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Research progress on the influence mechanism of climate anomalies in arid and semi-arid regions in China
Shanling Cheng, Haipeng Yu, Yu Ren, Jie Zhou, Hongyu Luo, Chenxi Liu, Yongqi Gong
Journal of Desert Research    2023, 43 (3): 21-35.   DOI: 10.7522/j.issn.1000-694X.2022.00126
Abstract366)   HTML23)    PDF (1396KB)(327)      

The arid and semi-arid regions cover more than half of China's land area, which are sensitive to global climate change and human activities with fragile ecological environment. Extreme climate events are frequent and strong in those regions, where the climate anomalies are not only modulated by the internal atmospheric variability, but also affected by the underlying surfaces such as sea surface temperature, sea ice and snow cover. These physical factors play a key role in the climate anomalies in arid and semi-arid regions. This article systematically reviews and sorts out the effects of these physical factors on climate anomalies in arid and semi-arid regions of China. Studies have shown that atmospheric teleconnection is an internal influencing factor of climate anomalies, and the circulation anomalies caused by its phase transition will cause climate anomalies in arid and semi-arid regions by regulating the position of jet stream, planetary wave activity, blocking intensity, and the location of trough-ridge. Sea surface temperature affects the climate anomalies in arid and semi-arid regions by influencing the intensity of monsoon and Walker circulation and the location of western Pacific subtropical high, in the meantime stimulating the response of atmospheric Rossby waves. Moreover, snow cover changes the thermal conditions of the underlying surfaces such as surface radiation and soil temperature and humidity through the albedo effect and hydrological effect, and then has a significant effect on the temperature and precipitation in arid and semi-arid regions by diabatic heating or changing atmospheric baroclinicity. On the basis of summarizing the existing research progresses and achievements, the paper points out that the synergistic mechanism among different factors and the contribution of each factor to the climate anomalies in the arid and semi-arid regions of China still need further research.

The surface flow pattern characteristics of barchan dunes
Linyan Luo, Xin Gao, Yongcheng Zhao
Journal of Desert Research    2023, 43 (4): 41-54.   DOI: 10.7522/j.issn.1000-694X.2022.00168
Abstract297)   HTML10)    PDF (11291KB)(199)      

At present, there is a lack of comprehensive understanding of the surface flow patterns over barchan dunes, especially the complex flow structure in the vortices zone, and thus further research is needed on the influence of morphological characteristics and flow velocity on the flow structure of barchan dunes. In this paper, the airflow characteristics over the surface of barchan dunes under different geometric parameters and different inlet velocities were studied using the CFD (Computational Fluid Dynamics) numerical simulation and the RNG k-ε turbulence model, focusing on the flow characteristics of the leeward side vortices zone and the relationship between its range and the geometric parameters of the dunes and the inlet velocities. The results show that: (1) The higher the height of the barchan dune, the larger the length of the wake vortices zone is, approximately 5-7 times the height of the dune. (2) The greater the gradient of the windward slope of the barchan dune, the greater the length of the wake vortices zone is, approximately 5-7 times the height of the dune. (3) The influence of inlet velocity on the position of the reattachment point is quite limited, and the length of the vortex zone caused by different inlet velocities is about 6-7 times the height of the dune, suggesting that the larger the inlet velocity is, the shorter the length of the wake protected zone and the smaller the disturbance of the dune on the flow can be found. This study comprehensively analyzes the shaping effect of the flow patterns on the shape of barchan dunes and further confirms the cause of the formation of small barchan dunes on the downstream of the horns of the upwind barchan dunes. Collectively, the current results can deepen the understanding of the evolution mechanism of barchan dune formation, and enrich the basic theory of aeolian geomorphology.

Research progress of environmental friendly sand fixation materials
Tingjie Ren, Limin Yuan, Yong Gao, Chunying Wang, Yanyan Xu
Journal of Desert Research    2023, 43 (3): 160-168.   DOI: 10.7522/j.issn.1000-694X.2022.00135
Abstract276)   HTML11)    PDF (1959KB)(197)      

Chemical measures, engineering measures and biological measures are called the three major sand control measures. The application and development of chemical sand fixation measures are strictly constrained by materials, and there is a trough period in the development of sand control technology. In recent years, with the development of materials science, inorganic, organic and inorganic organic composite chemical new materials have been widely used in the field of sand control, and chemical sand fixation measures have become a research hotspot. Sand fixation materials with low cost, high efficiency and good biocompatibility have become the key of chemical sand fixation technology, and environmental protection is the primary restrictive factor in the selection of materials. This paper summarizes the research progress of environmentally friendly sand fixation materials processed from natural materials, classifies environmentally friendly sand fixation materials, and analyzes the problems existing in the development of chemical sand fixation and the necessity of environmentally friendly sand fixation materials. This study will provide a theoretical basis for the development of high-performance environmental friendly chemical sand fixation materials.

Quartz OSL and K-feldspar pIRIR dating of typical sediments over the past 20 000 years from the Tengger Desert, northern China
Ying Wang, Shuangwen Yi, Zhiwei Xu, Haochen Zhang, Xusheng Li
Journal of Desert Research    2023, 43 (3): 69-85.   DOI: 10.7522/j.issn.1000-694X.2022.00136
Abstract223)   HTML7)    PDF (7939KB)(126)      

Sedimentary records of the late Quaternary preserved in the deserts are important archives to reconstruct the paleoclimate and paleoenvironmental change. In recent years, different dating methods have been used to establish chronologies of aeolian and lacustrine sediments in the deserts, especially the Optically Stimulated Luminescence (OSL) dating technology. However, it still has some uncertainties whether the luminescence dating techniques could provide reliable ages for relatively young samples. In this study, several sediments were collected from different sites in the Tengger Desert, and their ages were measured by quartz SAR-OSL and K-feldspar pIRIR150 dating methods. A set of tests, such as the dose recovery, fading and residual tests, were carried out to explore the applicability and reliability of the K-feldspar pIRIR150 dating protocol in this area. The results suggest that the K-feldspar samples were well bleached before deposition. Residual doses of pIRIR signals are between 0.07-0.27 Gy and the dose recovery ratio is basically equal to 1 within the dose range of 60 Gy (equal to about 20,000 years). The corrected K-feldspar pIRIR150 ages are generally overestimated, while the uncorrected pIRIR150 ages are in good agreement with the quartz SAR-OSL ages, indicating the uncertainties of g-value correction. Based on the quartz SAR-OSL and K-feldspar pIRIR150 ages, it is found that the geomorphological evolution at different sites in the study area show strong heterogeneity at local scales, while at glacial-interglacial time scales, their changes are broadly consistent with regional climatic changes. During the Last Glacial Maximum and Deglacial period, the dunes were mostly active and vegetation was degraded, and the areas of lakes and oases were relatively decreased. In contrast, dune activity was restricted and vegetation coverage was increased during the Early and Middle Holocene, and the lakes and oases were relatively expanded. During the past few hundreds of years, different sites in the Tengger Desert have probably undergone multiple phases of dune activation and stabilization, which may be related to not only regional environmental changes but also local disturbances.

Surface particle size composition and aeolian-sand flow structure of Zuo Lake Basin in the source of Yangtze River
Yawei Fan, Heqiang Du, Shanlong Lu, Zhiwen Han, Xiufan Liu, Xinlei Liu
Journal of Desert Research    2023, 43 (3): 47-56.   DOI: 10.7522/j.issn.1000-694X.2022.00138
Abstract217)   HTML12)    PDF (2607KB)(126)      

The dry lake basin is one of the main sources of sandstorms in arid and semi-arid areas. With the burst of Zuo Lake in the source region of the Yangtze River, a large number of fragmentary materials from the lake bottom was exposed to the surface and became the new source of sand. The increasing sand storm disaster seriously threatened the ecological environment of Zuo Lake Basin and the safe operation of the Qinghai-Tibet Railway. In this paper, the grain size distribution and aeolian-sand flow structure of surface and aeolian-sand sediments after levee breach of Zuo Lake were obtained through systematic observation of aeolian-sand activities in three typical parts of west bank, south bank and east side of Zuo Lake. The results show that the west bank of Zuo Lake is the most intense area of sand activity in the basin, and the west bank and the south bank are the main source of sand and dust areas in the basin. The east side is the sedimentation area, and its blown sand sediments include both local sand materials and the dust from the west bank and the south bank. Due to the fine grain size of lacustrine sediments, the sand flow structure of west bank decreases linearly with height. Combined with the grain size results of surface and aeolian-sand flow sediments, it is speculated that the sand and dust initiation in Zuo Lake Basin is mainly aerodynamic entrainment, rather than the saltation bombardment as traditionally believed. The characteristics indicate that the aeolian sand activity in the dry lake basin in the plateau region is unique, and the prevention and control mode of low altitude areas cannot be copied in the prevention and control of aeolian-sand.

Temporal variation and spatial pattern of soil erosion in the Yellow River Basin
Wenfeng Chi, Yuetian Wang, Xiaohong Dang, Xiaoguang Wu, Qiancheng Luo
Journal of Desert Research    2023, 43 (3): 305-317.   DOI: 10.7522/j.issn.1000-694X.2023.00062
Abstract213)   HTML29)    PDF (10740KB)(261)      

The soil erosion in China was characterized by various types and complicated processes. It is of great significance to accurately quantify the temporal variation and spatial patterns of soil wind erosion and water erosion intensity in watersheds, to identify regional dominant erosion types for reasonable arrangement of soil and water conservation measures. This study quantified the temporal and spatial patterns and evolution of soil wind erosion and water erosion intensity in the Yellow River Basin from 2000 to 2020 combined remote sensing monitoring, field survey, and model simulation, revealed soil erosion type area, and its significance to zoning control of soil erosion. The results showed that: (1) The intensity of soil wind erosion and water erosion in the region showed a downward trend as a whole, while the wind erosion and water erosion showed a fluctuation and continuous decrease, respectively. In the past 20 years, the modulus of soil wind erosion and soil water erosion have respectively decreased at a rate of 18.88 t·km-2·a-1 and 34.98 t·km-2·a-1. (2) The type zones dominated by soil wind erosion and soil water erosion accounted for 16.35% and 83.65% of the total land area of the region, respectively, and the overall performance of soil erosion type zoning from north to south was the transition from soil wind erosion to water erosion. The areas dominated by soil wind erosion were distributed in the upper reaches of the main stream of the Yellow River and the Ordos inland flow area, accounting for 41.53% and 28.57% of the area of soil wind erosion area, respectively. Moderate erosion intensity of soil wind erosion accounted for the largest proportion, 24.72%. The areas dominated by soil water erosion were distributed in the middle reaches of the Yellow River (25.04%), the Wei River-Yiluo River system (22.06%), the source water system of the Yellow River (18.60%), the upper reaches of the Yellow River (15.49%), Huangshui-Taohe River System (13.35%). Soil water erosion was mainly micro-erosion intensity, accounting for 49.30% of the soil water erosion area, and light (17.28%), moderate (14.98%) and strong erosion intensity (11.95%) were widely staggered. (3) Desertification control project and soil and water conservation engineering made soil erosion modulus and erosion intensity decrease significantly in areas with strong wind and water erosion. According to the zoning characteristics of soil erosion types, the measures of vegetation restoration and agricultural oases in the soil wind erosion area were discussed. Agricultural cultivation measures, forest and grass measures and engineering measures are used to protect and control soil water erosion areas, in order to provide scientific guidance for the high-quality development of the ecosystem in the Yellow River Basin.

Morphology and sedimentary characteristics of shadow dunes of dead Halogeton arachnoideus in the southern margin of Qaidam Basin, China
Ruicong Xu, Zhibao Dong, Weige Nan, Guoxiang Chen, Funing Yang, Lingling Kong
Journal of Desert Research    2023, 43 (4): 55-63.   DOI: 10.7522/j.issn.1000-694X.2023.00002
Abstract207)   HTML5)    PDF (2805KB)(164)      

The dead Halogeton arachnoideus can still remain upright and play a role in sand fixation, making it a hotspot in the study of wind prevention and sand fixation in arid and semi-arid regions. On the basis of field investigation and grain size experiment, this paper analyzes the morphological and sedimentary characteristics of the shadow dunes of H. arachnoideus, a dead vegetation in the southern margin of Qaidam Basin, by using relevant statistical methods. The results show that: (1) The correlation between the parameters of shadow dune is significant (P<0.01), in which the vertical and horizontal scales of dune have good correlation, and the fitting relationship between the length and width of dune (R2=0.6) is better than other parameters. (2) There is a significant positive correlation (0.8≥r>0.5, except dredge degree) between the parameters of dead H. arachnoideus and the shape of shadow dune. The contribution of vegetation length and width to the extension of dune length is gradually decreasing, while the contribution of vegetation height to it is increasing. (3) The canopy area, length and dredging degree of H. arachnoideus were significantly correlated with the volume of shadow dunes (P<0.01), and the fitting relationship between canopy area and volume was good (R2=0.8), which jointly affected the sand interception capacity of H. arachnoideus. (4) The main grain size fractions of the sediment are very fine sand and fine sand, Under the influence of plants, the wind force gradually decreases, and the grain size of sediment along the wind direction gradually becomes thicker.

Grain size analysis of two sand layers with parallel bedding in the sand hills around Poyang Lake and its implication for the sedimentary environment
Qiwei Li, Zhijun Gong, Ming Luo, Huaming Peng, Han Wang, Wei Wang
Journal of Desert Research    2023, 43 (3): 152-159.   DOI: 10.7522/j.issn.1000-694X.2023.00003
Abstract193)   HTML5)    PDF (2792KB)(194)      

Poyang Lake is the largest freshwater lake in China. At present, there are several sand hills around Poyang Lake, such as sand hills from Hukou county to Pengze county as well as Songmen Island in Wucheng Town. Previous studies suggest that these sand hills were formed by aeolian process, especially for the middle-top part of the sand hills. However, by field investigation, it was found that several sand/silt layers in the middle-top part of sand hills around Poyang Lake exhibit clear water-lain sedimentary structures. It is interesting that the elevation of these sand/silt layers was significantly higher than the highest water level of Poyang Lake since 1949. In this study, two representative sand layers with parallel bedding were targeted and two bulk samples were collected for particle size analysis. One sand sample (XZ-1) is collected from a sand layer with the parallel bedding within Shaling (sand hill) in Lushan city. Currently, the Wusong elevation of sand sample (XZ-1) is ~36.5 m. The other sand sample (HGDS-7) is collected from another sand layer with parallel bedding within a sand hill at Shazhou village in Hukou county. Currently, the Wusong elevation of sand sample (HGDS-7) is ~40.3 m. The results are as following: (1) Sand sample XZ-1 is moderately sorted, while sand sample HGDS-7 is poorly sorted. (2) The frequency curve of XZ-1 exhibits one main peak and a small peak, while that of HGDS-7 exhibits bimodal characteristics. (3) The log-probability accumulative curve of XZ-1 can be fitted by six distinctive populations, while the log-probability accumulative curve of HGDS-7 can be fitted by eight distinctive populations. (4) If the Sahu discriminant function is applied, Y value of XZ-1 is calculated at 3.71, while Y value of HGDS-7 is calculated at 8.89. The above particle size results are consistent with the interpretations by sedimentary structure, i.e. the targeted sand layers within the sand hills should be interpreted as water-lain sediments, rather than aeolian sediments, even though the targeted sand layers are much higher than the highest water level of Poyang Lake since 1949. In the future, more research should be carried out at different sand hills around Poyang Lake, to further understand the formation of the sand hills. It not only helps us better understand the evolution of Poyang Lake, but also be very useful for government policy on sustainable water supply, flood control and ecological safety on Poyang Lake.

Study of ecological environmental quality changes in the upper Yellow River basin based on remote sensing ecological index
Yating Cui, Huan Li, Longxiao Zheng, Mengquan Wu
Journal of Desert Research    2023, 43 (3): 107-118.   DOI: 10.7522/j.issn.1000-694X.2022.00148
Abstract189)   HTML6)    PDF (2333KB)(167)      

As the water source of the Yellow River, the upper Yellow River basin is an important ecological function area in China. Analysis of ecological environmental quality changes in the upper Yellow River basin is important for ecological protection and high-quality economic development of the Yellow River basin. Based on Google Earth Engine platform, this paper analyzes the change of ecological environment quality in the upper Yellow River basin from 2000 to 2021 through remote sensing ecological index (RSEI). The results show that: (1)The RSEI of the upper Yellow River basin is elevated. At the same time, it has the characteristics of stages. 2000-2005 is the stage of deterioration of ecological environment quality, and 2006-2021 is the stage of improvement of ecological environment quality. It is poor and moderate, accounting for 64.78% of the total area of the region. (2)The ecological quality of different river sections is different significantly, with the best ecological quality in the river source section and the worst ecological quality in the alluvial plain section. (3)The spatial clustering characteristics of ecological environment quality in the upper Yellow River basin are obvious, where high-high clustering areas are stably distributed near the river source section and low-low clustering areas are distributed in the canyon section and alluvial plain section where the intensity of human activities is higher. (4)Greenness, humidity, heat and dryness all have significant effects on the ecological quality of the upper Yellow River basin, with greenness as the dominant driver and dryness as the secondary driver. The increase of vegetation cover, climate regulation and soil and water conservation have significantly contributed to the ecological improvement of the upper Yellow River basin.

The practice on prevention and control of aeolian desertification and the development of desert science in China for 70 yearspioneering part2
Tao Wang
Journal of Desert Research    2023, 43 (3): 1-8.   DOI: 10.7522/j.issn.1000-694X.2023.00032
Abstract184)   HTML22)    PDF (569KB)(242)      

The Second National Conference on Combating Desert had been held in September, 1959 in Urumqi, which further to demonstrate the attention and expectation from the state's responsibility for prevention and control of aeolian desertification. In the years that followed, the Scientific Investigation Team for Combating Deserts, CAS and relevant provincial (autonomous region) departments carried out a more systematic investigation, experiment, research and practice. This paper focus on following three parts: (1) Based on the experimental investigations in the filed fixed station and semi-fixed station to comprehensive control of the desert, the author discusses some progress and function in the selection and introduction of plant species for moving dune fixing and optimal allocation, the mechanical sand fixation, the moving dune's moisture state and its stabilization and afforestation, the transpiration intensity of the major psammophytes, the process of soil formation in the fixed quicksand area and the dune soil microorganisms, etc. (2) Based on the research results of several major scientific and technological issues in prevention and control of aeolian desertification, the author discusses some main progress and function in the cause of the desert, the relationship between moving regular pattern of sand dune and wind prevention and sand-fixation, the assessment of aircraft seeding, the vegetation types and their evolution law in desert, the psammophytes characteristics, rational use of grassland in desert, the classification of the Gobi Desert and its transformation and utilization, water resources and their utilization, etc. (3) The author expounds briefly the process and the achievements of prevention and control of aeolian desertification during the establishment of the People's Republic of China (PRC) from 1949 to 1965,which affirmed the research objectives, formed the spirit of pioneering dedication and effective research method, and formed preliminarily in theory, practice, team and platform of the desert science. Thus laid the foundation and conditions for the start-up and pioneering of China Desert Science, so that let it enter the development period smoothly.

The practice on prevention and control of aeolian desertification and the development of desert science in China for 70 years: development part(1)
Tao Wang
Journal of Desert Research    2024, 44 (1): 1-10.   DOI: 10.7522/j.issn.1000-694X.2023.00162
Abstract179)   HTML16)    PDF (630KB)(208)      

The 10 years period of “Culture Revolution” from 1966 to 1976 had hindered the practice on prevention and control of aeolian desertification and the development of desert science to a certain degree. Nonetheless, relied on the foundation laid over the past decade, the science, technology and engineering teams from all levels of national to provincial and local carried on with scientific research, technological development and engineering implementation, field long-term observations and experiments, laboratory sample analysis and data statistics, blowing sand wind tunnel experiment, summary of results and writing of papers and monographs, etc. These efforts had obtained a batch of achievements, in which some of typical progress can be expressed as follows. (1) The construction and application of blowing sand wind tunnel created the pioneering work of wind tunnel experiment for prevention and control of aeolian desertification and research on law of wind-blown sand movement in China. (2) Some new results have been made in process and prevention of wind-sand disaster to the desert railway by systematically conducted on engineering technology experiments and theoretical research. (3) The work exchange meeting on desert control research of Chinese Academy of Sciences had successfully held in Lanzhou in March of 1975, which timely concluded and presented the theoretical and practical achievements and levels. (4) Systematically summarized the results of scientific investigations, observations, experiments, research, and practice, so that many scientific papers have been published as well as a series of monographs compiled and edited. There were some encouraged results of exploration and innovation on the distribution and general characteristics of deserts, causes of desert formation, source of sand material rising right on the spot, feature of wind-blown sand movement, formation and evolution mechanism of sand dunes in China and the development of aeolian geomorphology, morphological characteristics and movement patterns of sand dunes, regionalization of aeolian geomorphology and several landform issues for preventing blown sand disaster in the Taklamakan Desert. Other system summary results also delivered such as the management of farmland wind-blown sand disaster, railway's prevention and control of wind-blown sand damage, desert railway engineering construction as well as the successful experiences and effective measures from the Xinjiang, Gansu and Inner Mongolia Autonomous Region. All of the achievements and progress promoted the theoretical exploration and systematic composition of desert science in China.

Vegetation coverage change and its response to ecological protection project in Fenhe River Basin
Xiaohong Ma, Fei Lin, Liming Yuan, Junjie Niu
Journal of Desert Research    2023, 43 (3): 86-95.   DOI: 10.7522/j.issn.1000-694X.2022.00144
Abstract178)   HTML7)    PDF (5432KB)(124)      

Vegetation is an important component of terrestrial ecosystems, and it plays an important role in preventing desertification and conserving soil and water in arid and semi-arid regions. Fractional vegetation coverage (FVC), in turn, is an important indicator of vegetation and ecological environment status. To understand the ecological status from 2000 to 2020 in Fenhe River Basin, this study examined the spatial distribution and temporal variations of vegetation coverage, investigated the vegetation response to ecological protection project. Our results demonstrate that: (1) The FVC increase from 55% in 2000 to 72% in 2020, with an increase rate of 0.87% per year, which is manifested with the increase of the high FVC area (FVC>60%). The ecological environment quality of the region has been significantly improved. (2) Under the influence of ecological protection project, FVC increase in 77.1% of the area, and decrease in 1.7% of the area under the urbanization and mineral resources development. (3) The spatial and temporal variability of FVC are great, and the coefficient variation fluctuates between 0.01 and 2.20. The FVC is stable in original alpine forest area, valley agricultural area and urban construction. This study would provide a theoretical basis for formulating polices related to ecological environmental protection and sustainable development.

Characteristics of runoff change in the Shiyang River Basin
Ran Duan, Zongjie Li, Yu Wang, Xiaoying Liu, Juan Gui, Pengfei Liang, Yuchen Li, Jian Xue, Mengqing Liu, Bin Xu
Journal of Desert Research    2023, 43 (3): 57-68.   DOI: 10.7522/j.issn.1000-694X.2022.00142
Abstract178)   HTML210)    PDF (6991KB)(177)      

Based on the month-by-month precipitation and runoff data from 12 hydrological stations and 35 rainfall stations in the main stream and eight tributaries of the Shiyang River Basin, wavelet analysis and double accumulation curve were used to study the change characteristics of runoff in the Shiyang River Basin. The results showed that: (1) The overall trend of runoff in the Shiyang River Basin was decreasing, with an average decrease of 0.37 billion m3 per 10 a.The runoff in the main stream of Shiyang River, Jinta River, Zamu River, Huangyang River and Gulang River decreased, and the runoff in the Xida River, Dongda River, Xiying River and Dajing River increased. (2) Nine hydrological stations in the Shiyang River Basin have periodic variations on time scales of 2-10 a and 10-30 a, among which the Zamusi station and the Huangyanghe reservoir station also have long periodic variations of 30-60 a, and the nine hydrological stations have the most obvious changes in abundance and depletion on time scales of 24, 21, 21, 21, 43, 45, 22, 17, 21 a, respectively. (3) The abrupt changes in the Shiyang River main stream and eight major tributaries occurred in 1971, 2014, 2000, 2018, 1960, 1959, 1962, 1994 and 1965, respectively, in which the runoff decreased after abrupt changes in the Shiyang River main stream, Jinta River, Zamu River, Huangyang River and Gulang River, increased after abrupt changes in the Xida River, Xiyang River and Dajing River, and did not have abrupt changes in the Dongda River. The results of the study can provide reference for the scientific management and optimal allocation of water resources in the Shiyang River basin and the implementation of subsequent ecological projects.

Assessment of soil quality in typical wind erosion area of Qaidam Basin
Mengzhen Huang, Ruijie Lu, Jin Zhao, Luo Ma
Journal of Desert Research    2023, 43 (3): 199-209.   DOI: 10.7522/j.issn.1000-694X.2022.00125
Abstract171)   HTML6)    PDF (2249KB)(118)      

Soil quality assessment is the key to effectively protect soil, and it is crucial to ensure ecosystem stability, regional ecological security and sustainable development. The Qaidam Basin is the most serious wind erosion area in the Qinghai-Tibet Plateau. The change of soil system caused by wind erosion has a profound impact on the ecological security barrier and water conservation function of the Qinghai-Tibet Plateau. Based on the analysis of physical and chemical properties of surface soil in typical wind erosion areas of Qaidam Basin, this paper uses principal component analysis to establish the minimum data set, and constructs the comprehensive index of soil quality for soil quality evaluation. The results show that the soil bulk density, calcium carbonate, organic matter, total nitrogen, total phosphorus and available phosphorus content in Qaidam Basin only reach the fourth or fifth grade under the quality classification standard of the second national soil census. The quality of soil physical and chemical indicators is poor. In terms of spatial distribution, the contents of organic matter, total nitrogen, available phosphorus, total phosphorus and sand in the eastern region of Qaidam Basin are higher than those in the western region, while the contents of available potassium and gravel in the western region are higher than those in the eastern region. The minimum data set ( MDS ) of soil quality evaluation in Qaidam Basin includes five indicators : bulk density, organic matter, total phosphorus, available potassium and sand content. The soil quality comprehensive index ( MDS-SQI ) based on the MDS has good representativeness and applicability. The overall soil quality in Qaidam Basin is poor, and gradually deteriorates from the eastern region to the western region. The soil quality in the study area is divided into grade I-V from good to poor. Grade I-II sampling points are mainly distributed in the eastern region, and the area is small. Grade III-V sampling points are mainly distributed in the central and western regions. The wind erosion intensity in Qaidam Basin is significantly negatively correlated with MDS-SQI, and the prevention and control of soil wind erosion in Qaidam Basin is an important measure to curb the continuous deterioration of soil quality.

Research on the dynamic change of the ecological environment and its influencing factors in the Yellow River Basin based on Remote Sensing Ecological Index
Fangmiao Chen, Huiping Huang, Guang Yang, Xu Li
Journal of Desert Research    2023, 43 (4): 252-262.   DOI: 10.7522/j.issn.1000-694X.2023.00017
Abstract165)   HTML4)    PDF (3577KB)(119)      

The Yellow River Basin bears an important ecological, economic and cultural strategic position in China, and its ecological environment is a vital foundation for ensuring the high-quality development of the Yellow River Basin. In this study, the long-term sequence of Remote Sensing Ecological Index (RSEI) of the Yellow River Basin was used to dynamically monitor and analyze the ecological quality changes in the Yellow River Basin in the past 20 years. The RSEI mean value is 0.497 from 2001 to 2019, increasing 0.04, which shows a trend of overall improvement and slight fluctuations. Moreover, its influencing factors were analyzed from three aspects: natural factors, policy measures and socio-economic factors. The complex natural factors bring difficulties to the governance of the Yellow River Basin, and the socio-economic factors such as continuously increasing population and night light data correspondingly disturbed the ecological environment changes, while the ecological protection policies and restoration measures play a positive role.

Physical and chemical characteristics of aeolian sands in Jiudong Sandy Land of Hexi Corridor and its environmental significance
Xueyang Guo, Linhai Yang, Liangqing Cheng, Guangyin Hu, Jingjing Hu
Journal of Desert Research    2023, 43 (4): 17-30.   DOI: 10.7522/j.issn.1000-694X.2022.00156
Abstract161)   HTML4)    PDF (6590KB)(102)      

Jiudong Sandy Land is located between Zhangye Oasis and Jiuquan Oasis in the middle Hexi Corridor and its aeolian process is influential to the surrounding hμman activities. In this paper, the grain size, chemical elements and mineral characteristics of the surface aeolian sands of Jiudong Sandy Land were investigated. The results show that: (1) The average grain size of aeolian sands on the surface of Jiudong Sandy Land is between 218-308 μm and mainly consists of mediμm sand and fine sand with good sorting, nearly symmetrical skewness and kurtosis is moderate. The aeolian sands generally become finer from north to south; the aeolian sands in the hinterland of the sandy land gradually become finer from west to east, while the southern edge of the sandy land presents the opposite phenomenon. The content of saltation component is the highest, followed by short distance suspension component, creeping component and long-distance suspension component. (2) The major element is SiO2, and the content of CaO and MgO decreases along the dominant wind direction. Except for Cr, Ni and Co, trace elements show obvious enrichment while other elements are depleted to varying degrees. (3) The minerals are mainly hard minerals of quartz and feldspar, followed by dolomite, and the content of other minerals is very low. The mineral maturity index (Q/TF) is low. (4) The aeolian sands of Jiudong Sandy Land are in the initial stage of being basically free from or subject to weak chemical weathering, mainly in the process of strong physical weathering. It is speculated that they were formed in a dry and cold, weak chemical weathering and weak pedogenic environment.

Sustainable development evaluation of nine provinces in the Yellow River Basin based on energy ecological footprint
Chengjun Wang, Jingxiang Tang, Tao Feng, Chuanjia Du, Binglin Zhang
Journal of Desert Research    2023, 43 (3): 138-151.   DOI: 10.7522/j.issn.1000-694X.2022.00170
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Understanding the sustainable development level of each province in the Yellow River Basin can guide the formulation and implementation of high-quality development policies in the Yellow River Basin. Taking nine provinces in the Yellow River Basin as the research object, the four evaluation indicators of footprint depth, ecological utilization efficiency index, eco-economic coordination index and ecological footprint diversity index are calculated based on the improved energy ecological footprint model, on which the entropy weight method is used to calculate the comprehensive sustainable development index to evaluate the comprehensive sustainable development level of the nine provinces of the Yellow River Basin from 2009 to 2020. The results show that: (1) From 2009 to 2020, the footprint depth of all provinces except Qinghai Province exceeds 1; (2) From 2009 to 2020, all provinces show an overall decreasing trend in the ecological utilization efficiency index, among which Ningxia Hui Autonomous Region has the largest decrease of 57.55%; (3) From 2009 to 2020, the ecological and economic coordination indexes of four provinces, namely Shanxi, Shandong, Henan and Ningxia Hui Autonomous Region, do not exceed 1.05, all of which are lower than those of the remaining provinces; (4) From 2009 to 2020, the ecological footprint diversity indexes of Gansu Province all exceed 1, all of which are higher than those of the remaining provinces; (5) From 2009 to 2020, both Sichuan and Qinghai provinces are at sustainable development level, Gansu and Inner Mongolia Autonomous Region fluctuate between fairly sustainable and slightly unsustainable, and the rest of the provinces are at unsustainable development level, among which Ningxia Hui Autonomous Region fluctuates between slightly unsustainable and fairly unsustainable, Shandong and Henan Province are at fairly unsustainable year-round, Shanxi Province fluctuates between fairly unsustainable and very unsustainable, and Shaanxi Province is very unsustainable year-round. In the future, sustainable development strategies need to be developed and implemented according to local conditions to promote high-quality development in the Yellow River Basin.

Mapping oasis structure data based on ChinaCover dataset: a case study of Hexi Inland River Basin
Sen Li, Changzhen Yan
Journal of Desert Research    2023, 43 (3): 230-242.   DOI: 10.7522/j.issn.1000-694X.2022.00129
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The production of oasis thematic data with both oasis uniqueness and structural characteristics is a key basic problem to be solved in oasis research at present. In this paper, a secondary classification system of oasis ecosystem was constructed according to the characteristics of oasis. Then, taking the Hexi inland river basin (HIRB) as the study area, the object-oriented random forest classification and superposition analysis method was used to complete the land structure data mapping of oases in the HIRB from 1975 to 2020 in seven periods, combining with ChinaCover data and Landsat NDVI images. The results show that: (1) the oasis structure data mapping method based on ChinaCover data set can produce oasis thematic data quickly and accurately. (2) the overall accuracy of the primary type of the oasis ecosystem is 96.17%, and the accuracy of the secondary type is 82.64%-92.99%, which is significantly higher than that of the existing land cover products. (3) the proportion of oases in HIRB accounted for 8.97% of the study area in 2020, the primary type was mainly artificial oasis, and the secondary type was mainly cultivated land and grassland. (4) the artificial oasis in the HIRB showed a continuous expansion trend, the desert-oasis ecotone showed a shrinking trend, and the natural oasis shrank at first and then expanded in the past 45 years. The expansion of artificial oasis is mainly due to the increase of cultivated land and construction land, while the shrinkage of ecotone and natural oasis is mainly due to the decrease of grassland. This study can provide a simple and accurate data method for oasis mapping in arid areas.

Remote sensing monitoring of aeolian desertification and quantitative analysis of its driving force in the Yellow River Basin during 2000-2020
Hongyan Zhao, Changzhen Yan, Sen Li, Yahui Wang
Journal of Desert Research    2023, 43 (3): 127-137.   DOI: 10.7522/j.issn.1000-694X.2022.00152
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China has achieved remarkable prevention and control effects of aeolian desertification in northern China, and has shown an overall reversal trend since 2000. The Yellow River Basin is an important barrier to national ecological security, and its aeolian desertification prevention and control is a key link in consolidating the foundation for high-quality development of the basin. Based on the background of the overall reversal of aeolian desertification in northern China since 2000. The aeolian desertification process in the Yellow River Basin from 2000 to 2020 was discussed in this study, and the dominant factor which driving the dynamics of aeolian desertification in the basin and their relative contributions were analyzed using the quantitative method. The results showed that: (1) The aeolian desertification land in the Yellow River Basin mainly consisted of moderate and severe aeolian desertification lands, and was concentrated in the middle and upper reaches of the Yellow River Basin. From 2000 to 2020, the total aeolian desertification land decreased by 7 529 km2 (5.6%) in the Yellow River Basin. In detail, the serious aeolian desertification land continued to decrease by 47.1%, while the increasing trend of the slight, moderate, and severe aeolian desertification lands slowed down significantly after 2010. (2) In space, the aeolian desertification land was mainly distributed in the middle and upper reaches of the Yellow River Basin, and the total aeolian desertification land further shrank to the upper reaches of the Yellow River Basin from 2000 to 2020. The reversed aeolian desertification land with a large distribution area of 2020, 35 542 km2 (26.5%), and the developed aeolian desertification with a scattered distribution area of 2 823 km2 (2.1%) was mainly concentrated in the Hobq Desert, Mu Us Sandy Land, and the source area of the Yellow River. The reversal or development of aeolian desertification was dominated by the transfer to the aeolian desertification land with a lighter or a higher desertification degree, and the transfer has also slowed down significantly after 2010. (3) The area jointly driven by climate change and human activities accounted for 89.67% of the aeolian desertification dynamic area of the Yellow River Basin from 2000 to 2020, and that driven by individual climate change or individual human activities only accounted for 7.30% and 3.03%, respectively. The relative contribution of human activities (54.91%) was generally higher than that of climate change (45.09%), but this relative contribution of human activities decreased with the increase of the relative contribution of climate change in different periods. This work can provide a decision-making basis and reference for the key desertification control in the ecological protection and high-quality development strategy of the Yellow River Basin, and can also provide significant theoretical support for realizing the high-quality development of the Yellow River basin.

Soil fungal community structure and functional characteristics associated with Pinus sylvestris var. mongolica plantations in the Horqin Sandy Land
Dandan Li, Jiawen Li, Guanglei Gao, Ying Zhang, Yue Ren, Ye Liu, Peishan Zhao
Journal of Desert Research    2023, 43 (4): 241-251.   DOI: 10.7522/j.issn.1000-694X.2023.00035
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To explore a firm basis for sustainable management of Pinussylvestris var. mongolica, soil fungal community structure and functional characteristics as well as the driving soil properties were revealed in different stand ages of P. sylvestris plantations in the Horqin Sandy Land. We sampled the soil of P. sylvestris plantations with young-mature (13 a), half-mature (22 a), nearly-mature (34 a), mature (41 a) and over-mature (55 a), and soil fungal communities were identified by Illumina MiSeq high-throughput sequencing and FUNGuild platform. The results showed that: (1) In the Horqin Sandy Land, 922 fungal OTUs were obtained from soil samples of P. sylvestris plantations, and belonged to 254 genera, 98 families, 67 orders, 25 classes, and 14 phyla. Ascomycota and Basidiomycota were predominated, and the dominant genera were Calostoma and Amphinema. (2) With stand aging, the proportion of symbiotic fungi and the dominated functional groups ectomycorrhizal fungi climbed up and then declined, with a minimum in the mature plantations; the proportion of saprophytic fungi and the dominated functional groups undefined saprophytic fungi decreased after a little increase, with a maximum in mature plantations; the distribution of pathotrophic fungi was relatively uniform. (3) With stand aging, soil fungal network showed a differentiated tendency which simplified first and then complicated. The network of nearly-mature plantations was the simplest, and the over-mature plantations was the most complex followed by the mature plantations. (4) Soil organic matter, pH, alkali-hydrolyzable nitrogen and nitrate nitrogen were the most important driving factors for soil fungal community structure. The relative abundance of saprophytic fungi was positively and negatively correlated with soil total phosphorus and pH, respectively (P<0.05), and the relative abundance of saprophytic fungi had a significant positive correlated with soil organic matter (P<0.01). Stand age and soil properties play a key role in the soil fungal community construction associated with P. sylvestris plantations in the Horqin Sandy Land. From young to nearly-mature plantations, the dominant symbiotic fungi accumulation, which benefit the rapid growth of plantations. In mature and over-mature plantations, the soil fungal community structure is similar, saprophytic fungi are the dominant species, and the soil fungal community network tend to complex and stable, which contribute to the resistance improvement of plantations to changeable environments. This improved information will provide a better understanding of soil fungal functions of P. sylvestris plantations in the Horqin Sandy Land, as well as the forest and soil health from the perspective of soil fungi.

An analysis on the land use change characteristics and driving forces in Gansu part of the Qilian Mountain
Rui Guo, Wei Liu, Zongxing Li, Ya Wang, Yong Chen, Lihua Zhou
Journal of Desert Research    2023, 43 (3): 188-198.   DOI: 10.7522/j.issn.1000-694X.2022.00123
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Based on Landsat 30m land use data from 1990 to 2018, combined with the land use change analysis and statistics method, the spatial and temporal distribution characteristics of land use at the Gansu part of the Qilian Mountain in recent 30 years were studied and the function mechanism of natural factors and human activities on the land use change in the area was explored. The results show that: (1) The land use types in Gansu part of the Qilian Mountain were mainly unused land and grassland; from 1990 to 2018, except the water and unused land areas which showed decreasing trends, the areas of other types showed a dynamic increasing trend. (2) After 2000, the areas and types of the land participating related transfer were increasing, mainly between unused land-grassland, unused land-woodland and cultivated land-grassland. (3) Natural factors were the leading reasons for the land use changes in Gansu part of the Qilian Mountain. The ecological projects Three- north Shelterbelt Project and Natural Forest Protection Project which focused on returning farmland to forest and grassland, returning grazing land to grassland, restricted human agricultural and animal husbandry production activities, and also brought obvious local effects on the land use change in Gansu part of the Qilian Mountain.

Review on identification and forecasting of dusty weather
Siyu Chen, Shikang Du, Hongru Bi, Dan Zhao, Yue Zhang, Yu Chen, Gaotong Lou, Junyan Chen
Journal of Desert Research    2024, 44 (1): 11-21.   DOI: 10.7522/j.issn.1000-694X.2023.00054
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Dusty weather is an extreme weather phenomenon that occurs frequently in the northern China. It leads to a turbidity of the air and a sharp decline in visibility, causing adverse effects on various aspects of human society. Dust aerosols transported into the atmosphere by strong winds also have a significant impact on weather and climate by modulating atmospheric radiation budget and cloud microphysics. Accurate identification and forecasting of dusty weather are of great significance in ecological protection and climate change mitigation. This paper provides a comprehensive review of recent research on methods for identifying and forecasting dust events. Important methods are described in detail, and their advantages and disadvantages are analyzed and compared. Finally, this paper summarizes the research achievements related to the identification and forecasting of dusty weather and proposes valuable future research directions.

Distribution characteristics of soil organic carbon and its relationship with soil physical properties in Ali Desert Area, Tibetan Plateau
Yaofang Shi, Xian Xue, Quangang You, Fei Peng, Cuihua Huang
Journal of Desert Research    2023, 43 (3): 284-294.   DOI: 10.7522/j.issn.1000-694X.2023.00015
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In order to improve the soil background data in Ali Desert Area and improve the understanding of the level of soil carbon sink in alpine desert, this article took the 0-100 cm deep soil in Ali Desert Area of Qinghai-Tibet Plateau as the research object. Through field investigation, sample collection, and laboratory experiments of 34 soil samples distributed in the whole region, the vertical and horizontal distribution characteristics of soil organic carbon content (SOC) and soil organic carbon density (SOCD), as well as the relationship with vegetation types and soil physical properties were discussed. The results showed: (1) The average values of SOC and SOCD in the soil depth of 100 cm were 3.74 g?kg-1 and 4.91 kg?m-2, respectively, which were at a low level nationwide. In the vertical direction, SOC and SOCD gradually decreased from the surface layer to the deep layer, with the surface aggregation phenomenon. (2) In the whole region, SOC and SOCD showed strong variability and significant differences among different vegetation types (P≤0.05). In the horizontal direction, SOC and SOCD showed a decreasing trend from northeast to southwest, from the desert steppe, shrubby steppe desert, semi-shrubby and dwarf semi-shrubby desert to the non-vegetation area. (3) The soil bulk density and sand content gradually increased with the increase of soil depth, while soil water content, clay content, and silt content gradually decreased. In some areas with low vegetation coverage, the soil water content and clay content showed a low-high-low trend with soil depth. Soil water content, silt content, and clay content were significantly positively correlated with SOCD (P≤0.05), and soil sand content was significantly negatively correlated with SOCD (P≤0.05).

Response of vegetation coverage to precipitation change in the typical sandy lands of eastern China
Fanrui Bu, Ying Liu, Xueyong Zou
Journal of Desert Research    2023, 43 (3): 9-20.   DOI: 10.7522/j.issn.1000-694X.2022.00124
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Precipitation has an important impact on vegetation coverage in eastern desert regions of China. Understanding the response of vegetation coverage to precipitation changes is of importance to making strategies for vegetation restoration. Mu Us Sandy Land and Horqin Sandy Land, which are typical sandy lands in eastern China, were selected, the Landsat series data and MODIS data were used to obtain the normalized difference vegetation index (NDVI) data set in 2000-2020, and the pixel dichotomy method was used to compute the maximum vegetation coverage in each year and the average vegetation coverage in growing seasons. Then, the daily precipitation data observed by weather stations from 1999 to 2020 were combined with the data of the vegetation coverage to analyze the response of vegetation coverage to precipitation changes in different seasons. The results showed: (1) Both of the maximum vegetation coverage in a year and the average vegetation coverage in growing seasons appeared an increasing trend in Mu Us Sandy Land and Horqin Sandy Land, the increasing rate of the maximum vegetation coverage was 6.5%/10a and 4.1%/10a, respectively, and the increasing rate of the average vegetation coverage was 6.3%/10a and 3.6%/10a, respectively. Among them, the most significant increase with >30% of the average vegetation coverage in growing seasons was found in Mu Us Sandy Land, and that with >50% of the average vegetation coverage in growing seasons was found in Horqin Sandy Land. (2) The annual precipitation and the seasonal precipitation in the two sandy lands showed an increasing trend, the increasing rate was 50.4 mm/10a and 46.7 mm/10a, respectively. The precipitation was of the common characteristics of large variability and the largest summer increase. (3) Both of the yearly maximum vegetation coverage and the average vegetation coverage in growing seasons in Mu Us Sandy Land were most sensitive to the response of the summer precipitation in previous year, while those in Horqin Sandy Land were most sensitive to the response of the summer precipitation in the same year. (4) Different vegetation types have different lag times in response to precipitation changes.

Analysis of quantitative characteristics and spatial distribution for main shrubs on the eastern edge of the Badain Jaran Desert
Yadong Jiang, Shijie Lv, Hongmei Liu, Narenhua, Xinyu Liu
Journal of Desert Research    2023, 43 (3): 295-304.   DOI: 10.7522/j.issn.1000-694X.2023.00027
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The Badain Jaran Desert is the third largest desert in China, which typical desert vegetation is a shrub and semi-shrub dominated vegetation type formed under extreme continental arid climate, and its tolerance to harsh environments and ecological adaptation process have formed unique phenotypic plasticity and ecological response strategies. In order to explore the adaptive basis and spatial distribution status of major populations, this study focused on the vegetation grown on the hard surface of sandy land on the eastern edge of the Badain Jaran Desert, using a two-factor experimental design of sample area and scale construction, combined with comparative and geostatistical analysis, the preliminary conclusions are as follows. Haloxylon ammodendron is resistant to barrenness and sandstorms, resulting in a high crown diameter and height performance. Nitraria tangutorum increases its own diameter of bunch by capturing flowing sand. Reaumuria songarica has strong seed germination and seedling planting ability, resulting in a higher frequency of occurrence. The status and role of the three species in the plant community decrease in order. The spatial distribution of N. tangutorum and H. ammodendron populations is mainly centered on the mother plant and spreads along the prevailing wind direction, while the spatial distribution of R.songarica populations is weakly concentrated even under the effect of structural factors. The overall spatial distribution of the three plant populations is mainly affected by structural factors, presenting a mosaic distribution pattern, and the boundaries between species disappear. In summary, the differences in the adaptation basis of H. ammodendronN. tangutorum, and R. songarica populations to the environment can be reflected by quantitative characteristic indicators. Their status and role in the plant community decrease in order. The spatial distribution of a single population can reflect the diffusion pattern centered on the mother plant, and the spatial distribution of composite populations reflects the spatial coordination and adaptation situation, presenting a mosaic distribution pattern, and the boundaries between species disappear.

Analysis of herbaceous species composition and diversity in the Ordos Arsenic Sandstone Areas
Gaoling Han, Jianqiang Huo, Yanqiao Zhao, Rui Hu, Zhishan Zhang, Rihui Huang, Shuwen Xue
Journal of Desert Research    2023, 43 (3): 243-251.   DOI: 10.7522/j.issn.1000-694X.2023.00025
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In order to explore the species composition and diversity of herbaceous species in different types of arsenic sandstone areas and the impact of environmental factors on them, different types of arsenic sandstone areas were selected in the Inner Mongolia Ordos City, to investigate the species composition and diversity of herbaceous plant. The results showed that: The dominant herbaceous species was different in different types of arsenic sandstone areas. The soil-covered area was Stipa capillataSalsola tragusLespedeza bicolorTribulus terrestris; the sand-covered area was S. capillataSetaria viridisArtemisia argyi; the bare area was Chenopodium aristatum. The similarity index of sand-covered area and bare area was 50.0%, those of sand-covered area and soil-covered area and soil-covered area and bare area were 63.6% and 39.1%.There was no significant difference in the diversity index of herbaceous species among different types of arsenic sandstone areas.The evenness index of different topographic sites was significantly different (P=0.027) , which is significantly higher on the slope than on the middle and lower slopes. The results of principal component analysis showed that relative humidity, air temperature, precipitation and soil water content were the main environmental factors affecting species composition and diversity, relative humidity, air temperature and precipitation accounted for 42.4%, 44.5% and 33.4% of the first principal component respectively, and soil moisture accounted for 66.8% of the second principal component. Therefore, understanding the relationship between water conditions and species diversity is helpful for ecological restoration, construction of revegetation and control of soil erosion in arsenic sandstone areas. This study can provide a near-natural plant spatial allocation model for vegetation restoration in arsenic sandstone area, so as to promote the effect of ecological restoration.

Variation in NDVI and its response to climate change and human activities in Gansu Province during 2000-2020
Jianbing Lu, Ke Ju, Weibin Liao
Journal of Desert Research    2023, 43 (4): 118-127.   DOI: 10.7522/j.issn.1000-694X.2022.00162
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As a vulnerable eco-environmental area, Gansu is the earliest province where the State Council implements the Grain to Green Program. It is of great significance to clarify the spatio-temporal variation characteristics of vegetation cover and its response to climate change and human activities in Gansu, as well as great value for the construction of ecological civilization and the realization of the sustainable development strategy. In this study, the generalized additional two-way fixed effects model was used to quantitatively evaluate the impact of human activities and climate change on vegetation changes, linear trend analysis and partial correlation analysis were also used to analyze the spatio-temporal variation characteristics of vegetation cover. The results showed that: (1) Vegetation NDVI showed an increasing trend in Gansu during 2000-2020, with a rate of 0.004·a-1. Vegetation NDVI showed a significant upward trend in 81.43% of the area, while vegetation NDVI decreased significantly in 1.08% of the area, and the rest of area was found with no significant change. (2) NDVI of Gansu showed a better correlation with precipitation than with temperature; Temperature generally inhibit vegetation NDVI growth, while a significant and positive non-linear correlation is founded between NDVI and precipitation. (3) The regions where the NDVI increased caused by human activity were mainly located in in Central Gansu Loess Plateau and East Gansu Loess Plateau, with a contribution of 15.4%-48.6%; while the regions where the NDVI decreased caused by human activity were mainly located in Gannan Plateau, Hexi Corridor and Mazong Mountain. The results of this study can provide reference for assessing the vegetation cover change under the background of the Grain to Green Program in Gansu.

Scenario simulation and countermeasure suggestions for achieving the "carbon peaking and carbon neutrality goals" in Gansu province
Nan Ma, Xiaohong Deng, Zongxing Li, Zhenbang Ma, Shulin Yan, Huijuan Pei
Journal of Desert Research    2023, 43 (5): 66-73.   DOI: 10.7522/j.issn.1000-694X.2023.00042
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The work of accounting of carbon emissions and sinks, along with impact factor analysis and future projection, is of great importance for regions to adapt to climate change and achieve carbon peak and carbon neutrality targets. This study first quantitatively analyzed and simulated the current characteristics and future scenarios of carbon emissions and carbon sinks in Gansu province based on the LMDI model, STIRPAT model, and FLUS-InVEST model. Then qualitatively discussed the possible challenges and opportunities in the process of reducing emissions and increasing sinks in Gansu province, and finally proposed a pathway and specific countermeasure suggestions for Gansu province to achieve its carbon peak and carbon neutral targets. The results show that: (1) Gansu province's carbon emissions are on the rise, and secondary industries are the major contributors to carbon emissions. (2) Economic output is the dominant factor in the growth of carbon emissions in Gansu province. (3) Under the full optimization scenario, Gansu province's carbon emissions peak in 2030 as scheduled, and the emission reduction effect is the most satisfactory. (4) Gansu Province has a significant gap in newly added carbon sinks in the short term, making it difficult to offset all carbon emissions. It is recommended that Gansu province's pathway to achieve its carbon peak and carbon neutral targets be carried out in two stages, with multiple measures to reduce carbon emissions and increase carbon sinks and optimize economic development, industry structure and energy consumption.

Macrobenthos community structure and water quality evaluation in Gansu section of Yellow River Basin
Yu Wang, Xu Wang, Qi Feng, Wei Liu, Yuhua He, Jiale Zhu, Yupeng Wang
Journal of Desert Research    2023, 43 (4): 146-156.   DOI: 10.7522/j.issn.1000-694X.2023.00024
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To explore the impact of human activities on the aquatic ecosystem in the upper reaches of the Yellow River, the species composition, inhabit density, biomass, dominant species and the aquatic physiochemical parameters were investigated in August 2021 of the Gansu section of the Yellow River. A total of 32 macrozoobenthos species including 25 species of arthropods (78.13%), 5 species of mollusks (15.63%) and 2 species of annelids (6.25%) were identified. The dominant species were Sigara substriata, Ampumixis sp., Palaemon modestusGammarus sp., Radix Auricularia and Radix ovata in the whole study area. An obvious spatial heterogeneity in existing stock, with the values the density and biomass to be 271 ind.·m2 and 18.0105 g·m2 in the downstream section, and 95 ind.·m2 and 4.1275 g·m2 in the upstream section, respectively. The Shannon-Wiener diversity index and Margalef richness index were showed the downstream section greater than the upstream section, but the Pielou evenness index have little change along the way. The water quality was observed better in the upstream section sites than in the downstream section sites based on the evaluation results of integrated biological index and comprehensive pollution index, and the best water quality site is Y6. The water quality of Gansu section of the Yellow River generally reaches the limit of Class II surface water, the water quality of rivers is significantly improved after being purified by reservoirs and wetlands. According to the correlation matrix analysis between macrozoobenthos and environmental factors and RDA analysis, altitude and potassium permanganate are the key environmental factors affecting the benthos community structure in Gansu section of the Yellow River. Comprehensive macrozoobenthos community structure and water quality analysis, it shows that the water environment in the reservoir area and wetland is the best water. The water quality in the upstream natural reach is better than that in the downstream natural reach, but the biodiversity and abundance in the downstream reach are higher than that in the upstream reach.

Comparative analysis of two dust weather processes in Tarim Basin, China
Kader Mavlan, Lu Zhang, Xinhua Liu, Tunyaz Nurbiye, Muming Gulnafar, Shaobo Gao
Journal of Desert Research    2023, 43 (4): 76-88.   DOI: 10.7522/j.issn.1000-694X.2022.00160
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Using the conventional observation data, NCEP reanalysis data and CALIPSO satellite data, HYSPLIT model, potential source contribution factor analysis method and concentration weight trajectory analysis method, two typical dust weather processes in summer of 2015 and spring of 2022 in Tarim Basin under similar circulation situation were compared and analyzed. Taking Hotan as an example, the differences of weather system configuration, related physical quantity characteristics, dust transport path and potential source areas in the two processes were analyzed. The results show that the two weather processes were both affected by the upper trough, but the location of the upper trough in summer of 2015 was more southward than that in spring of 2022 and had obvious meridional characteristics. The collapse of the blocking high system caused the rapid outbreak of cold air and the strong vertical movement of the atmosphere, so the intensity of dust weather in summer of 2015 in the basin was stronger than that in spring of 2022. In spring of 2022, in addition to the dust weather caused by a little cold air over the bottom of the trough, the low-level easterly jet was stronger than in summer of 2015, which caused the sandstorm in the east of the basin and transported from west to east. The dust in summer of 2015 was mainly transported by west path, and the main source was the west of Taklimakan Desert, and some dust was transported from south of Kyrgyzstan. The dust particles in spring of 2022 were mainly driven by easterly airflow, and Taklimakan Desert was the main source of dust. During spring of 2022, the convergence of the westerly and easterly wind fields near Hotan made the dust particles converge. In addition, the stable circulation situation and relatively warm and humid atmospheric conditions made the dust difficult to diffuse. Therefore, the duration of low visibility in spring of 2022 was relatively longer. The special geographical location made the dust process from west to east or from east to west in the basin accumulated in Hotan area.

Coupling coordination pattern and driving factors of soil and water resources in Fenhe River Basin of China
Enyue Zhang, Yingqing Su, Yunfeng Zhang, Yuzhen Li, Kexuan Li, Geng Liu
Journal of Desert Research    2023, 43 (3): 169-177.   DOI: 10.7522/j.issn.1000-694X.2023.00018
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The research on coupling coordination of regional water and land resources aims to promote regional social and economic development and sustainable utilization of water and land resources. In this research, the Fenhe River Basin is selected as the research area. Based on the multi-source remote sensing data, socio-economic statistical data, and reanalysis product data in 2006, 2013, and 2018, the evaluation index system of water and soil resources coupling coordination is constructed. The coupling coordination degree model, spatial autocorrelation model, and geographic detector are used to measure the coupling coordination degree of water and soil resources in the study area from 2006 to 2018, and identify its dominant influencing factors. The results showed that: (1) In 2006, 2013, and 2018, the coupling coordination degree of water and land resources in the basin was mainly low coordination and moderate coordination, which was between [0.10, 0.50]. In space, the high-value area is mainly located in the middle and upper reaches of the basin, and the low-value area is concentrated in the middle and lower reaches and has obvious time heterogeneity. The multi-year evolution trend is characterized by an upward opening parabola. (2) The Moran's I values of coupling coordination of water and land resources in the study period were 0.274, 0.266, and 0.195, respectively. The whole basin experienced a high-high-low decline process, the global correlation level decreased, the spatial agglomeration effect decreased, and the regional differences decreased. Local autocorrelation is mainly shown as high-high (H-H) and low-low (L-L). (3) The dominant factors affecting the spatial differentiation of the coupling coordination degree of water and soil resources in the Fenhe River Basin are annual precipitation, the proportion of domestic water consumption, water production modulus, per capita construction land area, etc. Among them, the interaction between annual average precipitation and water production modulus is the strongest. Based on this, in the future we should strengthen the rational allocation of water and land resources in the basin, optimize the structure of land use, coordinate of water and land resources between the upper and middle reaches of the basin, large, medium, and small towns allocation and usage, and actively promote regional inter-basin water transfer and land resources remediation.

Analysis of temporal and spatial characteristics of hazard potential of wind blown sand environment in Xinjiang from 2001 to 2020
Yazhou Zhao, Shengyu Li, Shijie Wang, Jinglong Fan, Yan Wu
Journal of Desert Research    2023, 43 (3): 274-283.   DOI: 10.7522/j.issn.1000-694X.2022.00133
Abstract123)   HTML4)    PDF (5083KB)(122)      

Xinjiang has complex topography and climate, abundant sand sources, strong wind, and frequent sandstorm activities. Sandstorm disasters are an important threat to engineering construction and economic development. The assessment of the hazard potential of the wind blown sand environment can guide the construction of sand area projects and the formulation of sand control plans, and is an important basic work for disaster emergency management. In this paper, eight indicators including soil organic carbon content, soil water content, soil sand content, land use type, vegetation index, precipitation, evapotranspiration and resultant drift potential are selected to analyze the temporal and spatial variation of hazard potential of wind blown sand environment in Xinjiang from 2001 to 2020. Results show that: (1)The hazard potential of the wind blown sand environment in Xinjiang has obvious seasonal variation characteristics, and the area with the hazard potential value greater than 3 gradually increases in summer, autumn, spring and winter. Lower hazard potential values in February and November. (2)The hazard potential of wind blown sand environment shows the spatial distribution characteristics of high in the east and low in the west, low in mountainous areas and high in the plain. High value regions are located in Tarim Basin, Junggar basin, Turpan Basin and other regions with abundant sand and strong wind power. Low value regions are mainly distributed in areas with high vegetation coverage, such as mountains, oases and river banks. (3)From 2001 to 2020, the annual average value of the hazard potential of wind blown sand environment in Xinjiang showed a change process of first rising and then declining. The overall change trend is relatively stable, and the proportion of pixels that are stable, slightly improved and slightly intensified is 84.4%, 14.72% and 0.87% respectively. The research results can provide an important reference for the layout and decision-making of economic and social development in windy and sandy areas in Xinjiang.

The effects of desertification control on the patterns of vegetation in arid and semi-arid regions of northern China
Junhao Liu, Haisheng Zhou, Qun Guo
Journal of Desert Research    2023, 43 (5): 204-213.   DOI: 10.7522/j.issn.1000-694X.2023.000112
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China, especially the arid and semi-arid regions of northern China, is one of the leading contributors in global greening, and ecological projects has been thought as the main causal factors. As a key desertification-combating actions, the impacts of desertification control on vegetation temporal dynamics have not been fully clarified. This study analyzed the differences of temporal dynamics of normalized difference vegetation index (NDVI) and its influencing factors between desertification vegetation and its adjacent zonal vegetation in arid regions of northern China. The results showed that: (1) Desertification in the study region initially expanded, peaked in 2000, and then reversed, implying desertification control worked after 2000. (2) During 1982-2021, NDVI in 44.5% of the study area significantly increased, while 5.8% of the study area experienced a notable reduction, suggesting a generally greening. The greening primarily occurred in the Hetao Plains, Horqin Sandy Land, Kubuqi, Mu Us Sandy Land, Southern Xinjiang, Junggar Basin and the Tianshan Mountains. More area in desertified areas (45.7%) showed remarkable increase than their adjacent zonal vegetation (41.7%). (3) Notably, the increasing rate after 2000 (0.0055 a-1) markedly greater than that of pre-2000 (0.0036 a-1). Moreover, larger increasing rate was found in desertified areas after 2000 but in adjacent zonal vegetation before 2000. (4) Precipitation and specific humidity were the dominant factors in both the desertification and their adjacent zonal vegetation, with wind speed exerting a more significant influence in some natural units. The correlation coefficient of NDVI with moisture was lower in desertified areas compared with their adjacent zonal vegetation, whereas wind speed exhibited a stronger correlation. Our results will provide a scientific foundation to evaluate desertification control effectiveness in the past and improve related measures in the future.

Desertification evolution in the sandy region to the east of the Yellow River in Ningxia from 2000 to 2020
Yaozong Wang, Xinbin Yue, Jiali Xie, Zhipeng Liu, Yuan Ma, Yahui Wang, Yan Gong
Journal of Desert Research    2023, 43 (4): 31-40.   DOI: 10.7522/j.issn.1000-694X.2022.00166
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The sandy region to the east of the Yellow River in Ningxia is a transitional region in the agro-pastoral ecumenical zone in northern China. Understanding the law of the development of desertification in this region is helpful to coordinate the local man-land relationship and guide the implementation of ecological construction project. The Landsat data were used to extract the information of desertification land for five periods of 2000, 2005, 2010, 2015 and 2020 in the sandy region to the east of the Yellow River in Ningxia, then the temporal and spatial characteristics of desertification land were analyzed by combining the barycenter transfer model, and the effects of climate change and human activities on regional desertification evolution were stripped and recombined by multiple regression residual analysis method. The results show that the overall area of desertification land in the sandy region to the east of the Yellow River in Ningxia decreased, the degree of desertification was reduced, and the desertification was reversed from 2000 to 2020. The degree of desertification in the northern part of the region was more serious than that in the southern part. The barycenter of all kinds of desertification land moved northward, and the degree of desertification reversal was more significant in the south than in the north. Regional desertification reversal is mainly influenced by climate change and human activities.

The variation characteristics of main meteorological factors in Horqin Sandy Land during 1961-2021: A case study of Naiman Banner
Yayi Niu, Wei Liu, Jiarui Dong, Jie Lian, Xuyang Wang, Yuqing Li
Journal of Desert Research    2023, 43 (4): 263-273.   DOI: 10.7522/j.issn.1000-694X.2023.00043
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To analyze the variation characteristics of major meteorological factors in Horqin Sandy Land under the background of global climate change. Based on monthly meteorological data, the trend analysis, Mann-Kendall mutation point analysis and wavelet analysis were used to analyze the multi-scale temporal variation characteristics of main meteorological factors (temperature, precipitation and evaporation) in Naiman Banner from 1961 to 2021. The results showed that: under the global climate change, the major meteorological factors in the study area changed significantly, and the temperature increased significantly at a rate of 0.21 ℃/10a, the precipitation decreased significantly at a rate of -9.2 mm/10a, and the evaporation did not increase significantly at a rate of 32.50 mm/10a. From the seasonal variation, in spring and autumn, the temperature, precipitation and evaporation showed an increasing trend, while in summer and winter, temperature and evaporation increased and precipitation decreased. The time of mutation point of each meteorological factor was different, among which the temperature was about 1971, the precipitation was 1978 and 1987, and the evaporation were 2002, 2009 and 2013. All meteorological factors showed obvious periodic changes during the study period, including temperature of 3-7 a, 14-23 a and 34-43 a, precipitation of 3-6 a, 8-11 a, 13-23 a and 43 a, and evaporation of 5-7 a, 11-16 a, 27 a and 35 a.

Windbreak and sand- fixation effects of typical shrub plants in the desert- oasis transitional zone in the middle reaches of the Heihe River
Guanglu Hu, Haizhi Chen, Jin Ma, Hu Tao, Chengqian Zhou, Peng Liu
Journal of Desert Research    2023, 43 (5): 31-40.   DOI: 10.7522/j.issn.1000-694X.2023.00030
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In order to explore the windbreak and sand-fixation effects of typical shrub plants in the desert-oasis transitional zone in the middle reaches of the Heihe River, through field investigation and observation experiments, the influence laws of sand-fixation plants Haloxylon ammodendronNitraria sphaerocarpa, and Calligonum mongolicum on the quantity and structure of wind-blown sand flow were quantitatively analyzed, and the influence mechanism was analyzed using the principles of aerodynamics. The results showed that the windbreak effect was Haloxylon ammodendron>Calligonum mongolicum>Nitraria sphaerocarpa, and there was a significant difference between the windward side and the leeward side. The windbreak effect of Haloxylon ammodendron was more significant than that of other shrub plants, with the maximum wind speed reduction ratio of 62.9% and the maximum effective protection distance. The sand blocking efficiency of Haloxylon ammodendronNitrariasphaerocarpa and Calligonum mongolicum were 60.7%, 51.0% and 46.3% respectively, and the sediment transport rate of each shrub plant decreased with height in a stepwise manner under the same wind speed. The relationship between sediment transport rate of shrub vegetation and wind speed conforms to exponential function or polynomial function. The sediment transport rate increases most rapidly when the wind speed exceeds 7.0 m·s-1. Comprehensive analysis shows that the wind resistance effect of Haloxylon ammodendron is better than that of Nitraria sphaerocarpa and Calligonum mongolicum, but its near surface wind erosion prevention effect is average. Nitraria sphaerocarpa exhibits good wind erosion resistance due to its low and dense plant structure, but its effective protection distance is the smallest, and its wind erosion prevention effect is poor when the height is large. This result can provide a reference basis for the construction of sand-fixing vegetation in the desert oasis transitional zone in the middle reaches of the Heihe River.

Spatial differentiation of soil moisture and conductivity in Shiyang River Basin
Yuxi Wei, Lijuan Chen, Haiyang Xi, Chengqi Zhang, Kaiyuan Gan, Tian Yong, Jinxia Zhang
Journal of Desert Research    2023, 43 (3): 264-273.   DOI: 10.7522/j.issn.1000-694X.2023.00038
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Study on the spatial differentiation of soil water and salt is an important basis for the prevention and improvement of soil salinization, and also an important foundation for the development and utilization of saline land resource. At a watershed scale, relatively few studies have been conducted on the spatial differentiation of soil water and salt under different land-use types such as forest land, grassland, cropland, saline land and desert in the Shiyang River basin, which can hardly support the improvement and utilization needs of saline land under the changing environment in the new period. In this study, the spatial differentiation of soil water and conductivity in the Shiyang River basin were studied using geostatistical and traditional statistical methods, and the effects of different land-use types on soil water and salt distribution were analyzed. The results showed that the soil water content in the Shiyang River basin demonstrated a trend of high in the southwest and low in the east and west, and gradually increased from 8.75% in the surface soil layer to 10.19% in the deep soil layer. Soil conductivity showed a trend of low in the southeast and southwest and high in the northeast and northwest, and the area of moderately and heavily saline and saline soils accounted for 56.55% of the total watershed area. The highest average water content was exhibited in forest soils (21.08%), followed by arable land (15.60%), saline land (12.40%), grassland (6.98%), and desert (1.60%). The highest average soil conductivity was found in saline land (8.55 dS·m-1), followed by grassland (1.28 dS·m-1), desert (0.51 dS·m-1), cropland (0.48 dS·m-1) and forest land (0.18 dS·m-1). Land-use type had a significant effect on the vertical distribution of soil water and salt, and soil moisture was significantly and positively correlated with elevation, vegetation biomass, cover, and density, while significantly and negatively correlated with soil bulk density. There was no significant correlation between soil moisture and conductivity in forest land and grassland, while significant positive correlations were detected in cultivated land, saline land and desert showed, indicating that the dependence of soil salinity on soil moisture increased from the upstream to the downstream of Shiyang River basin.

Influences of soil crust development on soil seed bank of herbaceous plants in arid desert area
Haixuan Tao, Chunxiu Guo, Junmei Ma, Zhongwen Wang, Heran Zhao, Dacheng Song, Fanglan He
Journal of Desert Research    2023, 43 (4): 89-97.   DOI: 10.7522/j.issn.1000-694X.2023.00001
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Soil seed bank refers to the sum of all active seeds existing in the litter of soil surface and soil, supplying an important seed source for potential regeneration of aboveground vegetation. In order to explore the effects of soil crust development on the characteristics of herbaceous soil seed bank in arid desert area, the test sites were deployed on the southern margin of Badain Jaran Desert, where the surface morphologies of soil crusts at different development stages and characteristics of herbaceous soil seed bank were studied by field investigation and seed germination. The results showed that: (1) the succession from no crust stage to moss crust stage leaded to significant changes in the micromorphologies and thickness of soil crusts per unit area, of which obvious differences among development stages were observed (P<0.05). (2) With the continuous succession of soil crusts, some psammophytes in the seed bank withdrew gradually, while obvious increases in xerophyte species. At the same time, the successional processes of dominant species were as follows: Eragrostis pilosa and Bassia dasyphyllaE. pilosaB. dasyphylla and Halogeton glomeratuE. pilosa and H.glomeratuE. pilosa. (3) In the whole succession process of soil crusts, the densities and species diversity indexes of soil seed bank showed unanimous trends of increasing first and then decreasing (the peak value was in the algae-lichen crust stage), which in lichen moss stage or higher stage were significantly lower than those in the no crust stage (P<0.05). Meanwhile, the distribution of soil seed bank in horizontal direction gradually became homogenization, and its vertical distribution tended to centralization in soil crust layer; besides, the species similarity between seed bank and aboveground vegetation decreased significantly. Therefore, the formation and progressive succession of soil crusts not only influenced the spatial distribution of soil seed bank by enhancing stability and changing micromorphology of soil surface, but also affected the contribution ability of aboveground vegetation to soil seed bank by changing soil habitat conditions.

Calculation and analysis of summer stable boundary layer height in the hinterland of Taklimakan Desert, China
Guocheng Yang, Donglei Mao, Minzhong Wang, Jiantao Zhang, Honglin Pan
Journal of Desert Research    2023, 43 (4): 64-75.   DOI: 10.7522/j.issn.1000-694X.2023.00008
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In this paper, using the encrypted sounding observation data of Tazhong observation station in Taklimakan Desert on July 6-17, 2021, the stable boundary layer height was calculated by using Coen method, Rib method, Liu-Liang method and inversion intensity method respectively, and the differences among the calculation results of different methods were compared, and the relationships between near-surface meteorological factors and the height of stable boundary layer is analyzed in combined with 80 m observation tower gradient detection system data. The results show that: (1) During the experiment, the height of stable boundary layer in the hinterland of Taklimakan Desert was less than 1 000 m. The average height calculated by the four methods was 141, 269, 227, 173 m respectively, and the total average height was 202.38 m. The stable boundary layer began to develop after sunset and developed to the thickest around sunrise, and the average height of the stable boundary layer calculated by the four methods increased from 49, 257, 164, 121 m at 22:15 to 220, 290, 242, 188 m at 07:15, respectively. (2) The overall trend of the stable boundary layer height calculated by the four methods is consistent, but there are individual extreme values, and the extreme values are mostly related to special weather phenomena. The height distribution range (10-890 m) of stable boundary layer calculated by Rib method is larger than that calculated by the other three methods, which may be due to the consideration of both thermodynamic and dynamic factors. The heights calculated by the other three methods are slightly lower, probably because the boundary layer development is not uniform at each time, the four-time average at night lowers the overall average and is affected by the intensity of surface radiation cooling and turbulent motion during different observation cases. (3) The stable boundary layer height calculated by the four methods under different weather conditions is also different. Under clear night conditions, the average deviation of the stable boundary layer height calculated by the four methods is the smallest, and the height change trend is similar. In dust weather, the average deviation of the stable boundary layer height calculated by the four methods is in the middle, and the height difference is mainly reflected around sunrise or sunset. In the case of rainy days, affected by the changes of meteorological elements in the boundary layer, the overall height calculated by the four methods is quite different, and the average deviation is also the largest. (4) In sunny days, the stable boundary layer height determined by the Coen method shows a significant increase process, which can fully describe the development and change process of the stable boundary layer at night. There is almost no sudden increase or decrease in the abnormal height value, which is suitable for sunny days with significant thermal effects. Under special weather conditions, the Rib method is recommended. This method considers both the thermal effect and the dynamic effect. It is a comprehensive parameter that covers wind, temperature and humidity at the same time. The calculated boundary layer height has the least uncertainty and is easier to reduce the error. (5) The height of stable boundary layer in the desert hinterland is jointly affected by dynamic and thermal factors, and is significantly correlated with turbulent kinetic energy, wind speed, ground temperature and soil heat flux, with the maximum correlation coefficients of 0.9, 0.88, 0.63 and 0.5.

Effects of desert biological soil crusts succession on microbial community structure and soil enzyme activities
Shengnan Zhang, Haiyan Gao, Deren Yan, Haiguang Huang
Journal of Desert Research    2023, 43 (3): 178-187.   DOI: 10.7522/j.issn.1000-694X.2022.00121
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In order to understand the characteristics of microbial community structure and soil enzyme activities during the succession of biocrusts, biocrusts of differnt succession stages (CK, A30, AM30, and M30) in Hobq desert, China, was chosen as study objects, bacterial community structure, nitrogen-fixing bacterial community structure and fungal community structure in bioctrusts were sequenced via the high-throughput sequencing platform, biocrusts enzymatic activities were measured, and how biocrusts affect soil microbial community structure and enzyme activities were discussed. The results showed that the dominant bacteria changed from Cyanobacteria (CK: 36.1%, A30: 46.9%, AM30: 30.7%) to Proteobacteria (M30: 36.2%) as the succession level increased of biocrusts. The dominant nitrogen-fixing bacterial changed from Scytonema (A30: 80.2%) to Skermanella (M30: 60.6%), the relatively abundance of Basidiomycota (A30: 1.0%, AM30: 5.0%, M30: 13.5%) gradually increased as the positive succession of biocrusts. The unique OTUs of bacterial, nitrogen-fixing bacterial and fungi in M30 significant increased 1.8-8.3 times, 1.9-33.0 times and 1.8-33.0 times compared with CK, A30 and AM30, respectively. The order of increasing microbial diversity in positive succession of biocrusts was nitrogen-fixing bacterial>bacterial>fungi. The exaltation of soil mibrobial diversity significantly enhanced soil cellulase, sucrase and urease activities involved in carbon and nitrogen cycling (P<0.05). In conclusion, the soil microbial community structure and enzyme activities gradually improved as the succession level increase of desert biological soil crusts.