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2018 Vol.38 Issue.2,
Published 2018-03-20

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2018 Vol. 38 (2): 0-0 [Abstract] ( 6 ) [HTML 1KB] [ PDF548KB] ( 87 )
219 Dynamic Environment of Blown Sand at Honglianghe River of Qinghai-Tibet Plateau
Xie Shengbo, Yu Wenbo, Qu Jianjun, Pang Yingjun
Sand land in the Honglianghe River area of Qinghai-Tibet Plateau is widespread, and its blown sand activity rules are currently not sufficiently understood, which is not conducive to targeted sand prevention and control work. Therefore, the dynamic environments characteristics of blown sand at Honglianghe River are investigated using different methods, such as field observation, laboratory analysis, and calculation. The direction of yearly sand-moving wind at Honglianghe River is usually found to originates from the north direction, and the sand drift potential (DP) and the resultant drift potential (RDP) are high during winter and spring, low during summer and autumn. The variation of the monthly resultant drift direction (RDD) is stable. The yearly sand drift potential is 249.84 VU, which indicates an intermediate wind energy environment. The yearly resultant drift potential is 242.92 VU, and the yearly index of directional wind variability (RDP/DP) is 0.97, which indicate a high ratio. The yearly resultant drift direction is 173.8, which indicate a south direction. The yearly total sand transport quantity of the eight directions of Honglianghe River is 434.33 kg·m-1, and the sand transport quantity of the southwest direction reached its maximum. The research results have guiding significance for controlling sand hazards of the locale.
2018 Vol. 38 (2): 219-224 [Abstract] ( 10 ) [HTML 1KB] [ PDF4236KB] ( 156 )
225 Dynamic Mechanism Research on the Secondary Blown Sand Disaster in the 110 MW Photovoltaic Arrays of the Hobq Desert
Guo Caiyun, Han Zhiwen, Li Aimin, Zhong Shuai
In order to explain the dynamic mechanism of sand erosion and accumulation of sandy surface under the interference of photovoltaic facilities, two cross sections were set in the 110 MW photovoltaic Plant located in the Hopq Desert. MetOne 014A/024A 8 channel anemometer (with CR200X data collection instrument) were used, and the average wind speed of four heights (20 cm, 50 cm, 100 cm, 200 cm) around the photovoltaic panel were observed simultaneously. The variations of wind velocity around the photovoltaic panel were analysed. Results showed that:(1) The photovoltaic facilities resulted in the variations of flow field on both sides of the photovoltaic panels and generated four secondary flow field zones, namely, the conflux accelerating speed-up zone under the panels, the resistance decelerating zone in front and back of the panels, the uplift zone above the panels and the recovery area between the plates; Moreover, there were significant differences in the flow field pattern between the upwind edge region and the area within the photovoltaic plants. (2) The dynamical distribution indicated by develop degree of the flow field pattern was identical with the surface erosion and accumulation situation basically. (3)Vegetation can increase the surface roughness effectively, and reduce the transit speed below 50 cm near surface, and prevent the occurrence and aggravation of the sand erosion. (4) The conflux accelerating zone under the panels and the reverse vortex around the panels were the main dynamic mechanisms of shaping wind erosion ditches (PITS) and sand accumulation belts, respectively.
2018 Vol. 38 (2): 225-232 [Abstract] ( 9 ) [HTML 1KB] [ PDF3316KB] ( 75 )
233 Spatial-temporal Evolution of Aeolian Desertification Process in Ordos City during 1975-2015
Feng Kun, Yan Changzhen, Xie Jiali, Qian Dawen
The Ordos City is located in the semi-arid region and also an ecotone from temperate steppe to desert steppe, and it suffers the serious aeolian desertification problems like the other parts of Northern China. Due to its representative and typical characteristics of the development and reversal process of aeolian desertification and its driving factors, Ordos City has become one of the hot areas of desertification research. We derives the spatial and temporal patterns change information of aeolian desertification from 1975 to 2015 based on the Landsat images, and analyzed the driving factors with the principal component analysis (PCA) and meteorological and social-economic data. The results showed that in the context of the fragile ecological environment, the development of aeolian desertification in Ordos City in the forty years was mainly influenced by human factors, such as population increase, reclamation and overgrazing. The trend of land desertification and the dominant driving factors are different at different periods:The land desertification tended to deteriorate from 1975 to 2000, and the main driving factors were human activities, followed by natural factors; The land desertification was reversed in 2000-2015, and the natural factors played more important role than human activity in this period.
2018 Vol. 38 (2): 233-242 [Abstract] ( 10 ) [HTML 1KB] [ PDF3950KB] ( 116 )
243 The Spatial Variation and Grain Size Character of Different Land Cover Types in the Ulanbuh Desert
Song Jie, Chun Xi
The paper is based on the systematic sampling of the Ulanbuh Desert, one of the source areas of dust storm in China, and the grain size characteristics and spatial variation of surface sediments between different land cover types in the desert are analyzed. It is concluded that most of the grain size of surface sediments in the desert are medium and fine sand, and the average particle size is 2.84 φ. According to different land cover types and different spatial distribution laws, the grain size distribution of the surface sediments in the desert was the result of the interaction of the sediment source, the terrain and the carrying capacity. The saline alkali land in the middle of the desert, the farming land in the northeast and the sandy land in the desert should be the sources of the sand dust. Therefore, according to the different land cover types in the Ulanbuh Desert, to set up suitable models of initial plant population structure is the main method to control desertification.
2018 Vol. 38 (2): 243-251 [Abstract] ( 9 ) [HTML 1KB] [ PDF4056KB] ( 137 )
252 Characteristics of Sand Granularity and Its Environmental Significance in Nouakchott, Mauritania
Zhou Na, You Yuan, Lei Jiaqiang, Wang Yongdong, Wang Haifeng
The Nouakchott, Mauritania is located in the west of the world's largest tropical Sahara Desert. The local ecology is seriously threated by desertification. Studying the grain size characteristics in this area is important because it plays a key role in distinguishing the sedimentary environment and the source of the dust. In present study, 50 sediment samples from different positions of longitudinal dunes were collected and analyzed by means of sieving. The longitudinal dunes can be divided into three parts including southeast slope, top, and northwest slope, which are mainly composed of fine sand and very fine sand which together account for more than 64% in total sand. It is finer than sands in the longitudinal dunes in China. Sediment form southeast slope with highest content of fine sand and very fine sand, and with lowest content of silty sand, while sediment form northwest slope with lowest content of fine sand and very fine sand, but with highest content of silty sand. The grain size parameters show that the finest and the coarsest grains can be found on the northwest slope and southeast slope, respectively. In addition, kurtosis of southeast slope, top, and northwest slope represent leptokurtic or mesokurtic, leptokurtic, and platykurtic, respectively. Moreover, all the three parts exhibit a positively skewness distribution. The sediments from inter-dunes mainly composed of fine sand and have a mean grain size of 2.76 φ, which are coarser and better sorted than dune sands and with an approximately symmetric mesokurtic distribution. The sedimentary environment and origins of the surface sand in the area are varied, more than 70% of the sand samples are dominate by wind, while others are dominated by littoral deposits.
2018 Vol. 38 (2): 252-261 [Abstract] ( 10 ) [HTML 1KB] [ PDF3756KB] ( 77 )
262 Effects of Biodegradable Poly Lactic Acid Sand Barriers on Surface Sediment Grain-size Characteristics at Sand Dunes
Ding Yanlong, Gao Yong, Wang Ji, Sun Xiaorui, Dang Xiaohong, Han Yanlong, Li Peng
In this research, the surface layer(0-3 cm) of different specifications PLA(Poly Lactic Acid) sand barriers in the northern Jilantai Salt Lake was selected to analyse the grain-size characteristics. The sediment particle size distributions were identified by using laser diffraction technique. The grain-size characteristics parameters, such as average particle size, sorting, skewness and kurtosis were determined, then calculated and analysed sand-fixation benefits of sand barriers. The results indicated that the sediment particle size was mainly made up of fine sand, medium sand and very fine sand. The medium sand, very fine sand and fine sand were the key factors that affected the sediment particle thickness in the sand barriers. The PLA sand barrier increased the content of medium sand and coarse sand, decreased the content of fine particles, and the sorting became worse, the kurtosis deviated from normal distribution and turned negative partial. The frequency distribution curves became wider, while the cumulative frequency curve became slow. The sediment particle size distributions tended to be coarsen. The sand drift activities inside the 1m 1m specification PLA sand barriers on the entire sand dune was deposition. The sand drift activities in 2m 2m and 3m 3m sand barriers at windward and leeward slope performed as deposition as well, while the top of sand dune was erosion. Considering laying costs and protective effects, 2m 2m was the best specification of PLA sand barriers for the study area.
2018 Vol. 38 (2): 262-269 [Abstract] ( 10 ) [HTML 1KB] [ PDF4007KB] ( 72 )
270 Review on the Impact of Dust Accumulation on Photovoltaic Power Output
Cui Yongqin, Feng Qi, Sun Jiahuan, Li Fang, Xiao Jianhua
This paper summarized the impact of photovoltaic (PV) power output by dust accumulation, dust cumulated on PV modules caused a significant decrease of power output, and analyzed the effects of dust capacity, the amount of rainfall, rainfall intensity and rain frequency, wind velocity and wind direction, humidity, vegetation, air pollution, the material of PV module surface and the inclination, azimuth angle of PV modules on dust accumulation. Finally, some suggestions were presented:(1) to study how various factors affect the dust accumulation on photovoltaic module from the microscopic point of view; (2) to study the relationship between environmental air quality, climate characteristics and dust accumulation on PV modules; (3) to establish long-term and remote monitoring system of power output and dust accumulation; (4) to assess the impact of dust accumulation on PV power output, and design dust cleaning system.
2018 Vol. 38 (2): 270-277 [Abstract] ( 10 ) [HTML 1KB] [ PDF2245KB] ( 70 )
278 Climatic Change Reflected by Geochemical Features in Datong Basin, North China since 220 ka BP
Liu Miaomiao, Su Zhizhu, Kong Mengyuan, Zhang Caixia, Li Jinchang, Wang Guoling, Li Xiang
The Datong Basin developed thick fluvio-lacustrine sediments in Quaternary period and aeolian loess overlied, which recorded an abundant information on past climatic and environmental changes. To analyze the climate changes, we mainly use the primary oxides as climate proxies to establish the age framework according to stratigraphic dating data, combining formation susceptibility and particle size. The results showed that:(1)The average content of chemical elements of the sediments in the constant formation was SiO2 > Al2O3 > CaO > Na2O > TOFE > K2O > MgO from high to low,the sedimentary facies of different elements are obviously different, reflecting elements vary with climate change. (2) The Datong Basin climate change experienced the following 5 stages:The research area climate was warm-humid during the Middle Pleistocene of 220-199 ka BP, and cold-dry climate occurrenced during the Middle Pleistocene of 199-138 ka BP, and warm-humid climate occurrenced during the last interglacial period of 138-71 ka BP, and cold-dry climate was showed during the last glacial stage of 71-11 ka BP, and the Holocene periodclimate was alternate variationsof warm-wet and cold-dry. However, during each period there is still less-grade climate fluctuation level. (3) These climatic changes is similar with Salawusu River and Inner Mongolia Daihai region roughly in the same latitude, and are well accordant with the global climatic change reflected by the deep-sea oxygen isotope and the polar ice core, showing a consistency in time of climatic change between the study area and the global. The climate change in this area is regional response of global climate change influenced by the East Asian winter and summer monsoon.
2018 Vol. 38 (2): 278-285 [Abstract] ( 10 ) [HTML 1KB] [ PDF1974KB] ( 72 )
286 Transpiration of Reaumuria soongorica and Salsola passerine at Different Scales
Jin Yanxia, Wang Xinping, Zhang Yafeng, Pan Yanxia, Hu Rui, Xu Haojie, Shi Wei
The transpiration (T) characteristics of Reaumuria soongorica and Salsola passerine under drought and wet conditions were studied by LI-6400XT portable photosynthesis system combined with large lysimeter. The reliable determination method of leaf area of plant during switching of transpiration from leaf scale to shrub scale under non-destructive state was discussed in the study. The results showed that:it is feasible to obtain the leaf area of plant by image method under the condition of ensuring the normal growth of them. The transpiration obtained by switching from leaf scale to shrub scale based on the leaf area was higher consistency with lysimeter measurement (r=0.9752,P<0.01). Under the drought condition, transpiration rate diurnal changes of R. soongorica was unimodal and the main influencing factor was stomatal conductance (P<0.01). Under the wet condition, transpiration rate diurnal changes of R. soongorica and S. passerine were all unimodal and the main influencing factors were stomatal conductance, relative humidity, vapor pressure deficit and Photosynthetic radiation (P<0.01). In addittion, the water use efficiency and stomatic limitation of S. passerine were higher than that of R. soongorica. Moreover, the water use efficiency and stomatic limitation of R. soongorica under the drought condition were higher than those under the wet condition. The amount of shrub level transpiration measured by scale conversion and by weighing lysimeter were all indicated that the transpiration of R. soongorica was always greater than that of S. passerine at the leaf or shrub scale, and increased with the improvement of soil wetness. Under the drought condition, the ratio of transpiration to evapotranspiration (T/ET=21%) of R. soongorica was higher about 2% than that under the wet condition. Therefore, the leaf area parameters obtained by the image method can be used to study the conversion of plant transpiration from leaf (portable photosynthesis method) to plant and shrub level (lysimeter method).
2018 Vol. 38 (2): 286-293 [Abstract] ( 10 ) [HTML 1KB] [ PDF2794KB] ( 69 )
294 Effect of Single and Mixed Salt Stress on Leaf Physiological Characteristics of Lycium barbarum
Zhang Wenli, Liu Yubing, Liu Lichao
Lycium barbarum has strong ability to salt and alkali resistance, and its cultivation in salinized soil can improve soil quality to a certain extent. However, less information was found about physiological adaptation to different saline habitats under different salinization level in L. barbarum. In order to analyze the physiological response difference of L. barbarum to single salt (NaCl or Na2SO4) and mixed salt (NaCl+Na2SO4), we selected one year seedling of Ningqi No.5 as the materials to treatment under different saline solution with different osmotic potential gradients (-0.48, -0.82 and -1.18 MPa, respectively). The results showed that chlorophyll (Chl) content decreased, but the content of malondialdehyde (MDA), proline (Pro) and soluble sugar (SS), and activities of anti-oxidant enzyme superoxide dismutase (SOD) and catalase (CAT) increased with the decreasing of osmotic potential under different salt treatment. Peroxidase (POD) activity was inhibited at osmotic potential of -1.18 MPa. Among different salt solution with the same osmotic potential, the contents of Chl, Pro, MDA and SS and activities of SOD and CAT more or less increased under mixed salt treatment. MDA, Pro and SS contents and CAT activity increased during treatment. All these results suggested that the protective capability enhanced from osmo-regulated substances and anti-oxidant enzyme system of L. barbarum at high salinization level. The physiological responses of L. barbarum were different in different saline environments, and the effect of mixed salt stress was greater than that of single salt at -1.18 MPa. The accumulation of osmo-regulated substances and ability to saline adaptation of L. barbarum increased during salt treatment.
2018 Vol. 38 (2): 294-299 [Abstract] ( 11 ) [HTML 1KB] [ PDF2172KB] ( 81 )
300 Effects of Salt-alkaline Mixed Stresses on Seed Germination and Seedling Growth of Bassia dasyphylla in Desert Region
Li Xin, Zhao Wenzhi
Annual plant species are the main component of the vegetation in arid and semi-arid desert regions, with their unique traits as the good candidates for the study of many key bio-ecological issues. This paper studied the response of various salt-alkaline stress on seed germination and growth of annual plant Bassia dasyphylla in desert region. Thirty different salt-alkaline ecological conditions, which evenly covered all the cases within the ranges of 50-250 mmol·L-1 salinity and 7.10-10.19 pH values, were simulated by mixtures of varied proportions of sodium salts of chloride, carbonate, bicarbonate and sulphate. The germination indexes of germination rate, germination speed, germination index, seeding vigor index and growth indices of shoot length, root length, fresh weigh were determined. The results showed that germination indexes and growth indices of treatment group were significantly lower than control group, were both decreased with increasing salinity and pH, and were found significant different (P<0.05) from the negative control group. All of the indexes were also restraining affected by salinity, pH and their interactions (P<0.05). The order of rejection capability of sodium salts of chloride, carbonate, bicarbonate and sulphate was Na2CO3 > NaHCO3 > NaCl > Na2SO4. The effects of the interaction between high alkalinity and salinity are more severe than those of either salt or alkali stress, and such a cooperative interaction results in more sensitive responses of seed germination and seedling growth of B. dasyphylla. Salinity was the dominant factor for seed germination under mixed salt-alkaline stress conditions, and pH changed into the dominant factor for seedling establishment. Further, It was concluded that the mixed salt-alkaline stresses, which differ from either salt or alkali stress, emphasize the significant interaction between salt concentration (salinity) and salt component (alkalinity).
2018 Vol. 38 (2): 300-306 [Abstract] ( 10 ) [HTML 1KB] [ PDF1977KB] ( 62 )
307 Effects of Soil Moisture and Phosphate Fertilizer on the Growth and Drought Resistance Physiology of Potato Seedlings
Yang Hongwei, Liu Wenyu, Feng Huanqin, Zhang Junlian, Li Chaozhou
The effects of different amount of extra phosphate fertilizer on the growth and drought resistance physiology of potato seedlings under drought stress were reported in this paper, the results showed that:(1) The reduction of the soils' water content induced the decrease of the potato leaves water content and chlorophyll content, the enhancement of the content of soluble sugar, proline and MDA, the enhancement of the relative electric conductivity (REC), O2 production and antioxidant enzymes activities, and the reduction of plant height, stem diameter, root length, the number of stolon stem, tuber weight, and even the tuber's starch content, vitamin C content. (2) After the application of proper amount of extra phosphate fertilizer under drought stress, the leaf water content and chlorophyll content increased significantly, the activities of antioxidant enzymes enhanced, relative conductance, MDA content and O2 production rate reduced significantly, tuber weight, starch content, Vc content increased significantly. (3) The best amount of extra phosphate fertilizer in promoting the growth of potato seedlings under drought stress was 15.3 g·m-2 among all the 6 amount of extra phosphate fertilizer. So it can be concluded that the growth of potato seedlings was inhibited significantly by drought stress, but proper amount of extra phosphate fertilizer could increase the osmotic adjustment substances content and the anti-oxidative enzymes activities, alleviate the degree of lipid-peroxidation and the damage of cell membrane, thus alleviated the inhibition in growth and enhanced the drought resistance abilities of the potato seedlings.
2018 Vol. 38 (2): 307-314 [Abstract] ( 11 ) [HTML 1KB] [ PDF2401KB] ( 71 )
315 Population Structure Characteristics of Population euphratica in the Lower Reaches of Tarim River
Zhou Yingying, Chen Yaning, Zhu Chenggang, Chen Yapeng, Chen Xiaolin
Population structure characteristics can reflect the living conditions and future trends of one population. In this paper, we investigated the living status of Populus euphratica in the lower reaches of Tarim River, after years of ecological water conveyances to restore the ecosystem. The population density, age structure, sex ratio structure and spatial structure of P. euphratica were analyzed based on field investigation. The results indicated that the pattern of age structure of P. euphratica in the lower reaches of Tarim River followed the "inverted pyramid" pattern. The population dynamics index, population density, had similar patterns with that of the age structure, indicating the declining trend of P. euphratica will continue. The P. euphratica was significantly male-biased, and this deviation increased with the deterioration of habitats. The distribution pattern of P. euphratica showed a significant cluster distribution with no intensity difference among them. After 18 years, ecological water conveyances, the degradation trends of the P. euphratica distributed far from the river have not yet completely reversed although the ecological conditions near the river have improved. The ecological water conveyances along a natural river channel created a too narrow flooded area to improve the population regeneration rates. Therefore, during the processes of ecological water conveyances, artificial measures are suggested to be taken to extend the flooded area to provide conditions for the reproduction and regeneration of the P. euphratica.
2018 Vol. 38 (2): 315-323 [Abstract] ( 10 ) [HTML 1KB] [ PDF2537KB] ( 76 )
324 Effect of Enclosure on the Structure of Plant Community in Degraded Sandy Grasslands of Eastern Inner Mongolia
Xiong Bingqiao, Zhao Liya, Gao Dandan
This paper examined the effects of enclosure management on the structure of community in degraded sandy grasslands. Several conclusions were drawn from this study. (1)The coverage, density, aboveground biomass and average height of the fencing grassland were all superior to those of the grazing grassland, and there was a significant different(P<0.01). Compared with the grazing grassland, coverage of the fencing grassland increased by 237%, density, height and aboveground biomass respectively increased by 429%, 77% and 218%. The structure of community was significantly improved by enclosure. (2) Compared with the grazing grassland, the species of the fenced grassland increased by 69%. Species and important values of perennial herbs and shrubs in the fencing grassland were higher than the grazing grassland. The dominant species of grazing grassland were Corispermum macrocarpum, Setaria viridis and Artemisia halodendron, the ration of important value accounted for 72%. Lespedeza davurica, Cleistogenes squarrosa, Chloris virgate and Eragrostis pilosa were the dominant species of fencing grassland, their important value accounted for 57%. In the fencing grassland, the largest families were Leguminosa and Gramineae plants, which were adapted to their growing environment. C. macrocarpum, S. viridis and A. halodendron were gradually in a secondary status. By enclosure, Species composition of the community was diversified, the structure and function were improved,and desertification of sandy grasslands was restored. (3) The Shannon-Wiener index, Simpson index, Margalef index and evenness index of the fencing grassland were all larger than those of the grazing grassland. Enclosure increased the species diversity and stability of community.
2018 Vol. 38 (2): 324-328 [Abstract] ( 10 ) [HTML 1KB] [ PDF889KB] ( 76 )
329 Advances in the Study of Microbial Ecology in Desert Soil
Li Ting, Zhang Wei, Liu Guangxiu, Chen Tuo
The desert ecosystem accounts for a third of the earth's land area, and is a vital part of the biogeochemical cycle. Because of the bad environmental condition in the desert including extreme drought, lack of vegetation, strong UV radiation, deserts used to be considered lifeless, however there are a lot of microbial resources in this harsh environment especially in the desert soil which enriched with a large number of microbes. These microorganisms involve in the whole earth biochemical circulation of desert ecosystem, adjust the important ecological processes and play an important role in the restoration and stability of the desert ecosystem, its research is of ecological significance. With the development of molecular biological technique, molecular biological technique are revealed. In this paper, the structure characteristics, functionality of desert soil microbial community and the relationships between microbial community, microorganism and plant, microorganism and environment are reviewed. Aim to further understand the desert soil microorganism and to summarize the deficiency of ecological understanding of desert microorganism, provide reference for the ecological research direction of desert microorganism.
2018 Vol. 38 (2): 329-338 [Abstract] ( 9 ) [HTML 1KB] [ PDF1769KB] ( 77 )
339 Development Characteristics of Biological Crusts under Artificial Vegetation in Southern Mu Us Sandy Land
Wu Yongsheng, Yin Ruiping, Tian Xiumin, Hasi
Widespread biological crusts have been developed at the dune surface after implementation of desertification control and ecological rehabilitation projects in the sandy area in Northern China. Clarifying the relationships between characteristics of biological crusts development and different types of artificial vegetation has significant influence on the ecological rehabilitation of damaged ecosystem. Thicknesses, shear strength, coverage of biological crusts were examined under different types of artificial vegetation (Hedysarum mongdicum, Populus simonii, Salix psammophila, Amorpha fruticosa and Sabina vulgaris) in southern Mu Us sandy land by field investigation methods. The results showed that characteristics of biological crusts development under different vegetation types varied greatly. Thicknesses, shear strength, coverage of biological crusts under P. simonii site significantly higher than other sites (P<0.05). Coverage of biological crusts under H. mongdicum and S. psammophila site was lower relatively. P. simonii site were dominated by mosses crusts while the other sites were dominated by algae crusts. Correlation analysis indicated that coverage of biological crust decreased with increasing of vegetation cover, increasing with surface (0-5 cm) water contents of soil. These results suggest that plantation of P. simonii is recommended for establishment of biological crust, and plantation of S. psammophila with H. mongdicum is not conductive to development of biological crusts.
2018 Vol. 38 (2): 339-344 [Abstract] ( 10 ) [HTML 1KB] [ PDF2095KB] ( 81 )
345 Soil Alkalization Index Inversion Model Based on Spectral Reflectance of Ions Characteristics Band
Zhu Yuechen, Xiong Heigang, Zhu Zhongpeng, Zhang Fang
The thesis takes the alkalized soil in Xinjiang Qitai area as the research object, and through the analysis of correlation between the measured spectral reflectance curves of alkalized soil and eight ions, pH, alkalization index, the unitary or polynary spectral inversion models based on the reflectivity of ionic spectral waveband are established, and the accuracy is verified. The results shows that:Na+, CO32-, HCO3- content and spectral reflectance are positively correlated, and the correlation coefficients of the highest point are respectively 0.710, 0.798 and 0.749, while the Ca2+, Mg2+ content and spectral reflectance are negatively correlated with the highest correlation coefficient less than -0.370, which reflects that the relation between the ion concentration of first three kinds and spectral reflectivity is closer. The correlation coefficient between SAR (Sodium Adsorption Ratio), ESP (Exchange Sodium Percentage) and Na+ is 0.954, the correlation coefficients between TA (Total Alkalinity), RSC (Residual Sodium Carbonate), pH and CO32- are respectively 0.946, 0.949 and 0.953. Therefore, Na+ and CO32- have greater effect on alkalization index on the whole. The correlation between alkalization indexes and soil spectral reflectance is TA > RSC > ESP > pH > SAR, and the correlation coefficient between TA and spectral reflectance reaches 0.863. The inversion model of spectral reflectance of ion spectrum characteristic band of alkalization index is the best, and its R2 is 0.703, which is 14 percent higher than the R2 of the pH inversion model based on measured spectral reflectance, this shows that the former has higher accuracy and can better reflect the degree of soil alkalization in the research area. At the same time, the use of spectral reflectance of ion characteristic band to predict soil alkalization will become the focus of future research.
2018 Vol. 38 (2): 345-351 [Abstract] ( 8 ) [HTML 1KB] [ PDF2163KB] ( 64 )
352 Carbon Density in Dominant Desert Shrub Species Ecosystem in West Ordos Region
Dang Xiaohong, Gao Yong, Meng Zhongju, Gao Junliang, Ding Yanlong, Wang Zhenyi
To estimate carbon storage of natural desert shrub ecosystem in west Ordos plateau and reveal the distribution rules in different layers (shrub, herb, litter and soil) and organs of each shrub species, we set 3-5 sample plots respectively according to typical sampling method in five dominant desert shrub species(Ammopiptanthus mogolicus, Zygophyllum xanthoxylum, Tetraena mongolica, Helianthemum songaricum and Reaumuria songarica) in Yikebulage steppe desert experimental area and measured the carbon storage of desert shrub ecosystem using biomass harvest method. The results showed that the carbon storage differences among five desert shrub ecosystems and its carbon storage was in the range of 40.28-55.51 t hm-2, in which the carbon storage of soil layer was the most(97.15%-98.51%) and the carbon storage was in the range of 40.28-55.51 t·hm-2. The soil carbon storage was increasing with the soil depth. The biomass carbon density in plant layer was shrub layer > herb layer > litter layer. The biomass carbon density of shrub layer was more with the distance increasing to Yellow River and the biomass carbon density of the nearest site of A. mogolicus and the farthest site of H.songaricum was respectively 92.16% and 62.42% of the plant layer. However, the herb layer showed the opposite rule as the shrub layer. The root biomass carbon was the main part of shrub ecosystem and its biomass carbon density was in the range of 8.41-38.29 g·m-2, which was 5.36%-45.18% of plant layer carbon density. Except P. songarica shrub ecosystem, the carbon storage of belowground part in other four desert shrubs was more than aboveground part (P<0.05). The carbon storage of single shrub showed that branches>roots>leaves. The thick root sand branches were the main contributors to carbon storage of single shrub and showed obvious differences among shrub species (P<0.05). The roots and leaves carbon storage was 20.00%-33.53% and 2.02%-24.54% of the total plant layer.
2018 Vol. 38 (2): 352-362 [Abstract] ( 10 ) [HTML 1KB] [ PDF2077KB] ( 65 )
363 Estimation of Carbon Residence Times and Sequestration Potential of Grassland and Cropland Ecosystem in the Loess Plateau
Guo Ding, Li Xudong, Wang Jing, Fu Hua
A Bayesian probability inversion was applied to estimate the Carbon residence times and sequestration potential of grassland and cropland ecosystems in the Loess Plateau. The result shows that the shortest Carbon residence times ranged from 25 to 203 days were in the aboveground and belowground biomass pools, the metabolic litter pools and the active soil organic matter (SOC) pools, excluding the aboveground biomass pool in cropland. The structure litter pools had Carbon residence times between 2.4 and 3 years. The longest Carbon residence times were 57.4-79.6 years and 593-598 years in the slow and passive SOC pools, respectively. Carbon residences times for the belowground biomass pools were longer in grassland than those in cropland, whereas Carbon residences times in the metabolic litter and slow SOC pools in grassland were shorter than those in cropland. According to the parameters derived from the inversion model, the SOC pools in grassland and cropland would reach a stable state in 250 years. The Carbon sequestration potential would be 3 130 and 2 680 g C·m-2, respectively, in grassland and cropland ecosystems. The application of manure could result in higher (4 000 g C·m-2) Carbon sequestration. Compared to that in grassland, the application of manure and the longer Carbon residence times of soil pools could lead to higher SOC sequestration in cropland ecosystem.
2018 Vol. 38 (2): 363-371 [Abstract] ( 9 ) [HTML 1KB] [ PDF2615KB] ( 60 )
372 Characteristics of Dust Aerosol in both Clear-sky and Above-cloud Conditions over East Asia
Ru Jianbo, Wang Tianhe, Li Jiming, Han Ying, Zhang Beidou
Based on CALIPSO Level 2 VFM, 5 km Aerosol Profile, 5 km Cloud Layer and MISR products from June 2006 to December 2012, we reveal the spatial and temporal distribution of dust aerosol in different height layers over East Asia. Especially, the vertical distribution, extinction coefficient and optical depth of dust aerosol are contrasted and analyzed in both clear-sky (CS) and above-cloud (AC) conditions over East Asia. The results show that the Taklimakan Desert (TD) and the Gobi Desert (GD) are the main dust source regions over East Asia. The distribution of dust occurrence frequency has significant seasonal difference, with the highest in spring, and the lowest in winter. Dust occurrence frequency over the TD is greater than that over the GD whenever in CS or AC conditions. For the same area, the maximum height of dust aerosol above cloud is higher than that of clear sky, and the high-value areas of dust extinction coefficient above cloud over the TD is at the height of 2-4 km, while that about 3-5 km over the GD. But the dust extinction coefficient above cloud has no significant difference between two conditions. The aerosol over the TD is dominated by dust aerosol, which accounts for 77% of the total aerosol optical depth (AOD). The average dust optical depths (DOD) are 0.22 and 0.15 in CS and AC conditions respectively. The dust aerosol over the GD accounts for 52% of the total AOD, and the average DOD is 0.09 and 0.06 in CS and AC conditions respectively. The results are the basis of further study on dust mass fluxes estimation in CS and AC conditions and even dust-cloud-climate interactions.
2018 Vol. 38 (2): 372-383 [Abstract] ( 11 ) [HTML 1KB] [ PDF9392KB] ( 68 )
384 Impact Factors of Atmospheric Aerosol Scattering Coefficient in the Tazhong Area of the Taklimakan Desert
Peng Yanmei, Wang Shu, Xiao Gaoxiang, Gao Lei, He Qing, Liu Xinchun
The observation data from conventional observation instruments and single-band(525 nm)integral nephelometer, PM10 automatic monitor and visibility instrument of the Taklimakan Desert Atmosphere Observation Station in 2010 were used to analyze the relationship between the aerosol scattering coefficient and various factors in the Tazhong. The results showed that:(1) Scattering coefficient and mass concentration of PM10 had a significant positive correlation, and the correlation coefficient was 0.96 in autumn, 0.94 in summer, and 0.91 in winter.(2)For mass scattering coefficient, the lowest value was in March, the highest value was in October; the lowest value was 0.66 m2·g-1 in spring, the highest value was 1.386 m2·g-1 in fall. The mass scattering coefficient of Tazhong station was smaller than that of Zhangbei Station of Hebei Province, Minqin Station of Gansu Province, Xigu District of Lanzhou, Xilinhaote Station of Inner Mongolia, Crete Island of Greece and Negev Desert of Israel. (3) There were a significantly negative correlation between visibility and scattering coefficient, and the coefficient was 0.80. The correlation coefficient in summer, autumn and winter exceeded that in whole year. With correlation coefficients 0.913, 0.908, and 0.857,respectively, and the lowest value was in spring (0.723). (4)When the wind speed was large, the scattering coefficient values were relatively large, and the correlation coefficient was 0.45. When the scattering coefficient was less than 500 Mm-1, the wind direction was distributed in ENE and NE; when the scattering coefficient was more than 500 Mm-1, the wind direction was mainly distributed in ENE, NE and E. In the ESE wind direction, the average of the scattering coefficient was the largest, followed by the SSE direction, and the minimum value was the S wind direction.
2018 Vol. 38 (2): 384-392 [Abstract] ( 10 ) [HTML 1KB] [ PDF3774KB] ( 64 )
393 Change of Surface Albedo, Soil Temperature and Moisture under Snow Cover in the Hinterland of Taklimakan Desert in Winter
Liao Xiaohe, He Qing, Jin Lili, Yang Xinghua, Ali Mamtimin, Huo Wen, Yang Fan
Based on the 10-m gradient detection system at Taklimakan Atmosphere and Environment Observation Experiment Station in the hinterland of the Taklimakan Desert, the characteristics of surface albedo and multilayer soil temperature and moist and their relationship under snow cover are analyzed by using the meteorological and radiation data. The results showed that the surface albedo changes between 0.18 and 0.97 under snow cover, and the average value is 0.60. The daily variation of surface albedo tends to reverse "J" and the value in the morning is bigger than in the evening, and the average difference is 0.13. Snow makes the 0-40 cm depth soil temperature decrease, and soil temperatures at different layers are close to each other when soil moisture increases after the snow. Except the soil layer of 40 cm depth, the existence of snow makes the daily variation range of 0 cm, 10 cm, 20 cm soil temperature decrease by 41%, 39%, 39%, respectively. There is a negative correlation relationship between surface albedo and surface temperature under snow cover. Namely, high surface albedo corresponds to low surface temperature, and the correlation coefficient is -0.71. Under snow cover, surface albedo and 5 cm depth soil moisture present a negative correlation, and the high surface albedo corresponds to low soil moisture, and low surface albedo corresponds to high soil moisture, and the correlation coefficient is -0.74.
2018 Vol. 38 (2): 393-400 [Abstract] ( 10 ) [HTML 1KB] [ PDF3961KB] ( 76 )
401 Wet/dry Variation Recorded by Sarcozygium xanthoxylon Tree-rings in the Middle of Alashan Desert, China
Ding Aijun, Xiao Shengchun, Peng Xiaomei, Tian Quanyan
Based on the regional chronology established by the four ring-width standard chronologies of Sarcozygium xanthoxylon in the middle of Alashan Desert, we studied the response of Sarcozygium xanthoxylon radial growth to climate change and the wet/dry variation recorded by regional chronology. The results showed that the radial growth of Sarcozygium xanthoxylon was mainly affected by the pre-growing and growing season precipitation (October-December in previous year and April-July in current year). On the interdecadal scale, three dry periods were identified in the middle of Alashan Desert:the early 1920s to early 1930s, the early 1940s, the late 1970s to late 1980s; Four wet periods were the late 1900s to early 1920s, 1930s, the mid-1960s to mid-1970s, the late 1980s to the present. According to the results of wavelet analysis, the regional chronology in the middle of Alashan Desert had significant period cycles of 2-8 a, 11 a and 16-34 a, and the periodic oscillation occurred at the end of 1970s. These results could provide climate change information and decision-making basis for regional environmental evolution and desertification control.
2018 Vol. 38 (2): 401-409 [Abstract] ( 10 ) [HTML 1KB] [ PDF3706KB] ( 66 )
410 Spatio-temporal Characteristics of the Short-time Heavy Rainfall in the East of Northwest China
Bai Xiaoping, Jin Shuanglong, Wang Shigong, Shang Kezheng, Zhao Lu
In this paper, the spatio-temporal distribution and climate characteristics of short-time heavy rainfall in the east of Northwest China is studied based on every 6h rainfall observation data of 136 meteorological stations in the east of Northwest China from 2001 to 2011 and hourly precipitation data from 2009 to 2011 of 1674 automatic meteorological stations, by using climate statistical analysis, linear trend analysis, normalized analysis, subregional of statistics analysis, precipitation concentration degree (PCD) and precipitation concentration period (PCP) analysis. Results showed that the short-time heavy rainfall days interannual change is unobvious, but the regional short-time heavy rainfall process has increased significantly; the short-time heavy rainfall is mainly happened from early July to late August, and it has obvious diurnal variation; the spatial distribution of the short-time heavy rainfall frequency is accordant with the topography distribution, and high frequency area is located near the windward side of summer half year circulation prevailing southwest airflow; the PCD is more and more concentrated from southeast to northwest, and the PCP gradually postponed from east to west in the space.
2018 Vol. 38 (2): 410-417 [Abstract] ( 12 ) [HTML 1KB] [ PDF2974KB] ( 85 )
418 Spatial and Temporal Variations of NDVI in Gansu, China from 2000 to 2014
Cao Bo, Zhang Bo, Ma Bin, Wang Guoqiang, Tang Min, Zhang Yaozong, Jia Yanqing
Based on MODIS NDVI and climate datasets during 2000-2014, used linear regression and correlation analysis, the spatiotemporal variations of NDVI in Gansu and their linkage with regional climate change were analyzed. The results showed that in the last 15 years, average NDVI of growing season, spring, summer and autumn all showed an increasing trend. The trend of summer was the most significant at regional scale, with a rate of 0.071/10 a (P<0.01). At pixel scale, the area of increasing trend in growing season was the largest, area with excellent (P<0.01) and significant (0.01 < P < 0.05) increasing trend covered 50.03% and 14.44% of the whole vegetation area respectively. Precipitation and humid index are the most important factors of vegetation growth in growing season and summer. Temperature, precipitation and humid index played equal roles in spring, temperature was the most important driving factor in autumn. The lag effect of temperature was obvious to NDVI in growing season. The precipitation and humid index in last season had effect on the vegetation growth of the coming season.
2018 Vol. 38 (2): 418-427 [Abstract] ( 10 ) [HTML 1KB] [ PDF4781KB] ( 63 )
428 Assessments of the Efficacy of Farmers' Adaptive Behaviors to Climate Change
Sun Lifan, Shi Xingmin, Wang Lu
The impact of climate change is very significant on farmers who depend on natural resources for livelihood. It is essential to have a better assessment of the efficacy of farmers' adaptive behaviors for formulating appropriate adaptation policies and improving farmers' ability to adapt to climate change. Based on survey data from interviews with farmers in the hill and gully region of the Loess Plateau in northern Shaanxi, the characteristics of farmers' perceived adaptation efficacy was analyzed, and with the common cultivated land area and grain yield in statistical yearbook from 2000 to 2014, the effect of adaptive behavior was verified from the objective level. Three multiple linear regression models were used to analyze the efficacy of farmers' adaptive behaviors and identify factors influencing those assessments. The results are as follows:(1) In general, the adaptive behaviors with high perceived adaptation efficacy were used by most interviewees. Measures that had relatively low perceived adaptation efficacy were not commonly adopted, such as migration, buying insurance, changing planting and harvesting time. The food production of the surveyed areas rose in volatility during 2000-2014, indicating the actual effect of adaptive behaviors. (2) The key demographical and social factors of farmers' influencing assessments of the efficacy of adaptive behaviors were non-farming income, farming income, planting scale, the frequency of watching TV and going to the market and gender. Changes of the local natural disasters, the adjustment of planting and harvesting time, crop yield and diseases and insect pests caused by climate change were found to affect farmers' adaptation assessments. Average precipitation in 2005-2015 was found to influence farmers' adaptation appraisals significantly. The natural environment is not only a macroscopic factor limiting the distribution of crops, but also a driving factor for farmers to adopt micro measures.
2018 Vol. 38 (2): 428-436 [Abstract] ( 10 ) [HTML 1KB] [ PDF1354KB] ( 54 )
437 Principal Function Regionalization of Desert Tourism based on Suitability Analysis: A case study in Shapotou, Ningxia, China
Shi Lei, Li Longtang, Zhang Guanle, Yang Ping, GaoXiuyan, Zhao Yunpeng
Based on ArcGIS and YaAHP evaluation method, desert tourism suitability in Shapotou District of Zhongwei, Ningxia was evaluated by six indicators, just dune height, slope, suitalble days, the distance from water area, the distance from desert and the distance from city/road. And function regionalization of desert tourism in Shapotou District was given based on desert tourism suitability evaluation result and land use data. The results show that the desert tourism suitability in Shapotou District can be divided into five suitability regions, namely, high, relatively high, medium, relatively low and low, and functional region of desert tourism in Shapotou District is divided into desert tourism development zone, desert tourism restricted development area, desert tourism inadequate development zone and the desert tourism restricted area. Finally, according to the functional regionalization, we put forward corresponding development and management measures.
2018 Vol. 38 (2): 437-443 [Abstract] ( 11 ) [HTML 1KB] [ PDF2199KB] ( 69 )
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