Leaves and roots respond to drought stress through morphological, physiological, and biomass accumulation changes. Alhagi sparsifolia is the dominant plant in the desert-oasis transition zone of Cele. We analyzed the characteristics of growth and physiological changes in leaves and roots of 1-year-old A. sparsifolia seedlings through a pot experiment. Results revealed the adaptive strategy of A. sparsifolia to drought stress. We simulated three water conditions (CK is well-watered: 70%-75% field capacity (FC); W₁ is mild stress: 50%-55% FC; W₂ is severe stress: 25%-30% FC). The results show the following: (1) Drought significantly inhibited the growth of the aboveground and underground tissues of A. sparsifolia. The main manifestations are: leaf area, root length, root surface area, root tissue density, and soluble sugar content of leaves and roots decreased significantly under stress (P < 0.05). The leaf tissue density, leaf dry matter content, specific root length, proline and malondialdehyde contents of leaf and root increased. (2) In the early growth stage, the aboveground biomass of A. sparsifolia under all treatments was relatively high (root-shoot ratios under CK, W₁, and W₂ were 0.43 ± 0.14, 0.59 ± 0.1, and 0.83 ± 0.83), while in the late growth stage, the below-ground biomass under all treatments was relatively high. The root-shoot ratio was the highest under severe stress (3.12 ± 0.32). The results indicate that A. sparsifolia enhanced the investment of resources underground in the late growth stage, and the resource allocation characteristic is more obvious under severe drought stress. (3) Pearson-correlation analysis showed that there was a significant tradeoff between core traits related to leaf morphology and root physiology in A. sparsifolia (P < 0.05). Meanwhile, the leaf and root had synergistic changes in physiological metabolism. The results preliminary indicate the adaptive characteristics and A. sparsifolia seedlings under drought exhibit high dry matter storage, defense capacity, and low water consumption. A. sparsifolia can coordinate the resource allocation relationship between leaves and roots. At the same time, with drought stress time increased, the adaptive strategy of slow investment and conservative growth of A. sparsifolia was gradually formed. The results provide a reference for the restoration and management of desert vegetation in this region.

In this study, google earth engine (GEE) was used to extract the normalized difference vegetation index (NDVI) and Albedo parameters. The NDVI-Albedo space was constructed to monitor aeolian desertification in Ongniud Banner from 1991 to 2015, and the influence of key driving factors and mechanism of aeolian desertification in Ongniud Banner were analyzed using geographical detectors combined with natural and anthropogenic factors. The following key results were obtained: (1) Aeolian desertification in Ongniud Banner first experienced the development of evolution process, which then was reversed. During the development period from 1991 to 2000, the total area of aeolian desertified land increased by 2130.29 km², with extremely severe changes in both aeolian and non-aeolian desertified land, which had dynamic attitudes of 9.5 and -4.8, respectively. From 2000 to 2015, the total desertified land area of aeolian decreased by 3364.61 km², and the extreme severe aeolian and non-aeolian desertification land were the main changes, with dynamic attitudes of -4.2 and 8.3, respectively; (2) The extreme areas of aeolian desertification in the Ongniud Banner were mainly distributed in the central east and the north of Xiliaohe Plain, while the aeolian desertification in most areas of Jibeiliaoxi Mountain in southwest region is relatively light. From the perspective of transfer, the development area of various types of aeolian desertification land was 5333.75 km², while the reversed area from 1991 to 2000 was 1157.29 km². Notably, the non-aeolian desertified to moderate aeolian desertified land area was the largest covering 1000.24 km². From 2000 to 2015, the development area of all types of aeolian desertified land was only 424.65 km², while the reversed area was 7041.80 km². The area of moderate desertified land covering 1449.74 km² was reverted to non-desertified land; (3) From 1991 to 2000, both natural and anthropogenic factors drove the aeolian desertification process in the study area, with terrain and sand source as the main reasons for the formation of spatial distribution pattern of aeolian desertified land in Ongniud Banner. The warm and dry climate conditions, as well as intensified human activities led to the development of aeolian desertification in Ongniud Banner. From 2000 to 2015, aeolian desertification reversal was driven by the implementation of a series of anti-desertification policies and the improvement of natural conditions.

This study used the Lhasa River Basin, which is a typical plateau basin to clarify the spatiotemporal characteristics of land use change and its impact on a plateau basin habitat quality. The google earth engine (GEE) platform and random forest classification algorithm were used to interpret the land use information of the Lhasa River Basin from 1990 to 2020, and to analyze the spatiotemporal dynamic changes of land use in the past 30 years. The InVEST model was integrated to evaluate the habitat quality of the basin, and to explore the characteristics of its habitat quality changes. The results showed that the efficiency and accuracy of land use classification improved by selecting the vegetation growing season, supplementing and replacing missing data with images obtained in the previous and following years, and generating annual composite cloud free images for land use classification in the alpine and high-altitude areas. An optimal RF classification model combining the spectral, textural, and topographical features of Landsat images was established to classify land use information in the plateau basin. The observed OA, Kappa coefficient, and the F1-score were 88.16%, 0.84, and 0.70, respectively. Since the 1990, the features of the land use change in the Lhasa River Basin have been characterized by “five increases and three decreases,” with an increase being observed in the areas under grassland, construction, forest land, wetland, and water, while the areas under cultivated land, glaciers, and permanent snow or unused land having a decrease. Among them, the growth rate of construction land had the largest increase of 288.35%, while the largest decrease was detected in cultivated land with 50.18%, which could mainly be attributed to overpopulation in the urban areas. Most significant decrease occurred in the unused land area, and the changed area was mainly converted with grassland. During the study period, high quality habitats were mainly distributed in the downstream areas, southwest, and the main source areas of the basin, included the grassland, water, glaciers, permanent snow, and wetland. Poor qualities of habitats were observed in the Lhasa municipal district, Dazi District, Linzhou County, Qushui County, and Mozhugongka County, as well as in the unutilized land in the middle and upper reaches of the basin. The overall habitat quality of the watershed showed an alternating transition pattern of initial decrease, then increase, followed by a decrease, and a slowed down transition, while the habitat quality index increased from 0.53 to 0.57. Population growth and rapid urbanization accelerated the expansion of urban areas and the reduction of arable land, while climate change and ecological engineering played a positive role in improving the quality of habitat in Lhasa River Basin. This study provides a scientific basis and reference for formulating ecological restoration strategies, sustainable land use, and habitat quality improvement in a plateau area.

Nuomuhong region is an important Wolfberry cultivation base in Qinghai Province, China. Accurate and rapid extraction of the primary vegetation types is of critical significance for the sustainable development of agriculture in this region. However, the arid nature of the Nuomuhong area, characterized by sparse vegetation cover and significant soil background effects, presents challenges for vegetation extraction using only a limited number of remote sensing sources or partial features. Therefore, integrating multiple remote sensing data sources, exploring significant features for vegetation classification, and experimenting with different classification and optimization methods are paramount for enhancing the accuracy and reliability of vegetation classification in arid regions. Based on the Google Earth Engine (GEE) platform, this study used Sentinel-1 Synthetic Aperture Radar and Sentinel-2 optical data to explore the importance of red edge, texture, and radar features in extracting vegetation types in arid regions. Additionally, it verifies the feasibility of using the GINI index (GINI) to determine the optimal feature combination. The main geospatial types in Nomu Hong, Qinghai, China, in 2021 were extracted by combining them with the support vector machine algorithm. The classification results were processed using decision fusion methods. The results showed that: (1) Sentinel-2 red edge index, texture data, and Sentinel-1 radar band were beneficial for the extraction of vegetation-related information, with an overall classification accuracy and Kappa coefficient of 95.51% and 0.9406, respectively. (2) Based on the importance obtained by the GINI index, the features involved in the classification were reduced from 29 to 17, and the significance was radar polarization features > spectral features > texture features. (3) Using a simple noniterative clustering algorithm and neighborhood filtering voting decision fusion method not only achieved the optimal overall accuracy and Kappa coefficient but also had an excellent suppression effect on isolated noise. Using the GEE remote sensing cloud platform, multisource remote sensing data, and machine learning algorithms, this study can accurately, quickly, and efficiently extract large-scale arid region geospatial information, which can have great application potential.

Based on data from 152 meteorological stations in Northwest China and 16 climate models of CMIP6, the CMIP6 model data were bias-corrected using the RoMBC method. The Standardized Precipitation Evapotranspiration Index (SPEI) was then constructed to analyze the spatial and temporal distribution and variation of drought in Northwest China under the historical and future scenarios (SSP1-2.6, SSP2-4.5, SSP3-7.0, SSP5-8.5). The results are as follows: (1) Under the historical scenario, the northwest area experienced a notable increase in both the temperature and precipitation. The temperature and precipitation have been rising at a rate of 0.15-0.74 ℃ and 2.71-14.83 mm per decade, respectively, and the same is expected for future scenarios. (2) From 1975 to 2014, the annual and seasonal SPEI in Northwest China decreased overall. The maximum decline rate in spring was 0.19 per decade. Droughts in most areas were increasingly intense throughout the year, particularly in spring and winter. In terms of drought frequency in Northwest China, mild and moderate droughts appeared more than severe and extreme droughts, and this type of natural disaster was more frequent in the east of the country than in the west. (3) From 2020 to 2100, Northwest China is likely to suffer from droughts, but there are no distinct drought characteristics identified in the research under the SSP1-2.6 scenario. The northwest region is expected to experience an increase in the number of droughts, trends in drought, and drought frequency under the other three scenarios. The most severe drought conditions were observed under the SSP5-8.5 scenario. This study provides insights into the spatial and temporal development of drought in Northwest China using meteorological and model data. The findings can serve as a basis for drought risk assessment, scientific water resources management, and agricultural production in the region.

Water use efficiency (WUE) is an important measure of the tradeoff between photosynthetic carbon sequestration and water consumption in ecosystems. Estimation of vegetation’ WUE and analysis of the spatiotemporal distribution of vegetation WUE are crucial for ecosystem preservation as well as the wise use and development of water resources in this area. In this study, we assessed the spatial and temporal characteristics of vegetation WUE and its main influencing factors in Salt Lake County from 2000 to 2019 on the basis of GPP and ET data from MODIS. The results were as follows: (1) Both ET and GPP increased significantly from 2000 to 2019 (P<0.01), and the rates of increase were 7.61 mm·a^-1 and 7.23 g C·m^-2·a^-1, respectively. ET and GPP showed obvious heterogeneity in space. (2) Between 2000 and 2019, the vegetation WUE in Yanchi County fluctuated between 0.80 and 1.11 g C·kg^-1·H₂O, and the multiyear average value was 0.91 g C·kg^-1·H₂O. The rate of increase was 0.0013 g C·kg^-1·H₂O·a^-1, but it was not significant. The vegetation WUE showed high heterogeneity in space, with high values mainly distributed in the northeast and low values in the southwest. (3) From 2000 to 2019, WUE mainly increased and decreased in 54.70% and in 45.30% of the area, respectively, in Yanchi County. In the future, 61.48% of the area in Yanchi County will show the same change trends in WUE as in the past, and 38.52% of the area will show reversed trends in WUE. (4) The WUE of each land use type in different study periods decreased in the following order: forest land > cultivated land > grassland. (5) There was a significant correlation between WUE and GPP in Yanchi County (P<0.05), whereas variations in GPP were mainly driven by changes in ET, NDVI, and precipitation, indicating that GPP is the main reason for the changes in WUE in Yanchi County. The Yanchi County Ecological Restoration Project not only enhances vegetation productivity but also increases regional water consumption, resulting in fluctuations in the WUE of the regional ecosystem. This suggests that vegetation restoration in Yanchi County has intensified regional water depletion while enhancing vegetation productivity, which provides a theoretical basis for future ecological revegetation and codevelopment of water resources in Yanchi County.

In the semi-arid zone of the Liupan Mountains in Ningxia, soil water content is a key factor affecting the survival and growth of trees, and it is necessary to understand the differences in soil water content on different slope positions of forested slopes and their response to different rainfall amounts. For this purpose, a typical slope covered by Larix principis-rupprechtii plantations was selected in the small watershed of Diediegou in the Liupanshan Mountains. From May to October 2021, meteorological conditions (such as precipitation) and changes in soil water content on this slope were continuously monitored with automatic weather stations and soil moisture meters to analyze the differences in soil water content on the slopes and their response to the depth of individual rainfall events. The total precipitation depth during the monitoring period was 443.7 mm, which was close to the long-term annual average, but with severe drought in summer. The results showed the following: (1) The soil water content varied significantly within the growing season; the overall level first decreased and then increased, being the lowest in August (0.112 m³·m^-3). (2) There were clear differences in soil water content among slope positions, generally in the order upper slope [(0.191 ± 0.044) m³·m^-3] > middle slope [(0.158 ± 0.045) m³·m^-3] > lower slope [(0.146 ± 0.034) m³·m^-3]. This indicated that the main factor influencing the differences in soil water content along slope positions is the amount of evapotranspiration by forest/vegetation, rather than the redistribution of rainwater along the slope by slope runoff in this dry year. (3) To the same rainfall depth, the response of soil water content on the middle slope was the most sensitive, followed by that on the upper slope, and the lower slope was the least sensitive, owing to the integrated effects of soil porosity, water-holding capacity, and understory vegetation. (4) At the study site, rainfall was dominated by small rainfall events below 10 mm, with 7 mm representing the threshold for effective rainfall, above which the rainfall is likely to alleviate the soil dryness and recharge the soil moisture in the soil layer of 0-20 cm. The results of this study can aid understanding of the variation and spatial distribution of soil water content on forest slopes in semi-arid mountainous areas and help determine the water-carrying capacity of forest/vegetation and integrated

This study aims to provide reference for quantifying the selection model of plant water sources. MixSIAR model and IsoSource model are commonly used to quantify plant water sources by combining hydrogen and oxygen stable isotope technology. However, different models yield varying quantitative results. Hence, choosing the best model is important to reduce the uncertainty of results. In this work, the hydrogen and oxygen stable isotope compositions of stem xylem water and each potential water source of two shrubs were measured from July to September in 2019 and 2021. The dominant tree species Cotoneaster melanocarpus and Berberis heteropoda in the premontane shrub zone of the northern slope of Tianshan Mountain were selected as subjects. MixSIAR and IsoSource models were used to quantify plant water sources, and their results were compared and evaluated according to the root mean square error (RMSE) and parameter R. Results showed (1) differences in the quantification results of the two models for the main potential water sources of plants. These differences were related to the calculation principles of the two models. (2) Under the premise that the two models quantify the same main potential water sources of plants, the IsoSource model quantifies larger values than the MixSIAR model. (3) The results of RMSE and parameter R showed that the error of IsoSource model in quantifying plant water sources was smaller than that of MixSIAR model possibly due to the large difference between C. melanocarpus and B. heteropoda In summary, the MixSIAR model may be more accurate in quantifying the similarity of plant water sources than the IsoSource model.

Further exploration of trends in climate warming and humidification in Northwest China can deepen our understanding of important scientific issues regarding the responses to global warming of arid and semi-arid regions of the Northern Hemisphere in mid-and high latitudes. Using statistical methods such as linear trend, Kriging interpolation, and non-parametric Mann-Kendall test for temperature and precipitation data from 127 stations in Northwest China from 1961 to 2021, we show the following: (1) In the last 60 years, Northwest China as a whole has undergone significant warming and humidification. The regional warming trend was relatively consistent [0.32 ℃·(10a)^-1], while there was a clear regional imbalance of humidification, with the humidification in the west of Northwest China increasing earlier, more steadily, and more significantly than in the east. (Increases in the west were mainly distributed in Northwest Xinjiang, while those in the east were mainly in the Qinghai region). (2) There were pronounced interdecadal fluctuations of warming and humidification, and paradigm shifts in temperature and precipitation trends of Northwest China occurred in 1993 and 2010, respectively, after which the rates of warming and humidification were 0.08 ℃·(10a)^-1 and 37.60 mm·(10a)^-1 higher than beforehand. Warming and humidification were more prominent after these paradigm shifts, with the eastward expansion of warming and humidification being the main feature. (3) The seasonal imbalance of warming and humidification also showed that the warming was most significant in winter in western Northwest China, followed by that in summer; winter precipitation increased significantly in western Northwest China, while spring and summer precipitation increased significantly in eastern Northwest China. These results can provide a theoretical basis for formulating climate change countermeasures in Northwest China.

Castor fiber birulai is primarily distributed in the Ulungu river basin in China. Therefore, investigating the potential distribution of suitable regions is crucial for the conservation of C. f. birulai. A total of 97 distribution sites of C. f. birulai and 28 environmental factors collected from 2021 to 2022 were used to predict the distribution of suitable habitat regions for this species under different climatic scenarios using the MaxEnt model. Results showed that the distribution of suitable habitats was mainly affected by the distance from major roads (0.1-1 km), distance from water channel (within 100 m), landcover type (river, wetland, and forest), altitude (approximately 1000 m), mean temperature of wettest quarter(22-25 mm), and the standard deviation factor of seasonal temperature change (above 1500). In the 2050s (2041-2060, ssp585 climate scenario) and 2070s (2061-2080, ssp126 climate scenario), the high suitability area was the same or slightly increased compared with the current situation, and the area of suitable habitat, which decreased in the two future climate scenarios, was the same. The results of this study can provide a reference point for the protection and management of C. f. birulai under climate changes.

The study of vegetation dynamics and its influencing factors can reveal the response mechanism between vegetation cover dynamics and climate change and has important significance for regional vegetation restoration and ecological sustainability. Based on MODIS multitemporal remote sensing satellite data, this study investigated the quarterly changes in vegetation cover in the arid and semi-arid regions of Northwest China from 2000-2020 using variation coefficient, Theil-Sen median trend analysis, Mann-Kendall significance test, correlation analysis, and Hurst index. The study found that: (1) The spatial variability of the Normalized Difference Vegetation Index (NDVI) was high in winters, and the high fluctuation areas were mainly in the grasslands and unused land areas in the Daxinganling region of Xinjiang and Inner Mongolia. (2) NDVI fluctuates more with the seasons and is most obvious in forests and cultivated areas. (3) NDVI is mainly improving, with the largest improvement in springs (84.63%), the smallest in winters (72.52%), and the most significant improvement in the woodland areas. (4) Surface temperature and precipitation influenced NDVI in all seasons (Significance = 0.05), with precipitation changes significantly affecting NDVI trends in summers and weakly during winters and surface temperature changes significantly affecting NDVI trends in springs and weakly in autumns. (5) The future NDVI also mainly shows an improving trend, with an area of 70.89%; notably, the degraded areas are sporadically distributed in the Tarim and Junggar Basins of Xinjiang. This study’s results provide theoretical references for ecological restoration and management in the arid and semi-arid regions of Northwest China and the response to local climate warming and humidification.

The linear tendency, cumulative anomaly, and Mann-Kendall test were used to analyze the temporal and spatial variation of temperature in Dunhuang, Guazhou, and Yumen stations in the Shule River Basin from 1951 to 2020. The results revealed that (1) all stations experienced a significant upward trend in average temperature, with tendency rates of 0.244 °C·(10a)^-1 (P<0.05) for Dunhuang station, 0.209 °C·(10a)^-1 (P<0.05) for Guazhou station, and 0.195 °C·(10a)^-1 (P<0.05) for Yumen station. (2) Dunhuang and Yumen stations exhibited a significant upward trend in average temperature across all seasons, except for a nonsignificant upward trend in summer. (3) the mutation years for average temperature at Dunhuang, Guazhou, and Yumen stations were 1998, 1997, and 1995, respectively, with the first main cycles being 58 a, 30 a, and 13 a, respectively. (4) and annual and seasonal average temperatures gradually increased from east to west in the Shule River Basin, with decreasing nonuniformity coefficients and concentration degrees also observed.

The effects of water, salt, and nitrogen (N) regulation on changes in the soil water, transport of salt nutrients, and growth indices and yield of cotton (Gossypium hirsutum) were analyzed under drip irrigation covered by film. A two-year three-factor full-combination field experiment was conducted to study the effects of three levels of irrigation (W1: 2700 m³·hm^-2, W2: 3600 m³·hm^-2, and W3: 4500 m³·hm^-2), salinity (S1: 3 dS·m^-1, S2: 6 dS·m^-1, and S3: 9 dS·m^-1), and N (F1: 105 kg·hm^-2, F2: 210 kg·hm^-2, and F3: 315 kg·hm^-2). The effects of different combinations of water-salt-nitrogen on soil moisture, salinity, N distribution, plant growth, and yield were investigated. The results showed the following: the soil moisture was mainly located in the 30-40 cm soil layer, and the water content of different soil depths essentially first increased and then decreased. The average water content of the 0-40 cm soil layer in the bud and boll stages of S3F3W1 and S2F3W1 increased by 1.3%-21.8% compared with that of S1F3W1, and the average water content of the combination of S1F3 increased by 1.39%-13.83% compared with those of S1F2 and S1F1 under the same amount of irrigation. The soil salinity tended to decrease and then increase during the fertile period. The S1 treatment increased and then decreased the soil salinity as N application increased, and the soil salinity in S2 and S3 decreased as the N application increased. The N content was significantly higher with the F3 treatment than F1 or F2. In the W2 and W3 treatments, N slowly accumulated in the 40-60 cm soil layer, and the N content was significantly higher with the S1 treatment than S2 or S3. The soil moisture, salinity, and N content interacted; under appropriate soil moisture and N conditions, lower soil salinity enabled the plants to utilize nutrients more efficiently, which facilitated their growth, and thus enhanced yield. To obtain high economic benefit, the recommended rate of irrigation for low and medium saline soils is 3600 m³·hm^-2 and the rate of N is 210 kg·hm^-2. For highly saline soils, the recommended rate of irrigation is 4500 m³·hm^-2 and the rate of N is 315 kg·hm^-2. This study provides a theoretical basis to explore the mechanism of water and salt nutrient transport and the efficient use of water and fertilizer in cotton farmland ecosystems under multiyear drip irrigation under a membrane in arid areas.

To explore the main factors influencing soil salinization in irrigation region of Yellow River of Hongsipu, correlation analysis and principal component analysis were used to study the salinization characteristics of the 0-100 cm soil profile. The results showed the following: (1) The overall soil in the study area is strongly alkaline, with the pH of the lower layer of 20-100 cm soil being significantly higher than that of the upper layer of 0-20 cm (P<0.05), which increases with increasing soil depth. The total salt content of soil also increases with increasing soil depth, showing a bottom aggregation-type profile feature of high at the bottom and low at the surface. The difference in total salt content of each layer of soil was not significant (P<0.05), which the pH of each layer of soil exhibited weak variability, with a relatively uniform spatial distribution. The total salt content of soil in the upper layer showed moderate variability at depths of 0-20 cm, while in the lower layer of depths of 20-100 cm it showed strong variabilily, with differences in spatial distribution appearing with changes in depth. (2) The main cation in the study area is Na⁺+K⁺, with significant differences in the content of each cation (P<0.05). The main anion is \mathrm{S} {\mathrm{O}}_4^{2-}, which significant difference compared with other anions (P<0.05). The contents of the ions are in following order: \mathrm{S} {\mathrm{O}}_4^{2-} > Na⁺ +K⁺ > Ca²⁺ > Mg²⁺ > \mathrm{H} \mathrm{C} {\mathrm{O}}_3^{-} > Cl^- > \mathrm{C} {\mathrm{O}}_3^{2-}, and the concentration of each ion also increases with increasing of soil depth, consistent with the changes in total salt and pH. (3) Through correlation analysis and principal component analysis, it was found that the main factors affecting total salt in the irrigation area are \mathrm{S} {\mathrm{O}}_4^{2-}, Cl^-, Na⁺+K⁺, and Mg²⁺, while the main factors affecting pH are \mathrm{C} {\mathrm{O}}_3^{2-} and \mathrm{H} \mathrm{C} {\mathrm{O}}_3^{-}. The main salts are sulfate and chloride, but there are significant differences in salt types at different depth profiles. The upper layer of salt is mainly chloride, while the lower layer is a composite of sulfate and chloride. The results of this study prove the main factors affecting the soil salinity characteristics of irrigation region of Yellow River of Hongsipu, and provide a theoretical basis for the treatment of alkali soil in the study area.

To construct shelter forests in arid areas, selecting plant species with strong stress tolerance and adaptability is key. By simulating a pot water control experiment with different drought gradients, the ecological adaptability of the introduced plant Atriplex canescens and the native plant Tamarix ramosissima willow to drought stress were compared. The results showed that (1) With an increase in drought degree, the water content in the A. canescens and T. ramosissima leaves reduced gradually, and the water retention capacity, proline content, and relative conductivity gradually increased. The soluble sugar and malondialdehyde contents of A. canescens and T. ramosissima were the maximum in mild and severe drought, respectively, and the increase rate was greater in T. ramosissima. (2) The POD activity of A. canescens and T. ramosissima increased gradually, and under severe drought, the percentage increase of T. ramosissima compared with the control was approximatelythree times that of A. canescens; SOD activity was greatest under moderate drought, and the percentage increase in T. ramosissima compared with the control was approximatelyfive times that of A. canescens. The changes in the activity of both enzymes of T. ramosissima were greater than those of A. canescens. (3) The chlorophyll content of A. canescens and T. ramosissima were mildly dry > control > moderate drought > severe drought, the net photosynthetic rate, transpiration rate, stomatal conductance, and intercellular carbon dioxide concentration of T. ramosissima gradually decreased, and mild drought slightly promoted chlorophyll and photosynthetic capacity of A. canescens. (4) The correlation and principal component analysis results indicated that the relationship between the T. ramosissima traits was closer under drought stress, and the relationship between traits and traits was difficult to change in A. canescens, which was relatively conservative. Conclusion: A. canescens is less affected by drought stress, and its drought adaptability is slightly stronger than that of T. ramosissima.

Natural precipitation is an important source of water for vegetation in arid areas. To explore the coping methods of desert shrubs under different precipitation conditions, this study selected typical desert shrubs as subject and determined their leaf morphological traits and stoichiomental characteristics under different precipitation condition. The overall characteristics of leaf functional traits and the relationship between individual functional properties and environmental factors were also analyzed. Results showed that (1) with the decrease in natural precipitation, the degree of fleshiness and water content of leaves of Reaumuria soongorica increased gradually and the tissue density of Kalidium foliatum increased. (2) Meanwhile, the C contents in the leaves of R. soongorica and Nitraria tangutorum and the N contents in the leaves of N. tangutorum and Salsola passerina showed an overall increasing trend with the increase in drought stress. In addition, the leaf N:P ratios of S. passerina and K. foliatum were all less than 14, indicating that the growth and development of these species were mainly restricted by nitrogen. (3) The leaf tissue density of R. soongorica, N. tangutorum, and K. foliatum was positively correlated with the average annual precipitation. The specific leaf area of R. soongorica and N. tangutorum and the P content of R soongorica, N. tangutorum, and S. passerina were negatively correlated with altitude. In arid environments, different plants exhibit different ecological adaptation strategies. To adapt to the desert environment of drought and less rainfall, K. foliatum reduces its specific leaf area and increases its tissue density, N. tangutorum increases the N content of its leaves, and R. soongorica increases the degree of fleshiness and water content of its leaves. Average annual precipitation and altitude are the main limiting factors affecting their growth and development.

Based on the data on forest and grass vegetation coverage from 2000 to 2019, the spatiotemporal change of forest and grass vegetation in Hetao Irrigation District over 20 years was analyzed, and the influence of various factors driving forest and grass vegetation coverage was quantitatively analyzed using a geographical detector. The results showed the following: (1) The area of forest and grassland in Hetao Irrigation District showed a decreasing trend in the studied 20 years, with a decrease of 966.15 km². The vegetation coverage level of forest and grassland showed an overall upward trend. The average annual vegetation coverage of forest and grassland was 28.3%. On the spatial scale, the vegetation coverage of forest and grassland in Hetao Irrigation District showed a spatial variation characteristic of decreasing from northeast to southwest. (2) In the studied 20 years, the centers of gravity of low forest and grass vegetation coverage and medium forest and grass vegetation coverage have mainly been located in the northeast of Yongji irrigation area and the southwest of Yichang irrigation area, respectively. The centers of gravity of forest and grass vegetation coverage at all levels show a decreasing trend from northeast to southwest, and all show a trend of migration to the southwest. The migration distance in each period was between 0.71 and 15.46 km. (3) Distance from water, groundwater depth, temperature, and precipitation are the dominant environmental factors affecting the forest and grass vegetation coverage in the region, with explanatory power of 0.427, 0.439, 0.318, and 0.368, respectively. The interaction between distance from water, groundwater depth, annual average precipitation, and other factors is generally higher, and the regional water content is the main driving force affecting the growth of forest and grassland in Hetao Irrigation District.

Soil moisture is indispensable for the growth and development of plants in arid zones and determines the dynamics and direction of the succession of arid plant communities. It is particularly important to investigate the dynamic characteristics of soil moisture in different landscape types at the edge of the oasis in the middle reaches of the Heihe River and to develop effective, scientific, and reasonable measures to prevent wind and fix sand to prevent desertification. This study focused on three landscape types—protected forest landscapes, desert-oasis transition zone landscapes, and desert landscapes—at the edge of the oasis in the middle reaches of the Heihe River. HYDRUS-2D model simulation, LSD analysis, and Pearson correlation analysis were used to study the characteristics of soil moisture dynamics and the influencing factors of the three landscape types. The results were as follows: (1) the RMSE of soil volumetric water content ranged from 0.002 to 0.006 cm³·cm^-3, MRE ranged from 4.22% to 5.20%, and R² ranged from 0.725 to 0.967. The simulation results showed a high degree of agreement with the measured data, and the HYDRUS-2D model can be used for simulation studies of soil moisture in this study area. (2) The soil volumetric water content of protected forest landscapes and desert-oasis transition zone landscapes showed a trend of initial increase and subsequent decrease with increasing soil depth, whereas desert landscapes showed a trend of initial decrease and subsequent increase with increasing soil depth. (3) Effective precipitation plays a decisive role in the dynamics of the soil volumetric water content, and precipitation above 9.5 mm significantly increases the soil moisture content and infiltration depth over a short period. The depth of soil moisture infiltration in all periods after precipitation in desert landscapes was higher than that in protected forest landscapes and desert-oasis transition zone landscapes. (4) The soil volumetric water content of the three landscape types was related to factors such as precipitation, evapotranspiration, bulkiness, soil granular composition, and soil water-holding properties. The soil water-holding properties were significantly correlated with factors such as precipitation and evapotranspiration (P<0.01). Of these, precipitation and clay-powder grain content were significantly positively correlated with soil volumetric water content, whereas bulk weight and sand grain content were significantly negatively correlated with soil volumetric water content. Thus, planting windbreak shrubs in the study area can increase the content of soil sticky powder particles, improve the ability of the soil to collect and utilize rainwater, and slow the process of infiltration, thus positively affecting the soil water-holding properties.

In this article, using the parameters of hydrological, water resources, and the desertification area of the Shiyang River basin in different periods, the basin hydrology, water resources, desertification, and its changes in the relationship between them were quantitatively studied. It provides the data and the theoretical basis for hydrological, water resource features, and land desertification in this area. The research showed that although the precipitation in the Shiyang River basin had increased from 2005 to 2021, the variability was large and remained at a low level, with an average annual precipitation of only 234.70 mm. From 1993-2004, the annual precipitation at the Caiqi hydrological station reduced, whereas the annual sediment transport increased. The annual precipitation at the Zamusi hydrological station increased from 1999 to 2021, whereas the annual sediment discharge decreased. From 2005 to 2021, the total amount of water resources in the Shiyang River basin decreased by 0.24×10⁸ m³ ·a^-1, but water consumption and water consumption remained at high levels of 24.70× 10⁸ m³ and 17.07×10⁸ m³, with high water consumption and consumption in agriculture, forestry, and fruit industries, exacerbating the irrationality of water resource utilization in the basin. From 1975 to 2014, the total area of desertified land in the basin reduced, but the land changes in different periods and desertification types remained quite different, and the situation of desertification prevention and control in the basin was still grim.

Based on precipitation and soil water isotope data at different elevations in the north and south mountains of Lanzhou from April to October 2018, the lc-excess method and the lc-excess equilibrium equation were used to qualitatively and quantitatively analyze the soil water infiltration process in this area. The infiltration process of soil water, indicated by the soil water lc-excess value, was verified by correlation analysis and single factor analysis. The results showed that there are obvious variations in soil water content in the study area on a monthly scale and at different depths, with loss dominating from April to June and accumulation dominating from July to September. The soil water content in the high altitude areas was found to be greater than that in the low altitude areas, and the soil water content in the north mountains was found to be greater than that in the south mountains. Stable isotopes of soil water at each sampling site we found to be most depleted from August to September. At increasing soil depth, soil water isotopes showed a trend of gradual depletion and stabilization. The soil water lc-excess results showed that the piston flow mode and the priority flow mode co-exist in the infiltration and recharge process of soil water in the study area. The priority flow signal appeared at all sampling sites from July to August. The contribution of the preferred flow pattern to deep soil water was higher at the low elevation sampling sites than at the high elevation sampling sites. The soil water content and soil water lc-excess were found to be positively correlated. The monthly scale and depth of soil water lc-excess were not significantly different between the north and south mountain, indicating that the infiltration and recharge patterns of soil water in the north and south mountains are the same, and that both are dominated by the piston flow infiltration pattern of precipitation recharge. However, in the south mountains, where there is greater vegetation cover, the preferential flow pattern signal appeared more often, especially in July and August, when precipitation is concentrated. Based on the soil water infiltration and replenishment processes in the north and south mountains, it the selection of salt-and drought-tolerant, shallow-rooted shrubs and perennial grasses is recommended for the north mountains, while reasonable irrigation is recommended in the south mountains during the plant growing season (from April to June). The results of this study provide a theoretical reference for understanding the hydrological process in the north and south mountains of Lanzhou.

Stand density has an important effect on understory plant community structure and species diversity of Robinia pseudoacacia plantations. Identifying changes of understory plant community structure and species diversity under different stand densities is helpful for vegetation restoration and improving forest ecological function in loess regions. Taking a R. pseudoacacia plantation in the Loess area of western Shanxi as the focus of study here, the understory community composition characteristics, growth characteristics, and species diversity associated with six stand densities (950, 1450, 1950, 2450, 2950 and 3450 trees·hm^-2) were analyzed through field investigation. The following results were obtained: (1) The study identified 77 species of understory plants in 65 genera in 39 families, including shrubs of 36 species from 29 genera in 16 families, and herbs of 41 species from 36 genera in 25 families. The number of species in the shrub layer peaked when the stand density was 1950 trees·hm^-2, and the number of species in the herb layer peaked when the stand density was 2450 trees·hm^-2. The understory community of R. pseudoacacia forest mainly consists of Rosaceae, Compositae, Gramineae, and Caprifoliaceae. With increasing stand density, the dominant species transition from heliotropic species and intermediate species to shade species. (2) The height and aboveground biomass of shrubs decreased with increasing stand density. The aboveground biomass of herb layer had no significant difference among stand densities (P>0.05), and the total coverage of shrub and grass community showed little change. (3) With increasing stand density, Margalef richness index and Shannon-Wiener diversity index of the shrub layer first increased and then decreased, and peaked when the stand density was 1950 trees·hm^-2, while the Simpson dominance index and Pielou evenness index showed gradually decreasing trends. The Margalef richness index and Shannon-Wiener diversity index of the herb layer peaked when the stand density was 2450 trees·hm^-2, while the Simpson dominance index and Pielou evenness index peaked when the stand density was 1950 trees·hm^-2. (4) The similarity of species composition of understory communities in R. pseudoacacia forest of different densities was above the medium level. When the stand density was 1950-2450 trees·hm^-2, the understory community species diversity of R. pseudoacacia plantation was optimal, which was conducive to the improvement and sustainable development of its ecological function.

To find out the characteristics of the wind-sand environment along the under-construction Tumushuk-Kunyu desert highway, the wind-sand protection engineering practice was carried out based on the attributes of wind-sand elements along the desert highway. The wind-sand activity law along the highway was analyzed and summarized by a field survey, ERA5 wind speed data, and satellite image information. The annual average wind speed along the highway was 3.03-3.28 m·s^-1, the average yearly sand wind speed was 5.85-6.10 m·s^-1, and the annual sand wind frequency was 16.87%-21.41%. The sand-driving wind was concentrated in the spring and summer. April-August was the period with the highest frequency of sand-driving wind in a year. The easterly wind (NE, ENE, E, and ESE) was the main wind along the highway. The frequency of sand-driving wind in the south and west of the Mazatag Mountains was higher than in the north. The annual sediment DP along the line was 99.77-145.30 VU, which belongs to a low wind energy environment and medium variability. The volume and density of the sand dunes on the northern and southern sides of Mazartag Mountain were significantly different. The moving rate of dunes along the line was 1.19-3.69 m·a^-1, which was a medium moving speed. There is a significant negative correlation between the moving rate and the vertical projection area of the dunes. The moving direction ranged from 171.76° to 192.53°, consistent with the RDD. The design of the sand control system in the north of Mt. Mazatagh was mainly based on the east, and the south should consider both the east and the west.

Globally, China is one of the country’s most frequently and severely affected by drought. These frequent drought events have subsequently caused serious economic, social development, and ecological environment losses. Drought simultaneously leads to alterations in both space and time, and this paper aims to identify drought events and quantify their spatial and temporal dynamic evolution using a three-dimensional clustering algorithm for mainland China, from 1981-2020. The three-dimensional clustering algorithm can be used to effectively identify drought events and describe their dynamic processes. From 1981-2020 there were 102 drought events lasting 2 months or more in mainland China. Spatially, the trajectory of drought events was found to show a tendency to develop from east to west. Temporally, there are high time overlaps between different drought events. In addition, drought events with wide coverage and high severity were concentrated in the period from 2005-2010. The findings of this paper will help to elucidate the spatial and temporal evolution patterns of drought events and provide scientific references for drought monitoring and drought risk management in mainland China.

Analyzing the response of tree radial growth to climate change is crucial for accurately predicting the dynamic changes in forests in the future. The temperate coniferous forest, dominated by Picea schrenkiana, is widely distributed in the mid-mountain zone on the northern slope of the Tianshan Mountains. In this study, core samples of high-altitude Picea schrenkiana were collected, and the response characteristics of Picea schrenkiana radial growth to climatic factors and drought events were explored using tree-ring analysis. The results showed the following: (1) From 1960 to 2020, the tree-ring width index of Picea schrenkiana showed a significant upward trend without any growth recession, indicating favorable growth conditions in recent years. (2) The tree-ring width of Picea schrenkiana was mainly positively correlated with temperature from June to August, precipitation in April, and scPDSI in all months except July. Sliding correlation analysis showed an unstable relationship between tree-ring width and climatic factors. After 1991, the positive response of spruce to climatic factors was further strengthened. (3) The percentage of radial growth change in Picea schrenkiana was less than -25% from 1879 to 1880, indicating a growth decline from 1879 to 1885. An increase in drought frequency and intensity resulted in a decrease in the resistance and resilience of Picea schrenkiana to drought events. When Picea schrenkiana was in a relatively sufficient water environment for a long time and suffered from sudden drought events, it exhibited a significant decline in resistance and was prone to growth decline. In summary, under the influence of climate change, warming is still expected to promote the radial growth of high-altitude Picea schrenkiana in the region in the near future. However, the increase in the frequency and intensity of drought events during the warming process will further reduce the resistance and resilience of Picea schrenkiana, posing an increased risk of growth decline. In the near future, Picea schrenkiana will face the challenge of balancing growth promotion due to warming and growth inhibition due to drought. Further observation and research are required to understand the ultimate impact. In the future, various methods should be implemented to closely monitor the growth dynamics of Picea schrenkiana.

This study used yield and water and fertilizer usage efficiency as targets to explore a magnetized water fertilization system suitable for tomato processing via drip irrigation under film. Four magnetized water samples with an intensity of 0 Gs (M0), 2000 Gs (M1), 3000 Gs (M2), and 4000 Gs (M3) as well as three nitrogen application levels of 200 kg N·hm^-2 (N1), 250 kg N·hm^-2 (N2), and 300 kg N·hm^-2 (N3) were set up, and a split zone test design was adopted. Field experiments were conducted. By monitoring the soil moisture content, plant height, stem diameter, and above-ground biomass during the growth period of processed tomatoes, combined with the final yield index, the effects of magnetic nitrogen combination on the water and fertilizer usage efficiency of processed tomatoes were explored. The results showed that magnetized water drip irrigation significantly increased soil moisture content and soil water storage. Magnetic nitrogen coupling was also shown to significantly increase the soil moisture content in the 20-40 cm soil layer. When the magnetized water intensity was 2270-3678 Gs and the nitrogen rate was 220-230 kg·hm^-2, the growth of processed tomatoes was promoted. However, when the magnetization intensity was greater than 4000 Gs and the nitrogen rate was more than 250 kg·hm^-2, the growth of processed tomatoes could not be further improved. As magnetization was increased, the yield and water and fertilizer use efficiency of processed tomatoes increased before decreasing. As the nitrogen application rate was increased, the yield and water use efficiency increased, but the partial productivity of nitrogen fertilizer decreased. Among them, the M2N3 treatment had the highest yield and water use efficiency (169.67 t·hm^-2 and 35.61 kg·m^-3), while the M2N1 treatment had the highest nitrogen partial productivity (822.54 kg·kg^-1). Using regression and spatial analyses, the magnetic nitrogen range of yield, water use efficiency, and nitrogen partial productivity was 2270-3678 Gs and 220-230 kg N·hm^-2. This study can provide theoretical support for the scientific application of magnetized water and nitrogen fertilizer in tomato processing in Xinjiang and provide scientific guidance for optimizing the magnetic nitrogen combination configuration to improve the yield of tomato processing.

The agropastoral ecotone is an important ecological security barrier and grain producing area in northern China. Elucidating the spatial evolution law and influencing factors of production-living-ecology spaces in the ecologically fragile areas for land space optimization and sustainable development is extremely important. In this study, the methods of land use dynamic degree, land transfer matrix, and geographical detector were used to explore the spatial evolution characteristics and influencing factors of production-living-ecological spaces in Hohhot, a typical farming-pastoral ecotone in Inner Mongolia, from 2000 to 2020. The results show that during the study period, the overall dynamic changes in the production-living-ecological space of Hohhot were gentle (0.02%-0.04%). The spaces for ecology, agricultural production, and animal husbandry decreased, while the spaces for life and other production increased. From 2000 to 2020, the spatial patterns for production-living-ecological in Hohhot changed significantly, and this was mainly manifested in the occupation of agricultural and animal husbandry production spaces by the living space outside the urban area, and the mutual transformation of agricultural production, animal husbandry, and ecological spaces in the Tumochuan Plain and its northern and southeastern hilly areas. During the study period, the mutual transformation of ecological, agricultural, and livestock production spaces was intense, but this decreased after 2010. Living spaces and other production spaces were in a state of net inflow, especially in the latter decades. The average slope is the dominant factor affecting the spatial layout of agricultural and animal husbandry production (0.24-0.4). Industrial development, human activities and agricultural production scales have a greater impact on the local spatial patterns. Based on refined governance, the role of policy guidance is increasingly prominent.

This study focused on the natural Juniperus rigida population in the loess hilly region of Inner Mongolia. The structure and dynamic changes of the population were analyzed using a static life table, survival function, dynamic quantitative analysis, and time series model. The results showed that the population mainly comprised many individual seedlings, followed by medium and less mature trees. Combined with the dynamic change index V_pi > 0, the population was a growth type. The survival curve was verified using the curve model and tended to Deevey-II, indicating that the mortality rate of each age class was stable. Considering the external interference, the dynamic index tended to 0, and the population growth is not obvious under the interference condition. In the survival function analysis, the population showed a strong survival trend in the early stage, followed by a gradual decline in the middle stage. During the 2-to-8-year period, the number of seedlings decreased while middle-aged and adult trees increased. The seedling stage is crucial to the regeneration and development of the population. Therefore, implementing scientific protection measures for seedlings to promote population regeneration is recommended. Research on the internal mechanisms of the Juniperus rigida population can enrich vegetation construction in arid areas, provide a reference for population management, and provide a theoretical basis for vegetation protection and restoration in the loess hilly area.

Mountain grassland are an essential component of pasture resources in the Xinjiang Uygur Autonomous Region. However, mountain grassland are highly vulnerable to human-associated disturbance and climate change. The responses of the mountain grassland plant community characteristics and diversity to different grazing managements in Barkol County, Xinjiang, are still unclear. In this study, three different grazing management treatments were set up in 2012 to investigate the response patterns of the plant community characteristics, diversity, and the relationship between the diversity and the aboveground biomass in the mountain grasslands. The three grazing management blocks were M0, M1, and M2, which represented the permanent grazing prohibition, winter grazing, and year-round grazing management, respectively. During the peak growing seasons of 2013, 2017, and 2022, the data regarding the number of species, height, coverage, density, and aboveground plant biomass were collected for further analysis. The results indicated that the different grazing managements had no significant impacts on the importance value of the dominant species, such as Stipa glareosa. However, the importance values of the nondominant species such as Neotrinia splendens and Achnatherum inebrians (Hance) Keng increased under winter and year-round grazing. As grazing intensity increased, plant height, coverage, density, aboveground biomass, and their response ratios declined significantly (P<0.05). There were no significant differences in the Shannon-Wiener diversity, Simpson dominance, and Pielou evenness indices in M0, M1, and M2. In contrast, the Margalef richness index elevated markedly (P<0.05), indicating that grazing provided more survival resources helpful for other species. In the permanent grazing prohibition block, the aboveground biomass was negatively correlated with the Simpson dominance, Shannon-Wiener diversity, and Pielou evenness indices. In the winter grazing block, aboveground biomass was negatively correlated with the Margalef richness index. Overall, the importance value of the dominant species showed no remarkable differences under varying grazing management, and its dominance remained unchanged. Except for the Margalef richness index, the other diversity indices were not significantly influenced by grazing. Winter and year-round grazing enhanced the vital value of unpalatable species, altering the composition of forage, which was not conducive to future animal husbandry development. In summary, as the enclosure time increased, permanent grazing prohibition was beneficial for restoring degraded grasslands, improving community characteristic values, improving grassland productivity, and maintaining community stability to a certain extent. Grazing would affect resource redistribution in the ecosystem, releasing ecological niches for more species, but year-round grazing led to intensified grassland degradation because of overgrazing pressure.

This study examined the vegetation characteristics and species diversity of mixed herb communities in different years on the slope of expressway in the Loess Plateau, and explored the relationship between herb community characteristics, species diversity, and soil physical and chemical properties. The characteristics of herb communities, α species diversity, and their correlation with soil physical and chemical properties were studied using the Mantel test after 15 a, 12 a, 8 a, 4 a, and 2 a of restoration of herb communities on the highway slope of the Loess Plateau by space instead of time. In total, 13 species of 13 genera in 8 families were investigated in 15 a of slope restoration, 10 species of 10 genera in 7 families were investigated in 12 a of restoration, 5 species of 5 genera in 3 families were investigated in 8 years of restoration, 5 species of 5 genera in 3 families were investigated in 4 a of restoration, and 6 species of 6 genera in 4 families were investigated in 2 a of restoration. Patric species richness recovered in the order 15 a>12 a>8 a>2 a>4 a, the Shannon-Wiener and Simpson indices recovered in the order 15 a>12 a>2 a>8 a>4 a, and the Pielou evenness index recovered in the order 15 a>2 a>8 a>12 a>4 a. Patric species richness was significantly positively correlated with total porosity and capillary porosity, organic matter, total nitrogen, and total phosphorus (P<0.05), and the Shannon-Wiener index was significantly positively correlated with organic matter and total phosphorus (P<0.05). After spraying mixed grass species in different years on the slope, the herb communities mostly contained perennials, but there were differences in species composition and quantity of the community. The species richness, Shannon-Wiener index, and Simpson index of patric species showed an upward trend as the number of restoration years increased. Soil total porosity, capillary porosity, organic matter, total nitrogen, and total phosphorus were the key environmental factors affecting patric species richness and the Shannon-Wiener index.

The benefits of wind and sand control under the combined measures of sand-fixing plant species with regenerative sand barriers of Salix mongolica, polylactic acid (PLA) sandbags, and straw rope sand barriers in the Mu Us sandy land was studied. The wind speed, near-surface sand transport, and erosion pattern inside the barrier were measured at different heights under various combinations of measures, and the benefits of several sand barrier and combined measures under different materials, slope positions, and specifications were compared and analyzed. The results showed wind speed reduction was highest for the 1 m × 1 m S. mongolica regenerative sand barrier and straw rope sand barrier (up to 80.29% and 78.49%). The effectiveness of wind prevention for the 3 m × 3 m combination of straw rope and PLA sand barriers was 58.14% and 57.88%, respectively. The reduction rate of sand transport was as follows: S. mongolica > straw rope > PLA, and the trend increased with the specification. The sand-blocking effect of S. mongolica regeneration sand barrier combined measures is more stable, while the other two measures are less stable. The microtopography inside the barrier is mainly controlled by the wind direction from NW to NNW under various measures, and the morphological characteristics varies with the type of sand barrier material. The overall erosion is dominant, and the relative depth of erosion in the barrier is the largest for straw rope sand barriers combination, and the PLA barrier is the next, and the S. mongolica regeneration sand barrier is weakly eroded in the range of -10-5 cm, but the relative depth of erosion decreases with the increase of specification and slope. Comprehensive analysis shows that the artificial sand fixation vegetation system of Salix mongolica sand barrier combined with sowing sand fixation plant species is the most stable, with the best benefit of wind prevention and sand fixation, and is a more suitable mobile sand dune sand barrier in Mu Us sandy land. It is a more suitable technical measure for flowing dune sand barriers to promote vegetation restoration in Mu Us sandy land. The other measures can be appropriately adopted according to the difficulty of obtaining sand barrier materials, transportation conditions, quicksand environment, and control.

This study aimed to spatially and temporally characterize not only land surface temperature (LST) in the complex mountainous terrain of Daqingshan, Inner Mongolia but also the environmental factors affecting it. We used the Weather Research and Forecasting Mode (WRF) used to obtain LST data with high temporal and spatial resolution and analyze the variation of mountain influencing factors. The accuracy of the WRF simulated LST (WRF LST) was verified by the observation values of meteorological stations and MODIS LST values, and the relationship between LST and environmental factors was analyzed by the method of comprehensive impact factor analysis and the method of single impact factor analysis. The comprehensive impact factor analysis is based on regional WRF LST and regional environmental factors. Single impact factor analysis achieves the relationship between WRF LST and single environmental factors by fixing other environmental factors. The results revealed that the correlation coefficients between the simulated and observed values were >0.97 (P<0.001) and the spatial correlation with MODIS LST was 0.73 (P<0.05), indicating that WRF has good practicability in mountainous areas. After comprehensive impact factor analysis, it was found the annual WRF LST had the greatest correlation with elevation (R>0.97), followed by temperature at 2 m and water/air mixing ratio at 2 m (R>0.8), vegetation coverage and slope (R>0.3), and other factors. By single impact factor analysis, LST decrease rate with elevation was 0.83 K·(100m)^-1, 0.79 K·(100m)^-1, 0.80 K·(100m)^-1 and 0.32 K·(100m)^-1 in spring, summer, autumn and winter, and it increased by -0.05 K, 0.17 K, -0.14 K, and 0.02 K for every 10° increase in slope in spring, summer fall winter, respectively. LST also increased for every 10% increase in vegetation cover by 0.31 K, 1.41 K in summer and winter, and was not correlated with fall. The slope direction and average LST for the four seasons were south>southwest>southeast>west>east>northwest>northeast>north. The 2 m water-air mixing ratio increased logarithmically with LST, while the 2 m air temperature increased exponentially with LST. This study demonstrated that the WRF model can be used to simulate the spatial and temporal distribution of LST in mountainous terrain and analyze the LST relationship in complex mountain environments.

As the most widespread ecosystem on Earth, grassland is vital for maintaining ecological security, sustainability, and human well-being. In this study, we used systemic methods of maximum synthesis, regression analysis, and partial correlation analysis to investigate the spatiotemporal dynamics of grassland and its responses to temperature and precipitation on the northern slope of the Tianshan Mountains in Changji Hui Autonomous Prefecture, Xinjiang, from 2000 to 2020. The research was based on remote-sensed time series images (e.g., MODIS NPP and EVI) and related auxiliary data. The results indicate a significant increase in grassland NPP and EVI from 2000 to 2020, with temporal fluctuations. However, after 2016, both NPP, and EVI declined year over year. Over the past 20 years, the mean average NPP, and EVI of grassland vegetation were 0.095 kg C·m^-2 and 0.186, respectively. In 2020, grassland NPP (0.099 kg C·m^-2）and EVI (0.194) increased by 28.57% and 16.87%, respectively, compared to their values in 2000 (NPP: 0.077 kg C·m^-2; EVI: 0.166). The spatial heterogeneity of grassland vegetation NPP increased substantially and showed a trend toward expansion, while the spatial heterogeneity of grassland EVI increased annually. The range of variation observed during this research was 0.038 kg C·m^-2 for NPP and 0.059 for EVI. Overall, the spatial distribution of grassland NPP and EVI was generally coherent, but variations also existed. Grassland NPP and EVI showed an upward trend with altitude, with an elevated EVI along the oasis edge and the southern edge of the Gurbantunggut Desert. In this study, we suggest that abundant water and heat induce the formation of vigorous layers of short-lived plants, resulting in higher coverage than other grassland plants after withering. These short-lived plants begin their life cycle in early spring, when hydrothermal conditions (e.g., temperature, soil moisture, and root zone soil temperature) are favorable, and they complete their germination, growth, fruiting, and withering phases from April to June. The area percentages of NPP (65.01%) and EVI (21.93%) showed a significant increasing trend on the northern slope of Tianshan Mountains in the Changji Hui Autonomous Prefecture, Xinjiang, over the last 20 years. The proportion of vegetation NPP and EVI in the 9 grassland types showed a significant positive correlation with precipitation, which was much greater than that with temperature during the same period, confirming that precipitation is the major factor affecting grassland vegetation. Furthermore, the reactions of each grassland vegetation type (e.g., NPP and EVI) to precipitation varied. While precipitation remained a key driver for grassland, moderate warming, especially at high altitudes, was found to be suitable for the growth of grassland vegetation. These findings provide theoretical references for evaluating grassland ecological health and degradation, as well as the high-quality development of grassland on the northern slope of Tianshan Mountains in the Changji Hui Autonomous Prefecture, Xinjiang.

In order to explore the succession and species diversity of plant communities in the process of gangue treatment, the text used the time-space substitution method to select the different years (2, 5, and 10 a) of gangue treatment in Shuanglong ditch, Tianzhu Tibetan Autonomous County, Gansu Province, and the untreated gangue as the contrast (CK) sample plots. The vegetation was surveyed, and the succession characteristics and species diversity of plant communities were analyzed. The results show that: (1) during the process of Shuanglong ditch gangue treatment, we identified 55 species of plants belonging to 40 genera and 24 families in 4 sample plots. Among these taxa, 15 families were single families, single genus, and single species. There were 28 species of Asteraceae, Poaceae, and Rosaceae, which accounted for 12.5% of the total number of families and 50.91% of the total species. Most of the species belonged to a few families, and most plant species belonged to a single family and a single genus. (2) During the years of gangue treatment, the dominant species of the community gradually changed from annual or perennial herbs to perennial herbs and shrubs. The number of plant species in the CK was 11, and after 5 years of gangue treatment, we identified 28 species, which decreased to 18 species after 10 years of gangue treatment. Finally, Elymus nutans, Poa pratensis, and Hippophae rhamnoides become the dominant species in the sample plot; and these three plants comprised 48.107. (3) With increasing gangue treatment time, the number of species, Shannon diversity index, and Margalef richness index gradually increased from CK to 5 years after gangue treatment, reaching maximum values of 28, 3.506, and 2.877 respectively. The Pielou evenness index changed little, although we observed a trend of “falling-rising-falling.” In contrast, the Simpson dominance index showed a trend of “rising-falling-rising,” reaching the maximum value of 0.359 after 10 years of gangue treatment. (4) The length of time of gangue treatment greatly impacted the quantitative characteristics of the plant population. Plant height significantly increased from CK, 2-10 a (P < 0.05). Coverage significantly increased from CK to 5 a and 10 a of treatment (P < 0.05). The number of plants increased significantly from CK to 10 a of treatment (P < 0.05). Overall, the results indicate that years of gangue treatment greatly impacted vegetation succession and species diversity in the Shuanglong ditch of the eastern section of Qilian Mountains; and the plant community has gradually become single and stable.

Reservoirs play a pivotal role in regional economic development and societal well-being. In recent years, Xinjiang has experienced frequent extreme precipitation events, which pose significant challenges to reservoir safety. However, research on precipitation characteristics specific to Xinjiang’s reservoirs remains limited, preventing scientific guidance for water resource utilization and reservoir management. Using daily precipitation data from 1961 to 2022 and hourly precipitation data from 2009 to 2022 in the Xiagou reservoir watershed of Yiwu County, Hami City, this study analyzes long-term variations at different time scales and precipitation levels. The findings indicate following points: (1) During the rainy season from 1961 to 2022, the average precipitation in the Xiagou reservoir catchment area showed a weak increase, and the number of days with discontinuous precipitation enhanced significantly. The total number of precipitation days and the maximum number of continuous precipitation days reduced evidently. Together, these trends may lead to further enhancement of the precipitation intensity in the region. (2) The rainy season is mainly characterized by light rainfall; however, over the past 62 years, the number of light and moderate rain days has declined, unlike heavy and torrential rain days. The highest proportion of rainstorms to total rainfall during the rainy season was approximately 50.0%, which was the main reason for the increase in precipitation during the rainy season in the Xiagou reservoir catchment area. (3) Daily precipitation values displayed a rising pattern as the precipitation intensity strengthened. For instance, high values for light, moderate, heavy, and torrential rain occurred in the afternoon, midday, morning, and early morning, respectively. Except for torrential rain, high values for other precipitation levels were predominantly observed during the daytime. The daily variation curves for the average precipitation intensity exhibit multiple peaks with remarkable variations. The relationship between cumulative precipitation frequency and amount was more closely associated with light and moderate rain than with precipitation intensity. Conversely, the relationship between average precipitation intensity and cumulative precipitation amount was more closely related to heavy and torrential rain than to cumulative precipitation frequency.

In recent years, drastic and extreme forms of soil erosion, such as landslides, mudflows, and silt dam outbursts, triggered by extreme rainstorms on the Loess Plateau have attracted widespread attention. From October 3 to 6, 2021, a large shallow landslide disaster was triggered by heavy rainfall along the Caijiachuan watershed in Jixian County, Shanxi Province. In this study, the rainfall process, landslide initiation conditions, and erosion characteristics were analyzed using predisaster and postdisaster unmanned aerial vehicle imagery, historical remote sensing images, and rainfall data provided by the National Field Scientific Observatory for Forest Ecosystems in Jixian County, Shanxi Province. The results show that it was a typical “long-duration, low-intensity” rainfall, with a total precipitation of 121.8 mm in the first 72 h of the initiation of the massive, shallow landslides and a rainfall intensity of 33.2 mm·(6h)^-1 during the initiation of the landslides. The landslide triggered by this rainstorm required a slightly smaller catchment area and exhibited higher landslide mobility than the landslide triggered by a typical short-duration, high-intensity rainstorm in 2003; however, the slope of the landslide was not significantly different. Thus, the cumulative rainfall in the early stage was the main factor influencing the occurrence and flexibility of the massive landslide disaster. The magnitude of landslide number probability, area probability, and erosion intensity in catchments with different land use types decreased in the following order: farmland catchment>plantation forest catchment>closed catchment. This finding indicated that the land use type and vegetation cover affect the degree of landslide erosion to a certain extent and that an arboreal-dominated watershed is more unfavorable to landslide initiation.

Desert plants have developed highly evolved water preservation and transportation systems for collecting and storing water through air under chronic water scarcity, the accessory structures such as trichomes on the leaf surface have important biological significance in collection, storage and transportation of the condensed water. Based on the current research progress, this review briefly summarizes the biological and ecological effects of condensate on desert plants, and expounds the theories related to leaf surface wettability and water collection capacity. Based on this, the important role of special structure of desert plants’ leaf surface (trichome) in the formation, transport and absorption of condensate is mainly discussed. The research methods of surface retention and absorption of condensate water were summarized, which may provide guidance for further study on trichome function and is helpful to understand the mechanism of condensate collection by desert plants driven by its structural characteristics in arid areas of China.

Based on the monthly gridded precipitation in China and monthly ERA-interim reanalysis dataset from 1979 to 2018, the annual relationship between the position and intensity of West Asian subtropical westerly jet (WASWJ) and summer precipitation over the Three River Source (TRS) region and their corresponding physical mechanism are discussed. The results show that the position and intensity of WASWJ have evident interannual and interdecadal variability. The position of WASWJ is characterized by north-south oscillation before 2000s and dominated by southerlies during and after 2000s. On the interannual time scale, the position of WASWJ is more important than its strength in influencing summer precipitation over the TRS region. When the WASWJ locates at latitudes more southern than normal (more northern than normal), the summer precipitation over the TRS is higher (less). Further analysis shows that when the WASWJ moves southward, the anomalous upper-level positive and middle-level negative geopotential height and significant ascending movement over the TRS region favor the development of the plateau low-value system. The combination of the anomalous southerly flow in the east of anomalous cyclonic circulation at the middle to lower troposphere, which is beneficial for the warm and humid air flow from tropical ocean to the TRS region, increases precipitation and vice versa.

This study aims to examine the spatiotemporal variation characteristics of grassland vegetation cover at the regional scale and analyze its driving factors. The findings will provide a scientific reference and decision-making basis for the scientific formulation of protection and restoration models, treatment measures, and the sustainable management of the grassland ecosystem in Ningxia, which are crucial for maintaining the balance of the regional grassland ecosystem and promoting ecological protection and high-quality development in the Yellow River Basin. In this study, the NDVI time series dataset of SPOT/VEGETATION (2000-2019) was used as the data source. The annual mean method, Theil-Sen Median trend analysis, and Mann-Kendall test were employed to study the spatiotemporal distribution and variation characteristics of grassland vegetation cover in Ningxia. Furthermore, the Hurst index method was used to analyze the sustainability characteristics and future development trends of grassland vegetation cover. Simultaneously, the influence of 13 factors, such as average precipitation, altitude, and gross domestic product, on the spatiotemporal distribution was quantified based on the geographical detectors approach. The results show that from 2000 to 2019, the average annual NDVI of vegetation in Ningxia grassland showed a fluctuating growth trend, with a growth rate of 0.005 per year. The regional fluctuation was quite different, with extremely high and high vegetation cover areas concentrated in the Liupan Mountains and the irrigation area along the Yellow River. Overall, the NDVI change showed a low to medium fluctuation trend, and the regional fluctuation was quite different. The vegetation cover condition improved significantly over the 20-year period, with a small degradation area and a favorable overall change trend. However, 59.341% of the grasslands are projected to face potential risks of continuous degradation or transformation from improvement to degradation in the future. The most sensitive environmental factor influencing grassland vegetation distribution response was precipitation, and climate and soil had the strongest interaction explanatory power overall. The relationship between the factors affecting the distribution and variation characteristics of grassland vegetation primarily manifested as mutual reinforcement or nonlinear enhancement, with no independent relationship between the factors. This study provides a scientific reference and decision-making basis for the sustainable management of the grassland ecosystem in Ningxia.

A thorough investigation of the distribution of natural Populus euphratica, tree growth, regeneration characteristics, soil types, and factors in the Hexi Corridor was conducted. The distribution and regeneration status of natural P. euphratica in the Hexi Corridor, as well as its relationship with soil factors, were then examined. The results showed that: (1) Natural P. euphratica forests in the Hexi Corridor were mainly distributed in riparian terraces, ancient river terraces and the edge of oasis cultivated land in the lower reaches of Shule River, Black River, and Shiyang River. There are four main types of forest land: abandoned land, the land around cultivated fields and irrigation canals, land along the current river course, and land among ancient river course and Gobi low-lying land. (2) The growth status, age structure, and seedling regeneration of P. euphratica in the land around cultivated fields and irrigation canal, land along the current river course are better than those of the abandoned land, and among ancient river course and Gobi low-lying land. In terms of the number of renewed seedlings per unit area, the land around the cultivated field and irrigation canal was the largest, with an average value of 22.13, followed by abandoned cultivated land (20.92), land along the current river course (10.50), and among ancient river course and Gobi low-lying land (1.33). (3) Different types of P. euphratica forests have different soil factor contents: (i) Available P: In the 0-20 cm soil layer, the soil available phosphorus showed the trend as; land along the current river course < land among ancient river course and Gobi low-lying land < abandoned land, land around cultivated field and irrigation canal cultivated land; in the 20-40 cm soil layer, land along the current river course had significant less available phosphorus than the other three types of forest land (all P < 0.05); (ii) Moisture content was higher in the land around cultivated fields and irrigation canals, and land along the current river course than in abandoned land, land among ancient river course and Gobi low-lying land (all P < 0.05); (iii) In comparison to the other three types of forest land, abandoned land has significantly lower soil conductivity between the 0-20 cm and 20-40 cm soil layers (P < 0.05). There was no significant difference in the contents of total N and organic matter among different types of forest land (P > 0.05) and in the 40-60 cm soil layer, land among the ancient river course and Gobi low-lying land was significantly higher (P < 0.05). Except for the coarse sand in the 0-20 cm soil layer, the soil clay particles, silt particles, and coarse particles in the land around the cultivated field and irrigation canal performed significantly higher than those in the other three types of forest land (P < 0.05). (4) The contents of soil moisture and available P were positively correlated with the middle and young age of P. euphratica and the number of seedlings (P < 0.05). (5) To encourage the sustainable development of P. euphratica forest, improve forest management and protection, timely thinning, removal of branches and dieback, thinning, and irrigation.

To evaluate the ecological environment of Altay City in Xinjiang in a timely, objective, and quantitative manner, an improved remote sensing ecological index (MRSEI) was constructed based on multi-source remote sensing data. The spatial and temporal variation characteristics were then analyzed by combining a standard deviation ellipse and gravity center migration model. A geographical detector model was used to detect the five indicators, which were greenness, dryness, humidity, temperature, and air quality. (1) From 2015 to 2021, the greenness and humidity indexes of Altay City showed a significant positive correlation with the ecological environment in the region. In contrast, the three indexes for temperature, dryness, and air quality showed significant negative correlations. (2) From 2015 to 2021, the average value of the MRSEI in Altay City increased. The spatial migration ability of ecological index areas I and II was strong, while III-V were relatively stable in the spatial structure. The center of gravity for ecological index areas I-IV moved north, while the center of gravity for area V moved south, indicating that the distribution of the high ecological index in the south of Altay City increased significantly. (3) The dominant factors causing the changes in the eco-environmental quality differed each year. The spatial evolution of eco-environmental quality in Altay is the result of multiple factors. (4) The differences in spatial distribution and the differences between the MRSEI and RSEI data are related to the spatial distribution of AOD, indicating that even if Altay City had improved air quality, AOD would still have an impact on the ecological quality of the spatial distribution. From 2015 to 2021, the ecological environment of Altay City was thus found to be affected by many factors and tended to improve toward the south.