from regional climate model system PRECIS (Providing Regional Climate for Impacts Studies) under SRES A1B scenario so as to analyze the drought trend in northeast China in crop growing season (from May to September).The results showed that,under A1B scenario,an obvious drought trend would increase in northeast China in crop growing season during the period of 2011-2100,compared with baseline (1971-2000),the central and southern regions in Jilin Province and whole Liaoning Province would become moist,and the other places would be arid.Drought area in northeast China would significantly enlarge in crop growing season in the future,and the 30year averaged values of drought area during the periods of 2011-2040,2041-2070,2071-2100 would be changed by -1.3%,17.4% and 38.4% respectively compared with the baseline.The high drought occurring frequency might occur in the Qiqihar and Daqing regions in Heilongjiang Province,Baicheng in Jilin and Chaoyang in Liaoning,while the low drought occurring frequency in the Dandong region in Liaoning and the eastern region in Jilin.Compared with the baseline,it is estimated that the drought frequency in the future would decrease by 2% in the Liaodong Bay area,but increase by 8%-10% in southwest Heilongjiang and west Jilin and 2%-6% in other regions. References | Related Articles | Metrics

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Summer Drought in Altay Based on Drought K Index PAN Dong-Mei, PAN Xue-Mei 2013, 30 (2):  336-340.  Abstract ( 1439 )   PDF (2794KB) ( 881 )   In this paper,the characteristics of summer drought in recent 30 years were analyzed using the EOF and REOF methods based on the monthly precipitation and evaporation data and the calculated and drought K  index at 7 meteorological stations in Altay,Xinjiang during the period from June to August from 1981 to 2010,and the maximum entropy spectrum and the harmonic analysis were used to analyze the major cycles of the drought K  index in three regions of Altay.The results showed that,according to the drought [WTBX]K[WTBZ] index,the drought occurring frequency in the western and central regions was higher than that in the eastern region of Altay.The study area could be divided into 3 regions,i.e.the southwestern valleyplain region (region Ⅰ),eastern hilly region (region Ⅱ) and northern mountainous region (region Ⅲ).Summer drought intensity in these three regions was holistically in a decrease trend.The spatial distribution of drought was affected by not only the largescale weather system including precipitation change,but also by many other factors,such as geographical location and terrain.There were the relatively stable 10year and 3-5year fluctuations of drought,but their main periodic and annual changes were significant. References | Related Articles | Metrics

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Climatic Characteristics and Distribution of Wire Icing Days in the Eastern Part of Northwest China CHENG Xiao-Xia, FANG Jian-Gang 2013, 30 (2):  341-346.  Abstract ( 2049 )   PDF (1442KB) ( 1022 )   In this paper, the climatic characteristics of the wire icing and the realtime weather conditions for wire icing occurrence are analyzed using the data of wire icing days from the establishment dates of the meteorological stations to 2010 and the data of daily, daily maximum and minimum temperatures, relative humidity and averaged daily wind speed during the period of 1961-2010, and the distribution of wire icing days is discussed. The results are as follows: (1) Wire icing occurred generally during the period from October to next April in the eastern part of northwest China in the forms of fog glaze mainly in the most northern region and Xi’an and glazed frost in the southwestern part; (2) Wire icing occurred often under the specific weather conditions: It occurred in the regions below 1 000 m. when the averaged daily temperature varied in a range of -5-4 ℃, daily minimum temperature in a range of -10-0 ℃, relative humidity was higher than 70%, and wind speed varied in a range of 0-1 m•s-1; in the regions with elevation of 1 000-2 000 m, it occurred when the averaged daily temperature varied in a range of -15-4 ℃, daily minimum temperature in a range of -15-0 ℃, relative humidity was higher than 70%, and wind speed varied in a rrange of 0-4 m•s-1; in the regions above 2 000 m, it occurred when the averaged daily temperature varied in a range of -15-0 ℃, daily minimum temperature in a range of -15--5 ℃, relative humidity was higher than 60%, and wind speed varied in a range of 0-8 m•s-1； (3) Based on the climatic characteristics, the wire icing in the eastern part of northwest China occurred often in the west but rarely in the east, often in the regions with high altitudes but rarely in the regions with low altitudes. The potential occurrence of wire icing was high in the southwest and southeast, then in the northwest, central region and the region around the Huashan Mountain, and it was low in the east. In addition, the continuous wire icing occurred often in the regions with high occurring frequency of ice disasters. References | Related Articles | Metrics

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Dynamic Change of Urban Heat Island Effect in Xi’an Based on TM Images JIA Bao-Quan, QIU Er-fa 2013, 30 (2):  347-355.  Abstract ( 3045 )   PDF (2440KB) ( 2329 )   Urban heat island effect is a very common and serious problem in modern city. It affects not only the quality of urban environment, but also the daily life of citizen. There are generally two methods to study it. One is to compare the meteorological data from the weather stations located in a zone between city and rural area, and another is to analyze the remote sensing images. Xi[JP8]’a[JP]n is a very important city in west China. In recent 30 years, many environment problems were resulted in along with the rapid urbanization, such as the reduction of farmland, soil and air pollution and urban heat island effect. In this paper, a case study was carried out in Xi[JP8]’a[JP]n City so as to retrieve the values of relative brightness temperature from Landsat TM thermalinfrared data (August 9, 2006 and August 4, 2010). The stability of relative brightness temperature during the period from 2006 to 2010 was analyzed according to the transition probability matrix of relative brightness temperature. The results showed that the brightness temperature intensity in Xi[JP8]’a[JP]n City was increased during the period from 2006 to 2010. The mean surface temperature was 26.28 ℃ in 2006, but was increased to 28.14 ℃ in 2010, and the increase occurred mainly in the western, southwestern and southeastern parts of Xi[JP8]’a[JP]n City. Based on the results of the relative brightness temperature, it was found that the extremely heat island effect did not occur in 2006 and 2010, the slight heat island effect was dominant, and the proportion of area of the patches with slight heat island effect was 61.11% and 58.64% in these two years respectively. The proportion of area of green islands was secondary, and it was 34.08% and 35.98% in 2006 and 2010 respectively. From the view of landscape ecology, stability of the patches with slight relative brightness temperature and of the green island patches was the highest. The stability of patches with moderate and severe relative brightness temperature was the lowest. It was considered that climate change and urban construction were the main reasons causing a dynamic change of surface heat regime. Urban green land could reduce the urban heat island effect. References | Related Articles | Metrics

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Quantitative Estimation of Ecological Assets in Farmingpasturing  Ecotone Based on Remote Sensing and GIS ZHANG Chao, ZHANG Jian-Ming, WANG Peng-Long, ZHANG Chun-Mei 2013, 30 (2):  356-363.  Abstract ( 1645 )   PDF (2180KB) ( 983 )   Yanchi County in Ningxia Hui Autonomous Region, China is located in an area where the ecological environment is vulnerable, and it is a typical farmingpasturing ecotone in north China. In the county, the ecological conservation and environmental protection is paid great attention to at all levels since the grazingban policy was put into practice in Ningxia in 2003. In this study, the TM/ETM+ and MODIS NDVI data were used to retrieve the ecological parameters and estimate the value of ecological assets in the county, and it was tried to provide an evidence for the ecological conservation, environmental protection and substantial development. The results show that the gross value of ecological assets was 1.62×108, 2.15×108 and 2.70×108 yuan RMB in 2000, 2005 and 2010 respectively. In ecosystem service functions, the value proportion of soil and water conservation was the highest, in which the contribution of grasslands with the largest area was the highest in the land use/cover types. The value of ecological assets of rainfed farmland per unit area was the highest. The total value of ecological assets was in an increase trend in recent decade, especially in the loess hilly region, which demonstrated that the local ecological and environmental quality was trended to improvement under implementing the grazingban policy. References | Related Articles | Metrics

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Climate and Environment Information from Sand Accumulation Belt in Oasis Marginal Zone in the Hexi Corridor,Gansu Province LIU Shi-Zeng, CHANG Zhao-Feng, ZHANG Jian-Hui, TANG Jin-Nian, WANG Qiang-Qiang, ZHANG Da-Biao, ZHU Shu-Juan, ZHANG Guo-Zhong, FAN Bao-Li 2013, 30 (2):  364-371.  Abstract ( 1834 )   PDF (2047KB) ( 1098 )   Formation of sand accumulation belt in oasis marginal zone is one of the new scientific issues.A sand accumulation belt was formed in oasis marginal zone in the Hexi Corridor,Gansu Province after implementing the project of desertification control in recent 50 years.In order to study the relationships between the causes resulting in the formation of sand accumulation belt and the climatic and environmental factors,the sand accumulation belt in the oasis marginal zone was investigated from the eastern part to the central and western parts of the corridor.The results were as follows:(1) Annual precipitation was the key factor affecting the height and width of sand accumulation belt; (2) Climate and environment information was demonstrated by the vegetation,and precipitation was the key factor affecting the vegetation coverage.The effect of precipitation on the natural vegetation coverage was higher than on the total vegetation coverage including artificial vegetation.With the increase of precipitation,vegetation coverage of leeward slope was higher than that of windward slope; (3) Difference of vegetation coverage among the sample sites was mainly caused by the size of plants,that is,the effect of precipitation on plant size was higher than that on plant density. References | Related Articles | Metrics

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Discussion on RS Methods for Glacier Outline Detection—A Case Study in Headwaters of the Kanas River HUAI Bao-Juan, LI Zhong-Qin, SUN Mei-Ping, XIA Ming-Ying 2013, 30 (2):  372-377.  Abstract ( 4172 )   PDF (1639KB) ( 1480 )   In this paper, the manual digitization method and computer automatic interpretation method were integrated, and the traditional method of glacier interpretation and the objectoriented image feature extraction method were applied to extract the glacier boundary in headwaters of the Kanas River. Through the application, it was found that: (1) Human interpretation could be the best tool for extracting highlevel information from satellite imagery for many glacier types; (2) Classification methods based on threshold band ratios or normalized band differences like NDSI were proven to be accurate and as the robust methods for interpreting clean glacier ice, but they may lead to errors for the glaciers covered by surface moraine; (3) The objectoriented method could be used to extract the surface features, and its accuracy was high in extracting glacier information, especially the disturbance of cloud and snow cover could be restricted; (4) The classification method of automatic threshold decision tree needs to be further studied; (5) An interpretation of 40 glaciers in headwaters of the Kanas River was carried out, the various methods were compared, and the values of precise glacial boundary were derived. The results showed that the glaciers in headwaters of the Kanas River were holistically in a retreat trend, and their area was reduced about 23.43  km2 during the period of 1959-2011. References | Related Articles | Metrics

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Variation of Glacier Terminuses in the Tianshan Mountains, China，during the Period of 1960-2009 LI Shan-Shan, ZHANG Ming-Jun, LI Zhong-Qin, LI Hui-Lin, LUO Shu-Fei 2013, 30 (2):  378-384.  Abstract ( 1750 )   PDF (1142KB) ( 1072 )   The terminus variation of eight glaciers in the Tianshan Mountains, China,during the period of 1960-2009 was studied based on the located observation, field survey, aerial photography, remote sensing and topography analysis. Results showed that the eight glaciers kept retreat during the period of 1960-2009 under the background of the increase of both temperature and precipitation in the Tianshan Mountains, China, and the retreat rate reduced gradually from west to east. There were the regional and periodical changes of the glacier terminuses owing to climate change and the differences of geographical locations and glacier scales and types. Thereinto, the retreating rate of Glacier No.1 at headwaters of the Urumqi River was 5.96 m•a-1 during the period of 1962-1973, it was decreased to 3.28 m•a-1 during the period of 1973-1980, increased slightly (3.93 m•a-1) during the period of 1980-1993, and the glacier was divided into two independent ones in 1993. The retreating rate of Glacier No.4 in the Sigong River Basin in the Bogda Peak region was 6 m•a-1 during the period from 1962 to 1981, increased to 8.9 m•a-1 during the period of 1981-2006 and to 13.3 m•a-1 during the period of 2006-2009. Furthermore, Qingbingtan Glacier No.72 and No.74 covered by superglacial moraine retreated with rates of 41 m•a-1 and 30 m•a-1 during the period of 1964-2009, these rates were much higher than that (2.32 m•a-1) of the Miaoergou Flattopped Glacier without superglacial moraine during the period of 1972-2007. The surface morphology (superglacial moraine) is another cause resulting in the difference of glacier change in the Tianshan Mountains. References | Related Articles | Metrics