Search Results (254)

This study aims to analyze the differences in soil bacterial community structure under different vegetation restoration types, and to explore the role of microorganisms in the process of vegetation restoration on the soil ecosystem of the Grain for Green area in the Loess Plateau. High-throughput sequencing technology was used to analyze the alpha diversity of soil bacteria, community structure characteristics, and the correlation between soil environmental factors and bacterial communities in different artificial Hippophae rhamnoides forests. Soil microbial C and N show a decreasing trend with an increase in the 0–100 cm soil layers. The results indicated that the bacterial communities comprised 24 phyla, 55 classes, 110 orders, 206 families, 348 genera, 680 species, and 1989 OTUs. Additionally, the richness indices and diversity indices of the bacterial community in arbor shrub mixed forest are higher than those in shrub pure forest, and the indices of shrub forest on sunny slope are higher than those on shady slope. Across all samples, the dominant groups were Actinobacteria (37.27% on average), followed by Proteobacteria (23.91%), Acidobacteria (12.75%), and Chloroflexi (12.27%). Soil nutrient supply, such as TOC, TN, AN, AP, and AK, had crucial roles in shaping the composition and diversity of the bacterial communities. The findings reveal that vegetation restoration significantly affected soil bacterial community richness and diversity. Furthermore, based on the results, our data provide a starting point for establishing soil bacterial databases in the Loess Plateau, as well as for the plants associated with the vegetation restoration. Full article

In order to improve the durability of loess-based composite coal gangue porous planting concrete (LCPC), the effects of fly ash and slag powder content on the durability and microstructure of LCPC were studied. In this paper, fly ash and slag powder were mixed into LCPC, and freeze-thaw cycle and dry-wet cycle tests were carried out. The compressive strength, dynamic elastic modulus, and mass change were used as evaluation indices to determine the optimal mix ratio for LCPC durability. Scanning electron microscopy (SEM) was performed, and the experimental design was carried out with the water–cement ratio, fly ash, and slag powder content as variables. The microstructure characteristics of LCPC were analyzed. The results show that the maximum number of freeze-thaw cycles can reach 35 times and the maximum number of dry-wet cycles can reach 50 when 5% fly ash and 20% slag powder are used. With an increase in the water-cement ratio, the skeleton of the loess gradually became complete, and its structure became more compact. In the micro-morphology diagram, the mixed fly ash and slag powder particles are not obvious, but with an increase in dosage, the size of the cracks and pores gradually decreases. The incorporation of fly ash and slag powder can play a positive role in the durability of LCPC and improvement of its microstructure. The results of this study are crucial for improving the application performance of ecological restoration, soil improvement, and long-term stability of structures, and can provide a scientific basis for the sustainable development of environmentally friendly building materials. Full article

Loess Plateau is the region with the most concentrated loess distribution and the deepest loess soil layer in the world, and it is facing serious problems of soil erosion and ecological degradation. The nano carbon modification of soil surface properties is a novel strategy for soil improvement and enhancing the soil’s capacity to sequester carbon, which has been extensively researched. However, the mechanisms underlying the influence of carbon surface structure on the efficacy of loess soil remediation remain unclear. Herein, graphene oxide (GO) with a unique two-dimensional structure and adjustable surface properties was optimized as a model carbon filler to investigate the modification effect on loess. As a result, the addition amount of 0.03% GO significantly reduced the disintegration amount of loess, but, if inhibited for a long time, the disintegration effect would weaken. The highly reduced GO can delay the loess disintegration rate due to its enhanced hydrophobicity, but the inhibitory effect fails over a long period of time. After adjusting the reduce degree with a 50% SA (sodium ascorbate), the water-holding capacity of the modified soil in the high suction range is enhanced. This study reveals the synergistic mechanism of the sheet structure and surface properties of GO on the water stability of loess, providing a reference for the prevention and control of soil erosion and ecological restoration in the Loess Plateau. Full article

Wildfires play a pivotal role in shaping and regulating the structural characteristics of forest ecosystems. This study examined post-fire vegetation dynamics following the 2020 Bighorn Fire in the Santa Catalina Mountains, Arizona, USA, by integrating pre- and post-fire airborne LiDAR data with Landsat-derived burn severity indices from 2019 to 2024. We analyzed structural and functional vegetation traits across 12,500 hectares to assess the changes pre- to post-fire, and to evaluate how these changes were influenced by the burn severity. We applied a correlation analysis to explore the relationships among the structural variables across different vegetation cover types. Non-parametric LOESS regression revealed that the dNBR was more strongly associated with changes in the tree density than with vertical structural attributes. The functional recovery, indicated by the NDVI, generally outpaced the structural recovery captured by the NBR. Densely forested areas experienced greater declines in vegetation volumes and slower regeneration, whereas herbaceous and sparsely vegetated areas showed a more rapid, but compositionally distinct, recovery. The divergence between the NDVI and NBR trajectories underscores the importance of integrating structural and functional indicators to comprehensively assess the post-fire ecosystem resilience and inform targeted restoration efforts. Full article

As a vital bridge linking human well-being with ecological processes, cultural ecosystem services (CESs) play a pivotal role in understanding the equilibrium of social–ecological systems. However, the spatial supply–demand relationships of CESs remain underexplored in rapidly urbanizing regions. This study establishes an integrated framework by synthesizing multi-source geospatial data, socioeconomic indicators, and the Maximum Entropy (MaxEnt) model to investigate the spatial dynamics of CESs in Taiyuan City. Key findings include the following: (1) A pronounced spatial heterogeneity in CES supply distribution, exhibiting a core-to-periphery diminishing gradient, with inverse correlations observed among different CES categories. (2) Accessibility, topographic features, and fractional vegetation cover emerged as primary drivers of spatial supply differentiation, while climatic factors and elevation exerted non-negligible influences on this Loess Plateau urban system. (3) Four spatial mismatch patterns were identified through the supply–demand analysis: high supply–high demand (38.1%), low supply–low demand (37.2%), low supply–high demand (13.6%), and high supply–low demand (10.9%). The coupling coordination degree of CESs in Taiyuan City indicated moderate coordination, with severe imbalances observed in urban–rural transitional zones. This study reveals nonlinear interactions between natural landscapes and anthropogenic factors in shaping CES spatial distributions, particularly the trade-offs between esthetic value and transportation constraints. By integrating big data and spatial modeling, this research advances CES quantification methodologies and provides actionable insights for optimizing green infrastructure, prioritizing ecological restoration, and balancing urban–rural CES provision. These outcomes address methodological gaps in coupled social–ecological system research while informing practical spatial governance strategies. Full article

Vegetation restoration is critical for improving soil quality and microbial community dynamics in degraded mining areas. This study explored the effects of different vegetation types (grassland, shrubland, and mixed grass–shrub areas) on soil physicochemical properties, organic carbon fractions, and abundant versus scarce microbial taxa assemblies in a Loess Plateau coal mining area. Soil samples from four depths (0–100 cm) were analyzed using high-throughput sequencing for nutrient content; carbon components, soil organic carbon (SOC), particulate organic carbon (POC), mineral-associated organic carbon (MAOC), dissolved organic carbon (DOC), microbial biomass organic carbon (MBC), and readily oxidizable organic carbon (ROC); microbial diversity. Shrubland soils exhibited significantly higher total nitrogen (TN), total phosphorus (TP), and organic carbon components (SOC, MAOC, and POC) than other vegetation types (p < 0.05), with the greatest carbon accumulation noted in the surface layer depths (0–20 cm). Microbial communities displayed vegetation-specific patterns: abundant taxa (e.g., Actinobacteria, Proteobacteria) dominated nutrient cycling and exhibited resilience to environmental gradients, while rare taxa (e.g., Methylomirabilota, Olpidiomycota) correlated strongly with labile carbon fractions (DOC and POC) and demonstrated metabolic flexibility. Mantel tests identified soil pH, TN, and organic carbon components as key drivers of microbial community divergence (p < 0.01). Shrubland vegetation enhanced soil nutrient retention and carbon stabilization, whereas the mixed grass–shrub systems promoted niche partitioning among rare taxa. These findings highlight the roles of vegetation-mediated carbon inputs and environmental filtering in shaping microbial assembly, providing a scientific framework for optimizing restoration strategies in mining ecosystems. Full article

Caragana korshinskii, a key species in China’s Grain for Green Project on the Loess Plateau, is effective in enhancing soil C sequestration. However, whether its contribution to SOC (soil organic carbon) stability persists over multi-decadal restoration chronosequences remains unclear. Using the time–space substitution method, we investigated the SOC fractions (POC, particulate organic C, and MAOC, mineral-associated organic C) dynamics across soil depths (0–10, 10–30, and 30–60 cm) in a 40-year chronosequence of C. korshinskii restoration, which is located in a comprehensive managed watershed on the Loess Plateau, China. The results showed that the C. korshinskii restoration chronosequence improved soil C sequestration at different scales compared to abandoned sites. In the middle phase (10–30 years), the concentration of SOC peaked at 35.88 g/kg, exceeding natural grassland (32.33 g/kg). Above- and belowground biomass accumulation drove SOC enhancement. POC as transient C inputs, and MAOC through mineral interactions, reach a peak at 7.98 g/kg which shows the greatest increase (276.81%). In the subsequent phase (after 30 years), MAOC dominated SOC stabilization, yet SOC fractions declined overall. MAOC contribution to SOC stability plateaued at 20–30%, constrained by soil desiccation from prolonged root water uptake. C. korshinskii provides the optimal SOC benefits within 10–30 years of restoration, highlighting a trade-off between vegetation-driven C inputs and hydrological limits in arid ecosystems. Beyond 30 years, C. korshinskii’s high water demand reduced SOC sequestration efficiency, risking the reversal of carbon gains despite initial MAOC advantages. Full article

To clarify the response mechanisms of soil nematodes as bioindicators of ecosystem health to precipitation variations in loess hilly forests, this study investigated soil nematodes in pure Populus hopeiensis forests across different precipitation gradients in Wuqi County. Through soil physicochemical analysis and high-throughput sequencing of soil nematodes, we analyzed the characteristics of soil nematode communities and their responses to precipitation variation. The results demonstrated the following: (1) Dominant genera and trophic groups of soil nematodes were significantly influenced by precipitation, with Acrobeloides prevailing across all gradients while Paratylenchus reached maximum abundance (26.8%) in moderate precipitation zones. (2) Bacterivorous nematodes prevailed in both low- and high-precipitation zones, while herbivorous nematodes constituted the highest proportion in moderate precipitation zones. The abundances of herbivorous and fungivorous nematodes exhibited an initial increase followed by a decrease with rising precipitation, whereas predatory–omnivorous nematodes displayed the opposite trend. (3) The Chao1 and Shannon indices of soil nematodes initially increased and then decreased with increasing precipitation, reaching a peak in the Jinfoping site. Moreover, there were significant differences in nematode community structure among different precipitation gradients. (4) Redundancy analysis and PLS-PM modeling identified soil water content (SWC), total nitrogen (TN), and capillary water holding capacity (CWHC) as key drivers of nematode communities. Precipitation indirectly regulated nematode functionality by modifying soil physicochemical properties and microbial activity. (5) Ecological function analysis revealed bacterial-dominated organic matter decomposition (Nematode Channel Ratio, NCR > 0.75) in the Changcheng and Baibao sites, contrasting with fungal channel predominance (NCR < 0.75) in Jinfoping. This research elucidates the mechanism whereby precipitation drives nematode community divergence through regulating soil physicochemical properties and microbial activity. The findings provide scientific basis for soil biodiversity conservation and ecological restoration benefit assessment in regional ecological restoration projects, and soil health management and sustainable land use in agricultural ecosystems. Full article

Persistent climate change and anthropogenic activities have caused the degradation of urban ecosystems and the fragmentation of landscapes in the Loess Plateau region, situated in northern China. Ecological networks have been considered an effective measure for reducing urban habitat fragmentation, enhancing landscape connectivity, and identifying priority areas for ecological restoration. However, research on the spatiotemporal dynamics of ecological networks in cities in the Loess Plateau region, especially multi-scenario ecological networks under future climate change scenarios, and the drivers affecting these network elements are still limited. This study analyzed the spatiotemporal dynamic changes in the ecological networks in Shenmu City from 2000 to 2035, and used GeoDetector to explore the driving factors influencing changes in ecological source distribution. The results showed the following: (1) The ecological sources in Shenmu City continued to shrink from 2000 to 2020, while landscape fragmentation increased. By 2035, the results of scenario modeling will differ for different Shared Socioeconomic Pathways (SSPs) and Representative Concentration Pathways (RCPs), with the ecological source area increasing under scenarios SSP119 and SSP245, and continuing to decrease under scenario SSP585. (2) From 2000 to 2020, the α, β, and γ indices increased and then declined, while the ecological networks of the SSP119 and SSP585 scenarios will stabilize. (3) Under the optimal scenario SSP119, 27 ecological pinch points and 40 ecological barrier points will be identified, which are priority areas for the future execution of ecological restoration initiatives. (4) Precipitation is the primary factor that affects the distribution of ecological sources, followed by temperature. This study proposes a new research perspective on ecological networks, and provides a guideline for ecological restoration and conservation in cities (counties) in the Loess Plateau region. Full article

Habitat suitability assessment for forest and grassland ecosystems is a critical component of ecological restoration and land use planning in the Loess Plateau, aiming to advance soil and water conservation and foster sustainable ecological environment development. Despite progress in vegetation restoration, systematic evaluations of habitat suitability in complex geomorphic regions like the Loess Plateau remain scarce, particularly in balancing hydrological and ecological trade-offs. The Yanhe River Basin (7725 km²), a sediment-prone tributary of the Yellow River, exemplifies the challenges of soil erosion and semi-arid climatic constraints, making it a critical case for evaluating restoration strategies. This study employed a comprehensive approach utilizing Analytic Hierarchy Process (AHP), Geographic Detector, mathematical statistics, and other methods. An evaluation indicator system and methodology were established to assess the suitability of forest and grassland habitats in the Yanhe River Basin, evaluating the suitability and quality improvement potential under the current land use conditions. The results indicate: (1) The dominant factors influencing the suitable distribution of forests include photosynthetically active radiation (PAR), soil total phosphorus content, annual precipitation, and elevation. For grasslands, the dominant factors include photosynthetically active radiation, annual average temperature, elevation, and annual precipitation. (2) In the watershed, forestland and grassland areas classified as moderately suitable or higher cover 1064.9 km² and 4196.9 km², accounting for 91.9% and 94.7% of their total respective areas, indicating a generally rational spatial allocation of forest and grassland ecosystems. (3) The improvable area for forests measures 366 km² (34.4% of moderately or higher suitability zones), with most already meeting coverage thresholds. In contrast, grasslands have an improvable area of 2491.6 km² (59.4% of moderately or higher suitability zones), where over half of the area remains below coverage thresholds corresponding to their habitat conditions. (4) Forests can adopt natural restoration-focused low-intensity interventions through strengthened closure management, while grasslands require spatially tailored measures—such as precipitation interception and enhanced stewardship—targeting suitability-based potential grades, collectively achieving overall improvement in grassland vegetation coverage. This study represents the first systematic evaluation of forest–grassland habitat suitability in the Yanhe River Basin, elucidating its spatial distribution patterns and providing critical insights for watershed-scale ecological restoration. Full article

The Loess Plateau is threatened by severe gully erosion and tableland retreat, primarily driven by uncontrolled surface runoff. Numerical simulations of Gully Consolidation and Highland Protection (GCHP) demonstrate that individual measures such as check dams, terraces, and gully head backfilling can reduce sediment by 31–35% in the short term, but their effectiveness declines after approximately 10 years. This study classifies GCHP models into four types, progressively integrating drainage, filling, slope protection, and ecological measures. Simulation results confirm that the most comprehensive model—coupling all four types—offers the highest and most sustainable effectiveness in both erosion control and ecological restoration. To address long-term challenges, the study proposes a Sustainable Natural GCHP Management Method, combining cascade interception, guided drainage, and ecological retention, thereby enhancing project resilience and supporting China’s Yellow River Basin ecological protection strategy. Full article

Ecological transition zones spanning semi-humid to semi-arid regions pose distinctive monitoring challenges owing to their climatic vulnerability and geomorphic diversity. This study focuses on Shanxi Province, a typical ecologically fragile area in the Loess Plateau of China. Based on the Google Earth Engine (GEE) platform and Moderate Resolution Imaging Spectroradiometer (MODIS) datasets, we established the Remote Sensing Ecological Index (RSEI) series from 2000 to 2024 for Shanxi Province. The Theil–Sen Median, Mann–Kendall, and Hurst indices were comprehensively applied to systematically analyze the spatiotemporal differentiation patterns of ecological environmental quality. Furthermore, geodetector-based quantification elucidated the synergistic interactions among topographic, climatic, and anthropogenic drivers. The results indicate the following: (1) From 2000 to 2024, ecological restoration initiatives have shaped an “aggregate improvement-localized degradation” paradigm, with medium-quality territories persistently accounting for 30–40% of the total land area. (2) Significant spatial heterogeneity exists, with the Lüliang Mountain area in the west and the Datong Basin in the north being core degradation zones, while the Taihang Mountain area in the east shows remarkable improvement. However, Theil–Sen Median–Hurst index predictions reveal that 60.07% of the improved areas face potential trend reversal risks. (3) The driving mechanisms exhibit spatial heterogeneity, where land use type, temperature, precipitation, elevation, and slope serve as global dominant factors. This research provides scientific support for formulating differentiated ecological restoration strategies, establishing ecological compensation mechanisms, and optimizing territorial spatial planning in Shanxi Province, contributing to the achievement of sustainable development goals. Full article

Severe soil erosion and land productivity degradation caused by inadequate vegetation cover pose significant challenges to regional ecological protection and sustainable development. To assess changes and variations in soil quality, three sample areas with different distinct texture characteristics were selected from the Pisha sandstone region located northeastern of the Loess Plateau. The total data set (TDS) was determined through sampling experiments, and the minimum data set (MDS) was established using principal component analysis. A Random Forest (RF) machine learning model was applied to predict soil quality distribution. The prediction indices were derived from soil analysis dimensions, mean weight diameter measured via wet sieving, and soil enrichment ratio obtained from slope erosion experiments conducted at the corresponding sampling points. During the RF modeling process, 80% of the total soil quality index (SQI), calculated using TDS and MDS evaluation methods, was allocated for model training. The results indicated that pH, ammonia nitrogen, bulk density, silt content, clay content, soil water content, hygroscopic water content, total phosphorus, soluble calcium, and actinomycetes were identified as the optimal predictors for SQI. Furthermore, the RF model demonstrated superior performance in predicting the regional distribution of SQI, with evaluation metrics including (R² = 0.76–0.78, RMSE = 0.03–0.06, MAE = 0.04–0.09). This study confirms the reliability of RF in simulating SQI within the study area and highlights that, in regions undergoing extensive vegetation restoration and with limited sampling conditions, experimental measurements of soil particles and sediment parameters provide an effective approach for evaluating SQI. Full article

Drought threatens the stability of artificial black locust forests on the Loess Plateau, yet there is limited research on the physiological and metabolic responses of mature black locust to drought stress. This study employed a throughfall exclusion system—i.e., moderate drought (40% throughfall reduction), extreme drought (80% throughfall reduction), and 0% throughfall reduction for control—to analyze leaf microstructure, relative water content (RWC), osmotic adjustment substances, hormone levels, and flavonoid metabolites in black locust under controlled drought stress. The results demonstrated that as drought stress intensified, stomatal aperture and density decreased, while trichome density and length exhibited significant increases. MDA, proline, IAA, and osmotic adjustment substances (soluble protein, reducing sugar, and total sugar) first increased and then decreased as drought stress intensified. A total of 245 flavonoid compounds were identified through metabolomic analysis, among which 91 exhibited differential expression under drought treatments. Notably, 37 flavonoids, including flavonols and glycosylated derivatives, were consistently upregulated. These findings suggest that drought stress can lead to the accumulation of flavonoids. This study explored the physiological and metabolic responses of mature black locust trees to drought stress, offering insights for selecting drought-resistant species in vegetation restoration and informing ecological management practices in arid regions. Full article

The gullied Loess Plateau, a region characterized by the overlapping of ecological fragility and energy abundance in China, requires urgent analysis of its territorial spatial conflict mechanisms to harmonize human–environment relationships. This study integrated multi-temporal remote sensing data (1990–2020) to develop a Comprehensive Spatial Conflict Index (CSCI) and applied the Optimal Parameter-based Geographical Detector (OPGD) to unravel the driving mechanisms of territorial spatial evolution in Qingyang City, Gansu Province. The results revealed that: (1) Territorial spaces exhibit a transition pattern of ecological restoration, urban expansion, and agricultural contraction. Forest and grassland ecological spaces increased by 1.42 percentage points (to 13.14%) and 1.26 percentage points (to 49.29%), respectively, while industrial-mining production spaces expanded sevenfold (0.01% to 0.08%), and agricultural production spaces decreased by 3.36 percentage points. (2) Spatial conflicts transitioned through three phases: ① A low-intensity stabilization phase (1990–2000), with 90.55% of areas under weak and moderately weak conflict (CSCI ≤ 0.4); ② A moderate conflict contraction phase (2000–2010), where weak conflict zones surged by 28.18 percentage points (13.06% → 41.24%), with moderate and moderately weak spatial conflict (0.2–0.6) decreasing by 28.27 percentage points (86.06% → 57.79%); ③ A moderately strong to strong expansion phase (2010–2020), with moderate and moderately strong conflict areas rising to 16.82%. Strong conflict zones (CSCI ≥ 0.8) expanded to 0.61%, spatially clustered in the Xifeng urban area and the Malian–Pu River corridor, showing significant positive correlations with gully density (>3.5 km∙km⁻²) and nighttime light index (NL). (3) The interaction between NDVI and land use intensity (LUI) dominated conflict patterns (q = 0.2583). In northern energy development zones (Huanxian County), LUI and precipitation (PRE) synergistically intensified landslide risks, while facility agriculture in central plateau farmlands (Ningxian County) triggered groundwater overexploitation. The coupling of road density (RND) and population (POP) factors (q = 0.1892) formed a transportation–population axial belt compression. Policy interventions exhibited spatial heterogeneity: the Grain-for-Green Program increased weak conflict zones by 28.18 percentage points, whereas wind power development in the Huanxian–Huachi northern belt escalated moderately strong to strong conflict zones by 3.6 percentage points. A three-dimensional governance framework integrating geomorphological adaptation, development phasing, and ecological compensation is proposed to optimize territorial spatial planning in the gullied Loess Plateau. Full article