Vast deserts and sandy lands in the mid-latitudes cover an area of 17.64 x 106 km2, with 6.98 x 106 km2 experiencing seasonal frozen soil (SFG). Freeze-thaw cycles of SFG significantly influence local surface processes in deserts, impacting meteorological disasters such as infrastructure failures and sandstorms. This study investigates the freeze-thaw dynamics of SFG in crescent dunes from three deserts in northern China: the Tengger Desert, Mu Us Sandy Land, and Ulan Buh Desert, over the period from 2019 to 2024.Freezing occurs from November to January, followed by thawing from January to March. The thawing rate (2.72 cm/day) was 1.8 times higher than the freezing rate (1.48 cm/day). The maximum seasonal freezing depth (MSFD) exceeded 0.80 mat all dune slopes, with depths surpassing 1.10 mat the leeward slope and lower slope positions. Soil moisture content, ranging from 1 % to 1.6 %, is critical for freezing, and this threshold varies depending on the dune's mechanical composition. The hardness of frozen desert soil is primarily controlled by moisture, along with temperature and particle size.Temperature initiates freezing, while moisture and particle size control the resulting hardness.These findings shed light on the seasonal freeze-thaw processes in desert soils and have practical implications for agricultural management, engineering design, and environmental hazard mitigation in arid regions.

Desertification is a global environmental issue that significantly threatens ecosystem stability and vegetation restoration in arid regions. This study proposes a multiple treatment strategy combining Artemisia sphaerocephala Krasch. gum (ASKG) with Enzyme-Induced Carbonate Precipitation (EICP) to enhance wind erosion control and seed germination. The effects of this approach were evaluated through field experiments. The results showed that single EICP treatment improved soil water retention and surface strength. However, high-concentration EICP treatment (>= 0.2 mol/L Cementation Solution, CS) induced salt stress, which suppressed plant survival. In contrast, when low-concentration EICP (0.1 mol/L CS) was combined with ASKG, a stable crust formed, improving surface strength and crust thickness, while preventing damage to the crust during early plant growth. The addition of 1.0 g/L ASKG reduced wind erosion depth by 67%, increased average moisture content to 7.4%, and promoted better seed germination, showing strong ecological compatibility and long-term stability. Furthermore, the second EICP treatment optimized the soil pore structure by adding CaCO3 precipitates, which increased average moisture content to 10.6% and increased surface strength by 114.5%. Microstructural analysis revealed that ASKG formed film or mesh structure around CaCO3 crystals, enhancing soil wind erosion resistance and water retention. Overall, the findings suggest that the multiple treatment strategy of EICP combined with ASKG successfully overcomes the ecological limitations of traditional high-concentration EICP, providing a sustainable solution for wind erosion control and vegetation restoration in desert areas.

Climate change has exposed desert ecosystems to frequent extreme disturbances, including wet-dry cycles and freeze-thaw events, which accelerate desertification on a global scale. The limited nutrient availability characteristic of these ecosystems may constrain microbial survival and growth, making them more vulnerable to environmental perturbations and stressors. However, how nutrient availability modulates the stability of soil ecological communities and functions in desert ecosystems remains poorly understood. In this study, we examined how nutrient addition, applied either before or after disturbances, affects the resistance of bacterial communities and multifunctionality to drought and freeze events in desert ecosystems. Our findings revealed that freeze-thaw events, rather than drought, significantly reduced bacterial diversity, with all disturbances altering the community structure. Pre-disturbance nutrient addition notably improved the resistance of soil bacterial diversity and community composition to disturbances, which played a critical role in maintaining multifunctionality in desert ecosystems. This enhanced bacterial resistance was strongly associated with increased bacterial network complexity and the enrichment of disturbance-tolerant taxa. Our results highlight the pivotal role of nutrient availability in stabilising soil bacterial communities and multifunctionality under extreme climatic conditions in desert ecosystems. These findings offer valuable insights and practical strategies for the ecological protection and management of desertification.

The extreme conditions in arid ecosystems make these environments sensitive to environmental changes. Particularly, land use and seasonal changes are determinants of their soil carbon dynamics. The effect of those elements on soil respiration (RS) is still poorly known in several arid regions of the world. This study investigates the seasonal effect on the R(S )and its controlling factors throughout different land use systems in northeastern Mexico. RS and 34 biotic and abiotic variables were measured across agricultural crops, natural shrublands, livestock farms, walnut orchards, and industrially influenced soils during the dry and wet seasons. Six variables (soil water content, soil organic matter, soil temperature, silt, and pH) were found as drivers of R(S )on both local and regional scales. Seasonal and land use had a transversal effect on R-S and its controlling factors. R-S dynamics were primarily modulated by soil water content, with the wet season and managed lands showing increased sensitivity to climatic and anthropogenic changes. These results indicate that land management strategies are critical for carbon cycling, particularly in water-limited regions like northeastern Mexico, where land use changes are occurring at an accelerated pace.

Carbon neutrality is an important goal for addressing global warming. It can be achieved by increasing carbon storage and reducing carbon emissions. Vegetation plays a key role in storing carbon, but it is often lost or damaged, especially in areas affected by desertification. Therefore, restoring vegetation in these areas is crucial. Using advanced techniques to improve ecosystem structure can support ecological processes, and enhance soil and environmental conditions, encourage vegetation growth, and boost carbon storage effectively. This study focuses on optimizing Ecological Spatial Networks (ESNs) for revitalization and regional development, employing advanced techniques such as the MCR model for corridor construction, spatial analysis, and Gephi for mapping topological attributes. Various ecological and topological metrics were used to evaluate network performance, while the EFCT model was applied to optimize the ESN and maximize carbon sinks. In the Thal Desert, ecological source patches (ESPs) were divided into four modularity levels (15.6% to 49.54%) and five communities. The northeastern and southwestern regions showed higher ecological functionality but lower connectivity, while the central region exhibited the reverse. To enhance the ESN structure, 27 patches and 51 corridors were added to 76 existing patches, including 56 forest and 20 water/wetland patches, using the EFCT model. The optimized ESN resulted in a 14.97% improvement in carbon sink capacity compared to the unoptimized structure, primarily due to better functioning of forest and wetland areas. Enhanced connectivity between components contributed to a more resilient and stable ESN, supporting both ecological sustainability and carbon sequestration.

To investigate the synergistic effect of IAA and melatonin (MT) on three plants to alleviate the effects of salt damage on plants, we aim to determine the optimal concentrations of exogenous hormone treatments that improve salinity resistance for each species. In this experiment, three desert plants, Sarcozygium xanthoxylon, Nitraria tangutorum, and Ammopiptanthus mongolicus, which are common in Wuhai City, were used as plant materials. Two time periods (12 h,24 h) of exogenous hormone IAA (100 mu mol/L) and exogenous melatonin concentration (0, 100, 200, 300 mu mol/L) were used to treat the three desert plants in saline soil under different conditions of exogenous IAA and exogenous melatonin. The results indicate that under different concentrations of exogenous IAA and melatonin, the germination rate and vigor of the three desert plant species in saline-alkaline soil improved. However, as the concentration of melatonin increased, the germination rate and vigor of these desert plants were inhibited. Whereas, plant height, root length, leaf length, fresh weight, dry weight, and root vigor of the three desert plants were alleviated under different conditions of exogenous IAA and exogenous melatonin. under the action of two exogenous hormones, the low concentration of melatonin decreased their malondialdehyde content and increased their proline content. As melatonin levels increased, the activity of antioxidant enzymes also rose initially, followed by a subsequent decline. This study highlights the synergistic effects of two exogenous hormones on the critical role of cell osmomodulators and antioxidant enzyme activity in combating salinity damage in three desert plants.

The protection of the ecological environment and the scarcity of renewable resources are increasingly concerning global issues. To address these challenges, efforts have been made to use desert sand and fly ash in the preparation of building materials. This study attempts to replace river sand with desert sand and cement with fly ash to create an environmentally friendly and economical building material-desert sand dry-mixed mortar (DSDM). Through preliminary mix ratio experiments, five grades of DSDM were developed, and their durability in the saline soil regions of northwest China was studied. The study conducted macro-performance tests on the five strength grades of DSDM after sulfate dry-wet cycles (DWCs), analyzing changes in appearance, mass loss rate, compressive strength loss rate, and flexural strength loss rate. Using SEM, XRD, and NMR testing methods, the degradation mechanisms of the DSDM samples were analyzed. Results indicate that sulfate ions react with hydration products to form ettringite and gypsum, leading to sulfate crystallization. In the initial stages of DWCs, these erosion products fill the pores, increasing density and positively impacting the mortar's performance. However, as the number of cycles increases, excessive accumulation of erosion products leads to further expansion of pores and cracks within the DSDM, increasing the proportion of harmful and more harmful pores, degrading performance, and ultimately causing erosion damage to the mortar. Among the samples, DM5 exhibited the poorest erosion resistance, fracturing after 30 cycles with a mass loss of 43.57%. DM10 experienced failure after 60 cycles, with its compressive strength retention dropping to 78.86%. In contrast, DM15, DM20, and DM25 showed the best erosion resistance, with compressive strength retention above 75% after 120 cycles. Finally, the Wiener random probability distribution was used to predict the remaining life of DSDM samples under different degradation indicators, with flexural strength being the most sensitive indicator. Based on the flexural strength loss rate, the maximum sulfate DWCs for DM5, DM10, DM15, DM20, and DM25 were 132, 118, 78, 52, and 35 cycles, respectively. This study provides a theoretical basis for the promotion and use of DSDM in desert fringe areas.

Climate change and land degradation (LD) are some of the most critical challenges for humanity. Land degradation (LD) is the focus of the United Nations (UN) Convention to Combat Desertification (UNCCD) and the UN Sustainable Development Goal (SDG 15: Life on Land). Land degradation is composed of inherent and anthropogenic LD, which are both impacted by inherent soil quality (SQ) and climate. Conventional LD analysis does not take into account inherent SQ because it is not the result of land use/land cover change (LULC), which can be tracked using remote sensing platforms. Furthermore, traditional LD analysis does not link anthropogenic LD to climate change through greenhouse gas (GHG) emissions. This study uses one of the indicators for LD for SDG 15 (15.3.1: Proportion of land that is degraded over the total land area) to demonstrate how to account for inherent SQ in anthropogenic LD with corresponding GHG emissions over time using the state of Arizona (AZ) as a case study. The inherent SQ of AZ is skewed towards low-SQ soils (Entisols: 29.3%, Aridisols: 49.4%), which, when combined with climate, define the inherent LD status. Currently, 8.6% of land in AZ has experienced anthropogenic LD primarily because of developments (urbanization) (42.8%) and agriculture (32.2%). All six soil orders have experienced varying degrees of anthropogenic LD. All land developments in AZ can be linked to damages from LD, with 4862.6 km2 developed, resulting in midpoint losses of 8.7 x 1010 kg of total soil carbon (TSC) and a midpoint social cost of carbon dioxide emissions (SC-CO2) of $14.7B (where B = billion = 109, USD). Arizona was not land degradation neutral (LDN) based on an increase (+9.6%) in the anthropogenic LD overall and an increase in developments (+29.5%) between 2001 and 2021. Considering ongoing climate change impacts in AZ, this increase in urbanization represents reverse climate change adaptation (RCCA) because of the increased population. The state of AZ has 82.0% of the total state area for nature-based solutions (NBS). However, this area is dominated by soils with inherently low SQ (e.g., Entisols, Aridisols, etc.), which complicates efforts for climate change adaptation.

Two extremely devastating super dust storms (SDS) hit Mongolia and Northern China in March 2021, causing many deaths and substantial economic damage. Accurate forecasting of dust storms is of great importance for avoiding or mitigating their effects. One of the most critical factors affecting dust emissions is soil moisture, but its value in desert exhibits significant uncertainty. In this study, model experiments were conducted to simulate dust emissions using four soil moisture datasets. The results were compared with observations to assess the effects of soil moisture on the dust emission strength. The Integrated Source Apportionment Method (ISAM) was used to track the dust sources and quantify the contribution from each source region to the dust load over the North China Plain (NCP), Korea peninsula, and western Japan. The results show large differences in the dust load depending on the soil moisture datasets used. The high soil moisture in the NCEP dataset results in substantial underestimation of the dust emission flux and PM10 10 concentration. Despite a minor overestimation of PM10 10 concentrations in many Northern China cities, the ERA5 dataset yields the best simulation performance. During the two SDS events, about 7.5 Mt dust was released from the deserts in Mongolia and 2.8 Mt from the deserts in China. Source apportionment indicates that the Mongolian Gobi Desert is the dominant source of PM10 10 in the NCP, Korea peninsula, and western Japan, accounting for 60 %-80 %, while Inner Mongolia contributed 10 %- 20 %.

The Bulianta Coal Mine is among the problematic coal mining areas in China that is still creating environmental damage, especially associated with soil destruction. Therefore, a scientific investigation was conducted to establish a scientific basis for evaluating the impact of planted forest on soil physical and chemical properties, as well as the ecological benefits following 15 years of vegetation restoration in the area. The soil physicochemical characteristics and distribution of organic carbon storage in the 0-80 cm layer soils of Pinus sylvestris forests, Prunus sibirica forests, and Hippophae rhamnoides forests restored after 5, 10, and 15 years were investigated. The immersion method was used to determine soil porosity and density followed by the determination of soil indicators, and a statistical ANOVA test was applied to examine the differential effects of different vegetation types and restoration years on soil properties. The results clearly demonstrated the following: (1) The recovery of vegetation was achieved after a period of 15 years, with the average bulk density of the 0-80 cm soil layer as follows: P. sylvestris forest (1.513 gcm-3) > P. sibirica forest (1.272 gcm-3) > H. rhamnoides forest (1.224 gcm-3), and the differences among different forest types were statistically significant (p P. sibirica forest (44.56 thm-2) > H. rhamnoides forest (41.87 thm-2). In summary, during the ecological vegetation restoration process in the Bulianta Core Mine, both P. sylvestris forest and P. sibirica forest exhibit superior carbon storage capacities compared to H. rhamnoides forest, as well as more effective soil improvement outcomes.