Table of Content

15 September 2016, Volume 33 Issue 5 Previous Issue    Next Issue

Climatic Change

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Spatiotemporal Variations of Extreme Precipitation in the Semiarid Region in North China during the Period of 1961-2010 WANG Bing-qin, JIANG Yuan, DONG Man-yu, WEN Yan 2016, 33 (5):  913-920.  doi: 10.13866/j.azr.2016.05.01 Abstract ( 547 )   PDF (1466KB) ( 1144 )   Using the methods of Mann-Kendall test, moving T-test and R/S, the spatiotemporal variations of precipitation extreme events in the semiarid region in north China during the period of 1961-2010 were analyzed based on the daily precipitation data from 49 meteorological stations within or adjacent to the study area. The results showed that the maximum 5-day precipitation, daily heavy precipitation, precipitation intensity, maximum consecutive humid days, consecutive drought days, heavy precipitation days and annual precipitation in the study area were in a decrease trend in recent 50 years. In which the maximum 5-day precipitation and the daily heavy precipitation passed the significance test at 0.1 level (P<0.1). An analysis based on Hurst index showed that the six extreme precipitation indices will continually decrease in the future, especially for CWD. The abrupt change of consecutive drought days occurred around 1985 and 1995, and that of other six extreme precipitation indices occurred around 1999-2000. Except the change of consecutive drought days, other six indices decreased from the northwest to the southeast. There was a certain regional difference of variation trend of the extreme precipitation indices, these indices were dominated by a decrease trend in the east of the study area but an increase trend in some areas of the central part. There was a significant positive correlation between the annual precipitation and the extreme precipitation indices except for the consecutive drought days, and the extreme precipitation indices were the good indicators for annual precipitation in the study area. References | Related Articles | Metrics

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Trends of Surface Dry-wet State of Ganjiahu in Xinjiang Based on Humid Index LUO Qing-hong, NING Hu-sen, CHEN Qi-min 2016, 33 (5):  921-926.  doi: 10.13866/j.azr.2016.05.02 Abstract ( 1 )   PDF (2104KB) ( 0 )   The monthly meteorological data were observed during the period of 1953-2013 at Jinghe and Wusu meteorological stations in the Ganjiahu Haloxylon Nature Reserve in Xinjiang, on which the monthly potential evapotranspiration (ET0) and the humidity index (Ia) were calculated by the Ivanov method. The seasonal and annual changes of surface dry/wet conditions and their main impact factors were analyzed. Results showed that the average values of ET0 in winter half year, summer half year and the whole year during the past 60 years were 298 mm, 1 107 mm and 1 407 mm respectively. The ET0 decreased in winter half year but increased in summer half year and the whole year. The Ia decreased in spring and summer but increased in autumn, winter and the whole year. Based on the climate zoning standards related to Ia, the nature reserve is a semiarid region in spring, extremely arid or arid region in summer and autumn, and humid and sub-humid region in winter. Ia was positively correlated with precipitation, vapor pressure and relative humidity, and negatively correlated with wind speed, air temperature and sunshine duration. Ia was influenced maximally by relative humidity, followed by sunshine duration, air temperature, vapor pressure and precipitation, and minimally by wind speed. References | Related Articles | Metrics

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Inversion Algorithm of Snow Cover Depth in Mountainous Area Based on Topographical Correction LI Chang-chun, BAO An-ming, YUE Ji-bo, WANG Yu, MA Chun-yan 2016, 33 (5):  927-933.  doi: 10.13866/j.azr.2016.05.03 Abstract ( 2 )   PDF (1557KB) ( 0 )   Snow cover depth is a necessary parameter for the operation of weather and hydrological models,and its monitoring is of importance in predicting snow melting runoff,managing water resources and preventing and controlling flood. Microwave remote sensing can be used to invert snow cover depth on different scales and provide the effective snow cover parameters for climate model and water cycle on global or regional scale. The available inversion algorithms of snow cover depth are often based on microwave remote sensing,in which the effects of land covers are considered only,but the comprehensive influence of topographical factors on inverted results is not considered. In the mountainous areas with undulating terrain,the surface signals observed with microwave radiometer are affected by terrain,and the surface energy is redistributed. The energy redistribution can not only cause the measurement error of sensor,but also can change the microwave scattering and radiation on land surface,and the inversion accuracy of the key surface parameters is influenced. In order to improve the accuracy of snow cover depth inversion in mountainous area,the effects of slope and aspect on snow cover depth inversion were studied in this paper,the slope and aspect corrections were added in inverting snow cover depth with microwave remote sensing,and a microwave radiation model was developed based on the topographic effect. A snow cover depth retrieval algorithm based on topographic correction was proposed. Experimental results showed that RMSE of snow cover depth inversion without terrain correction was 10.41,RMSE was 7.22 after terrain correction,and the accuracy of snow cover depth inversion was improved to some extent. References | Related Articles | Metrics

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Spatiotemporal Distribution and Abrupt Change of Snowfall in the West of South Xinjiang Nurbiye Tunyaz, Buzuhra Mamat, ZHANG Yun-hui 2016, 33 (5):  934-942.  doi: 10.13866/j.azr.2016.05.04 Abstract ( 2 )   PDF (1955KB) ( 0 )   The spatiotemporal distribution,interannual variation and continuity of snowfall in the west of south Xinjiang in recent 50 years were studied using the methods of precipitation variability analysis,snowfall contribution analysis,linear trend analysis and R/S analysis based on the daily precipitation data observed by 17 meteorological stations in the west of south Xinjiang during the period from 1961 to 2010,and the data were provided by Xinjiang Meteorology Information Center. According to the topographical and climatic conditions,the west of south Xinjiang was divided into three regions,i.e. the mountainous area,northwest and southeast plain. The periodicity variation of snowfall in different regions was analyzed with Morle wavelet transform. The abrupt change of snowfall was studied through the Man-Kendall abrupt change test. Combining with a sliding T-test and signal-to-noise ratio test,the abrupt change years were determined. Results are as follows: ① The spatial distribution of snowfall was not uniform. In the west of south Xinjiang,snowfall decreased rapidly from the northwest to the southeast. Snowfall contributed less to the annual precipitation,and its contribution rate was very unstable. The interannual variation of snowfall was significant; ② The average annual snowfall in the west of south Xinjiang was in an increase trend,which was related to the snowfall intensity,but the snowfall days were in a decrease trend; ③ Spatially,the tendency rates at the stations varied in a range of -0.01-0.16 mm·a-1. Snowfall at all the stations was in an increase trend except a slight decrease at Bachu Meteorological Station; ④ The contribution rate of slight snow decreased significantly,that of moderate snow was relatively stable,and that of heavy snow increased significantly. Moreover,the days of slight snow decreased,but those of moderate and heavy snow increased slowly; ⑤ The periodicity of low frequency was similar among different regions,but that of high frequency was different. In recent 50 years,the abrupt change of snowfall occurred in 1977 and 2000 in the western plain,but in 1995 in the mountainous area. References | Related Articles | Metrics

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Spatiotemporal Variation of Extreme Precipitation Events in Tajikistan during the Period of 1901-2013 WU Yan-feng, Bake Bater, LUO Na-na, LI Wei, WEI Xiao-qin, Rasulov H 2016, 33 (5):  943-951.  doi: 10.13866/j.azr.2016.05.05 Abstract ( 514 )   PDF (5634KB) ( 1407 )   Changes in extreme precipitation events exert a huge impact on human beings, and it is of vital importance to study the regular patterns of meteorological and hydrological factors under climate change. Based on the monthly 0.5°×0.5° gridded evapotranspiration and precipitation data during the period of 1901-2013 from Climate Research Unite (CRU), the spatiotemporal variation of extreme precipitation events in Tajikistan was analyzed by the methods of trend analysis, Mann-Kendall and wavelet analysis. The results are as follows:① The frequencies of annual, spring, autumn and winter extreme precipitation events were all in an increase trend with increase rates of 0.33 times·(10a)-1, 0.15 times·(10a)-1, 0.07 times·(10a)-1 and 0.20 times·(10a)-1respectively. The frequency of extreme precipitation events in summer was in a slight decrease trend. There were the obvious abrupt changes in frequencies of annual and seasonal extreme precipitation events; ② The frequencies of annual, spring, autumn and winter precipitation extreme events were high in Gorno-Badakhshan but low in the northwestern region of Khatlon and the northern region of Leninabad. However, they were high in the western region of Gorno-Badakhshan, northern region of Leninabad and eastern region of Khatlon but low in the westernmost and eastern parts of Tajikistan. The extreme precipitation events were in a significant increase trend in the eastern region of Khatlon and Tadzhikista Territories. The significant increase of frequency of extreme precipitation events indicated that there was a significant humidification in Tajikistan under climate change. This paper can provide a reference for the research on the spatial and temporal variation of water resources and the management and planning of water resources in Tajikistan under global warming. References | Related Articles | Metrics

Ecology and Environment

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Coupled Simulation of Urban Climatic Effect and Building Thermal Environment in Lanzhou LI Guo-dong, ZOU Guo-fang, ZHANG Jun-hua, WU Dong-xing, ZHANG Xi 2016, 33 (5):  952-960.  doi: 10.13866/j.azr.2016.05.06 Abstract ( 1 )   PDF (1983KB) ( 0 )   Rapid urbanization makes urban canopy be a complex system with complex meteorological factors and energy exchange. In this study,the numerical model was used to research the matter and energy flows between building and urban local climate and reveal the physical mechanism of urban climate effect. It is of important significance to find the balance point between the thermal comfortable,energy saving and environmental protection. AUSSSM model with thermodynamics and dynamics theory was the foundation of this study. As a valley city with the distinctive topographical features,serious air pollution and significant urban heat island effect,Lanzhou City was chosen as the study area to simulate and analyze the local climatic parameters of typical building group in summer and the daily variation of air temperature in urban canopy. The profiles of air temperature and humidity ratio in different periods were simulated. The variation of temperature at the east,west,south and north metopes from the ground floor to the cockloft of building were simulated. The daily variation of surface temperature and evaporation of barer soil,asphalt,lawn and concrete roof were also simulated. The distribution of shortwave radiation in urban canopy,shortwave radiation of earth reflection,inverse long-wave radiation,ground long-wave radiation,net radiation and the effect of aerosol on radiation transfer were revealed. References | Related Articles | Metrics

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Wind-tunnel Simulation on the Effects of Sand Cemented Bodies with Different Sizes on Surface Wind Erosion and Windblown Sand Discharge ZHOU Jie, WANG Hai-feng, LI Sheng-yu, LIU Zhi-hui, YUAN Xin-xin, FAN Rui-jing 2016, 33 (5):  961-965.  doi: 10.13866/j.azr.2016.05.07 Abstract ( 2 )   PDF (2083KB) ( 0 )   Sand cemented bodies (SCB) were extensively distributed in the hinterland of the Taklimakan Desert. In this study, the effects of SCB with different sizes on restraining aeolian erosion and windblown sand discharge were researched by wind tunnel simulation. Results showed that wind velocity and SCB size were the main factors affecting aeolian erosion. Under certain wind conditions, aeolian erosion restraint rate was decreased exponentially with the increase of SCB size. Under a certain SCB coverage, wind erosion rate was increased with the increase of wind velocity, and the bigger the SCB size was, the more obvious the increase trend of wind erosion with the increase of wind velocity would be. SCB size was the dominant factor affecting the surface windblown sand discharge, but not wind velocity. With the increase of SCB size, there was a rising process of sand grains on the SCB mulch bed, and the windblown sand discharge was increased with the increase of SCB size. The effect of SCB mulch bed in restraining the windblown sand discharge was mainly reflected by SCB density, and the lower the coverage was, the higher the windblown sand discharge would be. At the same SCB coverage, the distribution density and number of the large-sized SCB were lower than those of small-sized SCB. Therefore, the surface windblown sand discharge was relatively high. The restraint of SCB with different sizes to wind erosion and windblown sand discharge was in an order of 2-3 mm<3-5 mm<5-7 mm<7-10 mm<10 mm. References | Related Articles | Metrics

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Effects of Simulated Nitrogen Deposition on Decomposition and Nutrient Release of Leaf Litter of Picea schrenkiana ZHANG Yu-tao, LI Ji-mei, LI Xiang, LU Jian-jiang, HAN Yan-liang, LI Jian-gui 2016, 33 (5):  966-973.  doi: 10.13866/j.azr.2016.05.08 Abstract ( 491 )   PDF (1729KB) ( 950 )   A field simulated experiment was conducted to research the effects of nitrogen deposition on the decomposition and nutrient release of leaf litter of Picea schrenkiana. Four treatments were designed,i.e. the CK (contrast,non-addition nitrogen),LN (low nitrogen,5 kg·hm-2·a-1),MN (mid nitrogen,10 kg·hm-2·a-1) and HN (high nitrogen,15 kg·hm-2·a-1). The results are as follows:① After a 24-month decomposition,the residual rate of leaf litter dry weight of P.schrenkiana in CK was 1.04,1.16 and 1.23 times of that in LN,MN and HN respectively,and the difference among the four treatments was significant (P<0.05). The required time for 50% decomposition of leaf litter in CK was 4.58 a,which was 0.46 a,0.75 a and 1.35 a longer than that in LN,MN and HN,and correspondingly,it was 2.01 a,3.24 a and 5.87 a longer for 95% decomposition,respectively. The results revealed that nitrogen deposition promoted the decomposition of leaf litter of P.schrenkiana,especially at latter stage of decomposition. Moreover,the promotion was more obvious with the increase of nitrogen deposition; ② Monthly decomposition rate was in an order of HN>MN>LN>CK. Moreover,the difference among the four treatments was gradually reduced with the time of decomposition; ③ Nitrogen deposition promoted the release of lignin,cellulose and carbon in leaf litter of P.schrenkiana,and increased the accumulated nitrogen,and decreased the C/N. References | Related Articles | Metrics

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Change of Ecosystem Service Value Scheme in the Yanqi Basin,Xinjiang LI Ya, LIU Jian-wei, WANG Yang 2016, 33 (5):  974-980.  doi: 10.13866/j.azr.2016.05.09 Abstract ( 1 )   PDF (1869KB) ( 0 )   In this paper, the land use/cover change (LUCC), system stability and ecosystem service value in the Yanqi Basin, Xinjiang, China were investigated based on the land use/cover classification data derived from the Landsat TM images in 1990, 2000 and 2010. The results are as follows: ① During the period of 1990-2010, the land use/cover change in the Yanqi Basin was obvious, which was characterized by the enlargement of cultivated land area and the reduction of grassland area to some extent, and the rapid expansion of cultivated land occurred during the period of 2000-2010; ② During the period of 2000-2010, the information entropy and balance degree of land use were rapidly increased, which revealed that the instability of land use system and the instability of oasis were serious, and then the ecological security in the lower reaches of the Tarim River was threatened; ③ The value of ecosystem services in the study area was increased at first and then decreased, and the harmonious development of the “ecology-economy-water” did not be achieved due to the big consumption of water resources, which should be emphasized. References | Related Articles | Metrics

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Short-term Dynamic Change of Mega-dunes around the Crescent Spring in Dunhuang AN Zhi-shan, ZHANG Ke-cun, NIU Qing-he, TAN Li-hai, PANG Ying-jun, WU Kai-dong 2016, 33 (5):  981-987.  doi: 10.13866/j.azr.2016.05.10 Abstract ( 1 )   PDF (1480KB) ( 0 )   The Crescent Spring is a special scenery,so the study on its formation and preservation attracts more and more attention. In this paper,the data observed by the field meteorological station and the total station were applied to analyze the short-term dynamic change of the mega-dunes around the Crescent Spring. Results showed that the mega-dunes were stable during the observation period,which was different from the former conclusions drawn from the interpreted results of perennial aerial photographs that the longitudinal dunes in the south moved northward,the pyramid dunes in the north moved southward,and the Crescent Spring was threatened. The crest line of the mega-dunes shifted in an oscillating way. Sand erosion or deposition occurred on the dune surface,which was closely related to the wind regime,sand sources,underlying surface,barriers,etc. The observation revealed that sand erosion occurred on the windward slope and sand deposition occurred on the leeward slope. The displacement laws of the mega-dunes around the Crescent Spring were revealed,which could be referred in protecting the Crescent Spring. References | Related Articles | Metrics

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Assessment of Landscapes along the China-Pakistan Karakorum Highway WANG Yu-di, WANG Yun, KONG Ya-ping, CHEN Xue-ping, WANG Ying, YE Cheng-yin, SHI Yao-hua 2016, 33 (5):  988-995.  doi: 10.13866/j.azr.2016.05.11 Abstract ( 2 )   PDF (1976KB) ( 0 )   Honoured as the “Eighth Wonder of the World”, the China-Pakistan Karakorum Highway (KKH) is a pathway along the ancient Silk Road, and it is one of the roads with the highest altitude in the world. Based on the ecological, aesthetic, cultural and safe views, in this study the indicator system of assessing the landscapes along the highway was developed, weights of the indicators were derived from AHP, scores of the indicators were obtained from the available data and also the experts, and the quality of landscapes on small scale (every 15 km) along the KKH was acquired from the comprehensive evaluation model. There were two advantages for the method of landscape assessment in this study: firstly, the safe factors were added into the indicator system because the geological disasters occurred frequently along the mountainous highway sections; secondly, the 360°-panoramic pictures were taken to simulate the landscapes along the highway as true as possible. The results indicated that the quality of landscapes along the KKH was holistically good, especially along the highway section in the Khunjerab National Park, and the aesthetic, ecological and cultural values were all high along the highway section from Passu to Hunza. Therefore, the roadside landscapes should be strictly preserved. The landscape quality along some highway sections is low because of the frequent occurrence of geological disasters, so we should preserve the landscapes under the conditions of controlling the disasters along the KKH. References | Related Articles | Metrics

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Eco-efficiency of Land Use Based on Ecological Green Equivalent in the Manas River Basin HU Meng-meng, ZHANG Jun-min, XU Li-ping, TANG Xiang-ling, WANG Ling 2016, 33 (5):  996-1002.  doi: 10.13866/j.azr.2016.05.12 Abstract ( 606 )   PDF (1451KB) ( 782 )   Based on the principles and methods of ecological green equivalent, firstly, the scores of ecological service functions of different land use/cover types were designed. Secondly, the equivalent values of land use change were estimated. On which an assessment model was framed to assess the eco-efficiency of land use in the Manas River Basin. The results showed that the net enlargement of ecological equivalent area was 150.71 km2 in the Manas River Basin in recent 30 years, and there was an enlargement trend in a slight fluctuation way. The enlarged areas of farmland and waters were the largest, they were 456.63 km2 and 181.7 km2 accounted for 29.25% and 77.32% of the equivalent area in 2013, respectively. The reduction of natural grassland, unused land and wasteland was obvious, and their equivalent areas were reduced by 129.12 km2, 132.98 km2 and 230.36 km2 and accounted for 29.48%, 11.32% and 17.49% of the equivalent area in 2013, respectively. The eco-efficiency of landscape was increased by land management, but the land reclamation and grassland degradation resulted in a fragile balance. References | Related Articles | Metrics

Biological Resources

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Spatial Distribution of Nitraria tangutorum Communities and Its Environmental Interpretations in the Minqin Oasis-desert Ecotone ZHAO Peng, XU Xian-ying, QU Jian-jun, YU Qiu-shi, ZHANG Jin-hu, MA Jun-mei, SUN Tao, WU Yong-mei 2016, 33 (5):  1003-1011.  doi: 10.13866/j.azr.2016.05.13 Abstract ( 2 )   PDF (2158KB) ( 0 )   Based on the survey of plant and environmental factors,the methods of TWINSPAN and RDA were applied to research the relationships between the spatial distribution of Nitraria tangutorum communities and environmental factors in the Minqin oasis-desert ecotone. The results showed that the species composition of N.tangutorum communities was simple. There were only 17 plant species in 17 genera and 8 families obtained from 31 samples. The two-way indicator analysis (TWINSPAN) was used to classify the N.tangutorum communities into 4 types: Ass.Nitraria tangutorum-Artemisia.arenaria+Agriophyllum squarrosum,Ass.Nitraria tangutorum+Reaumuria soongarica-Eragrostis pilosa,Ass.Nitraria tangutorum+Phragmites australis-Salsola collina,and Ass.Nitraria tangutorum+Lycium ruthenicum-Halogeton glomeratus. The composition variation of N.tangutorum communities was resulted in by the difference of environmental factors. The classified results of TWINSPAN were reflected clearly in the RDA two-dimensional ordination diagram for samples and environmental variables. The first axis of RDA two-dimensional ordination showed the moisture gradient dominated by groundwater depth. The second one reflected the gradient of sand sources and soil texture in response to the distance between samples and oasis. The tested results of Monte Carlo permutation of the selected environmental factor revealed that the effects of groundwater depth and distance between oasis and samples on the spatial distribution of N.tangutorum communities were significant. References | Related Articles | Metrics

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Effect of Layout Styles of Drip Irrigation on Grape aboveground Biomass in an Extremely Arid Area SU Li-jun, WANG Quan-jiu, WU Zhong-dong 2016, 33 (5):  1012-1019.  doi: 10.13866/j.azr.2016.05.14 Abstract ( 1 )   PDF (2479KB) ( 0 )   In this study,the experiments of 4 layout styles of drip irrigation in the Turpan-Hami Basin were carried out so as to understand the effects of drip irrigation on grape (seedless white) growth and yield and provide the theoretical basis for grape water-saving irrigation in arid area. The traditional furrow irrigation was taken as the contrast,and the soil moisture content,leaf area index,aboveground biomass of grape were analyzed. The results showed that the distribution of soil moisture content for T2 was uniform,it achieved the field capacity in the main rhizosphere,the whole rhizosphere was moist,and the moisture content in topsoil was low,thus the soil evaporation was reduced. The distribution of soil moisture content for T3 was not uniform,the soil moisture content in rhizosphere was lower than the field capacity,and the rhizosphere could not be completely wetted. Thus,T2 was the most appropriate layout style for grape irrigation in such extremely arid area. Moreover,the leaf area index and the dry biomass of grape were in an order of T2>T1>T4>T3. There was no significant difference between theoretical and measured values when the logistic model was used to simulate the relationship between leaf area index and accumulated temperature,and there was a high linear correlation between the theoretical values and the measured values of net dry biomass of grape. References | Related Articles | Metrics

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Variation Patterns of Characters of Twelve Parmotrema tinctorum Individuals in Different Habitats WANG YU-liang, Ardil Jiang, Abuttula Abas, ZHU Guo-ping 2016, 33 (5):  1020-1027.  doi: 10.13866/j.azr.2016.05.15 Abstract ( 1 )   PDF (1433KB) ( 0 )   The relationships between biological characters of Parmotrema tinctorum in twelve individuals and their environmental factors were analyzed by the methods including the Redundancy analysis (CDA),and the variation patterns of the characters in different habitats were described.The results showed that the biological characters manifested a stability to a certain extent within individual,but they holistically had a great variability,and the anatomical character hyphae diameter had the minimum variation coefficients not only within individuals,but also as a whole.Redundancy analysis showed that the humidity had a significant negative correlation with illumination (an environment factor),the most-positive one with hyphae diameter,and the most-negative one with medulla width (a biological index).While the altitude had the most-positive correlation with rhizoid density and the most-negative one with lower cortex width.The amount of algae layer could reflect the comprehensive environment change very well,while the content of atranorine in organism could response to illumination of certain habitat sensitively.The material investment among different function parts of lichen thallus,which is of great importance in revealing the response model of lichens to environment change,deserves to investigate deeply. References | Related Articles | Metrics

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Estimation of RS-based Biomass of Phragmites communis in Wetland of the Ulansuhai Lake BAO Han, ZHUO Yi, LIU Hua-min, LIU Dong-wei, QING Hua, WEN Lu, WANG Li-xin 2016, 33 (5):  1028-1035.  doi: 10.13866/j.azr.2016.05.16 Abstract ( 2 )   PDF (2690KB) ( 0 )   In this study, the biomass values of Phragmites communis in the Ulansuhai Lake in Inner Mongolia were estimated by the means of quantitative remote sensing. Based on monitoring the biomass in growing season of Phragmites communis on the fixed locations, the correlations between the measured data of fresh weight and dry weight at different monitoring points and the four vegetation indexes (NDVI, DVI, PVI and RVI) in the same period were analyzed. The linear estimation model and a variety of non-linear estimation models were developed. The results showed that there were the significant positive correlations between the aboveground biomass (including fresh weight and dry weight) of Phragmites communis in the Ulansuhai Lake and the selected four vegetation indices. The optimal models of fresh weight and dry weight were all based on the cubic polynomial estimation model of NDVI. The accuracy test results showed that the predicted values were close to the measured ones by using NDVI cubic polynomial model to calculate the fresh weight and dry weight. The average error of fresh weight was 19.90%, and the fitting accuracy was as high as 80.10%. The average error of dry weight was 18.71%, and the fitting accuracy reached 81.29%. These could meet the need of macro estimation of regional biomass of Phragmites communis in the Ulansuhai Lake. Through analyzing the spatial distribution of biomass of Phragmites communis in the study area in July 2013, it could be obtained that the dry and fresh weights of biomass of Phragmites communis varied in ranges of 1 000-1 500 g·m-2 and 3 000-4 500 g·m-2 respectively. References | Related Articles | Metrics

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Effects of Nitrogen Dressing Schedule on Photosynthetic Efficiency and Yield of Cotton Plant in Shade ZHENG Jian-chao, ZHANG Ju-song, YAN Man-man, ZHENG Hui, ZHANG Yu-ling 2016, 33 (5):  1036-1042.  doi: 10.13866/j.azr.2016.05.17 Abstract ( 1 )   PDF (2336KB) ( 0 )   The purposes of this study were to explore the appropriate nitrogen dressing schedule under fruit and cotton intercropping and provide the theoretical basis about the rational nitrogen application for intercropping cotton field. The experiment material was the central cotton No.49 and performed without shade (CK) and with 50% shade,and three nitrogen dressing schedules,i.e. the N1 (nitrogen dressing forward),N2 (normal nitrogen topdressing) and N3 (the proportion of nitrogen dressing forward was higher than that of N1),were designed for each treatment so as to explore the effects of nitrogen dressing on the photosynthetic characteristics and yield of cotton in shade under drip irrigation under mulch. The results showed that the chlorophyll content and leaf area index of cotton plant in 50% shade were increased,the net photosynthetic rate was decreased,the proportion of bolls before hot summer days was decreased,and the proportion of autumn bolls was increased compared with those in CK. Under 50% shade,the photosynthetic rate of cotton plant under nitrogen dressing forward (N1) was appropriately increased,the formation and accumulation of photosynthetic products were promoted,the proportion of bolls before hot summer days was increased,and the bolls per plant,weight per boll and lint yield were significantly increased. Therefore,the nitrogen dressing forward (N1) could be considered as an effective way to improve the efficiency of solar energy utilization and cotton yield under fruit and cotton intercropping. References | Related Articles | Metrics

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Effects of Feeding Stage and Food Type on Developmental Parameters of Chrysopa pallens(Neuroptera:Chrysopidae) Alipu Naser, MENG Ling, LI Bao-ping 2016, 33 (5):  1043-1045.  doi: 10.13866/j.azr.2016.05.18 Abstract ( 2 )   PDF (624KB) ( 0 )   Intra-guild predation is widespread in the aphid natural enemy communities,and the eggs are mostly the intra-guild prey. When and what kinds of food is influential on the larval growth until imagoes of Chrysopa pallens from crop fields in arid ecosystems in Xinjiang were investigated,and the growth and survival parameters of C.pallens were observed and compared based on the different larval stages (from neonate to the 4th instar) and the different kinds of food (cotton aphids,cotton aphids plus 7-spot ladybird Cocinellina septempuntata eggs,and 7-spot ladybirds' eggs. The results showed that there was a significant interaction between foot kinds and feeding stages. Survival of C.pallens from the larval stage to the imago stage performed a similar pattern,and it was higher when fed with“aphids”and “aphids plus 7-spot ladybird eggs” than with“7-spot ladybird eggs”. The survival rate was lower with feeding stage treatments from neonate than from the 4th instar larvae. The results of this study suggested that it was difficult to accomplish the growth of C.pallens larvae either from neonate stage or imago stage by feeding with C.septempuntata eggs only. References | Related Articles | Metrics

Plant Physiology

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Distribution of Carbon Isotope Composition of Epilithic Mosses and Their Environmental Significance in the Mount Taibai,China ZHANG Pu, DING Zong-ju, HOU Yao-yao, BAI Hong-ying, REN Xiao-qian, ZHAO Pei 2016, 33 (5):  1046-1056.  doi: 10.13866/j.azr.2016.05.19 Abstract ( 1 )   PDF (3314KB) ( 0 )   There are the congnitive differences in the response and mechanism of plant δ13C to altitude. Furthermore,it is difficult to find a plant species growing at different altitudes to reduce carbon isotope fractionation difference between species. Bryophytes are the good bioindicator plants with their relative simple structure,high sensitivity to environmental change,and wide distribution with altitude gradient. However,the effect of altitude change and environmental change on carbon isotope of bryophytes was discussed in few researches only. In this paper,carbon isotope composition (δ13C) of epilithic mosses at different altitudes in the north and south slopes of the Mount Taibai was analyzed. The effect of environmental factors on the relationship between carbon isotope of epilithic mosses and altitude was also discussed. A significant linear correlation between δ13C of epilithic mosses and altitude in the north and south slopes of the Mount Taibai was found (south slope:R2= 0.45 and P<0.01; north slope:R2=0.31 and P<0.01). The δ13C of epilithic mosses in the north and south slopes of the Mount Taibai increased by 2.0‰ and 1.1‰ when the altitude increased by 1 000 m. Moreover,the effect of atmospheric CO2 concentration and its carbon isotope composition,atmosphere pressure,precipitation,biomass,etc. on the response of carbon isotope composition of epilithic mosses to altitude was low. Temperature may be the main factor affecting δ13C of epilithic mosses in the Mount Taibai. References | Related Articles | Metrics

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Allelopathy of Aqueous Extracts from Stems,Leaves and Roots of Oxytropis glabra on Seed Germination of Three Common Plant Species in Grasslands LIU Li-hong, LIU Guo-hou, CAO Rui, WANG Jian, LAN Qing, LI Hong-ying, BA Tu-na-shun 2016, 33 (5):  1057-1062.  doi: 10.13866/j.azr.2016.05.20 Abstract ( 1 )   PDF (645KB) ( 0 )   Oxytropis glabra is a poisonous perennial herbaceous plant,it can become the dominant weeds on degenerated pastures. Melilotoides ruthenica,Astragalus Melilotoides and Agropyron mongolicum are the common high-quality forage grasses in grasslands. In this paper,O.glabra was taken as the donor plant to study the effects of aqueous extracts from roots,stems and leaves with different concentrations on seed germination of 3 receiver plants. The results show that there was an allelopathy of aqueous extracts from the stems,leaves and roots of O.glabra on the seed germination rate,germination index,plumule length and radicle length of the plants. The allelopathy of the two kinds of aqueous extracts on the germination index was higher than on the seed germination rate,and that on the radicle length was higher than on the plumule length. Allelopathy of different donor parts to the different receiver plants was significantly different,and that of the aqueous extracts from stems and leaves was higher than that from roots. Results showed that the allelopathic sensitivity of the three receiver plants to the two kinds of aqueous extracts was in an order of A.mongolicum>A.melilotoides>M.ruthenicus. The effects of two kinds of aqueous extracts with different mass concentrations on the receiver plants revealed that the higher the concentration was,the stronger the allelopathy would be. The inhibition of aqueous extract with high mass concentration (≥10 mg·mL-1) was significant,but that with low mass concentration (≤5 mg·mL-1) was not significant. References | Related Articles | Metrics

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Expression of Stress-resistant Gene of Two Grape Varieties to Manganese Toxicity Response GUO Wan-ying, XIAO Xin-long, YIN Wen-yan, YAO Yin-an 2016, 33 (5):  1063-1070.  doi: 10.13866/j.azr.2016.05.21 Abstract ( 2 )   PDF (2850KB) ( 0 )   Two grape varieties (Gold Finger and Campbell) were taken as the materials to carry out a sand culture experiment,study the different expressions of genes of roots and leaves under various MnSO4 stresses,and explore the differences in varieties and tissue in gene expression. It was found that,under the excess Mn stress,the up-expression folds of Vitis vinifera brassinosteroid-6-oxidase gene in the roots of Gold Finger were 2,and there was no significant change for other genes. In the leaves,the up-expression folds of V.vinifera copper chaperone for superoxide dismutase-like gene and V.vinifera brassinosteroid-6-oxidase gene were 2,and the up-expression fold of pathogenesis-related protein 1 gene were 5. For the expression of V.vinifera 4-coumarate:CoA ligase gene was a half of CK. At Campbell,the up-expression folds of V.vinifera brassinosteroid-6-oxidase gene,3-deoxy-D-arabino-heptulosonate 7-phosphate synthase gene and purple acid phosphatase 3-like gene in roots were 2,there was no obvious change for others,and those of pathogenesis-related protein 1 gene varied from 2 to 3. The experiment indicated that,under Mn stress,the tolerance of both the grape varieties to excess Mn stress responded through the different expressions of stress resistance gene,and phosphoric acid hydrolases also had a synergistic effect. There were the different regulatory approaches between roots and leaves of these genes due to the different ways of manganese enrichment in two grape varieties. From the different gene expressions,pathogenesis-related protein 1 gene and V.vinifera brassinosteroid-6-oxidase gene had the most significant manifestations,and they may be at an important position in the way of resistance to excess manganese. References | Related Articles | Metrics

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Relationship between Morphological or Anatomical Features of Leaves and Trunk Diameter at Breast Height at Different Growing Stages of Populus euphratica ZHAO Peng-yu, FENG Mei, JIAO Pei-pei, LI Zhi-jun 2016, 33 (5):  1071-1080.  doi: 10.13866/j.azr.2016.05.22 Abstract ( 608 )   PDF (2382KB) ( 1219 )   In this study,the leaf morphological and structural features of Populus euphratica at different growing stages and their relationships with DBH were researched. Results are as follows: ① Along with the increase of DBH and crown level from the base to the top,the leaf width,area,stomatal density and thickness of leaves of P.euphratica were gradually increased,while the leaf length and leaf index(leaf length/leaf width) were steadily decreased; ② The cell number,length of epidermal cells and thickness,and length and width of palisade tissue were gradually increased with the increase of diameter at breast height and crown level(from base to top),while the thickness of spongy tissue was gradually decreased with the increase of diameter at breast height but increased gradually from the base to the top; ③ Correlation analysis revealed that there were the extremely significant or significant positive correlations between the DBH and the leaf width,area and thickness,but there was a significant negative one between DBH and leaf index. There were the significant positive or negative correlations between palisade tissue thickness,epidermal cell length,cell number,thickness of epidermal tissue and DBH. There was a significant negative correlation between thickness of spongy tissue and DBH. There were also the significant positive or negative correlation between leaf morphological parameters and leaf anatomical and structure parameters. References | Related Articles | Metrics

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Anatomic Features of the Stems of 10 Species in Bryum from the Headwaters of the Urumqi River Aifeire Abuduaini, WANG Hong 2016, 33 (5):  1081-1087.  doi: 10.13866/j.azr.2016.05.23 Abstract ( 427 )   PDF (3781KB) ( 855 )   Comparative anatomy of the stems of 10 species in Bryum from the headwaters of the Urumqi River was researched using the paraffin sections and scanning electron microscopy (SEM).The results showed that the stems of 10 species in Bryum were constituted of three parts,i.e.the epidermal,cortex and central axis.Epidermal cells were small,and the cell wall thickened strongly.Cortex cells arranged neatly or in a mosaic way,and the cell wall thinned gradually from outside to inside.Axis cells occupied small area,and the corner of cell wall thickened.Pores were distributed irregularly on the cell wall of stem,and the adjacent cell walls were thick with flaky or granular cuticle ornamentation on their surface.These characters would be the survival strategy of plants in severe environment for a long time,and they revealed that the stem of Bryum was characterized by the strong cold-resisting and drought-enduring capabilities.These species are quite similar in morphology,but each species has different anatomical structure,which can provide a taxonomical basis for species identification. References | Related Articles | Metrics

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Application of Hyperspectral Indices for Estimating Leaf Chlorophyll Content of Assimilating Shoots of Tamarix ramosissima ZHANG Si-nan, WANG Quan, JIN Jia, XU Lu, GUAN Hai-ying 2016, 33 (5):  1088-1097.  doi: 10.13866/j.azr.2016.05.24 Abstract ( 1 )   PDF (1081KB) ( 0 )   The knowledge of dynamic change of leaf chlorophyll content is an important prerequisite for better understanding the featured carbon cycle as well as other ecological functions in desert ecosystems.Non-destructive rapid estimation of chlorophyll content is a prerequisite to dynamically monitor chlorophyll content,and it is an important research issue of vegetation remote sensing.In this study,a total of 86 spectral indices published previously were collected for assessing their capabilities of estimating chlorophyll content of assimilating shoots of Tamarix ramosissima,a constructive species in desert ecosystems.Three indices with simple structure and good performance,i.e.R860/(R550×R708),1/R700 and R550,were selected,their determination coefficients (R2) were 0.49,0.47 and 0.40,and their root-mean-square errors (RMSE) were 2.40,2.45 and 2.59 μg·cm-2,respectively.The validated errors of bootstrapping of the three indices were 2.47,2.53 and 2.67 μg·cm-2 respectively.Our results indicated that these identified indices may be used for monitoring the dynamic change of chlorophyll content of T.ramosissima in arid land to a certain extent,it remains an important challenge to develop new better hyperspectral indices for estimating chlorophyll content of assimilating shoots. References | Related Articles | Metrics

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Diversifolious Types and Spatiotemporal Characteristics of Populus pruinosa Schrenk LIU Shuai-fei, JIAO Pei-pei, LI Zhi-jun 2016, 33 (5):  1098-1103.  doi: 10.13866/j.azr.2016.05.25 Abstract ( 444 )   PDF (2039KB) ( 743 )   In this study,the diversifolious types and spatial distribution of Populus pruinosa Schrenk under the same site conditions in the northwestern marginal zone of the Tarim Basin were researched so as to reveal the growing and vertical distribution of heterophylls of P.pruinosa with the variation of diameter class stage as well as their relationship. The results are as follows: ① Broad oval leaves,round leaves and broad ovate leaves turned regularly and grew at different diameter class stages when broad oval leaves grew at 2-20 diameter class stage,while round leaves and broad ovate leaves grew from 4 and 6 diameter class stages,and they grew from the top canopy. Growth of heterophylls was associated with the individual developmental stages; ② The growing frequencies and the proportions of heterophylls at the vertical spatial distribution areas in the canopy height changed dynamically with the change of diameter class stage,in which the growing frequency and the proportion of broad oval leaves at the vertical spatial distribution area in the canopy height were gradually decreased with the increase of diameter class stage,those of round leaves were increased at first and then decreased with the increase of diameter class stage,and those of broad ovate leaves were gradually increased with the increase of diameter class stage; ③ There were the extremely significant negative correlations between the growing frequency in vertical space of canopy and the proportion of vertical spatial distribution in canopy height with the diameter at breast height and the tree height for broad oval leaves,and the extremely significant positive ones for both round leaves and broad ovate leaves. These revealed that the growing frequency and spatiotemporal variation of various heterophylls were closely related to the ontogenetic stage of P.pruinosa. References | Related Articles | Metrics

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Migration of Soil Nitrate Nitrogen and Ammonium Nitrogen in Cotton Field under Drip Irrigation SHAN Na-na, LAI Bo, YANG Zhi-ying, DING Feng, YANG Guo-jiang 2016, 33 (5):  1104-1109.  doi: 10.13866/j.azr.2016.05.26 Abstract ( 1 )   PDF (1676KB) ( 0 )   Nitrogen is of vital important in crop growth.Nitrogen application amount was increased year by year,and the annual surplus of nitrogen in China was 3.60×106-5.46×106 t·a-1.The nitrogen application affects not only crop growth,but also environment.Nitrate nitrogen and ammonium nitrogen in soil were observed by ion exchange resin membrane (IERM) in situ.The test results revealed the dynamic changes of nitrate nitrogen and ammonium nitrogen in soil,such as the migration,eluviation and transformation.The results are as follows:① The nutrient content of eluate of ion exchange resin membrane embedded in soil was similar to that obtained with the traditional test methods; ② Soil nitrate nitrogen was remarkably affected by cotton growth and nitrogen application.Nitrogen application could significantly improve the content of soil nitrate nitrogen,and a deficit of soil nitrate nitrogen occurred around 80 days after the emergence of cotton seedlings; ③ The content of soil ammonium nitrogen in cotton field under drip irrigation was low,its spatiotemporal change was complicated,and the reference value of the content of soil ammonium nitrogen for fertilization was low. References | Related Articles | Metrics

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Effects of Local Dynamic Change of Groundwater on Soil Salinity in Wasteland under Drip Irrigation in Saline or Alkaline Land of Oasis in Xinjiang LI Wen-hao, WANG Zhen-hua, ZHENG Xu-rong, ZHANG Jin-zhu 2016, 33 (5):  1110-1118.  doi: 10.13866/j.azr.2016.05.27 Abstract ( 2 )   PDF (2435KB) ( 0 )   Groundwater level and salinity in some areas has been improved as drip irrigation is applied in oasis saline or alkaline land in Xinjiang. In this study,the effects of drip irrigation on groundwater level and salinity in wasteland in Xinjiang were explored. The wasteland between the drip irrigation farmland of typical oasis and the native saline or alkaline land in the Xiayedi Irrigated Area in north Xinjiang was taken as the study area to monitor the variation of groundwater level and salinity during the period of 2009-2013. The results revealed that the soil salinity and moisture content in soil layer of 0-140 cm deep in wasteland fluctuated in a periodic“sine or cosine”way from the cotton growth season to freezing-thawing period. Soil salinity was increased in cotton growth season but decreased in the freezing-thawing period. The groundwater level of cotton field was raised due to the influence of drip irrigation,because the transmission path of capillary water was shortened,and the abundant salt sources were increased. The storage of soil salt in soil layer of 0-140 cm in depth was increased by 1 179.05 g·a-1,and the salt composition was mainly dominated by the increase of Ca2+,Cl-,Na+ and Mg2+. References | Related Articles | Metrics

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Effect of Soil Environmental Factors on the Distribution of Shrub Communities in Urumqi YE Qin, ZHOU Hua-rong, YUAN Lei, ZONG Zhao-lei 2016, 33 (5):  1119-1124.  doi: 10.13866/j.azr.2016.05.28 Abstract ( 1 )   PDF (1958KB) ( 0 )   Based on the TWINSPAN classification,the relationship between the shrub communities in Urumqi and the main environmental factors were analyzed by CCA. The results are as follows: ① CCA biplots revealed that the distribution pattern of shrub communities was most strongly associated with environmental factors,and they reflected clearly the habitat gradient of shrub communities; ② The effect of elevation on the distribution of shrub communities was more significant than that of soil environment factors; ③ In the soil environment factors,the effect of total salt content on the distribution of shrub communities was the most important,and that of total phosphorus was the lowest; ④ The shrub communities were likely to survive in coarse soil; ⑤ The distribution pattern of mountainous shrubbery and shrub desert was strongly affected by the topsoil properties,and the effect of shallow-moderate and deep soil properties was low. References | Related Articles | Metrics

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Spatial Distribution of Fluorion in Water in the Keriya River Basin Namat Tohti, ZHANG Feng, SHI Qing-dong 2016, 33 (5):  1125-1131.  doi: 10.13866/j.azr.2016.05.29 Abstract ( 2 )   PDF (1764KB) ( 0 )   Fluoride is a chemical element with important effects on the biosphere,lithosphere and human health. In this study,21 surface water samples,8 groundwater samples and 1 lake water sample were collected from the Keriya River Basin and the Ulugkol Lake in the Kunlun Mountains in northern marginal zone of the Tibetan Plateau in different seasons from 2014 to 2015. The fluorion content,pH values and total dissolved solids (TDS) were measured. The fluorion content of surface water varied from 0.09 and 6.08 mg·L-1,that of groundwater ranged from 2.68 to 6.0 mg·L-1,and that of lake water was measured as 4.81 mg·L-1. The measured pH values of surface water and groundwater varied from 7.28 to 8.60 and from 7.26 to 7.87 respectively,and the measured pH value of lake water was 8.95. The TDS of surface water and groundwater ranged from 216 to 2 884 mg·L-1 and from 1 113 to 3 884 mg·L-1 respectively,and the TDS of lake water was 17 281 mg·L-1. The results are as follows:① The Ulugkol was a lake with high fluorion content,high alkalinity and high salt content; ② There was basically no seasonal variation of chemical parameters of surface water in the upper reaches. In the middle and lower reaches,however,the fluorion content,EC value,TDS and water hardness (excluding pH valuje) were all notably lower in summer because of flood water dilution,and the fluorion content in river water was higher in winter due to groundwater recharge; ③ The fluorion content and TDS of surface water from the upper to the lower reaches of the Keriya River was holistically increased because of the dissolution of chemical elements and water evaporation. The fluorion content in river water at the upper reaches was much lower than that in the Yutian Oasis and the Daryaboy Oasis. However,the fluorion content in groundwater in the former was higher than that in the latter because of soda salinization;④ There was a good correlation between the fluorion content in river water and groundwater and TDS,but not between it and pH value; ⑤ The fluorion content in the Keriya River Basin was slightly higher than that in other drainage basins in the Tarim Basin,such as the Aksu River Basin and the Yarkant River Basin. References | Related Articles | Metrics

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GIS-based Assessment on Risk of Snow Avalanche to Glacial Lake:A Case Study in the Koshi River Basin,Himalayas ZHANG Fu-cun, LI Jing, WU Li-zong, WANG Wei-dong 2016, 33 (5):  1132-1140.  doi: 10.13866/j.azr.2016.05.30 Abstract ( 2 )   PDF (3078KB) ( 0 )   Snow avalanche is one of the factors of assessing glacial lake risk,and it is necessary to research the risk assessment of glacial lakes by using snow avalanche models developed by Europe and America for the Himalayas where flood caused by glacial lake outburst occurs frequently. In this paper,based on ICIMOD IKONOS DEM and Landsat-TM data,the factors attributed to avalanche formation,such as the altitude,plan curvature,slope and land cover,were extracted by using the GIS means,and then the PATAs (Potential Avalanche Trigger Areas) in the study area were assessed,according to Av=(Al+Fy)×S×Rg model. In addition,the snow avalanche run-out distance was estimated by using GIS methods and α-β model. According to the estimated results,the "low" values were mainly distributed over the valley floor and slope with dense forest,where the generation probability of potential snow avalanche was very low,while the“high”and“relatively high”values were mainly distributed over the glaciers or hillsides with slope of 30°-50°,full of rock or grass,and probability of generating potential snow avalanche. The results also showed that there were 98 PATAS in the study area,ten of them could spread into the glacial lakes,and the stability risk of these glacial lakes was resulted in. On which potential snow avalanche should be considered as one of the factors inducing the outburst of only 9 glacial lakes in assessing the glacial lake risk in the study area. References | Related Articles | Metrics