Table of Content

15 July 2019, Volume 36 Issue 4 Previous Issue    Next Issue

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Cover 2019, 36 (4):  0-0.  Abstract ( 492 )   PDF (414KB) ( 91 )   References | Related Articles | Metrics

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Contents 2019, 36 (4):  0-0.  Abstract ( 156 )   PDF (309KB) ( 147 )   Related Articles | Metrics

Land and Water Resources

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Redistribution of Rainfall in Canopy of Caragana intermedia TIAN Na, GU Jun-long, YANG Xin-guo, WANG Lei, WANG Xing, CHEN Lin, SONG Nai-ping 2019, 36 (4):  85-94.  doi: 10.13866/j.azr.2019.04.08 Abstract ( 5 )   In this study,the effects of rainfall and its intensity on the throughfall,stemflow and interception of two kinds of shrubberies (healthy and degenerated groups) of Caragana intermedia planted in a desert steppe were examined.Results showed that: ① 33 effective rainfall events were observed during the experiment,and the total volume,average volume and average intensity of rainfall were 251 mm,7.6 mm and 1.14 mm·h-1,respectively.In which the frequency of rainfall events with volume 2 mm and intensity 1 mm·h-1 was the highest.② There were the significant differences (P＜0.05) in the throughfall and interception between the healthy and degenerated groups,and the average percentages of throughfall,stemflow and interception were 66.7%,8.5% and 24.8% in the healthy group and 75.4%,8.7% and 16.0% in the degenerated group,respectively.③ The throughfall,stemflow and interception of the two kinds of shrubberies had the linear,logarithmic and power functions with rainfall,and the percentages of throughfall,stemflow and interception had the logarithmic and power relationships with rainfall and rainfall intensity.The morphological degeneration of the shrubberies changed significantly the redistribution pattern of rainfall in canopy,thus the canopy interception was significantly reduced,but the throughfall was significantly increased,which were beneficial to potentially improve soil moisture content and maintain the stability of C.intermedia shrubberies. References | Related Articles | Metrics

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Hydrochemical Composition of Natural Waters and Its Affecting Factors in the East Hunshandak Sandy Land REN Xiao-zong, LI Jian-gang, LIU Min, LI Ji-yan 2019, 36 (4):  791-800.  doi: 10.13866/j.azr.2019.04.01 Abstract ( 863 )   PDF (2076KB) ( 629 )   The East Hunshandak Sandy Land is located in the Inner Mongolia Plateau.Compared with other deserts in West China,water resources in Hunshandak Sandy Land are relatively abundant,even some rivers originate from the sandy land.In this study 24 water samples including 11 groundwater samples,6 lake water samples,5 river water samples and 2 spring water samples were collected from 2011 to 2012.Physical parameters including the pH value,oxidation-reduction potential,electrical conductivity,total dissolved solids and salinity were measured on site with a portable instrument.Major anions(Cl-,NO-3 and SO2-4) and cations(Na+,K+,Mg2+,Ca2+ and NH+4) were determined by electrochemical detectors of ion chromatography at the Institute of Geology and Geophysics,Chinese Academy of Sciences.The concentration of HCO-3 was measured by titration with HCl following Gran Method.The results showed that total dissolved solids(TDS) of water samples ranged from 67 mg·L-1 to 660 mg·L-1,which revealed that freshwater was dominant in the natural waters in Hunshandak Sandy Land.Moreover,the concentration of calcium was the highest in cations in almost all water samples,while that of bicarbonate was the highest in anions except for some groundwater and spring water samples.The pH values of groundwater were commonly slightly lower than 7,while those of others,such as lake water,river water and spring water,were slightly higher than 7.In addition,almost all concentrations of cations and anions in groundwater were the highest in natural waters.The hydrochemical types were determined by the original Durov Diagram.The results showed that surface water was dominated by bicarbonate,but groundwater was dominated by bicarbonate,mixed type or sulfate.Gibbs Diagram was used to determine the factors affecting the hydrochemical composition of natural waters.Different from the deserts in the western and central parts of China,where the evaporation was so strong that evaporation-crystallization affected mainly the hydrochemical composition of the natural waters,and the water-rock interaction was the main factor affecting the natural waters in East Hunshandak Sandy Land.Ion ratios in samples indicated that the rock weathering in waters was different.The weathering degree of evaporative salt rock and silicate rock in groundwater is higher,while that of carbonate rock is lower,which may be caused by the insufficient supply of carbon dioxide due to the long water-rock interaction time in groundwater.On the contrary,due to the short water-rock interaction time and sufficient supply of carbon dioxide,the degree of weathering of evaporative and silicate rocks in surface water is low,while that of carbonate rocks is high. References | Related Articles | Metrics

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Dynamic Snowmelt Process and Its Relationship with Air Temperature in a Small Watershed in the West Tianshan Mountains Gulimire Hanati, Haimidan Helili, LIU Qian-qian, SU Litan 2019, 36 (4):  801-808.  doi: 10.13866/j.azr.2019.04.02 Abstract ( 13 )   PDF (1313KB) ( 0 )   Snowfall,snowmelt and air temperature in a small watershed named as Aredubai in the west Tianshan Mountains were synchronously observed every 30 minutes from 2017 to 2018,and the relationship between snowmelt and air temperature was analyzed.The results showed that the snowfall in the mountainous area increased at first and then decreased.The duration of snow cover accumulation was from December 27,2017 to March 8,2018,and the maximum snowfall intensity was as high as 9.6 mm·h-1 (when the value of snow water was converted into fresh snow depth,it was 96.5 mm·h-1).The rule of snowmelt in the mountainous area was opposite to that of snowfall,that is,the snowmelt was decreased at first and then increased.The snowmelt was divided into three stages.The snowmelt rate was gradually decreased from 3.24 mm·h-1 to 0 mm·h-1 with the decrease of air temperature at the first stage.The snowmelt did not occur when the air temperature was lower than the critical temperature of snowmelt (-13.5--12.0 ℃) at the second stage.The snowmelt rate was gradually increased from 0 mm·h-1 to 3.87 mm·h-1 with the increase of air temperature at the third stage.In the big data relation between snowmelt and air temperature,the correlation coefficient between snowmelt and air temperature was not so significant,and the correlation was 0.708.Under the conditions without precipitation,the correlation coefficient between the 7-day average snowmelt and air temperature was significant,the Pearson correlation coefficient was 0.907,and R2=0.823.When the hysteresis was further considered,the correlation coefficient between snowmelt and air temperature was increased significantly,the correlation coefficient was as high as 0.943,and R2=0.889,which all passed the two-tailed test at significance level 0.01.There was a close correlation between the dynamic change of snowmelt and air temperature in the small watershed named as Aredubai in the west Tianshan Mountains.The response relationship and analysis method of snowmelt to temperature change have certain reference value for improving the ability to cope with future climate change and preventing flood and water resources management. References | Related Articles | Metrics

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Variation of Soil Temperature in the Desert-Oasis Ecotone GOU Qian-qian, LI Qiao-qiao, QU Jian-jun, WANG Guo-hua 2019, 36 (4):  809-815.  doi: 10.13866/j.azr.2019.04.03 Abstract ( 544 )   PDF (1565KB) ( 385 )   In this study,the data of soil temperature and meteorological factors at a station in an inland river basin in Linze from 2004 to 2014 were used to analyze the soil temperature variation and its main affecting factors in the desert-oasis ecotone in central Hexi Corridor.The results showed that both the daily and monthly changes of soil temperature were sine-curve-shaped,and the occurrence time of the highest and lowest temperature in each soil layer was gradually delayed with the increase of soil depth.The average annual soil temperature was generally decreased at first and then increased with the increase of soil depth.The correlation between air temperature and soil temperature was the most significant.Three distinct layers of soil temperature in this region were defined,i.e.,the soil layers of 0-20 cm deep,around 40 cm deep and 60-100 cm deep.Finally,the empirical prediction equations between meteorological indexes and soil temperature of each soil layer were developed using the correlation analysis and the multiple stepwise linear regression. References | Related Articles | Metrics

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Soil Nutrient Characteristics and Plant Response in Meadow Wetland in the Yinchuan Plain SU Zhi-tun, WU Chun-yan, HE Tong-hui, QIAO Bin, FENG Yan-qiong, WANG Xiao-ping 2019, 36 (4):  816-823.  doi: 10.13866/j.azr.2019.04.04 Abstract ( 17 )   PDF (921KB) ( 0 )   In this study,three types of meadow wetlands (marsh meadows,typical meadows and salty meadows) in the Yinchuan Plain were selected as the research subjects.An analysis of soil nutrients and plant nutrients was conducted with classical statistical methods through field investigation and laboratory analysis.The main conclusions are as follows:① At the horizontal gradient,except for soil total phosphorus (TP),the difference of soil nutrient level in soil layer of 0-20 cm in depth among the three meadow wetlands was obvious (P<0.05).② The vertical variation of soil total nitrogen (TN) and soil alkali-hydrolyzed nitrogen (AN) in the salty meadow was not obvious (P>0.05),but the vertical fluctuation in the typical meadow and swamp meadow was larger.The vertical change of TP in meadow wetland soil was not obvious (P>0.05).An enrichment of soil available phosphorus (AP) and available potassium (AK) occurred in topsoil in the meadow wetland to a certain extent,and the vertical change was very obvious (P<0.05).③ The change trends of C,N and P contents in soil were consistent.There was a significant correlation between soil AK content and soil P content (P<0.05).④ Plant nutrients in the meadow wetland was affected by N,in which the C∶N and C∶P were negatively correlated with soil nutrients,and plant N∶P was significantly affected by soil organic carbon(SOC) and AN. References | Related Articles | Metrics

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Evaluation and Their Sources of Heavy Metals in Uncultivated Saline-Alkaline Soil in the Junggar Basin,Xinjiang MI Xiao-jun, REN Wen, LUO Qiong, MA Jian 2019, 36 (4):  824-834.  doi: 10.13866/j.azr.2019.04.05 Abstract ( 12 )   PDF (1738KB) ( 0 )   The uncultivated saline-alkaline soil samples were collected from the Junggar Basin,Xinjiang.Seven kinds of heavy metals including Hg,Cd,Pb,Cr,Ni,As and Se in soil samples were examined.The multivariate statistical analysis and the pollution indexes were used in the survey,and the sources of heavy metals in different soil layers (0-20 cm and 20-40 cm in depth) were evaluated based on the soil background values of the heavy metals in Xinjiang (the soil background values of Se in Urumqi were adopted).The results showed that the average concentrations of Hg,Cd,Pb,Cr,Ni,As and Se in soil layer 0-20 cm in depth were 0.023,0.165,17.999,62.587,29.928,16.325 and 0.696 mg·kg-1,and those in soil layer 20-40 cm in depth were 0.021,0.148,17.497,61.091,29.995,17.384 and 0.634 mg·kg-1,respectively.Except for Pb,the contents of other elements were higher than the soil background values of the heavy metals in Xinjiang.The evaluation results of the single factor pollution index of each element in the study area were mainly pollution-free or slight pollution.The proportions of pollution-free and slight pollution of the seven elements in the two soil layers varied from 66.2% to 100% and from 74.7% to 100%,respectively.The Nemero comprehensive index showed that the slight pollution was dominant in the study area,and the proportions of the sites with slight pollution in the two soil layers were all 78.4%.The sources of heavy metal elements such as Cd,As and Se were mainly natural factors,which are mainly related to the composition and properties of soil parent materials.The sources of Cr,Pb and Hg were mainly affected by human factors.Heavy metals carried by industrial development,transportation and coal combustion fall into the soil,which is the main reason for the increase of background values of uncultivated and undamaged natural saline-alkaline soil.The source of Ni may be the result of human and natural factors. References | Related Articles | Metrics

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Sequestration Efficiency and Component Characteristics of Soil Carbon and Nitrogen Contents during Restoration of Sand-Fixing Forests in North Shaanxi Province Hasier, ZHENG Si-rui, TU Yi-nan, WAN Jia-ming, YANG Mi-mi, HUANG Yue, YU Ke, TONG Xiao-gang 2019, 36 (4):  835-843.  doi: 10.13866/j.azr.2019.04.06 Abstract ( 14 )   PDF (1657KB) ( 0 )   The soil samples were collected from 0-10 cm topsoil in the semi-fixed sand land and fixed sand land under the shrubberies and arbor forests regenerated for 23-54 years in the MU US sandy land in North Shaanxi Province. Each soil sample was separated as the light and heavy fractions by density grouping method,and the evolution and accumulation rates of organic carbon and total nitrogen,C/N and the characteristics of contribution proportion for sequestrating carbon and nitrogen in these two soil fractions were analyzed. The results indicated that the organic carbon contents in soil light fraction under the shrubberies and arbor forests regenerated for 23-54 years increased by 14.0-40.6 times and 8.8-19.2 times respectively,which were significantly higher than those in the corresponding heavy fractions (3.2-7.7 times and 3.5-8.1 times). In the same period of vegetation regeneration,the total nitrogen contents in soil light fraction under the arbor forests and shrubberies were increased by 14.5-40.9 times and 11.8-29.1 times respectively,which were also significantly higher than those of the corresponding heavy fractions (4.6-8.5 times and 4.4-12.6 times). These results indicated that the soil organic carbon and total nitrogen in light fraction were more sensitive to the desertification reversion than that in heavy fraction. Increase of the contents of organic carbon and total nitrogen in the light fraction and heavy fraction of soil also made the growth rates of organic carbon density of light fraction under the forests and shrubberies reach to 0.57 mg·hm-2·a-1 and 0.26 mg·hm-2·a-1 respectively. The growth rates of the organic carbon density in heavy fraction under the forests and shrubberies were only 0.18 mg·hm-2·a-1 and 0.20 mg·hm-2·a-1 respectively. Moreover,the growth rates of the total nitrogen density in light fraction reached to 0.03 mg·hm-2·a-1 and 0.02 mg·hm-2·a-,and they in heavy fraction reached to 0.02 mg·hm-2·a-1 and 0.04 mg·hm-2·a-1,respectively. According to these growth rates of carbon and nitrogen fractions,the carbon of light fraction under the forests and shrubberies could contribute 75.9% and 59.4% of the total organic carbon increment respectively during the 54-year restoration. The nitrogen in heavy fraction could contribute 44.6% and 63.9% of total nitrogen increment respectively. In addition,the C/N ratios of soil heavy fraction under the two woodlands regenerated for 54 years were significantly reduced by 11.4% and 38.5% respectively compared with those in semi-fixed sand land. However,there was no significant change of C/N in the light fraction under the forests,and the C/N in the light fraction under the shrubberies regenerated for 23-54 years was decreased by 21.7%-31.0%. As a result the quality of soil carbon pool was improved significantly. Therefore,the soil of restoration under the sand-fixing forests in North Shaanxi affected significantly the sequestration of carbon and nitrogen. Moreover,arbor forests has better carbon sequestration ability and shrubberies has better nitrogen sequestration effect. References | Related Articles | Metrics

Plant Resources

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Age Structure of Malus sieversii Population in Ili of Xinjiang and Kazakhstan ZHANG Ping, LYU Zhao-zhi, ZHANG Xin, ZHAO Xiang-ping, ZHNAG Yong-guang, Gulzhanat Tanabekova, Maisupova Bagila, Adilbayeva Zhanera, CUI Zhi-jun 2019, 36 (4):  844-862.  doi: 10.13866/j.azr.2019.04.07 Abstract ( 904 )   PDF (1405KB) ( 527 )   Environmental and human stress accelerate the loss of wild apple habitats in Central Asia,causing the decline of population and viability of wild apples. In this paper,the population of a tertiary relict plant Malus sieversii (Ledeb.)Roem.was studied. The status of wild apple population was systematically surveyed,and the age structure,fruit yield and population dynamic change of wild apple in Xinjiang (Ili River Valley) of China and Kazakhstan were compared. The results showed that the population age structure was currently and even in the 1970s dominated by the middle-aged (15-50 cm) trees,and the proportion of young (0-15 cm) and old (50-75 cm) trees was low in the Ili River Valley of Xinjiang and Kazakhstan. Compared with the population in Xinjiang,the life vitality of wild apple population was weaker while the fruit yield was relatively high,and the population was in a severe decline (Deevey-Ⅲ) in Kazakhstan from 1969 to 1970. In 2013,the population of wild apple trees in Kazakhstan showed a strong life vitality and stable population structure (Deevey-Ⅱ). The key factor that resulted in the decline of wild apple population was the lack of young individual trees. Detailed advices were proposed to the conservation and regeneration of wild apple forest in Xinjiang and Kazakhstan. For Kazakhstan,an appropriate level of grazing was suggested to enhance the seed spreading and germinating. For Ili of Xinjiang,the conservation areas should be established,while the wild apple fruit collection and mowing in wild apple forest should be prohibited or under well control so as to protect the seedlings as well as the natural seed bank. References | Related Articles | Metrics

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Inversion of Vegetable Aboveground Biomass in the Manas River Basin Based on Neural Network ZHANG Yuan, WANG Ling, BAO An-ming, LIU Hai-long 2019, 36 (4):  863-869.  doi: 10.13866/j.azr.2019.04.09 Abstract ( 18 )   PDF (1741KB) ( 1 )   Aboveground biomass reflects the capability of ecosystems to obtain energy.Analysis on the spatial distribution pattern is of great significance for understanding the structure and function of ecosystems.The accuracy of inverting aboveground biomass with the conventional approach is low due to the lack of samples and the uncertainty of impact factors.In this study,Extreme Learning Machine (ELM) was used to train the remote sensing factors of 105 samples which included seven-band pixel values of TM image and vegetation factors,and the remaining 34 samples were used for verification.The results confirmed that ELM approach could invert vegetable aboveground biomass with a higher accuracy,and its determination coefficient of curve fitting reached 0.89.In addition,the inversion of vegetation aboveground biomass in the Manas River Basin from 2010 to 2015 found that the biomass was relatively stable in the upper area of the Manas River Basin,was in an increase trend in the middle plains and was in a deterioration trend in the downstream desert. References | Related Articles | Metrics

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Response of Plant Seedling Growth to the Changes in Precipitation and Wind Velocity in Horqin Sandy Land SUN Shan-shan, LIU Xin-ping, WEI Shui-lian, ZHANG Tong-hui, HE Yu-hui, Chelmeg, LYU Peng, WANG Ming-ming 2019, 36 (4):  870-877.  doi: 10.13866/j.azr.2019.04.10 Abstract ( 792 )   PDF (1287KB) ( 561 )   To study the response of plant seedling growth to the change of precipitation and wind velocity in sandy land,we carried out simulation control experiments by artificial precipitation and wind screen reduction in 40 concrete square pools of 2 m×2 m×2 m during the period of seed germination starting in mid-April 2016.The results showed that:① Wind velocity,precipitation and interaction of these two treatments had no significant effect on the species richness (P>0.05).The seed germination rates could be increased by 4.9% and 1.3% under the 20% wind velocity reduction and 60% precipitation increment,respectively,compared with those of controlled experiment.The species richness was increased by 7.2% under 20% reduction of wind velocity and 60% precipitation increment.②The seedling density and height fluctuated greatly under different precipitation treatments.A wind speed reduction can significantly promote seedling growth height in sandy land,especially for Salsola collina and Corispermum macrocarpum (P<0.01).Under the condition of natural wind speed,30% precipitation increment obviously promoted the growth of seedling height,while 60% precipitation increment was contrary.Under the 20% wind velocity reduction,the growth height of Bassia dasyphylla seedlings could be greatly promoted by the 60% precipitation increment.The synergistic effects of the 40% wind velocity reduction and 30% and 60% precipitation increments resulted in a significant decrease in the growth height of the seedlings of Bassia dasyphylla,Salsola collina and Corispermum macrocarpum.③ The effects of different wind velocity and precipitation treatments on species diversity,including the Simpson index (D),Shannon-Winner index (H) and Pielou evenness index (J),were not significant (P>0.05).In conclusion,the effect of 30% precipitation increment on the species richness during the period of seed germination was significant,wind velocity was the main factor affecting the height of plant seedlings.Under the natural conditions,the increase of seedling height was the maximum under 40% wind velocity reduction.The response of species diversity to the change of wind velocity and precipitation was not sensitive,which indicated that the community structure of the ecosystem was comparatively stable in the Horqin Sandy Land. References | Related Articles | Metrics

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Effect of Salt Coupled with Drought Stress on Seed Germination and Seedling Growth of Salsola ferganica Tayier Maimaitijiang, MA Ya-li, LAN Hai-yan 2019, 36 (4):  878-885.  doi: 10.13866/j.azr.2019.04.11 Abstract ( 11 )   PDF (1511KB) ( 1 )   In this study,the effects of different stress conditions,e.g.,salt (NaCl),drought (PEG 6000) or salt coupled with drought,on seed germination (SG) and seedling growth (SGr) of Salsola ferganica were researched.Results showed that:① SG of S.ferganica could tolerate relatively high NaCl and PEG concentrations.There was no effect of low NaCl and PEG concentrations on SG;at higher concentration,however,SG was significantly decreased but its percentage still exceeded 35%,which suggested that S.ferganica was salt- or drought-tolerant.Under salt stress coupled with drought stress,the inhibition of seed germination was significantly relieved by increasing the PEG concentration under the low and medium concentration of NaCl.② Under NaCl stress,the recovery rate of winged perianth (WWP) seeds was increased with increasing NaCl concentration,while that of dewing perianth (NWP) seeds was remained at low level.With increasing the PEG concentration,however,the recovery rates of both WWP and NWP seeds were significantly decreased.The recovery of germination of WWP and NWP seeds under salt coupled with drought stress was similar as that under NaCl stress.③ The effect of NaCl or PEG treatment on the growth of the seedlings from NWP seeds of S.ferganica was stronger than that from WWP seeds.With increasing the NaCl or PEG concentration,the growth of plant height and root length of seedlings from WWP and NWP were inhibited.The growth of S.ferganica seedlings Under salt stress coupled with drought stress,the effect of low NaCl concentration on the growth of the WWP seedlings was less than that of NWP seeds (except for 100 mmol·L-1NaCl+25 g·L-1PEG).The effect of NaCl concentration on the seedlings of NWP seeds was stronger than that of WWP seeds.With increasing the PEG concentration at high NaCl level,the growth of plant height and root length of seedlings from WWP and NWP were inhibited.In conclusion,S.ferganica was much more tolerant to salt and drought in seed germination and seedling growth.Salt stress coupled with drought stress could relieve salt ion toxicity to some extent,which has important ecological significance for S.ferganica to survive the early harsh environment.Moreover,the fruit wing plays an important role in puting the seed to dormancy under stress and then replenishing the soil seed bank. References | Related Articles | Metrics

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Ephemeral Plants and Their Newly Recorded Species in the Southwest Taklimakan Desert Aysajan Abdusalam, Pataimu Yiming, Kadir Abdurixit, ZHANG Kai 2019, 36 (4):  886-892.  doi: 10.13866/j.azr.2019.04.12 Abstract ( 6 )   PDF (1892KB) ( 1 )   In this paper,the ephemeral plants growing in desert environment in the southwest Taklimakan Desert were studied by the means of field investigation,specimens of finishing and data access,and their species compositions,life history characters (phenological characters) and flora characteristics were analyzed.The results showed that:① The ephemeral plants including 27 species in 21 genera and 8 families in the study area were preliminarily identified,which were Brassicaceae,Asteraceae,Solanaceae,Geraniaceae,Papaveraceae,Plantaginaceae,Boraginaceae,and Poaceae,in which there were 15 species in Brassicaceae.There were also 10 newly recorded species,i.e.,the Malcolmia scorpioides,Sisymbrium altissimum,Koelpinia linearis,Rromus squarrosus,Eremopyrum triticeum,Hyoscyamus pusillus,Sisymbrium heteromallum,Echinops gmelinii,Erodium stephanianum and Cardaria draba,accounting for 37% of the ephemeral species in the study area.② The life cycle of the ephemeral plants in this area was characterized by spring ephemeral plant type,winter ephemeral plant type and summer ephemeral plant type.The low-altitude environment was mainly expressed by the winter ephemeral plant type and spring ephemeral plant type,and the high-altitude environment was expressed by the winter ephemeral plant type and summer ephemeral plant type.③ The ephemeral plants in the study area belonged to the distribution patterns of northern temperate zone,the zone from Mediterranean-West Asia to Central Asia,Old World temperate zone,world temperate and Central Asia.Among them 15 species belonged to the distribution patterns of northern temperate zone and the zone from Mediterranean-West Asia to Central Asia,and they accounted for 51.86% of the total in the study area.Accordingly,especially the newly recorded species,enriched the database of plant genetic diversity in the special habitat of south Xinjiang,and also were of the important scientific significance for researching the response of ephemeral plants to different ecological environments. References | Related Articles | Metrics

Plant Physiology

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Effects of Soil Water Stress on Photosynthetic Characteristics and Biomass of Medicago sativa LIU Jun, QI Guang-ping, KANG Yan-xia, MA Yan-lin, LI Zhi 2019, 36 (4):  893-900.  doi: 10.13866/j.azr.2019.04.13 Abstract ( 537 )   PDF (1850KB) ( 462 )   Medicago sativa is an important legume forage in China,and it is strong in drought resistance. However,water deficit is still the main stress factor affecting its yield.The photosynthetic characteristics and yield of M.sativa under different water stress conditions were studied by carrying out the field experiments.The results showed that:① Soil water stress affected significantly the photoresponse parameters of M.sativa(P<0.05).With the increase of soil water stress,the maximum net photosynthetic rate,apparent quantum yield and light saturation point were decreased gradually,but the dark respiration rate and light compensation point were gradually increased,thus the dyssophotic absorption and conversion efficiency of M.sativa in its photosynthesis were directly affected.② With the increase of soil water stress,the net photosynthetic rate (Pn) and transpiration rate (Tr) of M.sativa leaves were reduced significantly,but the stomatal conductance (Gs) was decreased at first and then increased,which revealed that the stomatal factors under slight water stress were the main factors resulting in the Pn reduction,and the non-stomatal factors under moderate and severe water stress were the main factors resulting in the Pn reduction.③ When the photosynthetically active radiation (PAR) value was 1 200 μmol·m-2·s-1,the water use efficiency (WUE) of slight water stress was significantly higher than that of full irrigation (P<0.05),indicating that moderate water stress could improve the water use efficiency of M.sativa.④ There was no significant difference of hay yield between slight water stress and fully irrigation,indicating that high forage yield and water-saving irrigation could be achieved under slight water stress. References | Related Articles | Metrics

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Threshold Responses of Leaf Photosynthetic Physiological Parameters of Spring Maize to Soil Moisture and Its Productivity Classification REN Li-wen, WANG Xing-tao, ZHAO Hong, WANG Run-yuan 2019, 36 (4):  901-908.  doi: 10.13866/j.azr.2019.04.14 Abstract ( 16 )   Two modes including normal irrigation treatment and water stress treatment were designed in this experiment to discuss the threshold responses of leaf photosynthetic physiological parameters of spring maize to soil moisture and its productivity classification.The results showed that the change curves of photosynthetic rate (Pn),transpiration rate (Tr) and stomata conductance (Gs) were unimodal under normal irrigation treatment.The response of intercellular CO2 concentration (Ci) to soil moisture was opposite to that of stomata limitation (Ls).The Pn and Tr values were significantly decreased under water stress treatment,and the reduction of Pn value was mainly caused by the stomata limitation before grain-filling.As the degree of water stress was aggravated and the photosynthetic structure was damaged,the reduction of Pn was mainly caused by non-stomata limitation.Short-term water stress reduced the water use efficiency (WUE) of maize plant appropriately,which,however,was not significant,and the WUE could be reached a medium level.After a long-term and serious water stress,the WUE was decreased significantly compared to the situation under normal irrigation.Based on the photosynthetic physiological parameters,the soil moisture availability and the productivity of maize were classified and evaluated.The relative water content (RWC) ranging from 36.8% to 42.7% was classified as the low-yield and low-efficiency water treatment,that from 42.7% to 60.4% as the medium-yield and medium-efficiency one,that from 60.4% to 77.5% as the medium-yield and high-efficiency one,and that from 77.5% to 80.6% as the high-yield and high-efficiency one.It was observed that the RWC about 77.5% was optimal. References | Related Articles | Metrics

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Physiological Response and Transcriptome of Hordeum brevisubulatum to Drought Stress SONG Shi-wei, JIAO De-zhi, CHEN Xu, ZHAO Ze-long, YANG Yun-fei 2019, 36 (4):  909-915.  doi: 10.13866/j.azr.2019.04.15 Abstract ( 8 )   PDF (1496KB) ( 0 )   The physiological response of Hordeum brevisubulatum to drought stress was researched so as to identify the drought tolerance related to the genes,physiological indexes and transcriptome sequencing of H.brevisubulatum seedlings under different concentrations of polyethylene glycol (PEG) 6000 stress.The results showed that the content of proline in leaves of H.brevisubulatum was increased continuously after the PEG 6000 stress for 2 days,and the activity of soluble sugar and superoxide dismutase (SOD) was increased at first and then decreased.The membership function method was used to select the transcriptome analysis and sequencing of H.brevisubulatum leaves under the treatment of 30 mmol·L-1 PEG 6000.Compared with the control group,the 6 868 up-regulated genes and 2 081 down-regulated genes were identified.The differentially expressed genes were classified into three categories and 54 functional groups by Go function classification.The 6 579 differentially expressed genes were enriched into 136 pathways by KEGG pathway enrichment.Arginine and proline metabolism,glycolysis and gluconeogenesis,starch and sucrose metabolism,peroxisome pathways and other pathways,and the related up-regulated expression genes in various metabolic pathways were discovered. References | Related Articles | Metrics

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Dynamic Decomposition of Foliar Litters of Three Plant Species in Arid Habitats YANG Jing-jing, ZHOU Zheng-li, LYU Rui-heng, LIANG Ji-ye, WANG Xiong 2019, 36 (4):  916-923.  doi: 10.13866/j.azr.2019.04.16 Abstract ( 13 )   PDF (1122KB) ( 0 )   In this study,Populus euphratica,Tamarix ramosissima and Glycyrrhiza inflate in the Tarim Basin were taken as the research objects to analyze the dynamic decomposition of foliar litters of three plant species in arid habitats.The results showed that:① The residual rates of foliar litters of P.euphratica and G.inflata were 48.93% and 38.07% after a decomposition for 810 days,and the residual rate of foliar litters of T.ramosissima was 69.55% after a decomposition for 630 days.The decomposition time affected significantly the residual rates of foliar litters of the three plant species.The treatments affected significantly the residual rates of foliar litters of P.euphratica and G.Inflate.② The k values of foliar litters of the three plant species were significantly affected by understory-forest gap treatment (P<0.05),and the k values were in an order of kforest gap > kunderstory,kG.inflate > kP.euphratica > kT.ramosissima,the t0.95 values of P.euphratica and G.inflate were in ranges of 9.15-9.48 a and 6.75-7.03 a during 810-day decomposition.After a 630-day decomposition,the t0.95 value of T.ramosissima was in a range of 13.82-15.05 a.③ The effects of the decomposition time and treatments on the release process of C,N and P were different because of the difference of plant species.There was a release-accumulation-release process of C content of the three plant species,a process of release-accumulation of N content of T.ramosissima and G.inflata,and also a process of accumulation-release-accumulation of P content of P.euphratica understory during the observation period; ④ The k-value was significantly correlated with decomposition time,total nitrogen,the remaining amount of mass,total phosphorus,lignin,ratio of lignin and nitrogen (P<0.01),and soil moisture,total carbon,C/N were significantly correlated with kforest gap and kunderstory.Changes of micro-habitats (understory and forest gap) in arid areas have significant influence on litter decomposition,and litter quality and soil moisture play a leading role in litter decomposition. References | Related Articles | Metrics

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Estimation of Chlorophyll Content of Typical Oasis Vegetation in Arid Area Based on Sentinel-2 Data GU Feng, DING Jian-li, GE Xiang-yu, GAO Shi-bao, WANG Jing-zhe 2019, 36 (4):  924-934.  doi: 10.13866/j.azr.2019.04.17 Abstract ( 5 )   PDF (2901KB) ( 0 )   The Ogan-Kuqa River Delta Oasis,a typical oasis in the arid zone in China,was taken as the study area.The method of Random Forest with a comparative advantage in machine learning was chosen to model and estimate the relative contents of chlorophyll (SPAD values) of leaves from four kinds of representative vegetation (cotton,reed,poplar and jujube).The 23 broadband spectral indices of vegetation,which are sensitive to chlorophyll content,were obtained based on the reflectance of original Sentinel-2 image with rich spectral information in the “red edge” bands.These vegetation indices were extracted again in the original band order on the firstly-derived Sentinel-2 image and secondly-derived Sentinel-2 image.Three soil parameters (soil moisture content,SMC;soil organic matter,SOM;electrical conductivity,EC) related to vegetation growth were all conducted as the characteristic variables affecting SPAD values.According to the characteristic variables above,three modelling schemes could be developed to monitor the SPAD values of vegetation leaves in oasis.The results showed that: ① Vegetation indices obtained from the firstly-derived image played a more important role than the original vegetation indices in the SPAD estimation model. ② It could be concluded that SPAD-RF regression model,based on the Sentinel-2 satellite image data,could be used to effectively monitor the SPAD values of leaves of the four vegetation types.Especially for the estimation model of SPAD of reed leaves,R2 reached 0.926. ③ By analyzing and comparing the model prediction capability under the three schemes,the prediction capability of scheme 3 (including soil parameters) was excellent (2.143<relative percentage deviation (RPD)<2.692),and the prediction capability was ranked as scheme 3>scheme 1>scheme 2.There was a significant nonlinear correlation between the soil properties and the model prediction results.Holistically,Sentinel-2 data has great potential for predicting chlorophyll content of oasis vegetation.This study provided an efficient,low-cost,potentially high-precision solution to estimate SPAD. References | Related Articles | Metrics

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Effects of Arbuscular Mycorrhizal Fungi on Growth and Active Constituents of Carthamus tinctorius ZHAO Xiang, ZENG Guang-ping, YANG Pan, ZHAI Ya-ping, ZHANG Xia, LIU Hong-ling 2019, 36 (4):  935-942.  doi: 10.13866/j.azr.2019.04.18 Abstract ( 8 )   PDF (1554KB) ( 0 )   Arbuscular mycorrhizas (AM) fungi is widely distributed excellent microbial resources in soil ecosystems and it is often used in medicinal plants with important economic value.In this study, Carthamus tinctorius was inoculated with different AM fungi: Glomus mosseae, Glomus intraradices and Mixed AM fungi (G.mosseae, G.etunicatum, G.microagregatum, G.caledonium, G.cladoideum and G.intraradices), respectively and inoculated with the same amount of inactivated bacteria as the control group.The inoculation effect of AM fungi was identified by measuring the infection rate and spore density, and the content of HSYA and kaempferol in C.tinctorius velvet was determined by high performance liquid chromatography at different picking stages.The purposes of this study were to investigate the effects of AM fungi on the growth and active constituents of C.tinctorius, and to analyze the effects of different flowering stages on HSYA and kaempferol so as to provide an important theoretical basis for promoting agricultural production of C.tinctorius in Xinjiang.We measured the content of hydroxysafflor yellow A and Kaempferol in C.tinctorius velvet by the high performance liquid chromatography method at different picking stages.The results showed that AM fungi could significantly promote the accumulation of aboveground parts, underground roots and floral biomass of C.tinctorius.In terms of the synthesis of secondary metabolites, there was no significant difference in the content of hydroxysafflor yellow A and Kaempferol in C.tinctorius under different AM fungi treatments and different growth stages. References | Related Articles | Metrics

Water and Climate

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Drought Characteristics in Inner Mongolia Based on Precipitation Anomaly Percentage WU Ying-jie, LI Wei, WANG Wen-jun, QUAN Qiang, CHEN Xiao-jun, YIN Hang, ZHOU Quan-cheng, XU Kai-ran 2019, 36 (4):  943-952.  doi: 10.13866/j.azr.2019.04.19 Abstract ( 1032 )   PDF (2441KB) ( 395 )   The monthly precipitation data from 52 meteorological stations in Inner Mongolia from 1971 to 2015 were used. The methods of M-K test and precipitation anomaly percentage (Pa) were used to analyze the change trend and abrupt change of precipitation,and the spatiotemporal variation of drought at different time scales was also analyzed. The results showed that the inter-annual precipitation variation trend was basically maintained,and two abrupt changes took place in 1998 and 2012 in recent 45 years. Precipitation increased in spring,autumn and winter,but it was opposite in summer. Drought events occurred mainly in winter during the period from 1999 to 2011,and their frequency was the lowest in summer. Spatially,the annual precipitation decreased gradually from the east to the west. The change rate of precipitation was high in the area east of the Greater Khingan Mountains and west Bayan Nur,but it was low in Northwest Hulun Buir,central and southern parts of Tongliao,central part of Chifeng,and western Alxa. In addition,the probability of occurring drought at different levels was in an order of slight drought > extreme drought > moderate drought > severe drought. Drought events occurred generally in west Hulun Buir,Central-North Chifeng,North Tongliao,Central-West Xilin Gol League and West Alxa League. The Pa was in an increase trend in Central-East Hulun Buir,West Bayan Nur and East Alxa League,but it was in a decrease trend from South Hinggan League to Erdos and in Central-West Alxa. References | Related Articles | Metrics

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Variation of Aerosol and Its Effects on Precipitation in China Based on CMIP5 Models ZHAO Hong-fei, YANG Yi, DONG Jia-qi, LI Yu-zhen, LI Long-hui 2019, 36 (4):  953-962.  doi: 10.13866/j.azr.2019.04.20 Abstract ( 784 )   PDF (1860KB) ( 365 )   Aerosol plays an important role in the physical and chemical processes in the atmosphere.As more and more aerosols are discharged into the atmosphere due to the enhancement of human activities,the climate problems caused by aerosol emissions have also attracted wide attention.The purposes of this study were to analyze the change of aerosol optical thickness (AOD) and its effects on precipitation by applying the linear trend analysis,correlation analysis and empirical orthogonal function (EOF).The spatiotemporal variation of aerosol and its effects on precipitation since the industrial revolution in China was also approached based on the multi-mode experimental data provided by the Phase Five of the Coupled Model Intercomparison Project (CMIP5).The result showed that the variation of AOD in China was in an increase trend from 1860 to 2000 (P<0.001),the increase trend was more significant in the area east of the “Hu’s Line” than that in the area west of it and after 1945.The increase rate after 1945 〔0.380 7·(100a)-1〕 was significantly higher than that before 1945 〔0.029 0·(100a)-1〕.In the experiments in which the aerosol change was considered only,as the aerosol emissions were increased,precipitation was obviously decreased in 89.1% area of China (P<0.001).Precipitation was reduced predominantly in most of the southeast China,Sichuan Basin and southeast of Qinghai-Tibet Plateau,while the trend of precipitation reduction in northwest China was moderate.The decrease trend of precipitation was more significant after 1962 than that before it.The decrease rates were 118.04 mm·(100a)-1 in period after 1962 and 26.67 mm·(100a)-1 in period before 1962.The increase of aerosol emission served a role in the lessening of rainfall events' frequency and precipitation intensity by inhibiting the light precipitation,and their reduction rates were 3.16 d·(100a)-1,0.162 4 mm·d-1·(100a)-1,respectively.It provides an important scientific basis to study the climatic effects of AOD’s change on precipitation since the industrial revolution for better response to regional climate change in the future. References | Related Articles | Metrics

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Spatiotemporal Variation of Extreme Precipitation Indices in Inner Mongolia in Recent 55 Years CHUN Lan, QIN Fu-ying, BAO Lu, NA Yin-tai, BAO Yu-hai, BAO Shan-hu 2019, 36 (4):  963-972.  doi: 10.13866/j.azr.2019.04.21 Abstract ( 20 )   PDF (2491KB) ( 0 )   Nine extreme precipitation indices recommended by the Climate Change Monitoring and Index Expert Group (ETCCDI) were selected.The Sen’s slope,the Mann-Kendall nonparametric statistical test and Geostatistical Analyst methods were used to study the spatiotemporal variation of these indices based on the daily precipitation data from 100 meteorological stations in Inner Mongolia from 1960 to 2014.The results showed that the average extreme precipitation indices of the study area were in a decrease trend in varying degrees,and their interannual fluctuations were significant.Their interannual trends in the subareas were different,that is,in the eastern area,the wet days (NW) was in an increase trend,and other indices were in a decrease trend,among which the continuous drying index (CDD) was in a significant decrease trend (P<0.05); in the central area,all the extreme precipitation indices were in a decrease trend,and the reduction of total annual precipitation was more obvious; in the western area,the continuous wetness index (CWD),heavy precipitation (R95),monthly maximum 1-day precipitation (Rx1day),and monthly maximum consecutive 5-day precipitation (Rx5day) were in a decrease trend,and other indices were in an increase trend.Viewing from the spatial distribution of the change trend of extreme precipitation indices,the regional difference was significant.The stations with a general decrease trend of these indices were mainly distributed in the eastern and central areas of Inner Mongolia,and those with an increase trend were mainly distributed in the northeastern and western parts of Inner Mongolia. References | Related Articles | Metrics

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Spatiotemporal Variation and Driving Factors of Pan Evaporation in the Weihe River Basin ZHANG Peng-fei, ZHAO Guang-ju, MU Xing-min, GAO Peng, SUN Wen-yi 2019, 36 (4):  973-979.  doi: 10.13866/j.azr.2019.04.22 Abstract ( 17 )   PDF (1344KB) ( 0 )   It is better to quantitative assess the spatiotemporal variation and driving factors of pan evaporation for understanding the hydrological cycle and water resources management.In this study,it was attempted to use the data of daily pan evaporation observed with 20 cm pan from 1978 to 2002 and E-601 evaporator from 1985 to 2015 at 21 meteorological stations in the Weihe River Basin.A linear regression model was used to reconstruct the evaporation data at the observation sites.Spatiotemporal change of pan evaporation was analyzed using the Mann-Kendall test.Sensitivity analysis was employed to evaluate the contribution of meteorological factors to pan evaporation.The results showed that the multi-year average evaporation capacity of the evaporating dish in the study area was lower than that in the Yellow River Basin and the pan evaporation values were 1 015.5-1 705.6 mm.the mean annual pan evaporation decreased from the north to the south.The annual mean evaporation increased generally with an increase rate of 1.371 mm·a-1 in the whole watershed. The pan evaporation was the most sensitive to the actual vapor pressure.Temperature was the dominant factor affecting pan evaporation,and its contribution rate was approximately 304.5%. References | Related Articles | Metrics

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Spatiotemporal Change of the Beginning and Ending Dates of Snowfall in Jilin Province WANG Li-wei, HUANG Xiao-long, XU Hui, REN Jing-quan, MA Yun-fei, LIU Yu-ying 2019, 36 (4):  980-989.  doi: 10.13866/j.azr.2019.04.23 Abstract ( 12 )   PDF (2573KB) ( 0 )   The spatiotemporal changes of the beginning and ending dates of snowfall in Jilin Province were analyzed based on the data of daily precipitation and weather phenomena during the period of 1961-2015. The results showed that there were the spatial differences of the beginning and ending dates of the snowfall in Jilin Province,the beginning time of snowfall in the eastern mountainous area was early but the ending time was late,the ending time of snowfall in the western plain was early but the beginning time was late,the average snowfall dates began on October 22 and ended on April 18 next year. The first spatial pattern of beginning and the ending dates of snowfall was the early (late) pattern in the whole province. The second spatial pattern of beginning dates were the north-south reverse pattern,and the second spatial pattern of ending dates was the east-west reverse pattern. The beginning dates of snowfall occurred mainly in October and November,especially in mid-October,and the ending dates occurred mainly in April and May,especially in mid-April. There was a significant 8-year period of beginning dates of snowfall and a significant 5-year period of ending dates. There was a direct relationship between the beginning and ending dates of snowfall and the atmospheric circulation,the area of the West Pacific subtropical high was smaller and farther northward in the late years of the beginning dates but larger and farther southward in the early years. The area of the West Pacific subtropical high was smaller and farther southward in the late years of the ending dates of snowfall but larger and farther northward in the early years. The beginning and the ending dates of snowfall were also related to the geographical factors,they delayed with the decrease of altitude,while the ending dates became earlier with the increase of latitude and the decrease of altitude. References | Related Articles | Metrics

Ecology and Environment

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Spatiotemporal Variation of Ozone Concentration and Its Influential Factors in Inner Mongolia in Recent 3 Years CHEN Zhi-qing, SHAO Tian-jie, ZHAO Jing-bo 2019, 36 (4):  990-996.  doi: 10.13866/j.azr.2019.04.24 Abstract ( 680 )   PDF (1811KB) ( 385 )   In order to study the O3 pollution in Inner Mongolia and its influential factors,the data from the national environmental monitoring stations and national meteorological stations in 12 cities in Inner Mongolia from 2015 to 2017 were analyzed.The overall O3 pollution in 2017 was aggravated compared with that in 2015 and the O3 concentration was the highest and the most serious during the period from May to August,especially in July. Spatially,the O3 pollution was relatively more serious in the central and western parts of Inner Mongolia,while lower in the east parts which was synchronous with the economic development level. Particles,precursors and meteorological factors were the important factors affecting O3 concentration. There were the significantly negative correlations between the O3 concentration and the PM2.5,CO and NO2,and the O3 concentration decreased gradually with the increase of relative humidity. References | Related Articles | Metrics

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Factors Affecting Carbon Emission from Energy Consumption in Tianjin LI Xue-mei, ZHANG Qing 2019, 36 (4):  997-1004.  doi: 10.13866/j.azr.2019.04.25 Abstract ( 14 )   PDF (1142KB) ( 0 )   The LMDI model was applied to analyze the factors affecting carbon emission from energy consumption in Tianjin from 2000 to 2016 based on the estimated carbon emission data.The results indicated that the carbon emission in Tianjin was significantly affected by the scale of economy and energy intensity,which played the promotion and inhibition of carbon emission respectively.On which the economic variables were classified into high,medium and low scenarios,and the emission reduction variables were divided into two modes of medium emission reduction and strong emission reduction.By means of the combination,6 development modes including the high economic growth with strong emission reduction and the medium economic growth with strong emission reduction were obtained.Based on the STIRPAT extended model,the trend of carbon emissions in Tianjin under the 6 combination modes was predicted.The results showed that the mode of medium economic growth with strong emission reduction was the best for maintaining the economic development in Tianjin,and the carbon emission peaks and their occurring years were optimized compared to those of other modes. References | Related Articles | Metrics

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Change of Landscape Pattern Vulnerability in the Songhua River Basin in Jilin Province and Its Driving Forces SUN Hong-chao, ZHANG Zheng-xiang 2019, 36 (4):  1005-1014.  doi: 10.13866/j.azr.2019.04.26 Abstract ( 13 )   PDF (2944KB) ( 0 )   The Songhua River Basin in Jilin Province was taken as the study area,and the three Landsat TM/ETM images in 1995,2005 and 2015 were used as the data sources.The landscape pattern,spatiotemporal distribution of ecological vulnerability and its driving forces were studied.The main conclusions were as follows:① Climate change in the drainage basin was different from different periods.The dominant landscapes were cultivated land and woodland,the areas of urban and rural land and grassland were steadily enlarged,but the areas of woodland,cultivated land and waters were in a reduction trend.② The areas with low and moderate ecological vulnerability were dominant in the middle and lower reaches of the drainage basin,and the areas with high ecological vulnerability were mainly distributed in the southeast of the basin,northwest desertified land in the lower reaches,woodland and grassland.③ Ecological vulnerability of the drainage basin was relatively stable and in slight increase and polarization trends.The distribution of ecological vulnerability was closely related to the human activities,and it was related to the topographical conditions to some extent.The effect of climate change was not significant,which,however,could still reflect some ecological problems. References | Related Articles | Metrics

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Spatiotemporal Differentiation of Ecological Environment Quality in the Manas River Basin WANG Li-hong, ZHANG Jun-min, CHEN Wen-hao, ZHANG Ya-ru, KANG Zi-wei, SHI Hong-wei 2019, 36 (4):  1015-1023.  doi: 10.13866/j.azr.2019.04.27 Abstract ( 14 )   PDF (2282KB) ( 0 )   The ecological environment and its spatial differentiation is the basis for the sustainable development in arid region,and it profoundly affects the socio-economic and healthy development pattern in oasis.As a typical inland drainage basin,the Manas River Basin was taken as the research area,and the 3S spatial analysis and geostatistical analysis were used to select the normalized ecological indexes (such as vegetation coverage,slope and soil),and the transfer matrix model of superposition of ecological factors and functions was applied to analyze the spatiotemporal differentiation of ecological factors and environmental quality in the Manas River Basin in Xinjiang.The results could be concluded as follows:① In general,the spatial differentiation pattern of mountains,oases and deserts was still maintained in the Manas River Basin,the overall quality of the ecological environment was poor,but there was an improving trend.The change of urban and rural construction pattern determined the dynamic evolution of local environment.② The ecological environment quality of artificial oasis,mountainous area and piedmont buffer zone was the best,especially the vegetation coverage,soil restoration and soil and water conservation of mountain forest and grassland.The ecological quality of artificial oasis was the best,but the change was significant.Although soil salinization was controlled well,a big amount of salt was discharged into the downstream and surrounding areas,thus some new disasters were resulted in the natural oases.③ During the period of 2000-2008,the ecological environment in the drainage basin was slowly improved.Although the ecological regeneration in the oasis-desert ecotone was obvious,the shrinkage of alpine ice-snow continued.The ecological environment in the drainage basin was improved significantly during the period of 2008-2016. References | Related Articles | Metrics

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Wildlife Protection Awareness of the Community Herdsmen in the Karamori Mountain Ungulate Nature Reserve CHU Wen-wen, FENG Jin, LI Kai, HU De-fu, CHEN Gang, CHU Hong-jun 2019, 36 (4):  1024-1031.  doi: 10.13866/j.azr.2019.04.28 Abstract ( 8 )   PDF (1006KB) ( 0 )   The livelihoods of herdsmen and the influence of nomadic activities to the wildlife were investigated through face-to-face interviews with the herdsmen at winter-spring grazing sites in the Karamori Mountain Ungulate Nature Reserve.The purposes of the study were to reveal the understanding and awareness of wildlife conservation,competitive relationship between the nomadic herding and wildlife survival,concerns about the ecological compensation and other impacts related to the livelihoods of herdsmen in the nature reserve.The results showed that:① The economic income of 96.67% herdsmen in the nature reserve was steadily increased,and the traditional stock farming was the main economic income.② The herdsmen had strong awareness on wildlife conservation,and the main factors affecting the survival of ungulates in desert were snowstorms and droughts.③ The community herdsmen in the nature reserve thought that the ungulates in the deserts around the winter grazing sites in the nature reserve were increased,and they were optimistic about the coexistence of wildlife and livestock. ④ The community herdsmen in the nature reserve were willing to take actions based on the national policies including settlements,grazing restriction and even grazing prohibition,but the local government should establish and implement the rational ecological compensation and resettlement mechanism after implementing the grazing restriction. References | Related Articles | Metrics

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Low-Altitude Structure of Sandstorms for Inside and Outside the Shelterbelt in the Northeast Marginal Zone of the Ulan Buh Desert LUO Feng-min, GAO Jun-liang, XIN Zhi-ming, HAO Yu-guang, GE Gen-batu, LI Xin-le, DUAN Rui-bing, LIU Fang 2019, 36 (4):  1032-1040.  doi: 10.13866/j.azr.2019.04.29 Abstract ( 13 )   PDF (1669KB) ( 0 )   In this paper,the data of horizontal and vertical sand-dust flux and the annual wind speed and direction during eight sandstorms,collected from the sandwatch tower near the surface layer (0-50 cm) of Inner Mongolia Dengkou Desert Ecosystem National Observation Research Station,were used.The purposes of the study were to analyze the variations of sand-driving wind regime,distribution of wind-blowing sand and the effect of shelterbelt on sandstorms on small scale in the northeast marginal zone of the Ulan Buh Desert.The results were as follows:① The average wind speed inside and outside the shelterbelt increased with the increase of height,the wind speed profiles during sandstorms could be expressed by the power exponential function,the prevailing wind directions inside and outside the shelterbelt were W,WNW and NE,but their proportions were different.② The horizontal wind-blowing sand flux and the sand-dust concentration outside the shelterbelt decreased with the increase of height.The distribution of wind-blowing sand accorded with the exponential function,the horizontal wind-blowing sand flux and sand-dust concentration inside and outside the shelterbelt increased slowly with the increase of height,and the distribution of wind-blowing sand accorded with the power exponential function.The vertical wind-blowing sand flux inside and outside the shelterbelt decreased significantly with the increase of height,and the distribution of wind-blowing sand accorded with the power exponential function.③ When sandstorm passed through the shelterbelt system,the wind speed was significantly decreased with an average reduction of 31.03%,while the horizontal and vertical fluxes of wind-blowing sand were reduced by 298.16 g·m-2 and 0.37 g·m-2 respectively,and the concentration of wind-blowing sand was decreased by 22.48 g·m-2. References | Related Articles | Metrics

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Effect of Several Engineering Measures on Vegetation Coverage on Steep Slope in the Loess Region LIU Le, SUN Hong-yi, ZHANG Jian-xin, LI Dong-ze 2019, 36 (4):  1041-1048.  doi: 10.13866/j.azr.2019.04.30 Abstract ( 15 )   PDF (1467KB) ( 0 )   In this study,a section of steep slope in Lanzhou New Area was taken as the experimental site to analyze the characteristics of vegetation coverage over 4 kinds of micro-topography (long pit,small circular pit,large circular pit and original slope) formed after artificial land preparation at the early stage of vegetation reconstruction. Moreover,the environmental factors affecting vegetation coverage,including the soil hardness,soil moisture content,surface temperature,air temperature,slope position and slope covered with nonwovens,were also analyzed so as to look for several engineering measures to effectively improve the vegetation coverage.The results showed that: ① The vegetation coverage on the slope covered with nonwovens was significantly higher than that on the control slope,and the vegetation coverage at the different positions of steep slope was in an order of lower slope>middle slope>upper slope,which was consistent with the distribution of vegetation coverage on natural slope.② The vegetation coverage over 3 kinds of micro-topography was significantly higher than that on the steep slopes,in which the vegetation coverage,soil moisture content and duration of maximum vegetation coverage over the long pit were the highest and longest.③ The vegetation coverage over the micro-topography and slope was positively correlated with soil moisture content,but negatively correlated with air temperature and surface temperature.The soil hardness of micro-topography at 3 kg·cm-2 was suitable for plant growth,and it would restrict the plant growth if it was higher than this value.It was conducive to the growth of vegetation on the upper slope if it was covered with nonwovens.The results above revealed that,under the conditions that the slope gradient,slope position and temperature of steep slope could not be changed,the vegetation coverage could be effectively promoted by some engineering measures,such as land preparation and tillage on compacted slope,increase of the number of long pits and covering of nonwovens. References | Related Articles | Metrics