Based on the data from 19 sounding stations in 2022-2023, this study investigates the temporal and spatial variations of the temperature inversions in the lower, middle, and upper troposphere in northwest China. The results indicated the following: (1) In terms of monthly variations, inversions across all three tropospheric levels exhibit similar patterns, peaking in December and January-February of the following year and reaching a minimum from June to August. (2) In terms of spatial distribution, among the low-level inversions, low-level inversions were most frequent in northern Xinjiang, at 40%-60%; the greatest thickness of low-level inversions was observed in northern Shanxi, exceeding 90 m; the intensity of low-level inversions was stronger in most areas of Xinjiang, ranging from 2 ℃ and 3 ℃. For mid-level inversions, their frequency was highest in Qinghai and decrease outward from this region. High-level inversions were most pronounced in northern Xinjiang, with their frequency decreasing outward from this region. (3) The occurrence of low-level inversions in northwest China is influenced by surface radiation and topography, the occurrence of mid-level inversions is associated with warm advection and subsidence movement, and the occurrence of high-level inversions may be related to the top of the temperate troposphere and ozone. (4) In the summer of northwest China, influenced by solar radiation and surface cooling. below the 0 ℃ isotherm height, the intensity of inversions is stronger; above the 0 ℃ isotherm height, the inversions have weaker intensity.

Da Xing’anling Mountains was of immeasurable significance in maintaining regional ecological balance and ecological security. However, it was also one of the key fire risk areas. The prediction model of aircraft cold cloud precipitation enhancement potential was established to provide important technical support for the precise operation of artificial rain enhancement for fire prevention and extinguishing in the Daxing’an Mountains. Based on the number concentrations of small and large cloud particles observed by aircraft from 2017 to 2020 and 2023, the potential for enhancing precipitation was divided into three categories: strongly seedable, seedable, and not seedable. Based on the ERA5 reanalysis data, the environmental parameters of the three types of precipitation enhancement potential samples were discussed, and the results showed that the relative humidity values of 750 hPa were 79.1% and 95.6%, that is, the relative humidity of the not seedable sample was less than 79.1%, and the relative humidity of the strongly seedable sample was greater than 95.6%, and the relative humidity value of the seedable sample was between the two. The dew point temperature differences at 700 hPa were 0.3 ℃ and 2.4 ℃, the vertical velocities at 650 hPa were 0.7 and -0.06 Pa·s^-1, the liquid water contents at 650 and 700 hPa were 0.01 and 0.08 g·kg^-1, the rainwater mixing ratios at 850 hPa were 0.01 and 0.07 g·kg^-1, and the vertical cumulative supercooled water was 0.5 and 2.2 mm. Considering the accuracy with which the three samples could be distinguished using the environmental parameter thresholds and the collinearity relationships between the parameters, four environmental parameters were finally selected, and two model for predicting the potential to enhance precipitation were established using the Fisher and Bayes methods. The average recognition rate of the two models was 88.6% for the training set and 98.6% for the test set, providing strong support for the implementation of scientific and accurate weather modification operations.

The biogeophysical process of land use change is an essential part of global change studies. Recognizing the characteristics of land surface heat flux under different vegetation cover is of great scientific significance for further understanding global change. Based on the eddy observation of the surface heat flux and gradient micrometeorological data of the Tuotuohe and Longbao field stations, the sensible and latent heat transfer coefficients were constructed by an inverse algorithm. Using this coefficient, the monthly heat flux values from 1981 to 2020 were constructed based on the Tuotuohe and Yushu meteorological stations. The interannual and monthly changes of heat flux were analyzed. The relationship between heat flux and meteorological elements is discussed systematically, and the calculated heat flux data are compared with the reanalysis data in detail. The conclusions are as follows: (1) Compared with the heat flux calculated by the total transport method and the field station’s eddy observation value, the correlation of the two stations’ surface sensible heat flux is better than that of the surface latent heat flux; that of the Tuotuohe station is better than that of the Longbao station. (2) The interannual variation of surface heat flux of different underlying surface types is not consistent. From 1981 to 2020, the surface latent and sensible heat fluxes and surface heat source of the Tuotuohe station displayed a weak decreasing trend. The Yushu station’s surface sensible and latent heat fluxes and surface heat source display an upward trend. (3) The monthly averages of surface sensible and latent heat fluxes display a single peak at both stations. The surface sensible heat flux reaches its maximum in May, and the surface latent heat flux reaches its maximum in July. The surface heat source differs slightly between the two stations: it exhibits a single peak at the Tuotuohe station, reaching a maximum in June, and a double peak at the Yushu station, reaching a peak in May and August. (4) The correlation between the calculated heat flux and the reanalysis data of the Tuotuohe station is better than that of the Yushu station. The surface sensible heat flux of the Yushu station is overestimated and underestimated. The calculated value of the Yushu station’s surface latent heat flux is lower than the reanalysis value before 2008 and higher than that after 2008.

Assessment of the risk of soil salinization and associated monitoring are particularly significant for the precise management of saline soil and to ensure sustainable agricultural development. Taking Dali County as a focus, this study used the CRITIC weighting method to construct a comprehensive salt index, comprehensive soil index, comprehensive vegetation index, and comprehensive geographical index based on the soil salt driving mechanism and process, combined with the characterized soil salt state. It also used the analytic hierarchy process-entropy combined weight method to construct a model for assessing the risk of soil salinization. Monitoring revealed that the risk of soil salinization in Dali County is mainly mild, although the level of salinization risk in 2021 was relatively high. Meanwhile, the total area with salinization risk that is moderate or above peaked in the last four years, accounting for approximately 50% of the total. From 2020 to 2023, the changes in the level of soil salinization risk mainly involved risk escalation, and the stability of the soil salinization risk level around the Yellow River Basin in the east was relatively poor. Cultivated land is the main land cover type in the warning zone and restoration zone within the saline soil management zoning and both warning zone and restoration zone are mainly distributed in the eastern part of Dali County. Upon efforts to confirm the findings by determining the correlations between the soil salinization risk assessment results and the soil conductivity samples measured in the same period, there was a significant strong correlation between them. The model for assessing the risk of soil salinization can effectively characterize the spatiotemporal evolution of soil salinization in Dali County. In addition, the increased risk of soil salinization was shown to be mainly associated with multiple factors such as concentrated heavy rainfall, rising temperatures, rising groundwater levels, increased surface evapotranspiration, and agricultural production. Therefore, assessment of the risk of soil salinization in Dali County can provide a theoretical and scientific basis and data support for the precise and efficient management of saline soils and effectively promote the adjustment of agricultural production structure and achieve ecologically sustainable agricultural development.

Soil multifunctionality is a vital component of ecosystem multifunctionality. Exploring the multifunctionality of soil in the Picea schrenkiana plantation at various ages offers valuable insights into soil capabilities. This research should enhance our understanding and support the management of vibrant forest ecosystems, making a significant contribution to environmental science. This study investigated the Picea schrenkiana plantation at the ages of 30, 40, 50, and 60 years, focusing on 15 indicators related to soil carbon, nitrogen, and phosphorus, to evaluate the soil multifunctionality of the Picea schrenkiana plantation. The findings reveal the following: (1) Soil moisture content, total nitrogen, and available nitrogen initially decreased before increasing with forest age, while daily average temperature and organic matter content exhibited a consistent decline with increasing forest age. (2) The activity of soil urease displayed an inverted “N” shaped trend concerning forest age, whereas the activities of cellulase and invertase initially rose and then declined. Catalase activity gradually decreased with increasing forest age. (3) Soil multifunctionality increased and then decreased with aging of the forest. The main factors affecting soil multifunctionality included the available nitrogen and urease. Therefore, forest age is a significant ecological factor that influences soil multifunctionality of the Picea schrenkiana plantation. In addition, managing related factors such as soil physical and chemical properties and enzyme activity is crucial. These research findings are significant for the sustainable management of Picea schrenkiana plantation on the northern slopes of Tianshan Mountains in Xinjiang.

Desertification is a serious environmental problem globally, severely restricting the sustainable development of regional economies. In recent years, clay minerals have been widely used for improving wind-eroded and sandy soil, and bentonite with its unique 2:1 layered structure has particularly good prospects for application in the improvement of wind-eroded and sandy soil. In this study, the effects of different proportions of bentonite [without bentonite addition (B0), 2% bentonite addition (B2), and 4% bentonite addition (B4)] on the physical and chemical properties of wind-eroded and desertified soil and plant growth were studied. The results showed the following: (1) Bentonite addition increased the content of fine-grained soil and improved the soil’s water retention and water holding capacity (12%-88%). (2) The shear strength of wind-eroded and sandy soil supplemented with B2 and B4 bentonite was increased by 150% and 205%, respectively, compared with that upon B0 treatment. (3) Bentonite addition can lead to crust formation on the sandy surface, which is beneficial for sand fixation. (4) Among the treatments, B4 bentonite addition significantly increased plant coverage, biomass, and plant height by 32%-33%, 56%-85%, and 71%-107%, respectively. In summary, the addition of bentonite not only improved the soil’s water retention capacity, improved the soil’s physical properties, and fixed the sandy surface, but also promoted plant growth.

To explore the differences in the responses of different soil microbial community characteristics to grazing intensity, grasslands with different grazing intensities in the middle section of the northern slopes of Tianshan Mountains were selected as a focus for this study. Combining field investigation and indoor analysis, the changing patterns of soil microbial community characteristics with grazing intensity and their intrinsic correlation with soil factors were analyzed. The results showed that Actinobacteria and Ascomycota were the dominant phyla of bacteria and fungi, respectively. Compared with the findings upon heavy grazing, light grazing significantly increased the alpha diversity of microbial communities (P<0.05) and promoted the accumulation of soil microbial biomass carbon, nitrogen, and phosphorus contents. Redundancy analysis and Mantel test showed that the soil microbial community characteristics were positively correlated with the soil total nitrogen and negatively correlated with the soil bulk density (P<0.05). Furthermore, the structural equation model showed that grazing negatively impacted the microbial diversity, richness, biomass, and OTUs characteristics by increasing the bulk density and reducing the soil nutrients (P<0.05). Compared with other indicators, soil microbial community diversity was more sensitive to grazing. In summary, light grazing is conducive to improving the microbial community, and reasonable regulation of grazing intensity is a feasible strategy to ensure the stable development of microbial communities.

The characteristics of variation in leaf functional traits of different plant types (shrubs, herbaceous plants) in Hexi Corridor and the relationships between these functional traits are extremely important for maintaining the stability of the ecosystem in this region. To explore the mechanisms of adaptation and the ecological strategies of different plant life forms in arid environments, we established survey sites in the eastern, central, and western sections along Hexi Corridor, following a gradient of decreasing natural precipitation from southeast to northwest. We selected 26 dominant desert plant species, including 14 shrubs and 12 herbaceous plants, and analyzed their variability and regional patterns of 14 key leaf functional traits. We also investigated the trade-offs and adaptive strategies among these traits. The following results were obtained: (1) The coefficient of variation for leaf-bound water content (BW), carbon to phosphorus ratio (C:P), plant height (H), and leaf free water content (FW) of dominant desert plant species in the Hexi Corridor exceeds 100%. (2) Plants in different regions of Hexi Corridor displayed diverse survival strategies: plants in the eastern section adopted a “slow-return” strategy, shrubs and herbaceous plants in the central section exhibited “slow-return” and “fast-return” strategies respectively, while shrubs in the western section adopted a “rapid resource acquisition” strategy under resource-rich conditions, and herbaceous plants adopted a “slow-return” strategy under unfavorable soil conditions. The survival strategies of plants are influenced by multiple ecological factors, and they adapt to arid environments through trait optimization and resource allocation.

The natural mixed shrub forest in the Mu Us Sandy Land, also known as Willow Bay, is a unique type of shrub community in sandy regions. However, to date there has been limited research on precipitation dynamics in Willow Bay communities compared with that in pure forest stands, making it challenging to reveal differences in water competition between the two. This study focused on Salix psammophila and Hippophae rhamnoides pure forests as well as Willow Bay. Using artificial rainfall simulations, we simultaneously monitored the processes of rainfall redistribution in different forest stands and quantitatively analyzed the relationships between rainfall characteristics and redistribution. The results showed that the effective rainfall for S. psammophila, H. rhamnoides, and Willow Bay was 18.58 mm, 21.14 mm and 20.25 mm, accounting for approximately 85.46%, 97.24%, and 93.15% of the total+rainfall, respectively. Canopy interception losses were 3.15 mm, 0.60 mm and 1.49 mm, accounting for approximately 15.69%, 3.60% and 7.31% of the total rainfall, respectively. Significant differences were observed in the spatial distribution of throughfare among the three forest types. In Willow Bay, the spatial distribution of throughfare was more evenly divided into “rain extreme,” “drought extreme,” and “intermediate zones,” whereas the distributions in S. psammophila and H. rhamnoides pure forests were more uniform. The rainfall redistribution processes in all three forest types increased with greater rainfall amounts, but the changes tended to stabilize as the canopy interception capacity approached saturation. By combining the morphological and structural characteristics of S. psammophila and H. rhamnoides, Willow Bay demonstrated better stability under complex and variable environmental conditions, ensuring ecological balance and stability within the Willow Bay community.

In heterostylous plants, the floral morph composition and frequency of populations are a consequence of mating events over generations. “Homostyly” with anthers and stigmas at the same level within a flower is a floral morph that frequently appears in the evolution of heterostyly and is often accompanied by breakdown of the heteromorphic incompatibility system and the decline of genetic diversity. To explore the formation of the H-morph and its effects on the population, we studied five Limonium aureum populations exhibiting a widely distributed floral morph (H-morph), similar to “homostyly,” in the southern margin of Tarim Basin. The floral morph composition and heterostylous syndrome were investigated by field observations and hand pollination experiments. Meanwhile, the genetic diversity and genetic structure were studied using SSR molecular markers. The results showed the following: (1) The Atushi (ATS) population consisted only of the H-morph, while the remaining four populations were composed of the long- and short-styled morph, and H-morph. All populations had a moderate level of genetic diversity, dimorphism of stigma-pollen morphology, and a strict heteromorphic incompatibility system, revealing that the floral morphs with different pollen ornamentation and stigma papilla cell morphology were compatible. (2) Genetic structure analysis, principal coordinate analysis, and phylogenetic analysis showed that the ATS population had emerged earlier and was independent of the other four populations phylogenetically, with a significant correlation between genetic distance and geographic distance. (3) The H-morphs of the two types of populations may be at different stages of the evolution of heterostyly. The self-incompatibility of the H-morph and the heteromorphic incompatibility system of the population maintained the population’s genetic diversity.

Hippophae rhamnoides is a plant that is light-loving, cold-resistant, heat-resistant, wind/sand-resistant, thrives in arid climates, and has high nutritional value. This study combines data on the distribution of sea buckthorn in Xinjiang, historical (last glacial period, mid-Holocene), current, and future (2050s, 2070s) climate data, and altitude data to simulate the potential geographical distribution of Hippophae rhamnoides under different climate scenarios based on the MaxEnt model. The main climatic and environmental factors affecting the natural distribution of sea buckthorn in Xinjiang were analyzed, and its distribution and migration were expounded. The results showed that the AUC values of each climate scenario exceeded 0.9, indicating high accuracy of the model prediction. The main environmental factors in the areas suitable for sea buckthorn are annual average temperature of -1 to 8 ℃, precipitation in the warmest quarter of 50-110 mm, highest temperature in the warmest month of 22-32 ℃, and precipitation in the driest month of 5-13 mm. In terms of altitude, the main range suitable for sea buckthorn survival is 500-1000 m. In the current climate, sea buckthorn is distributed in both northern and southern Xinjiang, particularly in northern and southwestern Xinjiang. Analysis of the centroid migration of the distribution of sea buckthorn under future climate scenarios revealed migration to the northeast. The results of this study can provide theoretical support for the development of plans to maximize the use of sea buckthorn resources.

Vegetation cover in the Upper Yellow River in Gannan plays an important role in maintaining the structural stability of the alpine ecosystem and conserving water sources. Exploring the spatiotemporal variation of vegetation cover and its relationship with topographic factors and characterizing the spatiotemporal distribution of vegetation can deepen our understanding of the dynamics and functions of the alpine vegetation ecosystem and provide theoretical support for maintaining ecological balance and restoring vegetation. This paper is based on four periods of Landsat images and Digital Elevation Model data for 1990-2020 at the Upper Yellow River in Gannan, used a pixel dichotomous model, superposition analysis, geographic detector, intensively study the spatiotemporal changes of vegetation coverage and the correlation of topographic features in the study area. The results showed the following: (1) From 1990 to 2020, the vegetation coverage in the Upper Yellow River in Gannan experienced a transition from degradation to recovery and then to significant improvement. The area with medium and high vegetation coverage (0.6-0.8) constituted the largest proportion, accounting for 77.68% of the total study area. (2) Between 1990 and 2020, the vegetation coverage in the study area showed a significant improvement trend. Among them, the area where vegetation coverage improved (Slope>0) accounted for approximately 91.26% of the total area, which was much larger than the area where it declined (Slope<0). (3) There were significant differences in the explanatory power of the topographic factors for vegetation coverage. Elevation is the main driving factor for vegetation coverage, and the explanatory power of the interaction of topographic factors such as slope, slope direction, and elevation is greater than that of a single factor. (4) Vegetation cover in the study area showed a single-peak pattern of increasing and then decreasing with both elevation and slope; the highest vegetation cover was found on southerly slopes, while the lowest was on northeasterly slopes. In the time series, the area of vegetation coverage from the north to the southwest shows a shrinking trend, while the areas in the southwest, west and northwest directions are increasing. The results of this study can provide scientific support for ecological protection and high-quality development in the Upper Yellow River in Gannan.

In this study, the oasis-desert transition zone at the northern margin of Tarim Basin was divided into three types: oasis with stony bare mountains, sandy desert, and gravelly desert, used Landsat remote sensing image data of the oasis at the northern margin of Tarim Basin, supplemented by Google Earth Pro 4800-pixel high-resolution remote sensing images to establish interpretation markers. At four different scales (30, 60, 90, and 120 m), the NDVI of the oasis edge showed two linear trends, and the distance between the intersect of the two trend lines and the oasis boundary was determined as the width of the ecotone. At the same time, buffer zone analysis and focal point analysis methods for different scales were used to analyze the width and scale dependence characteristics of the transition zone in the northern edge of Tarim Basin from 1994 to 2020. The results showed that the linear trend of NDVI changes in the northern margin of the Tarim Basin were all highly significant (P<0.01), and the width of the oasis-stony bare mountain transition zone was stable at 540 m from 1994 to 2020. Meanwhile, the width of the transition zone between the oasis and gravelly desert had decreased year by year, from 540 m in 1994 to 420 m in 2009 and 360 m in 2020. Moreover, the width of the transition zone between the oasis and sandy desert had also significantly decreased, from 600 m in 1994 to 420 m in 2009 and 300 m in 2020. This was mainly due to the continuous increase in the area of cultivated land at the edge of the oasis gravel desert and sandy desert in the northern margin of Tarim Basin in the last 30 years, At the same time, the temperature and precipitation decreased, and the changes in both anthropogenic activities and natural climate led to the gradual shrinkage of the width of the transition zone between oasis-gravelly and sandy desert. However, the area of bare rock surface had not changed, and the width of the oasis stone bare mountain transition zone had remained stable. The findings showed that the process of oasis transformation in the northern margin of Tarim Basin had significantly accelerated, and the width of the transition zone between the oasis gravel desert and the sandy desert had decreased significantly. There is thus a need for further efforts to protect and improve the environment in the oasis-desert transition zone in this region.

Land use change is a key factor affecting carbon emissions.Studying the spatiotemporal evolution of regional carbon emissions is significance for promoting reasonable emission reduction. Based on the measured data of land use carbon emissions in Ningxia at two scales of county (district) and 10 km grid from 1990 to 2020, combined with trend analysis, spatial autocorrelation analysis, and GTWR model, this study discusses the spatiotemporal variation characteristics and influencing factors of carbon emissions in Ningxia. The results show that: (1) Both scales of land use carbon emissions show an upward trend in time series, and construction land is the main source of carbon emissions in Ningxia. (2) There are differences in carbon emissions among different counties (districts), with Xingqing District and Lingwu City showing the most rapid growth in carbon emissions. (3) Carbon emissions show a distribution pattern of northwest region>central region>southern region in space. Grid-scale carbon emissions have significant spatial autocorrelation, and the agglomeration pattern of carbon emissions increases with time. (4) The proportion of construction land and human activities are important factors driving the spatial and temporal differentiation of carbon emissions in Ningxia, which has a significant positive effect and the impact intensity increases year by year.

Qingyang City is located in the loess plateau region of eastern Gansu Province, which is endowed with abundant natural resources and serves as one of the key zones for supplying energy to the country. It plays a crucial role in fostering development, safeguarding ecological integrity, promoting high-quality growth, and enhancing environmental protection within the western region. Exploring and analysing the ecological risk patterns and coupled the coordination of the production-living-ecological space landscapes is of profound significance. This study focused on Qingyang, located in the loess plateau region of eastern Gansu Province, employing methodologies such as land use transfer matrix analysis, landscape ecological risk assessment models, and coupling coordination degree models to investigate and analyze changes in land use structure from 2000 to 2020. This work also incorporated the patterns of landscape ecological risk, and the degree of coupling coordination among production-living-ecological space based on comprehensive evaluation. The following results were obtained: (1) Over the last two decades, the ecological and residential space in Qingyang City has consistently increased year after year, whereas the area designated for production has exhibited a gradual decline. (2) The overall landscape ecological condition of Qingyang City is in a low-risk state, and the distribution of the degree of risk is “low in the east and high in the west.” (3) The degree of coupling coordination of the production-living-ecological space is well developed and concentrated, presenting a distribution of “high in the south and low in the north.” The coupling coordination area is expanding continuously year by year, while the uncoordinated area is shrinking. (4) By analyzing the coupling coordination of the production-living-ecological space using natural and social economic factors, it is concluded that socioeconomic factors have a more significant impact on this. Therefore, the driving factors are integrated with the needs and characteristics of the production-living-ecological space, and the layout of the production-living-ecological space is optimized to facilitate the coordinated development of the ecological risk pattern of the landscape, enhance the regional ecological security of the landscape, and advance the sustainable development of the ecological economy of Qingyang City.

The structure of near-surface wind-blown sand flow over dry playa represents the macroscopic characteristics of micro-wind-blown sand movement at such locations. It is important to study such sand flow in order to understand the processes of wind-blown sand movement and dust emissions in dry playa. In this study, a dry playa at the end of a typical alluvial fan around North Mountain of the Ejin Banner was selected for analysis and field observations were conducted on its near-surface wind-blown sand flow structure. The results revealed an exponential wind speed profile over the dry playa surface and the aerodynamic roughness z₀ was 0.058 mm, which is smaller than those of sand and gobi surfaces. The sand flux of mixed-particle-size sand decreased exponentially with height over the dry playa surface. The average saltation height z_q of sand particles in the desert-crossing wind-sand flow was 15 cm, and 90% of the transport sand was concentrated within the height of 0-34 cm. The vertical profile curve of the sand flux in the fine-sand-particle-size group was similar to that of the mixed-particle-size sand. With increasing particle size, the sand flux in the dry playa changed with height, and the “elephant nose” curve transitioned to an “oblique Z” curve for coarse sand. Thus, this work proposes the mode of sand movement on the dry playa bed.