Table of Content

15 September 2019, Volume 36 Issue 5 Previous Issue    Next Issue

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Cover 2019, 36 (5):  0-0.  Abstract ( 331 )   PDF (3370KB) ( 139 )   Related Articles | Metrics

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Contents 2019, 36 (5):  0-0.  Abstract ( 145 )   PDF (313KB) ( 117 )   Related Articles | Metrics

Pan-Third Pole Enviornment and Green Silk Road

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Spatiotemporal Changes and Driving Factors of Cultural Relicts on the Tibetan Plateau Since the Holocene JIN Sun-mei, HOU Guang-liang, XU Chang-jun, Lancuo Zhuoma, LI Sheng-mei 2019, 36 (5):  1049-1059.  doi: 10.13866/j.azr.2019.05.01 Abstract ( 785 )   PDF (3801KB) ( 857 )   Based on the ArcGIS spatial analysis,in this paper the geostatistical methods including the kernel density estimation,average nearest neighbor index and global spatial autocorrelation were used to study the spatiotemporal evolution of 14 339 ancient cultural relics and the affecting factors on the Tibetan Plateau since the Holocene.The results showed that the nearest neighbor index of each ancient cultural relic was less than 1.The value of the global Moran’s I was between 0 and 1,there was a positive spatial autocorrelation of the ancient cultural relics,and the ancient cultural relics were distributed in an agglomeration way.The distribution core of the ancient cultural relics experienced a transition from the plateau hinterland (the Paleolithic period) to the southeastern marginal valley (the Neolithic period) and to the eastern region (after the Bronze Age).The morphological characteristics of the ancient cultural relics experienced a uniform distribution (the Paleolithic period),the marginal valley type (the Neolithic period),the valley agglomeration type (bronze period),the degraded dispersion type (the Tibetan regime tribe period),and the half-moon widespread type (the Tubo Dynasty period),the plaque-type (the Yuan Dynasty),and the contiguous cluster (the Ming and Qing dynasties) changes.The spatiotemporal distribution of the ancient cultural relics on the Tibetan Plateau was the result jointly affected by the altitude,climate change,changes of vegetation and other natural conditions,and production mode,technology,war,population migration,political policies,etc. References | Related Articles | Metrics

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Summer Precipitation in Tibet and Its Prediction Mirmah Zhuoga, QIN Zeng-liang, XIAO Zhuo-jing, Ciren Deji, Ciren Quzhen 2019, 36 (5):  1060-1069.  doi: 10.13866/j.azr.2019.05.02 Abstract ( 18 )   PDF (2208KB) ( 2 )   Study on the characteristics and prediction of summer precipitation in Tibet during 1981-2017 was carried out using the Empirical Orthogonal Functions (EOF),cross-validation,anomaly correlation coefficient (ACC),time correlation coefficient (TCC) and some other methods.The results showed that the spatial distribution of summer precipitation was very uneven,and the precipitation decreased from the southeast to the northwest.In addition to some regions,the precipitation was in an increase trend in most areas of Tibet,but the increase trend was not significant.There was not only a regional similarity in spatial distribution of summer precipitation in Tibet,but also a regional variation from the south to the north and from the east to the west.The results suggested that,when a one-year sample was randomly removed,the temporal stability of the first three EOF modes was high.It was attempted to predict summer precipitation in Tibet on the basis of the stability of EOF modes for the first time,and the key indices which were found had a good prediction capability for PCs coefficient of stable modes.The anomaly correlation coefficient between the observed and predicted values of summer precipitation could be reached 0.31.The temporal correlation coefficient was higher than zero in most areas.TCC passed the significance test of α=0.05 in most areas.The predicted results of summer precipitation were ideal,and the application prospect was wide. References | Related Articles | Metrics

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Distribution of Precipitable Water Vapor of Low Vortex over Xinjiang and Surrounding Central Asia in Summer LIANG Qian, GUANG Ying, LIU Qiong, SHI Wen-hao, CHEN Yong-hang, YANG Lian-mei, LI Jian-gang, WANG Yu-jia 2019, 36 (5):  1070-1078.  doi: 10.13866/j.azr.2019.05.03 Abstract ( 8 )   PDF (2142KB) ( 1 )   The Central Asian Vortex is the main precipitation system over Xinjiang and Central Asia. Based on the data of AIRS Version 6 Level 2 from Aqua satellite in summer during the period of 2003-2014,the monthly variation of the Central Asian Vortex precipitation and the distribution of atmospheric precipitable water vapor from different paths were analyzed so as to reveal the atmospheric precipitation potential. The results showed that: ① Occurrence of the South Vortex and North Vortex over Central Asia was significantly different. The proportions of the North Vortex and the South Vortex accounted respectively for 68.51% and 31.69% of the total Central Asian Vortex. In July and August,the frequency of the vortex over Central Asia was the highest; ② According to the classification of different paths of the Central Asian Vortex,the occurrence of the paths was obviously different,in which the occurrence of Central Asia Vortex moving southeastward was the highest; ③ According to the monthly variation,the distribution trend of average atmospheric water vapor during the period from May to September was higher over Central Asia than that over Xinjiang,China,and it was higher over the Turpan and Tarim basins in Xinjiang than that over the areas distributed along the mountains; ④ According to the path type,the distribution trend of average atmospheric water vapor of the North Vortex was similar. Compared with the North Vortex,there were the large high-value (26 mm or more) areas along the paths,and the water vapor content along the paths of the South Vortex was low and mostly less than 18 mm. The study results could be referred in weather forecast and artificially enhancing precipitation in Xinjiang and Central Asia. References | Related Articles | Metrics

Climate and Climatic Resources

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Climate Change in the Qinling Mountains in Spring during 1959-2018 QI Gui-zeng, BAI Hong-ying, MENG Qing, ZHAO Ting, GUO Shao-zhuang 2019, 36 (5):  1079-1091.  doi: 10.13866/j.azr.2019.05.04 Abstract ( 567 )   PDF (3555KB) ( 494 )   In this paper,the characteristics of climate change and future climate trend in the Qinling Mountains in spring were studied and predicted by using the linearity estimation,ANUSPLIN spatial interpolation method,Mann-Kendall test and R/S analysis based on the data of daily temperature and precipitation and the calculated SPEI data from 32 meteorological stations in the study area from 1959 to 2018. The results showed that: ① There was a significant warming-drying trend in the Qinling Mountains in spring during the period of 1959-2018,and the fluctuation was not synchronized. The temperature increase rate in the study area in spring was 0.33 ℃·(10a)-1,and the precipitation descending rate in the same season was 4.90 mm·(10a)-1. The SPEI value in the Qinling area in spring was in a significant downward trend with a decrease rate of 0.14·(10a)-1; ② There was a spatial difference of the warming-drying trend in the Qinling Mountains,and the change was fast in the north but slow in the south. The temperature was in a significant increase trend in 99.65% pixels,the precipitation was in a significant decrease trend in 64.46% pixels,and the SPEI value was in a significant downward trend in 75.28% pixels. The areas sensitive to the climate change in spring were located in Baoji,Zhouzhi,Huxian and Chang’an in the north and Taibai,Zhashui and Zhen’an in the sourth; ③ The occurring frequency of drought was high and its level was serious during the period of 1994-2008,but the situation was alleviated after 2009. The occurring frequency of drought was high in the north and west,and low in the south and east. Such warming-drying climate trend in the Qinling Mountains in spring would continue in the future. References | Related Articles | Metrics

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Environment Evolution and Its Response to Climate Change in the Dalai Nur Lake Area in the Last 2 400 Years LIU Jing-jing, ZHANG Sheng, LI Wen-bao, SHI Xiao-hong, XU Qiong, ZHEN Zhi-lei 2019, 36 (5):  1092-1101.  doi: 10.13866/j.azr.2019.05.05 Abstract ( 590 )   PDF (1818KB) ( 452 )   In this paper,the Dalai Nur Lake (named DL-1) located in the northern marginal zone of the East Asian summer monsoon was taken as the research object. Through collecting,testing and analyzing the sediment core samples,the environmental evolution and its response to climate change in the Dalai Nur Lake area in the last 2 400 years were discussed using n-alkanes and related indicators. The results showed that the carbon number distribution of n-alkanes in the sediment of Dalai Nur Lake varied in a range of C17-C33. In which the curve of C25 distribution was unimodal and its proportion accounted for 57% of the total samples; the curves of C19 and C25 distribution were bimodal and their proportion accounted for 30%; the curves of C25 and C27 distribution were bimodal and their proportion accounted for 13%. The change of the index parameters of n-alkanes revealed that the environmental evolution in the Dalai Nur Lake region was not only consistent with the global climate events,but also affected by the changes of precipitation in East Asian summer monsoon and of cold-warm events in the lake region over the past 2 400 years. The climate change could be divided into six stages. Stages 1,3 and 5 (75 a BP present,985-600 a BP and 2 180-1 550 a BP) were the warm-humid climatic stages. At these stages,the effective humidity in the lake area was high,woody plants were dominant,aquatic plants grew vigorously,and the nutrient status of the lake was fine. Stages 2,4 and 6 (600-75 a BP,1 550-985 a BP and 2 355-2 180 a BP) were the cold-dry climatic stages. At these stages,bacterial algal reproduction was fast,the proportion of herbaceous plants increased,and the primary productivity of the lake was lower. Overall,climate change in the Dalai Nur Lake area changed from warm-humid pattern to cold-dry pattern over the past 2 400 years. References | Related Articles | Metrics

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Drought Change Trend and Its Affecting Climatic Factors in the Bosten Lake Basin WANG Yuan, JIAO Li, DONG Yu 2019, 36 (5):  1102-1108.  doi: 10.13866/j.azr.2019.05.06 Abstract ( 5 )   PDF (847KB) ( 0 )   Aridity index (AI) is one of the important indices for characterizing a regional aridity/humidity status.It played an important role in developing the local agriculture and improving water resources management and ecological environment.Based on the meteorological data from five meteorological stations from 1970 to 2016 in the Bosten Lake Basin,the Penman-Monteith formula was used to calculate the potential evapotranspiration (ET0),and then the values of aridity index were calculated via ET0/precipitation.The multi-annual change characteristics of the aridity index were analyzed using the moving average,M-K,R/S analysis,etc.The sensibility of meteorological factors to aridity index was analyzed by sensibility analysis.The results showed that the average aridity index of the Bosten Lake Basin was 13.9,which revealed that the study area was arid.The aridity index of the Bostten Lake Basin during the period from 1970 to 2016 was decreased,and its change trend in the future would be similar as that in history.Seasonally,the aridity index of the Bosten Lake Basin was the lowest in winter,and it would be continuously decreased with the time.The sensitivity of meteorological factors to the aridity index was in an order of maximum temperature>relative humidity>average wind speed>minimum temperature>sunshine duration>average temperature. References | Related Articles | Metrics

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Grain-Size Distribution and Its Environmental Records of Modern Lacustrine Sediments from the Bosten Lake in Xinjiang HUA You-sheng, MA Long, Jilili Abuduwaili, LIU Wen 2019, 36 (5):  1109-1116.  doi: 10.13866/j.azr.2019.05.07 Abstract ( 5 )   PDF (2654KB) ( 1 )   In this study,the 210Pb dating method was used to establish the sedimentary chronology sequence of lacustrine sediments of the Bosten Lake in Xinjiang,China. The purposes of the study were to research the grain size distribution of core sediment (41 cm),analyze the sediment components sensitive to environment by applying the grain size-standard deviation method,and reconstruct the history of lake water level change over the past 150 years. The contents of clay (<4 μm),fine silt (4-16 μm),medium silt (16-32 μm),coarse silt (32-64 μm) and the sand (>64 μm) in the core sediment of the Bosten Lake were 18%,40.2%,23.3%,13.4% and 5.1% respectively,and the vertical variations of different fractions were obvious. The average grain size of component C2 (with particle size of 7.59-22.91 μm) was consistent with the median particle size (r=0.7,P<0.01),and the component C2 was very sensitive to the change of sedimentary environment in the Bosten Lake Basin,which could be used to reconstruct the water level of the lake over the past 150 years. Water level of the Bosten Lake was low from the 1910s to the 1930s,which revealed that a large-scale regional drought occurred during this period. Under the joint effect of climate change and human activities,water level of the Bosten Lake was significantly fallen in the mid- and late-1980s. The change of sensitive components C2 was consistent with the change of lake water level,and the water level fluctuation history of the Bosten Lake could be reconstructed from the sensitive components in lake sediments. References | Related Articles | Metrics

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Characteristics of Wind Filed over Different Underlying Surfaces in the Oasis-Desert Ecotone in Qira,Xinjiang MAO Dong-lei, CAI Fu-yan, YANG Xue-feng, WANG Xue-mei, LAI Feng-bing, XUE Jie 2019, 36 (5):  1117-1126.  doi: 10.13866/j.azr.2019.05.08 Abstract ( 8 )   PDF (2038KB) ( 0 )   Based on the meteorological data in Qira County,Xinjiang from August 2010 to July 2011,the statistical analysis method was used to analyze the wind regime over four different underlying surfaces including the shifting sandy land,semi-fixed sandy land,fixed sandy land in oasis-desert ecotone and oasis in Qira.The study results could provide a theoretical basis for further studying the spatial and temporal characteristics of wind field and the effects of vegetation against wind and drifting sand.The results showed that the wind directions in the study area were dominated by WNW and W,and their frequencies were 41.43% and 33.74% respectively.The calm frequencies over the shifting sandy land,semi-fixed sandy land,fixed sandy land and oasis accounted for 44.30%,52.44%,54.29% and 85.39% respectively,and these frequencies were decreased gradually with the increase of wind speed.The changes of air temperature and wind speed were in a synchronous trend.The high sand-driving wind frequency and the monthly-averaged maximum wind speed occurred mostly in spring and summer,especially in June.Although the maximum values occurred in different months,the change trend was similar.From the periphery to the central area of the oasis,the wind direction and the frequency of prevailing wind direction were decreased,which indicated that the vegetation could reduce wind speed and disperse wind direction.The average wind speed and sand-driving wind frequency were gradually decreased from the shifting sandy land to the central area of the oasis.There was a significant correlation between the monthly-averaged air temperature and monthly-averaged wind speed,and the correlation was gradually decreased from the shifting sandy land to the central area of the oasis.Vegetation types,vegetation coverage and topography are the main factors affecting the variation of wind fields over the different underlying surfaces. References | Related Articles | Metrics

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Climatological Footprints in Dune-Meadow Cascade Ecosystem under Different Meteorological Conditions in the Horqin Sandy Land HUANG Tian-yu, WANG Guan-li, LI Dong-fang, DUAN Li-min, LIU Ting-xi 2019, 36 (5):  1127-1135.  doi: 10.13866/j.azr.2019.05.09 Abstract ( 7 )   PDF (1978KB) ( 0 )   A cascade ecological belt in the Horqin Sandy Land in Inner Mongolia was taken as the study area to lucubrate the variation of water and heat fluxes and the climatological footprints in vegetation growth season 2017,and their values were calculated and analyzed by using the large aperture scintillometer (LAS) and the “FELM” footprint model. The results showed that: ① On sunny days,the curves of the branches of surface energy were unimodal,and the latent heat flux curve fluctuated slightly; on cloudy days,the curves of daily variation of surface energy fluctuated irregularly;② The areas and locations of climatological footprints in the cascade ecological belt were different under different wind directions and different level of atmospheric stability,and the four source areas in the northeast,southeast,southwest and northwest of the study area in July 2017 were 0.265 km2,0.538 km2,0.239 km2 and 0.524 km2 respectively; ③ The source area under stable conditions was 0.599 km2 and occupied 92% of that under unstable conditions; ④ On sunny days,the source area was reduced from 0.665 km2 at 8:00 a.m. to 0.292 km2 at 11:00 a.m. due to the strong turbulent exchange; in the afternoon,the turbulent exchange was weakened and the source area was enlarged from 0.283 km2 at 14:00 to 0.479 km2 at 17:00; ⑤ Affected by wind direction,atmospheric stability and other factors,the climatological footprints in early-,mid- and late-July were different. The source area was in an order of late->early->mid-July. The study results could provide a scientific basis and theoretical support for the sustainable utilization of hydrothermal resources and the environmental protection and regeneration in the Horqin Sandy Land under the complex conditions of underlying surface. References | Related Articles | Metrics

Plant and Plant Resources

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Changes of Carbon Storage and Carbon Density of Forests in the Kanas National Nature Reserve,Xinjiang LI Yuan-yuan, WANG Lei, LIU Qi-jing, ZHOU Hua 2019, 36 (5):  1136-1145.  doi: 10.13866/j.azr.2019.05.10 Abstract ( 8 )   PDF (1135KB) ( 0 )   In this paper,the equations were established for calculating the conversion between aboveground biomass and stem volume of main forest types by using the forest resources inventory data in 2009 and 2014 and the surveyed data of sample plots.On which the aboveground carbon storage and carbon density of the forests in the Kanas Nature Reserve were analyzed.The results showed that,in the 5 years from 2009 to 2014,the aboveground carbon storage in the Kanas Nature Reserve was about 2.14×106 Mg,and the average carbon density was decreased from 55.34 Mg·hm-2 to 54.61 Mg·hm-2,while the forest area was enlarged by 496.77 hm2.Among the carbon density changes of different forest types,the carbon densities of Larix sibirica,Pinus sibirica and Populus tremula forests were decreased,while those of Picea oborata,Abies sibirica and Betula pendula forests were increased.From 2009 to 2014,the carbon stocks of the mature forests was the highest and accounted for 63% of the total carbon storage in the arborous layer,and then that of post-mature,premature,middle-aged and young forests.The carbon density of the middle-aged forests was the highest (66.69-68.68 Mg·hm-2),that of the young forests was low (40.99-44.55 Mg·hm-2),and that of other tree-aged groups ranked as mature and post-mature forests > premature forest.In which the carbon density of middle-aged and premature forests of L.sibirica,A.sibirica,P.oborata and B.pendula was increased,but that of all other post-mature forests was decreased except for P.sibirica and A.sibirica.The compared results revealed that the carbon density of the arborous layer in the study area was higher than the national average level,and the carbon sequestration potential of the arid and semiarid areas in China is high. References | Related Articles | Metrics

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Characteristics of Sap Flow of Dwarf Red Jujube Trees and the Response to Environmental Factors in South Xinjiang LIU Yi, JIN Qian, GUI Dong-wei, XUE Jie, SUN Huai-wei, YAN Dong, ZENG Fan-jiang 2019, 36 (5):  1146-1152.  doi: 10.13866/j.azr.2019.05.11 Abstract ( 9 )   PDF (1159KB) ( 0 )   In this paper,the characteristics of sap flow of the dwarf red jujube trees in the Qira Oasis were analyzed,and the relationship between the sap flow and environmental factors was researched.The results showed that the curve of daily variation of sap flow was unimodal,and it was occasionally bimodal in summer.Weather conditions affected significantly the change of sap flow,the sap flow rate was the highest on sunny day,then under sand and dust weather,and it was the lowest on rainy day.The seasonal difference of sap flow rate was significant,the sap flow started earlier in summer than that in spring and autumn; the duration of sap flow was the longest in summer,it was relatively short in spring and autumn; the peak value of sap flow was the highest in summer but low in spring and autumn.There was a significantly positive correlation between the sap flow rate and the solar radiation intensity and air temperature,but a significantly negative one between the sap flow rate and the relative humidity.Among the environmental factors,the effect of solar radiation intensity on the sap flow rate was the highest,then that of air temperature,and that of the relative humidity was the lowest. References | Related Articles | Metrics

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Age Composition and Quantitative Dynamic Status of Malus sieversii Population SU Zhi-hao, LI Wen-jun, CAO Qiu-mei, ZHOU Xiao-bing, ZHANG Yuan-ming 2019, 36 (5):  1153-1160.  doi: 10.13866/j.azr.2019.05.12 Abstract ( 13 )   PDF (1725KB) ( 1 )   Malus sieversii is a Tertiary relic species.With the continuous reduction of population quantity and distribution area,the species is now on the verge of extinction.In this study,the analyses on the life tables,survival curves and time series of M.sieversii were carried out so as to illuminate the age composition and developing trends within the populations.The results showed that there were almost no the seedlings in the first-age class in all the populations,and only a few ones in the second-age class were survival in the population at Agricultural Improvement Station in Xinyuan County,Xinjiang.The dominant age classes in the most populations were the 4th and 5th and even up to 6th and 7th in the Balian population.In short,the mid- and old-aged individuals were dominant in all the populations.The survival curves of M.sieversii populations trended to Deevey-II type.It was predicted that the dominant age classes in all the populations would become much more ageing after 20,40 and 60 years.It was suggested to build a genetic resources center of M.sieversii,grow and transplant the seedlings,and strengthen the management to the populations. References | Related Articles | Metrics

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Cultivation of Helianthus tuberosus under Saline or Alkaline Stress TENG Mei-yao, XU Xiao-hong 2019, 36 (5):  1161-1167.  doi: 10.13866/j.azr.2019.05.13 Abstract ( 10 )   PDF (975KB) ( 0 )   The field planting test data and the recorded growth data of Nanju No.1 were obtained based on investigating the physiochemical properties of saline or alkaline soil of tidal flat.These data were finally sorted and summarized,and the SPSS 17.0 was used for the statistical analysis.Results were as follows: ① Nanju No.1 was able to adapt the saline or alkaline soil in west Jilin Province with its high yield and good adaptability.The introduction was relatively successful.The survival,wintering status and growth status of the Nanju No.1 on the light chernozem (pH 8.1) were significantly superior to those in the experimental field (pH 8.3).The survival rates of Nanju No.1 on light chernozem and sandy alkaline soil were 94.56% and 82.27% respectively,and the differences were significant (P<0.05); ② At the emergence stage,the dry matter accumulation of stems and leaves was slow; during the rapid growth period,the dry matter accumulation of stems and leaves began to transfer to underground; during the tuber expansion period,the nutrients absorbed by tubers increased rapidly.The dry matter accumulation and yield of Nanju No.1 on the light chernozem were significantly higher than that on the sandy alkaline soil.The dry matter accumulations of stems on the light chernozem and the sandy alkaline soil during the fast growing period reached 912.26 g·plant-1 and 756.02 g·plant-1,and the difference was significant (P<0.05); ③ The main factors affecting the survival and growth status of Nanju No.1 under the saline or alkaline stress in west Jilin Province were the moisture content,organic matter content and total nitrogen content in soil; ④ The improvement effect of Nanju No.1 on the light chernozem was significantly better than that on the sandy alkaline soil.In conclusion,Nanju No.1 could adapt to the light chernozem and the sandy alkaline soil well in west Jilin Province,and the light chernozem soil is more suitable for Nanju No.1. References | Related Articles | Metrics

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Effects of Closing Grazing on the Litter Amount in Desert Steppe CHEN Xiao-ying, SONG Nai-ping, LI Min-lan, WU Ting, CHEN Juan 2019, 36 (5):  1168-1174.  doi: 10.13866/j.azr.2019.05.14 Abstract ( 10 )   PDF (2679KB) ( 0 )   In this study,the line intercept method and variance analysis were used to analyze the effects of closing grazing and fenced grazing on the soil nutrient content in desert steppe.The litter amount over two soil matrixes (aeolian sand soil and sierozem) in three-paired enclosure plots and fenced grazing plots fenced for different years in Yanchi County,Ningxia Hui Autonomous Region were studied,where the grazing rates were 0.58,0.65 and 0.80 sheep·hm-2.respectively.The response of litter accumulation to grassland utilization and soil matrix was discussed.The results showed that: ① There was a significant effect of enclosure on the litter amount in the community.The litter amount in the enclosure plots in desert steppe varied in a range of 53.2-141.9 g·m-2,and it was 2.82 times of that in the fenced grazing plots; ② There was no significant difference in litter amount between the two kinds of plots on the aeolian sandy soil; on sierozem,however,the litter amount in the enclosure plot was 3.86 times of that in the fenced grazing plot; ③ Compared with the above-ground biomass,the reduction of litter amount of herbaceous plants and the increase of litter amount of shrub plants may be caused by the difference of decomposition and transformation. References | Related Articles | Metrics

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Effects of Soil Types and Precipitation Variation on Dynamic Status of Artemisia scoparia Population SU Ying, LI Yue-fei, CHEN Lin, ZHU Zhong-you, YUAN Chuang, MENG Wen-ting, ZHU Lin 2019, 36 (5):  1175-1185.  doi: 10.13866/j.azr.2019.05.15 Abstract ( 11 )   PDF (1924KB) ( 0 )   Artemisia scoparia,a herbaceous plant species in the desert steppe in Yanchi County,Ningxia,was taken as the research object.Three soil types including sandy soil,weathered bedrock residual soil and sierozem soil were selected,a field device was used to change the rainfall pattern,and the samples were collected from the delimited sample plots to analyze the effects of these factors on the dynamic status of A.scoparia population.The results showed that the bulk moisture content of weathered bedrock residual soil was higher than that of sandy soil and sierozem soil.In the rainfall-increased zone,the bulk moisture contents of sandy soil,weathered bedrock residual soil and sierozem soil were increased by 10.6%,6.6% and 20.2% respectively,but they were decreased by 44.1%,9.2% and 20.1% respectively in the rainfall-decreased area.The survival curve of A.scoparia was concave,and the plant species was a typical r-strategist.Comparatively,the canopy of A.scoparia growing on sandy soil was larger,but the density of the plants growing on sierozem soil was larger.At the middle growth stage of A.scoparia,the plant height and canopy on sandy soil in the rainfall-increased zone were higher,but the plant density in the rainfall-reduced area was higher.On weathered bedrock residual soil,the plant density in the rainfall-decreased was high,but the plant height and canopy were higher.On sierozem soil,the plant density in the rainfall-decreased zone was the lowest,but the plant height and canopy were higher.At the early growth stage,the soil type,soil moisture,plant height and canopy were negatively correlated.At the middle growth stage,there were the significant negative correlations between soil moisture and plant density,between soil type and plant height,and between soil type and canopy.At the later growth stage,the soil moisture content was extremely negatively correlated with plant density,and the soil type was extremely negatively correlated with canopy.The biomass of A.scoparia was positively correlated with total carbon content and total nitrogen content (P<0.05),and negatively correlated with total phosphorus content (P<0.05). References | Related Articles | Metrics

Biological Resources

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Change of Plant Diversity in the Taitema Lake Area before and after Implementing the Ecological Water Conveyance WANG Ya-mei, ZHANG Qing-qing, XU Hai-liang, ZHAO Xin-feng, LIU Xing-hong, LI Jin 2019, 36 (5):  1186-1193.  doi: 10.13866/j.azr.2019.05.16 Abstract ( 9 )   PDF (1328KB) ( 0 )   It is of great significance for regenerating the ecological environment in the lower reaches of the Tarim River to study the change of plant diversity in the Taitema Lake area before and after implementing the ecological water conveyance.Through the comprehensive research on the continuous data of vegetation in the Taitema Lake area during the preiod of 2000-2017,in this study the field investigation and data collection were carried,and the difference in vegetation variation between the overflow plots and the non-flood plots (i.e.the controlled plots) was compared.The results were as follows: ① With implementing the ecological water conveyance,the ecological benefits of the vegetation in the Taitema Lake area have gradually emerged,and the biodiversity has been increased significantly.In the flooded area,the average number of plant species per unit area,vegetation coverage and vegetation density were 6.8 number·(100m2)-1,30% and 1 350 number·(100m2)-1,and they were increased by 3,3.29 and 49 times of those in the regions where the groundwater level was risen only.Before implementing the ecological water conveyance,there were 7 plant species in 3 genera and 2 families in the lake area.After that they were increased to 26 species in 21 genera and 10 families;② After implementing the ecological water conveyance for 10 years,the vegetation in the Taitema Lake area was developed towards the salinized lowland meadow dominated by reeds and tended to be simplified.The vegetation evolution was characterized by that the newly germinating vegetation was dominated by annual herbs with an important value of 0.50 at the early stage of the ecological water conveyance (2000-2006),followed by perennial herbs with an important value of 0.20 and by shrubs with an important value of 0.10.With the continuous ecological water conveyance,the annual herbs decreased in 2009 and was gradually replaced by shrubs and perennial herbs.The shrubs were the native halophytes including Halostachys caspica and Halocnemum strobilaceum,and some newly germinated seedlings appeared.Under the environment with abundant water resources during the period from 2012 to 2016,the dominant species composition tended to be simple,and the vegetation developed towards the salinized lowland meadow dominated by reeds. References | Related Articles | Metrics

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Diversity of Mycorrhizal Fungi of Picea schrenkiana Forest and Its Affecting Factors in the Tianshan Mountains DU Hai-yan, CHANG Shun-li, SONG Cheng-cheng, ZHANG Yu-tao 2019, 36 (5):  1194-1201.  doi: 10.13866/j.azr.2019.05.17 Abstract ( 561 )   PDF (1156KB) ( 519 )   Picea schrenkiana is an edificator on the northern slope of the Tianshan Mountains and plays an important role in the coniferous forests in north China.In this study,the mycorrhizal and topsoil samples were collected from the northern slope according to the altitude gradient in the Tianshan Mountains.The mycorrhizal fungi were identified by molecular biology techniques,and the contents of soil organic carbon,total N,effective P and total K were measured.Phylogenetic tree and typical correspondence analysis (CCA) were used to investigate the diversity of mycorrhizal fungi and their affecting factors.The results showed that: ① There were 21 mycorrhizal fungi symbiotic with P.schrenkiana forest,belonging to 2 genus,6 classes,10 orders,12 families and 14 genera; ② Basidiomycota fungi were distributed in various elevation and altitude zones,while Ascomycota fungi were mainly distributed in the low-altitude zone.With the increase of altitude,the mycorrhizal infection rate (13%-36%) and the Shannon-Weiner index (1.14-2.03) were increased at first and then decreased.The Simpson’s index was in a gradual decrease trend in a range of 0.49-0.63; the uniformity index varied from 0.47 to 0.63,and it was decreased at first and then increased with altitude; ③ The distribution,infection rate and diversity index of mycorrhizal fungi were mainly affected by altitude and soil organic carbon content.The total N content affected significantly only the Shannon-Werner index and the uniformity index.This study could provide a basis for the recognition and utilization of mycorrhizal fungus resources of P.schrenkiana. References | Related Articles | Metrics

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Diversity of Bacterium Communities in Saline or Alkaline Soil in Arid Area WANG Wei-qi, Li Bian-bian, ZHANG Jun, YANG Lei, ZHANG Feng-hua 2019, 36 (5):  1202-1211.  doi: 10.13866/j.azr.2019.05.18 Abstract ( 630 )   PDF (1495KB) ( 544 )   The high throughput sequencing was used to sequence the bacterium communities in four types of saline or alkaline soil including the sulfate-chloride,chloride-sulfate,carbonate and sulfate types.The 137 822 gene sequences were obtained from the soil samples.The results revealed that the Shannon and Chao1 indexes were in an order of carbonate>sulfate>sulfate-chloride>chloride-sulfate,which indicated that the diversity and abundance of soil bacterial communities in carbonate soil samples were significantly higher than those in the other soil samples.In this study,the saline or alkaline soil was mainly comprised of ten phyla.The dominant bacterial phyla were the Proteobacteria,Bacteroidetes and Actinobacteria in sulfuric acid-chloride,chlorinated-sulfate and sulfate soils separately.The Firmicutes,Proteobacteria and Actinobacteria were the dominant populations in carbonate soil.At the genus level,the composition of soil bacterial communities was different from each other.As shown in the cluster analysis,the bacterial communities of all soils were divided into three groups.One was made up of sulfuric acid-chloride salt and chlorinated-sulfate soils,and the others were composed of sulfate and carbonate soils.Effects of the contents of total salt,chlorine,sulfate and nitrates on the bacterial communities were significant (P<0.05).There were the significant differences in bacterial communities within several types of saline or alkaline soil in the Manas River Basin,and also many types of bacterial communities,especially in carbonate-type soils.The results revealed the composition of bacterial communities in different types of saline or alkaline soil and the main environmental factors affecting the community composition,which provided a scientific basis for developing the microbial resources in saline or alkaline soil and improving it. References | Related Articles | Metrics

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Diversity of Coleoptera Insects in the Altay Mountains,Xinjiang ZHANG Dong-kang, ZHU Dan, LI Zhao-guang, ZHONG Wen, XIONG Jia-wu, HU Hong-ying 2019, 36 (5):  1212-1218.  doi: 10.13866/j.azr.2019.05.19 Abstract ( 26 )   PDF (1367KB) ( 1 )   This study aimed at investigating the diversity of Coleoptera in the Altay Mountains in Xinjiang based on the insect specimens from the Insect Collection of Xinjiang University and the field survey in 6 national forest farms in the Altay Mountains in 2015.A total of 2 061 Coleoptera in 129 species,85 genera and 22 families were collected from the Altay Mountains.The diversity analysis indicated that the dominant groups were Chrysomelidae and Scarabaeidae,which accounted for 43.76% (31.44%,12.32%) of the total number of Coleopteran species,and Pallasiola absinthii(Pallas) and Gymnopleurus flagellates(Fabricius) were the dominant species.Biodiversity analysis showed that the Shannon-Wiener index at family level was the highest in Fuyun Forest Farm (2.18),and then in Fuhai Forest Farm (2.17).Shannon-Wiener index at species level was the highest in Fuhai Forest Farm (3.01).Margalef indexes at species and family levels were the highest in Fuhai Forest Farm (2.79,7.94).The similarity coefficient between Fuhai and Fuyun forest farms at family level was the highest (0.17).Because the vegetation and habitat types in the Burqin and Altay forest farms were similar,the similarity coefficient between the Burqin and Fuyun forest farms at species level was the highest (0.82) due to the similarity of both vegetation and habitat types.The results showed that there were the differences in species richness,species composition and abundance of Coleoptera insects among different forest farms in the Altay Mountains. References | Related Articles | Metrics

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Models for Estimating the Biomass of 26 Temperate Shrub Species in Inner Mongolia,China ZHAO Meng-ying, SUN Wei, LUO Yong-kai, LIANG Cun-zhu, LI Zhi-yong, SHEN Hai-hua, NIU Xia-xia, ZHENG Cheng-yang, HU Hui-feng, MA Wen-hong 2019, 36 (5):  1219-1228.  doi: 10.13866/j.azr.2019.05.20 Abstract ( 24 )   PDF (1284KB) ( 2 )   Biomass Model is one of the important methods used to estimate the shrub biomass.Little attempt has been tried to systematically investigate the biomass in shrublands compared with that in forest and grassland ecosystems because of the harsh conditions to carry out field work.In this study 4 common mathematical models (monadic linear model,binary linear model,logarithmic function model and power function model) and 3 prediction variables (height,H; canopy,C; and volume,V) were used to establish the equations for estimating the biomasses of 26 common temperate shrub species in Inner Mongolia,and the R/S ratios of these shrub species in different habitats were compared.The results showed that: ① The power function and linear function models were the main models used for estimating the biomass,and C and V were the optimal predictors; ② The optimal equations and their prediction variables for estimating the biomasses of different organs of 17 shrub species were the same,which indicated that the equation forms for estimating the biomass were similar.However,the coefficients for different organs in the model were different,it was more accurate to estimate the biomass by using the species-specific biomass equations for each species and organs; ③ The R/S ratio of shrub species in grassland and mountainous habitats was significantly higher than that in desert habitat.Through developing the biomass models and studying the R/S ratios of common temperate shrub species in Inner Mongolia,the vegetation biomass and carbon storage of the shrubland ecosystem in Inner Mongolia could be conveniently estimated. References | Related Articles | Metrics

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Correlation between Precipitation and NDVI in Vegetation Growing Season in a Typical Desert in North China LI Ya-feng, TANG Li-song 2019, 36 (5):  1229-1237.  doi: 10.13866/j.azr.2019.05.21 Abstract ( 20 )   PDF (1520KB) ( 1 )   Precipitation change in vegetation growing season is an important factor causing inter-annual fluctuation of vegetation growth.The correlation between NDVImax and precipitation in vegetation growing season in a typical desert in north China was analyzed using the MODIS normalized vegetation dataset and the daily precipitation data from May to September during the period of 2000-2017.The results indicated that the values of NDVImax in four sample plots in the study area were in an increase trend from 2000 to 2017.Precipitation in the study area in vegetation growing season was in an increase-decrease-increase trend.The precipitation concentration degree (PCD) was high in the west but low in the east,and it became later in the study area.In addition to Yulin,the effects of PCD and PCP on NDVImax in other three sample plots were higher than that of precipitation,which revealed that the inter-annual fluctuation of NDVImax values in these sample plots was mainly affected by the changes of PCD and PCP,and there were the positive correlations among them.In Yulin,however,the NDVImax had a positive correlation with the precipitation in vegetation growing season,but a negative one with PCD,and its correlation with the precipitation in vegetation growing season was the highest,indicating that the vegetation growth to precipitation in vegetation growing season was more sensitive. References | Related Articles | Metrics

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Spatiotemporal Variation of NDVI and Its Affecting Factors in Ulanqab City in Growing Season from 2000 to 2015 LI Jian-fei, LI Xiao-bing, ZHOU Yi 2019, 36 (5):  1238-1249.  doi: 10.13866/j.azr.2019.05.22 Abstract ( 578 )   PDF (2660KB) ( 481 )   In this paper,the spatiotemporal change of the Normalized Difference Vegetation Index (NDVI) and its affecting factors in Ulanchab City in recent 16 years were analyzed.The study was based on the monthly synthetic product data of MODIS China 500M NDVI from 2000 to 2015 and the precipitation and temperature data in the same period.The trend line analysis,differential method,complex linear regression analysis and residual method were used.The results showed that: ① The vegetation NDVI in Ulanqab City varied in a range of 0.354-0.555 during the period of 2000-2015,and the overall trend fluctuated and its spatial distribution was obvious.It was high in the southeast but low in the northwest; ② The vegetation types in Ulanqab City were in a trend of improvement → degeneration → improvement during the periods of 2000-2004,2005-2009 and 2010-2015,and the degenerated vegetation was regenerated slowly; ③ Vegetation growth in Ulanqab City was affected by both precipitation and temperature.There was a significantly positive correlation between the NDVI and the annual precipitation (r=0.730,P=0.001),which passed the significance test at 0.01 level,but a negative one between the NDVI and the temperature (r=-0.351,P=0.182),and the correlation between the two climatic factors was not significant.Without considering the influence of human activities,the contribution of precipitation and temperature to vegetation NDVI was gradually increased from 0.213 to 0.805 from the northwest to the southeast; ④ The areas where human activities played a role in reducing vegetation index and increasing it accounted for 55.92% and 44.08% of the total study area respectively. References | Related Articles | Metrics

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Spatiotemporal Variation of Vegetation NDVI and Its Relationship with Climatic Factors on the Northern Slope of the Tianshan Mountains Nijiati Yimier, Mansur Shabiti, Yusufu Maimaiti 2019, 36 (5):  1250-1260.  doi: 10.13866/j.azr.2019.05.23 Abstract ( 517 )   PDF (2534KB) ( 523 )   In this paper,the monadic regressive analysis was employed to investigate the annual and monthly as well as spatial variations of vegetation NDVI on the northern slope of the Tianshan Mountains from 2000 to 2015 based on the MODIS NDVI data and the corresponding climate data.The results are as follows: ① In recent 16 years,the average annual NDVI on the northern slope of the Tianshan Mountains fluctuated between 0.27 and 0.31 and in a significant increase trend.The average monthly NDVI value began to increase rapidly in April,reached its maximum in July,and then began to decrease in August.The curve of average monthly NDVI was unimodal.The increase of vegetation index on the northern slope of the Tianshan Mountains was different from different seasons.Spatially,the vegetation coverage was high in the west and south but low in the east and north.There was a significant spatial difference of average annual vegetation NDVI and NDVI in growing season,and the vegetation coverage was increased in the central area but decreased in the northeast,west and south; ② The average temperature and precipitation on the northern slope of the Tianshan Mountains in the past years were gradually increased and in an increase-decrease-increase fluctuation trend.Spatially,the temperature was low but the precipitation was high in the southern mountainous region,the situation in the northern plain,however,was opposite;③ There was a certain correlation between the vegetation NDVI and the temperature and precipitation,especially in growing season.The vegetation NDVI in spring was more closely related to the temperature,but in summer was more closely related to the precipitation.Comprehensively,and the effect of precipitation on the vegetation coverage was higher than that of temperature; ④ There was a hysteresis of vegetation NDVI than the temperature and precipitation in growing season from May to September. References | Related Articles | Metrics

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Spatiotemporal Evolution of the Oasis and Change of Landscape Pattern in the Manas River Basin HUANG Li, XU Li-ping 2019, 36 (5):  1261-1269.  doi: 10.13866/j.azr.2019.05.24 Abstract ( 605 )   PDF (2004KB) ( 601 )   Based on the Landsat MSS/TM/OLI remote sensing images in 1976,1989,1998,2006 and 2016,the information of oasis distribution in the Manas River Basin in recent 40 years was extracted,and the methods of mathematical statistics model and landscape index were used to analyze the spatiotemporal evolution of the oasis and the change of landscape patterns in the study area.The results showed that,in recent 40 years,the oasis in the middle and lower reaches of the Manas River Basin was in a trend of reduction-expansion-sharp expansion,except the oasis was retreated from 1976 to 1989,the oasis was expanded after 1989,especially during the period from 2006 to 2016,area of the oasis was expanded by 3 266 km2,and the net change rate was as high as 4.43%.The change trend of the oasis was imbalanced and even extremely imbalanced.From 1989 to 2006,the contribution of grassland to the oasis reduction was the highest.After 2006,the reduction of waters was the main contributor to the oasis retreat.After 1989,the contribution of cultivated land to the oasis expansion was the most significant.The main part of the oasis was holistically shifted northwestward,and it was shifted northeastward,southwestward,northwestward and southwestward during different periods.The geometric shapes of the landscapes in the oasis were trended to simplification,and the fragmentation of the landscapes in the oasis became more serious,which was related to the increasing fragmentation of the grassland landscape.The oasis was trended to centralization,which was closely related to the continuous centralization of cultivated land. References | Related Articles | Metrics

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Estimation of Future Land Use Change in the Tianshan Mountainous Based on FLUS Model QIN Qi-rui, LI Xue-mei, CHEN Qing-wei, TIAN Ya-lin 2019, 36 (5):  1270-1279.  doi: 10.13866/j.azr.2019.05.25 Abstract ( 612 )   PDF (1808KB) ( 434 )   In this paper,the 31 global climate models were integrated from the Phase 5 of Coupled Model Intercomparison Project (CMIP5) to study the overall prediction of land use change in the Tianshan Mountains under three emission scenarios,i.e.,the Representative Concentration Pathways (RCPs) 2.6,4.5 and 8.5.In the study,the observed climatic data from 53 meteorological stations,socioeconomic data and natural geomorphological conditions in the Tianshan Mountains were used.The results showed that: ① FLUS model could be used to simulate the historical land use change in the study area with high accuracy; ② Compared with the base period from 1970 to 1999,the average annual temperature would be increased by 1.67-2.16 ℃ during 2021-2050,and its increase would be low in spring and summer but high in autumn and winter.It was revealed that the average annual precipitation would be increased by 22-25 mm under RCPs 2.6,4.5 and 8.5.Under the three scenarios,precipitation reduction would occur in some years compared to the base period,but there would be holistically an increase trend; ③ Compared with the situation of land use change in 2017,it was estimated that,under the RCP2.6,RCP4.5 and RCP8.5 scenarios,the glacier and snow areas in the Tianshan Mountainous in 2050 would be reduced by 29.2%,34.6% and 38.4% respectively.The enlargement of urban land area in 2050 would not be significant under RCP2.6 and RCP4.5.Some of the cultivated land would be converted into urban land and grassland,and the area of woodland would be slightly enlarged.The urban land area under the RCP8.5 scenario would be nearly three times of that in 2017.Part of woodland would be converted into grassland.The total area of waters would be slightly enlarged,and the area of unused land will be in a reduction trend. References | Related Articles | Metrics

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Valley Landform Evolution under Aeolian-Fluvial Joint Erosion in the Baerdong River Basin in Inner Mongolia,China MA Yu-feng, YAN Ping, YANG Yu-hui, LI Shuang-quan 2019, 36 (5):  1280-1291.  doi: 10.13866/j.azr.2019.05.26 Abstract ( 12 )   PDF (4622KB) ( 2 )   The study area is located in the middle reaches of the Baerdong River in Inner Mongolia.This study focused mainly on the dynamic geomorphological evolution caused by aeolian-fluvial joint erosion.Based on the field work and collecting the related data,the meteorological observation,runoff plot experiment,topographic survey and remote sensing analysis were applied to study the modern process of aeolian-fluvial joint erosion.The change of erosion pattern of different landforms and the evolution process of valley morphology were quantitatively analyzed.The results showed that the geomorphic types in the middle reaches of the Baerdong River are mainly the dunes on the river bed,valley slopes and terraces as well as the gullies on the terraces and alluvial fans.The erosion and morphologic evolution of these landforms repeat circularly in a year.Because of the periodic changes of wind speed and water regime,these aeolian-fluvial jointly eroded units have evolved regularly and controlled the change of valley landforms in the middle reaches of the Baerdong River for many years.The morphological changes could be mainly manifested in the river curvature,width of the river channel,shifting direction of the river channel,tilt direction of transverse section of riverbed,size of the alluvial fans and the migration distance of the sand dunes in valley.The study results could be referred in further researching and controlling soil erosion in the aeolian-fluvial joint erosion area. References | Related Articles | Metrics

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Morphological Complex and Classification of Gullies in the Liudaogou Minor Drainage Basin in North Shaanxi Province ZHAO Ying, DONG Shuang, JIA Yu-hua 2019, 36 (5):  1292-1299.  doi: 10.13866/j.azr.2019.05.27 Abstract ( 15 )   PDF (1878KB) ( 1 )   The appearance and development of permanent gullies considerably change the catchment geomorphology and natural environment in the Loess Plateau.Research on gully morphology is beneficial to understand the development process and evolvement mechanism of gullies.Through a field survey in 32 typical gullies in the Liudaogou minor drainage basin with portable GPS,the morphological characteristics and the main results are as follows: ① The number of gully >100 m in length accounted for 81.2%.The widening extent of the gullies was larger than their deepening.Specifically,the width of the gullies was two times higher than their depth.Moreover,the mean width and depth were significantly different among the head-cut,cross-section and outlet of the gullies; ② Inconsistent information was achieved from the box dimension and the shape index.In comparison,the box dimension was sufficient in expressing the shape complex of gullies,which ranged from 1.011 to 1.293 in this study; ③ According to the incorporated gully branch information,the permanent gullies were divided into four types: linear,head-expanded,head-branched and outlet-branched.In view of the spatial links between the main and branched gullies,the branches of the permanent gullies would be important for recognizing the gullies and understanding the fragmentation of the drainage basins. References | Related Articles | Metrics

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Soil Moisture Content under Artificial Robinnia pseudoacacia Forest at Different Slope Positions in the Zhonggou Minor Basin,Jingchuan County,Gansu Province ZHANG Xiao-mei, DI Li, SHI Zai-jun, FEI Jun-e, WANG Zheng-an 2019, 36 (5):  1300-1308.  doi: 10.13866/j.azr.2019.05.28 Abstract ( 617 )   PDF (1121KB) ( 442 )   The soil hydrophysical properties under the artificial Robinia pseudoacacia forests in different landforms in a minor drainage basin in Jingchuan County,Gansu Province were measured using the “ring knife” method,and the soil moisture content was also measured using the oven drying method. The soil bulk density in 0-100 cm soil layer under the R.pseudoacacia plantations at different slope positions was in an order of the R.pseudoacacia forest on the hill top (1.24 g·cm-3)>R.pseudoacacia forest at the gully bottom (1.20 g·cm-3)>R.pseudoacacia forest (1.18 g·cm-3)>R.pseudoacacia forest on the hill slope (1.16 g·cm-3). The total soil porosity was in an order of the R.pseudoacacia forest on the hill slope (51.99%)>R.pseudoacacia forest in the gully (51.31%)>R.pseudoacacia forest at the tableland bottom (50.52%)>R.pseudoacacia forest at the tableland top (49.33%). The saturation moisture capacity and non-capillary moisture capacity of soil under the R.pseudoacacia forest on the hill slope were both the highest,then those under the R.pseudoacacia forests in gully and at the tableland bottom,and they were the lowest under the R.pseudoacacia forest on the hill top. The seasonal variation of soil moisture content under the forest was obvious,which could be divided into the soil moisture consumption period (from May to June),soil moisture supply period (July) and soil moisture reduction period (from August to September). The variable coefficient of soil moisture content under the forests in different landforms was increased at first and then decreased with the increase of soil depth,and it reached the highest value (Cv＞0.3) in 40-80 cm soil layer. The results revealed that the soil moisture content was the highest under the R.pseudoacacia forest on the hill top,and then under the forests at the gully bottom and the on the gully tableland,and it was the lowest on the hill slope. References | Related Articles | Metrics

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Wind Speed Fluctuation at Kubuqi Desert Ecological Photovoltaic Power Station YANG Shi-rong, LING Xia, MENG Zhong-ju, DANG Xiao-hong, DANG Meng-jiao, SHI Tao, LIU Xiang-jie 2019, 36 (5):  1309-1317.  doi: 10.13866/j.azr.2019.05.29 Abstract ( 11 )   PDF (1920KB) ( 1 )   The characteristics of wind speed fluctuation under the disturbance of photovoltaic panels in sandy area were studied,and the law of wind erosion and sand burial at the photovoltaic power station was revealed. The study is of a theoretical foundation for preventing and controlling sand disasters at the photovoltaic power station in sand area. Two sections at the eco-photovoltaic power station were selected,and the values of wind speed at 20,50,80,100 and 200 cm heights and the typical positions of the panel arrays were are measured. The wind speed fields at the station were analyzed. The results showed that:① Wind speed at the photovoltaic panel margin was the highest,the anode wind speed was significantly reduced,and the wind speed after the arrays was gradually reduced,especially near the ground surface. The average wind speeds 20 cm under the panels,at the front and between the panels were increased by 44.7%,54.8% and 7.2% respectively; ② The wind speed fluctuation and intensity at three locations of the PV panels were decreased at first and then increased with the increase of height,and the turbulence was the most serious at the height of 20-80 cm. Compared with the contrast,the turbulence under the photovoltaic panels and at the front of panels was increased with the increase of height;③ The fluctuation of wind speed around the photovoltaic panels was the main driving force for forming the vortex under the panels and at the front of panels,which resulted in the erosion of the photovoltaic base and the development of the sand belt between the panels. References | Related Articles | Metrics

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Delimitation of Urban Growth Boundary in Arid Oasis Based on Evaluating the Suitability of Construction and Development:A Case Study in Urumqi City ZHU Tian-zhu, DU Hong-ru, ZHANG Xiao-lei, WANG Bo-li 2019, 36 (5):  1318-1324.  doi: 10.13866/j.azr.2019.05.30 Abstract ( 444 )   PDF (1348KB) ( 981 )   It is an effective way to scientifically and rationally delimit the urban growth boundary for controlling the disorderly urban expansion and reducing the inefficient urban land use.It is also one of the important contents of space planning exploration in China.The urban growth boundary demarcation should be based on the regional resources conditions and construction and development level of different regions,and the appropriate indicators and methods should be selected according to the local conditions so as to more accurately reflect the actuality and demand of urban development.The urban development in arid areas is significantly affected by the oasis-desert ecosystem.The contradiction between people and land is more prominent in the process of urban expansion.The delimitation of urban growth boundary must reflect the coordination of resources,environment and economic and social development.In this paper,it was attempted to carry out the delimitation of urban growth boundary in Urumqi so as to explore the feasible methods for delimiting the urban growth boundary in arid regions based on the research ideas of resources environment background and construction and development level.The results showed that: ① The combination of restrictive evaluation and suitability evaluation could be used to well delimit the urban growth boundary in arid area; ② Oasis could be regarded as an evaluation unit of land potential so as to make the delimitation of urban growth boundary in arid area more reasonable and applicable; ③ Delimitation of urban growth boundary was divided into the permanent boundary and periodic boundary,which could be used to guide the development of urban land. References | Related Articles | Metrics