Search Results (172)

In ecological restoration of arid/semi-arid sandy lands, micro-topographic variations and artificial shrub arrangement synergistically drive vegetation recovery and soil quality improvement. As a typical fragile ecosystem in northern China, the Mu Us Sandy Land has long suffered wind erosion, desertification, soil infertility, and vegetation degradation, demanding precise vegetation configuration for ecological rehabilitation. This study analyzed soil nutrients, plant diversity, and their correlations under various micro-topographic conditions across different types of artificial shrub plantations in the Mu Us Sandy Land. Employing one-way and two-way ANOVA, we compared the significant differences in soil nutrients and plant diversity indices among different micro-topographic conditions and shrub species. Additionally, redundancy analysis (RDA) was conducted to explore the direct and indirect relationships between micro-topography, shrub species, soil nutrients, and plant diversity. The results show the following: 1. The interdune depressions have the highest plant diversity and optimal soil nutrients, with relatively suitable pH values; the windward slopes and slope tops, due to severe wind erosion, have poor soil nutrients, high pH values, and the lowest plant diversity. Both micro-topography and vegetation can significantly affect soil nutrients and plant diversity (p < 0.05), and vegetation has a greater impact on soil nutrients. 2. The correlation between surface soil nutrients and plant diversity is the strongest, and the correlation weakens with increasing soil depth; under different micro-topographic conditions, the influence of soil nutrients on plant diversity varies. 3. In sandy land ecological restoration, a “vegetation type + terrain matching” strategy should be implemented, combining the characteristics of micro-topography and the ecological functions of shrubs for precise configuration, such as planting Corethrodendron fruticosum on windward slopes and slope tops to rapidly replenish nutrients, promoting Salix psammophila and mixed plantation in interdune depressions and leeward slopes to accumulate organic matter, and prioritizing Amorpha fruticosa in areas requiring soil pH adjustment. This study provides a scientific basis and management insights for the ecological restoration and vegetation configuration of the Mu Us Sandy Land. Full article

In the Mediterranean region, the high frequency of fire events is combined with climatic conditions that hinder vegetation recovery. This underscores the urgent need for a post-fire restoration of natural ecosystems and implementation of emergency rehabilitation measures to prevent further degradation. In this study, we investigated the performance of three types of erosion control structures (log dams, log barriers, and wattles), two years after fire, in three Mediterranean areas that were burnt by severe forest fires in 2021. The wooden structures’ ability to infiltrate precipitation was evaluated by 100 infiltration experiments in 25 plots, one and two years after the wildfires. The unsaturated hydraulic conductivity K was determined at two zones formed between consecutive wooden structures, i.e., the erosion zone (EZ) where soil erosion occurs, and the deposition zone (DZ) where the soil sediment is accumulated. These zones showed significant differences concerning their hydraulic behavior, with DZ presenting enhanced infiltration ability by 130 to 300% higher compared to EZ, during both years of measurements. The findings suggest that the implementation of emergency restoration actions after a wildfire can highly affect the burned forest soils’ ability to infiltrate water, preventing surface runoff and erosion, whereas specific structures such as the log dams can be even more effective. Full article

Abandoned pits and quarries in Ontario, Canada, are on the rise due to industrialization, leading to ecosystem disruption and soil contamination with pollutants such as cadmium, cobalt, nickel, and barium, which may leach into nearby water systems. Current rehabilitation processes are slow to initiate, and therefore, the site remains in a contaminated condition for years. Phytoremediation, which involves using plants to remove contaminants from soils, is receiving increased attention for cleaning up decommissioned mines. This type of rehabilitation is normally practiced in situ by hand-planted and managed vegetation chosen for the specific purpose of contaminant removal. This study investigated the phytoremediation potential of indigenous plants as local seed sources to rehabilitate decommissioned quarries in Ontario. This study also investigated the potential of native plants to naturalize in the disturbed areas, thus providing a natural clean-up of the contaminants. Thus, if successful, this process will also initiate the re-establishment of native wildlife in the area. Through a literature review, 74 plant species were identified as capable of remediating 20 contaminants often found on the decommissioned quarry sites. The results may help ecosystem managers to adopt environmentally sustainable strategies to clean up contaminated sites such as decommissioned mines and quarry areas. Full article

Unmanned aerial vehicles (UAVs) have increasingly proven to be flexible tools for mapping mine terrain, offering expedient and precise data compared to alternatives. Photogrammetric outputs are particularly beneficial in open pit operations and waste dump areas, since they enable cost-effective and reproducible digital terrain models. Meanwhile, UAV-based LiDAR has proven invaluable in situations where uniform ground surfaces, dense vegetation, or steep slopes challenge purely photogrammetric solutions. Recent advances in machine learning and deep learning have further enhanced the capacity to distinguish critical features, such as vegetation and fractured rock surfaces, thereby reducing the likelihood of accidents and ecological damage. Nevertheless, scientific gaps remain to be researched. Standardization around flight practices, sensor selection, and data verification persists as elusive, and most mining sites still rely on limited, multi-temporal surveys that may not capture sudden changes in slope conditions. Complexity lies in devising strategies for rehabilitated dumps, where post-mining restoration efforts involve vegetation regrowth, erosion mitigation, and altered land use. Through expanded sensor integration and refined automated analysis, approaches could shift from information gathering to ongoing hazard assessment and environmental surveillance. This evolution would improve both safety and environmental stewardship, reflecting the emerging role of UAVs in advancing a more sustainable future for mining. Full article

Understanding plant nitrogen (N) uptake strategies during vegetation recovery is essential for restoring and rehabilitating degraded ecosystems. However, there are few studies on plant N uptake strategies in karst regions. In this study, space-for-time substitution was used to investigate the dynamic changes in plant N uptake strategies during vegetation restoration. Grassland, shrub–grassland, shrubland, and woodland naturally recovering in karst ecosystems were chosen as the research objects. The dominant species at each stage were investigated. Dominant plant N uptake rates were measured using the ¹⁵N labeling technique, and plant root functional traits and available soil N were determined. Our results showed that soil inorganic N content and composition varied significantly with vegetation recovery. In early vegetation recovery stages, the soil inorganic N content was low and dominated by ammonium (NH₄⁺), while in the late stages, soil inorganic N content increased, and nitrate (NO₃⁻) became the dominant form. In early vegetation recovery stages, dominant plants preferentially absorbed NH₄⁺, contributing to 90.3%–98.5% of the total N uptake. With vegetation recovery, plants increased the NO₃⁻ uptake ratio from 1.48%–9.42% to 30.1%–42.6%. Additionally, the root functional traits of dominant plants changed significantly during vegetation recovery. With vegetation recovery, specific root lengths and specific root areas decreased, while root N content and plant N uptake rates increased. In summary, plants developed N uptake strategies coordinated with soil N supply by modifying root functional traits following vegetation recovery in karst regions. Full article

Rocky desertification, a severe form of land degradation in tropical and subtropical regions driven by vegetation loss and soil erosion, poses significant ecological and economic challenges. Field trials in Fengshan County, Guangxi, China, evaluated the efficacy of NPK compound fertilizers, slow-release fertilizers, and bio-organic fertilizers on soil rehabilitation, microbial diversity, and the growth of Mahonia fortunei, a key species for ecological restoration and understory cash crop cultivation. The results demonstrated the bio-organic fertilizer’s superiority in soil regeneration, increasing organic matter by 30.4% (Bolin), 15.73% (Longlai), and 21.83% (Longlei) compared to NPK compound fertilizers, alongside elevating the total nitrogen (reaching 19.4 g/kg in Bolin) and phosphorus (85.45% higher in Bolin). Bio-organic fertilizer increased enzyme activities by 27–202% and enhanced microbial diversity, notably Proteobacteria and Actinobacteria. Slow-release fertilizers maximized micronutrient availability (e.g., Cu increased by 151.65% in Bolin) and improved plant growth, achieving peak Mahonia fortunei (Lindl.) Fedde height (3.62 cm, increasing 9.04%) and ground diameter (4.5 cm, increasing 18.42%) in Longlei compared to NPK compound fertilizers. Regional variability highlighted the bio-organic fertilizer’s dominance in soil fertility metrics, while slow-release formulations excelled in micronutrient enrichment and plant performance. NPK compound fertilizers exhibited the lowest efficacy, potentially exacerbating soil degradation. This study advocates integrating bio-organic fertilizers for soil regeneration with targeted slow-release applications for crop productivity, particularly in understory cash crop systems. Such a dual approach bridges ecological restoration with economic resilience in karst ecosystems, offering scalable solutions for global rocky desertification mitigation. Full article

The vegetation restoration of contaminated sites plays a critical role in ensuring the sustained stability and functional integrity of natural ecosystems. However, during the natural revegetation process, the variations in habitat conditions, bacterial community structure, and metabolic functions in aged, polluted soil are still unclear. In the present study, we investigated aged, polycyclic aromatic hydrocarbon (PAH)-polluted soils at closed, abandoned oil well sites from the Yellow River Delta. Using gene amplification and real-time qPCR methods, the abundance, taxonomy, and diversity characteristics of indigenous bacterial communities and functional bacteria carrying C12O genes in both vegetated soils and bare soils were investigated. The results show that natural revegetation significantly changes the physicochemical parameters, PAH content, and bacterial community structure of aged, PAH-polluted soils. When comparing the abundance and components of PAH-degrading bacterial communities in vegetated and bare soils, the PAH-degrading potential was revealed to be stimulated by vegetation communities. Through correlation analysis, dual stress from soil salinity and PAH contamination in bacterial communities was revealed to be mediated through alterations in the soil’s physicochemical properties by local vegetation. The network analysis revealed that bacterial communities in vegetated soils have higher network connectivity. These results elucidate the alterations in habitat conditions, bacterial components, and PAH-degrading communities following vegetation restoration, providing critical insights for optimizing ecological rehabilitation strategies in salinized and contaminated ecosystems. Full article

Soil aggregate stability and carbon–nitrogen content are critical indicators for assessing the vegetation restoration effects. Salix cupularis plays a vital role in rehabilitating desertified alpine meadows on the eastern Qinghai–Tibet Plateau. However, research remains limited about how afforestation influences the soil aggregate stability and associated carbon and nitrogen dynamics. In this study, sandy land (0 years) served as the control, and the spatial time replacement method was used to examine changes in the soil water-stable aggregate composition, stability, organic carbon (OC) and total nitrogen (TN) contents, and density at a 0–60 cm depth after 5 and 10 years of afforestation restoration (Salix cupularis). Ecological restoration significantly enhanced the proportion of macroaggregates (>0.25 mm) in the topsoil (0–20 cm), and improved aggregate stability. After 10 years of restoration, macroaggregates increased by 45.04% and 51.32%, respectively. The average weight diameter and geometric mean diameter of the aggregates increased by 51.32% and 59.53%, respectively. Following restoration, there was a gradual increase in the OC and TN contents in the soil, with the highest increase observed in the 0–10 cm layer (266.67% and 391.67%). The OC and TN of the aggregates also displayed a similar trend. Correlation analysis results indicated a significant positive relationship between the soil OC and TN contents and density, OC content in aggregates of various diameters, and the stability of these aggregates. The Pearson’s correlation coefficient for OC in aggregates > 1 mm was the highest. Compared with 5 years, 10 years of recovery were more conducive to the formation of macroaggregates, enhancement in aggregate stability, and the accumulation of OC and TN. Therefore, vegetation restoration on the Zoige Plateau can significantly enhance the soil water-stable aggregate composition and stability and can also increase the soil and OC and TN contents and density, thereby enhancing the soil ecological quality. This study provides fundamental data and theoretical support for rehabilitating desertified grasslands on the eastern Qinghai–Tibet Plateau. Full article

Background/Objectives: The aim of this study was to evaluate the impact of chronic heart failure (CHF), chronic kidney dysfunction (CKD), and the combined CHF-CKD comorbidity on the outcomes of rehabilitation in stroke patients. Methods: A total of 586 patients who had suffered a stroke (mean age, 70 ± 13; 47.6% female; 72.4% ischemic and 27.6% hemorrhagic strokes) and who were admitted immediately after acute stroke care to a rehabilitation center were included in this cohort study and followed up with until their death or discharge from the rehabilitation center. The clinical characteristics of the patients were obtained from their medical records. The relationship between the background comorbidities (CHF, CKD, and concurrent CHF-CKD) and fatal and non-fatal unfavorable outcomes (emergency readmission to a primary hospital or transfer to a long-term care facility in a vegetative or minimally conscious state) were investigated. Results: Unfavorable outcomes were more common in the groups with background CHF and/or CKD. From the Cox multivariate analysis, both CHF and CKD were independent prognostic factors for the occurrence of unfavorable outcomes, with a hazard ratio (HR) of 2.28 (95% CI = 1.2–4.29; p-value = 0.01) and 2.19 (95% CI = 1.24–3.87; p-value = 0.007), respectively. Moreover, the combined CHF-CKD comorbidity showed a more than 5-fold increased risk of an adverse post-stroke outcome (HR of 5.8; 95% CI = 2.5–13.44; p-value < 0.001). Conclusions: The combined CHF-CKD comorbidity is an important independent complicating factor that, along with other known influencing factors, can affect unfavorable post-stroke outcomes more than CHF or CKD alone, and necessitates critical attention to its diagnosis and management as a separate mixed syndrome. Full article

Vegetation dynamics and their underlying driving mechanisms have emerged as a prominent research focus in ecological studies of the Chinese Loess Plateau (CLP). Current investigations, however, employ simplified methodologies in analyzing the influencing factors, limiting their capacity to comprehensively elucidate the intricate and multidimensional mechanisms that govern vegetation transformations. Utilizing fractional vegetation cover (FVC) datasets spanning 2000 to 2021, this research applies both XGBoost-SHAP and Geodetector approaches for comparative analysis of the driving factors and precise quantification of climatic change (CC) and human activity (HA). The results indicate that: (1) The CLP has experienced an annual FVC increase of 0.62%, with 95.1% of the region demonstrating statistically significant vegetation improvement. (2) Precipitation and land use emerge as the primary determinants of FVC spatial distribution, with their interactive effects substantially exceeding the impacts of individual factors. (3) While both XGBoost-SHAP and Geodetector methodologies consistently identify the primary driving factors, notable discrepancies exist in their assessment of temperature’s relative importance, revealing complementary dimensions of ecological complexity captured by different analytical paradigms. (4) Approximately 94.3% of FVC variations are jointly influenced by HA and CC, with anthropogenic factors predominating at a contribution of 67%. Land use modifications, particularly transitions among cropland, grassland, and forests, constitute the principal mechanism of human influence on vegetation patterns. This investigation enhances the understanding of vegetation responses under combined natural and anthropogenic pressures, offering valuable insights for ecological rehabilitation and sustainable development strategies on the CLP. Full article

The natural regeneration of Larix gmelinii plantations plays a pivotal role in rehabilitating ecosystem services in Northeast China’s degraded forests. However, mechanistic linkages between soil aggregate nutrient fluxes and fungal community assembly remain poorly constrained. Combining space-for-time substitution with particle-size fractionation and high-throughput sequencing, this study examined successional trajectories across regeneration in Langxiang National Nature Reserve to resolve nutrient–fungal interplay during long-term forest restructuring. The results demonstrated that microaggregates (<0.25 mm) functioned as nutrient protection reservoirs, exhibiting significantly higher total carbon (TC) and nitrogen (TN) contents and greater fungal diversity (p < 0.05). Both stand regeneration stage and aggregate size significantly influenced fungal community composition and structural organization (p < 0.05). Aggregate-mediated effects predominated in upper soil horizons, where fungal dominance progressively transitioned from Mortierellomycota to Ascomycota with increasing particle size. In contrast, lower soil layers exhibited regeneration-dependent dynamics: Basidiomycota abundance declined with L. gmelinii reduction, followed by partial recovery through mycorrhizal reestablishment in Pinus koraiensis broadleaf communities. Fungal co-occurrence networks displayed peak complexity during Juglans mandshurica germination (Node 50, Edge 345), with 64.6%positive correlations, indicating the critical period for functional synergy. Basidiomycota showed significant negative correlations with nutrients and major fungal phyla (R² = 0.89). This study confirms that natural vegetation regeneration reshapes belowground processes through litter inputs and mycorrhizal symbiosis, while microaggregate management enhances soil carbon sequestration. Near-natural plantation management should incorporate broadleaf species to preserve mycorrhizal diversity and amplify ecosystem services. These findings provide an essential soil ecological theoretical basis for sustainable plantation management in Northeast China. Full article

Composite grids serve as reinforcement in concrete structures, offering alternatives to conventional steel reinforcement. These grids can be fabricated from various materials, including synthetic polymers, metals, and natural fibers. This study explores the use of composite grids as lateral confinement of self-compacting concrete (SCC) cylinders and examines their impact on the failure mode under axial compression. In the experiment, the types of grids and mesh shapes used were plastic grids of diamond mesh (PGD) and regular mesh (PGT), metallic grids of diamond mesh (MGD) and square mesh (MGS), vegetable grids of Alfa fiber mesh, 10 × 10 mm (VGAF-1) and 20 × 20 mm (VGAF-2), and vegetable grids of date palm fibers (VGDF). The binder of SCC mixtures incorporated 10% marble powder as a partial replacement for ordinary Portland cement (OPC). SCC mixtures were tested in the fresh state by measuring the slump flow diameter, V-funnel flow time, L-box blocking ratio, and segregation index. Cylinders with a diameter of 160 mm and a height of 320 mm were made to assess the mechanical properties of hardened SCC mixtures under axial compression. The results indicate that most of the confined cylinders exhibited an increase in ductility compared to unconfined cylinders. Grid types MGD and PGD provided the best performance, with ductility increases of 100.33% and 96.45%, respectively. VGAF-2 cylinders had greater compressive strength than cylinders with other grid types. The findings revealed that the type and mesh shape of the grids affects the failure mode of confined cylinders, but has minimal influence on their modulus of elasticity. This study highlights the potential of lateral grid confinement as a technique for rehabilitating, strengthening, and reinforcing weaker structural concrete elements, thereby improving their mechanical properties and extending the service life of building structures. Full article

The parameters of Low-Impact Development (LID) facilities significantly influence their operational performance and runoff control effectiveness at the site. Despite extensive research on LID effectiveness, limited studies have focused on optimizing design parameters at a community-wide scale, integrating both hydrological and statistical methodologies. A novel approach to optimizing LID design parameters was presented in this study. This study established a community-scale SWMM model, identified the key parameters by the Morris screening method, and determined the reasonable parameter ranges based on runoff control effects. The Response Surface Methodology (RSM) was applied to optimize the key parameters under different return periods and impervious area ratios. The results showed that key LID parameters for runoff volume control were the berm height of the surface layer of sunken greenbelt (SG_Surface_H), the conductivity of the soil layer of sunken greenbelt (SG_Soil_I), the permeability of the pavement layer of permeable pavement (PP_Pavement_I), and the thickness of the storage layer of permeable pavement (PP_Storage_T). The reasonable ranges were 50–265 mm, 5–80 mm/h, 50–140 mm/h, and 100–165 mm, respectively. The key LID parameters for peak flow reduction were SG_Surface_H, SG_Soil_I, PP_Pavement_I, and the berm height of the surface layer of vegetated swale (VS_Surface_H). The reasonable ranges were 50–260 mm, 5–50 mm/h, 50–195 mm/h, and 50–145 mm, respectively. The optimization results of LID parameters showed that for the runoff volume control rate, the optimization strategy involved increasing SG_Surface_H as the return period increased and when the impervious area ratio was large, especially in the rehabilitation of old communities. Meanwhile, the optimal value of SG_Soil_I for runoff volume control was greater than that for peak flow reduction. In contrast, the optimal value of PP_Pavement_I was larger for peak flow reduction. This study provides a significant reference for LID planning and design by emphasizing the optimization of LID design parameters. Full article

Intensive mining activities in the Zhungeer open-pit coal mining area of China have resulted in drastic changes to land use and landscape patterns, severely affecting the ecological quality and stability of the region. This study integrates 36 years (1985–2020) of Landsat multiband remote sensing imagery with 30 m resolution CLCD land cover data, establishing a “Sky–Earth–Space” integrated monitoring system. This system allows for the calculation of ecological indices and the creation of land use transition matrices for internal and external regions of the mining area, ultimately completing an assessment of the ecological stability of the Zhungeer open-pit coal mining region. By overcoming the limitations posed by a singular data source, it facilitates a dynamic analysis of the interrelationships among mining activities, vegetation responses, and engineering remediation efforts. The findings reveal a significant transformation among various land types within the mining area, with both the area of mining pits and the area rehabilitated through artificial restoration undergoing rapid increases. By 2020, the area of the mining pits had reached 2630.98 hectares, while the area designated for rehabilitation had expanded to 2204.87 hectares. Prior to 2000, bare land and impermeable surfaces dominated the internal area of the mine; however, post-2000, the Normalized Difference Built-up Index (NDBI) value continuously decreased to −0.0685, indicative of an ecological transition where vegetation became predominant. The beneficial impacts of rehabilitation efforts have effectively mitigated the adverse environmental consequences of open-pit coal mining. Since 2000, the mean Normalized Difference Vegetation Index (NDVI) within the mining area has shown a consistent increase, recovering to 0.2246, signifying a restoration of the internal ecological environment. Moreover, this area exerts a notable radiative influence on the vegetation conditions outside the mining zone, with a contribution value of 1.016. Following rehabilitation efforts, the landscape patch density, landscape separation, and landscape fragmentation in the Zhungeer open-pit coal mining area exhibited a declining trend, leading to a more uniform distribution of landscape patches and improved structural balance. By 2020, the adaptability index had risen to 0.35836, achieving 93.69% of the restoration level observed prior to mining operations in 1985, thus indicating an improvement in ecosystem stability and the restoration of ecological functions, although rehabilitation efforts display a temporal lag of 10 to 15 years. The adverse impacts of open-pit coal mining on the regional ecological environment are, in fact, predominantly short-term. However, human intervention has the potential to reshape the ecology of the mining area, enhance the quality of the ecological environment, and foster the sustained development of regional ecological health. Full article

The Syrdarya Delta, located in semi-arid and arid Central Asia, is an important water source for fertile landscapes. The environmental history of the Syrdarya Delta (SD) during the 19th and 20th centuries is a diverse and understudied subject, and its natural and anthropogenic aspects changed drastically during this period. As a result of the Syrdarya Delta’s location, on the shores of the former Aral Sea, there is a vital need to expand our understanding of the phases and policies that led to the current condition. This study argues that by integrating methods from social and natural sciences and applying them to selected historical materials, among them, former classified materials from the Cold War period, we can expand our understanding regarding the extent and types of disruptions in the Syrdarya Delta ecological system. The main findings of this study show that between the second part of the 19th and the 21st centuries, a period of roughly a hundred and fifty years, the SD changed drastically in aspects of urban areas, which increased during the Soviet period, changes in land use and hydrography, with changes in the amounts, size and flowing directions of water streams in the SD. The findings also present changes in vegetative cover and amounts parallel to salinization of the soil, which increased in the 1970s–1980s, and changes in the meeting point of the former Aral Sea with the SD. The findings of the study indicate that most of these changes can be attributed to anthropogenic factors, which have taken place mainly since the 1960s–1970s under the USSR regime. As this study presents, such materials can assist in reconstructing land use and land cover from the years to which our data are limited by integrating them with modern satellite image analysis, thus being able to quantify and estimate the amounts and types of these changes regarding salinization, land use and land cover and hydrology, which are crucial for studying deltas located in arid and semi-arid landscapes, such as the SD. This study presents evidence and argues that these data are of pivotal importance and should be used when attempting to rehabilitate and manage today’s Syrdarya Delta landscapes and hydrology. Full article