Search Results (1,485)

Bauxite mining causes severe soil degradation in the ecologically fragile karst region of Southwest China, yet targeted vegetation restoration schemes remain poorly developed. This study aimed to screen promising selected restoration species and preliminarily explore their soil improvement characteristics in karst bauxite mine wastelands through a field observational survey. We investigated six vegetation-soil conditions at 0–10 cm topsoil (two-year monocultures of Robinia pseudoacacia, Ligustrum lucidum, Zea mays, Miscanthus sinensis, topsoil from >15-year Z. mays with straw return, and unvegetated bare land), alongside paired 10–20 cm subsoil from the same long-term Z. mays stand as a depth-profile reference, and analyzed soil physicochemical properties, enzyme activities, and bacterial/fungal communities via high-throughput sequencing. Results showed that vegetation cover neutralized strongly acidic mine soil and significantly increased soil organic matter (SOM), total nitrogen (TN), and available nutrients compared with the bare control (p < 0.05). The long-term Z. mays cropland showed the strongest soil nutrient accumulation, with topsoil SOM, available phosphorus, and available potassium, increased by 428.6%, 250.0%, and 65.3%, respectively, relative to the bare control. Notably, the subsoil of long-term Z. mays also maintained high nutrient levels, but its absolute values are not directly comparable with topsoil treatments due to different sampling depths. All vegetation conditions elevated soil enzyme activities and microbial alpha diversity and significantly shifted bacterial and fungal community structure (beta diversity) compared with the control. Several bacterial phyla (including Chloroflexi and Proteobacteria) that have been associated with carbon-cycling functions in prior studies were relatively more abundant in revegetated soils; however, their functional roles in this system remain to be verified. Redundancy analysis identified SOM, TN, and available potassium as key environmental correlates of bacterial community variation. Overall, the long-term crop–straw return pattern shows comprehensive soil improvement effects, providing observational baseline data and reference for ecological restoration of karst bauxite mining areas in Southwest China. Full article

To overcome the dual bottlenecks of scarce actual strong earthquake records and high computational costs of nonlinear time history analysis, this study proposes a fast prediction method for structural nonlinear response that integrates systematic seismic sample expansion and machine learning technology by studying mature methods in the industry. A total of 500 ground motion records were created through the application of the amplitude scaling approach. Subsequently, the development of the steel frame structure was carried out through the application of the Abaqus software(Abaqus 2021 Edition) for the purpose of carrying out the nonlinear time history analysis to obtain the maximum interstory drift ratio (IDR) as the target response parameter. The XGBoost model was optimized to obtain improved results through the application of various evaluation criteria. Subsequently, the Shapley Additive exPlanations (SHAP) tool was applied to “open the black box” model to obtain the coupled effect of the various parameters, including displacement-related intensity measures such as RMSD and PGD on the maximum IDR during significant structure deformations. The method developed within this research has the potential to be a powerful tool for the prediction of the seismic responses. The method can be used in many areas, including probabilistic seismic demand, fragility assessment, and rapid evaluation of earthquake damage. Full article

Recreation suitability in national parks refers to the capacity of a place to support low-impact recreation while maintaining ecological integrity and complying with conservation objectives. In alpine protected areas, high landscape attractiveness does not necessarily indicate feasible recreation space because ecological fragility, remoteness, and strict protection requirements may constrain use. Using Sanjiangyuan National Park, China, as a case study, we integrated multi-source geospatial data to construct an Ecological Recreation Suitability Index from Ecological Recreation Provisioning, the Landscape Attractiveness Index, and the Wilderness Degree Index. WDI was transformed into a nonlinear compatibility function that constrained the realization of landscape attractiveness, and ecological support was then integrated with wilderness-compatible attractiveness. Relatively high- and high-suitability zones accounted for 30.88% of the valid assessment area and were mainly concentrated in the eastern and southeastern parts of the park, where higher ecological recreation provisioning and landscape attractiveness under suitable wilderness constraints jointly contributed to greater recreation suitability. Western and northwestern areas were constrained chiefly by weak ecological support and high wilderness conditions. These findings show that recreation suitability is not a direct expression of landscape attractiveness. The principal scientific contribution is a condition-dependent coupling structure that distinguishes potential attraction from conservation-compatible recreation suitability. Full article

Freshwater scarcity can weaken water governance when hydrological pressure interacts with intensive agricultural demand, regulatory weakness, and political conflict. This research evaluates whether Irrigation District 005 (IR 005) in Chihuahua, northern Mexico, demonstrates local water-governance fragility across three domains: public security, the rule of law, and the ability to sustain water access and food production. A mixed-methods approach integrates legal and human rights documentation, institutional records, published studies, and a structured media review with hydrological, agricultural, climatic, and reservoir data. Water balances were analysed for 1998–2023, precipitation trends for 1980–2020, and crop water requirements were estimated using the Food and Agriculture Organization’s Irrigation and Drainage Paper No. 56 (FAO-56) Penman–Monteith framework, the crop coefficient (Kc), the water-stress coefficient (Ks), the United States Soil Conservation Service (SCS) Curve Number method, and application-efficiency assumptions. The 2020 water conflict resulted in fatalities, injuries, arrests, and documented human rights violations. Rule-of-law capacity was further diminished by unauthorised withdrawals, cultivation beyond authorised irrigation plans, and limited enforcement. The annual water balance shifted to persistent deficits after 2016, reaching an estimated deficit of 2268 cubic hectometres (hm³) in 2020. Annual precipitation did not exhibit a statistically significant monotonic decline during 1980–2020 (Mann–Kendall Z = −0.79, τ = −0.0878, p = 0.4251; Sen’s slope = −1.1628 mm yr⁻¹; Mann–Whitney p = 0.5313), indicating that recent stress is more closely linked to production scale, crop mix, governance conditions, and irrigation efficiency than to a long-term reduction in rainfall. Sensitivity analysis revealed that ±15% changes in Kc and Ks altered gross water requirements by approximately ±16–17%, while equivalent changes in effective precipitation produced changes of only 1–3%. These results demonstrate heightened water-governance fragility resulting from mutually reinforcing hydrological, institutional, and conflict-related pressures. Future research should refine locally calibrated water-demand parameters and develop reproducible monitoring systems that combine hydrological, institutional, satellite, and participatory data to support anticipatory, transparent, and rights-based water governance. Full article

Tourism is a major driver of economic growth in tropical island destinations but also places increasing pressure on fragile marine ecosystems. This study examined tourists’ environmental awareness, perceptions, and conservation-related behaviors on Cozumel Island, part of the Mesoamerican Reef System and home to multiple protected areas, including the Arrecifes de Cozumel National Park. Between June and September 2022, surveys were conducted with 144 tourists at major tourism hubs across the island. Although 86% of respondents identified themselves as environmentally conscious, awareness of local environmental impacts associated with tourism remained limited, and only 6% reported engaging in environmentally conscious actions during their visit. Awareness of the protected status and regulations of the Arrecifes de Cozumel National Park was also low (39%), and only 19% reported purchasing the required conservation bracelet or park pass. Short-stay cruise visitors represented 65% of respondents, potentially limiting opportunities for deeper environmental engagement and conservation education. These findings highlight the need for stronger pre-trip environmental communication, visible on-site interpretation, and targeted outreach strategies to support sustainable tourism and coral reef conservation in the Mexican Caribbean. Full article

Subjected to high-intensity development, enclosed tropical islands frequently face severe spatial resource constraints and acute risks of ecological degradation. To seek a comprehensive solution to multidimensional spatial conflicts, this study selected Hainan Island—a region facing development pressure from the Free Trade Port construction—as the study area. By coupling the XGBoost-SHAP, NSGA-II, and PLUS models, we constructed an integrated modular spatial planning framework of “mechanism interpretation—macro optimization—micro reconstruction”. The main findings are as follows. (1) Over the past 15 years, the fragile ecosystem of the island has faced immense pressure. Lacking an external buffer hinterland, land-use transitions exhibited a distinct chain transmission characteristic of “built-up land occupying agricultural land, and agricultural land squeezing forest”. This internal spatial cascading substitution constituted the core mechanism of ESV decline. (2) The reconstruction of the spatial pattern is governed by dual thresholds of natural constraints and economic pulling. A rigid ecological defense baseline (NDVI ≥ 0.40) restricts disorderly urban sprawl, while spatial inflection points (8.46 km from the coastline and 271 m from roads) precisely delineate the coastal and traffic-oriented agglomeration boundaries for built-up land. (3) Among the predefined scenarios, the Sustainable Development (SD) scenario emerges as the optimal pathway. By proactively reducing inefficient agricultural land space at the macro level and strictly implementing identified threshold controls alongside “infill” urban agglomeration at the micro level, the SD scenario is expected to successfully achieve a Pareto-optimal synergy between socioeconomic growth and the restoration of regional ESV. This study not only establishes an objective benchmark for the refined multi-objective spatial governance of the Hainan Free Trade Port, but also provides a referential planning paradigm for vulnerable enclosed islands globally facing high-intensity anthropogenic stress. Full article

The Shendong Mining Area, located in the transition zone between the northern Loess Plateau and the Mu Us Sandy Land, is a representative ecologically fragile region and desert coal base in China. Using Google Earth Engine (GEE) and Landsat imagery from 1999 to 2024, this study constructed a long-term remote sensing ecological index (RSEI) dataset and integrated the Theil–Sen median slope estimator, Mann–Kendall test, and Hurst exponent to examine the spatiotemporal evolution, future trajectories, and multi-stage driving mechanisms of eco-environmental quality (EEQ) at the mining-area and individual-mine scales. At the mining-area scale, RSEI showed pronounced interannual fluctuations and a weak downward trend, characterized by a two-stage, wave-like trajectory with a narrowing amplitude. The mean RSEI and standard deviation decreased from 0.5669 and 0.0855 during 1999–2010 to 0.5182 and 0.0501 during 2011–2024. Moderate and good grades predominated, with lower EEQ in the mining core and higher EEQ in peripheral buffer zones. Across 13 representative mines, ecological quality generally remained moderate but exhibited spatial and stage-dependent heterogeneity, with Liuta Mine showing the greatest variability. Slight degradation was the dominant trend, although local recovery occurred, and Hurst analysis revealed marked spatial differences in future trajectories. RSEI variations in the Shendong Mining Area exhibited pronounced spatial and stage-dependent associations with high-intensity mining, climatic water–heat conditions, topographic background, and ecological governance and restoration processes. No continuous and irreversible overall decline was observed; however, without an independent non-mining control, the findings represent integrated ecological responses within the mining area rather than causal estimates of mining’s net ecological effect. Full article

Background: Large surface area burn injuries compromise skin integrity and are associated with significant morbidity and mortality. Skin autografts are essential for wound healing but are limited in patients with extensive burns due to insufficient donor site availability, resulting in delays in wound coverage. Cultured epidermal autograft (CEA) provides burn wound coverage in patients with extremely limited donor sites, but its success is limited by fragility, lack of basement membrane–anchoring cells, and susceptibility to shear and pressure, particularly over the lower extremities. Methods: We present two adult patients with total body surface area burns greater than 80% who underwent treatment with CEA and external fixation of the lower extremities. Burn wounds were excised and temporarily covered with allograft skin prior to CEA application. A triplanar external fixation device was used to suspend the lower extremities off the bed surface to minimize shear and pressure on CEA-treated areas. Results: Following application, both patients demonstrated near-perfect graft adherence, with wounds healing within four weeks and durable epithelial coverage at 12 weeks. No complications related to external fixation were observed. The use of external fixation to suspend the lower extremities reduced shear forces and improved CEA take. This approach provided stable wound healing, facilitated wound care, and demonstrated excellent functional recovery. Conclusions: External fixation may serve as a valuable adjunct in improving outcomes of CEA in patients with extensive burn injuries involving the lower extremities. Full article

Soil erosion and the nutrient loss it causes are core issues threatening sustainable land use in arid and semi-arid regions. In this study, our aim was to reveal the spatiotemporal differentiation characteristics of soil erosion and soil nutrients in an ecologically fragile area of eastern Inner Mongolia—Tuquan County and clarify the relationship between them in order to provide a scientific basis for the precise management of water and soil resources and ecological construction in this region. Based on four sets of remote sensing images and ground observation data from 2012, 2016, 2020, and 2024, the Revised Universal Soil Loss Equation (RUSLE) was used to evaluate the dynamics of soil erosion, statistical methods were employed to analyze the spatial distribution and grade characteristics of soil nutrients (organic carbon, SOC; total nitrogen, TN, total phosphorus, TP) and pH values, and correlation analysis was conducted to explore their association with environmental factors (rainfall erosivity, R; soil erodibility, K; slope length, LS; vegetation cover and management factor, C). Our results demonstrate the following: (1) From 2012 to 2024, the intensity of soil erosion in the study area showed an increasing trend, with the average annual soil erosion modulus increasing from 551.4 t/(km²·a) to 859.6 t/(km²·a), and the high-intensity erosion areas were mainly distributed in the northwest. (2) The soil nutrient content was generally at medium to low levels, with the SOC and TN in the study area mainly categorized as “deficient” and “adequate”. The SOC ranged from 5.8 to 33.8 g·kg⁻¹, with an average content of about 23.5 g·kg⁻¹, while the TN content ranged from 0.45 to 4.63 g·kg⁻¹, with an average content of about 1.50 g·kg⁻¹, and was significantly affected by soil type. (3) There was a significant negative correlation between the soil erosion modulus and the SOC and TN content (p < 0.05), which was a key driving factor for nutrient loss. This conclusion suggests that soil erosion in Tuquan County is intensifying: the risk of nutrient loss is severe, and its spatial pattern is jointly restricted by topography, vegetation cover, and soil background characteristics. Therefore, future ecological engineering should focus on high-intensity erosion areas and combine the prevention of soil and water loss with the conservation of soil fertility in order to achieve sustainable land use in the region. Full article

The wind–water erosion crisscross region in the middle reaches of the Yellow River is a typical ecologically fragile area in China, which seriously restricts the sustainable development of the regional ecological environment. For the soil wind erosion issue in typical wind–water compound erosion zones, this study selected three representative watersheds from different sub-regions, namely Liudaogou, Zhifanggou, and Hailesitaigou, as the research objects. Indoor wind tunnel experiments were conducted to investigate the driving mechanisms of wind speed, soil moisture content, and vegetation coverage on wind erosion processes under different underlying surface conditions, and to compare near-surface soil wind erosion responses among three typical watersheds with different soil backgrounds. The results indicated that when soil moisture content increased from 0.01 to 0.05 g/g, the threshold wind velocities for sand entrainment in Liudaogou, Zhifanggou and Hailesitaigou increased by 5%, 10%, and 5%, respectively. Regression analysis was adopted to establish the empirical formulas of critical sand-blowing wind speed for each watershed, and soil moisture content exerted the most significant influence on the critical wind speed in the Zhifanggou watershed. At a constant wind speed, the increases in soil moisture content and vegetation coverage could markedly reduce wind erosion yield. Under the wind speed of 12–18 m/s, wind erosion yield was strongly dominated by wind speed and weakly affected by soil moisture content. The improvement of vegetation coverage could substantially mitigate wind erosion intensity. Additionally, soil moisture content and vegetation coverage presented more prominent inhibitory effects on near-surface sediment transport. The three watersheds exhibited different wind erosion response patterns and sensitivity characteristics, indicating that soil type and underlying surface conditions should be fully considered when conducting wind erosion risk assessment and vegetation restoration planning in the wind–water erosion crisscross region. Full article

Quantifying the soil moisture (SM) response to precipitation is pivotal for predicting hydrologic resilience and ecosystem stability in fragile cold regions. This is true in alpine permafrost environments characterized by variable precipitation phases and strong seasonal freeze–thaw dynamics. However, critical knowledge gaps persist due to the scarcity of high-resolution, multi-layer in situ observations in these remote areas. Using hourly data from three sites in the Tanggula Mountains (2020–2024), this study employs an event-based analytical framework combining logistic regression and linear regression to quantify multi-layer (10–100 cm) SM responses to rain, snow, and mixed-phase precipitation across seasons. Core findings indicate the following: (1) Precipitation thresholds with 80% probability of triggering SM responses rise sharply with depth during the cold period (10 cm: 1–11 mm; 50–100 cm: often >15 mm or unreachable) but increase gradually in the warm period (10 cm: 0.4–5 mm; 50 cm: <15 mm). Mixed-phase precipitation refers to the lowest amount of precipitation (0.4–2.5 mm at 10 cm), followed by rain (1–11 mm) and snow (2–5 mm). (2) Warm-period regression slopes are consistently steeper than cold-period slopes (at 10 cm, 0.0024 vs. 0.0010 for rainfall). Mixed-phase precipitation yields the steepest slopes, approximately 50% higher than rainfall at 10 cm in the warm period (0.0037 vs. 0.0024), due to its longer duration and dual-supply mode. For lag time, cold-period values are more widely dispersed due to multiple interacting factors, while warm-period values are concentrated; only warm-period rainfall exhibits a clear monotonic increase in lag time with depth, consistent with unsaturated flow theory. (3) The quantified regression slopes, threshold values, and phase-specific efficiencies provide transferable metrics for calibrating infiltration models and evaluating frozen-ground hydrology schemes. The finding that mixed-phase events are the primary driver of deep-layer recharge, despite accounting for a smaller fraction of the total event count, has direct implications for water resource assessment in high-altitude catchments where precipitation phase composition is often oversimplified. Overall, this study moves beyond qualitative descriptions by providing quantifiable, transferable metrics that advance the mechanistic understanding of precipitation–SM coupling in alpine permafrost regions. Full article

This research investigates the development of integrated knowledge systems for built heritage located in Italian Inner Areas, marginal territories characterised by socio-economic fragility and the progressive weakening of traditional settlement systems. Within these contexts, built heritage is deeply interconnected with the landscape as a result of long-standing interaction processes between man and territory. Yet it is often affected by limited, fragmented information and inadequate digital management frameworks. This study addresses these issues by developing a methodological approach grounded in multidisciplinary, multiscalar, transcalar, and diachronic principles to reconnect territorial and architectural dimensions within a unified interpretative framework. The Alpine municipality of Dosso del Liro (Northern Italy) was selected as a representative case study for testing the applicability of an integrated H-GIS-BIM workflow under conditions typical of marginal contexts. The research combines desk-based and field-based investigations. Information was organised with regard to the historical and diachronic features of assets and then integrated into a digital environment developed using GIS, HBIM, and conversion workflows. The results demonstrate the accessibility of H-GIS-BIM strategies through a methodological approach and their support for enriching analyses of diffuse heritage, while also highlighting current limitations regarding workflow, interoperability, semantic preservation, and dynamic data updating. Full article

Climate-related disturbances are increasingly identified as major determinants of food insecurity in fragile environments, yet empirical evidence remains scarce in conflict-affected areas such as the eastern Democratic Republic of Congo (DRC). Using high-frequency FAO DIEM-Monitoring surveys (2022–2026), this paper estimates the causal effect of climate shocks on household food security in the provinces of Ituri, North Kivu, South Kivu, and Tanganyika. Food security is measured with five validated indicators (FCS, HDDS, HHS, FIES, and rCSI); capturing multiple dimensions of access, consumption, and coping. To address endogeneity in self-reported shock exposure, the authors apply an instrumental-variable Conditional Mixed Process (IV-CMP) model and triangulate results with a pseudo-panel fixed-effects ordered probit model based on FIES severity. Objective climate proxies (rainfall and NDVI) are used to reinforce robustness. The results indicate that climate shocks lead to a significant deterioration in food consumption and raise the likelihood of households experiencing both moderate and severe food insecurity, thereby undermining sustainable food security. Effects are heterogeneous across provinces, reflecting the interaction between climate variability, conflict intensity, and market access constraints. Female-headed households are disproportionately affected in some areas, highlighting gendered vulnerabilities, while income, education, livestock ownership, and land access mitigate vulnerability. These findings highlight the need for integrated and sustainability-oriented policy responses combining climate-smart agriculture, adaptive social protection, early warning systems, and conflict-sensitive programming. Overall, this research advances existing knowledge by delivering rigorous causal insights based on multiple food security indicators and advanced econometric techniques in a highly fragile setting. Full article

Livelihood space serves as a fundamental medium for the livelihood practices of rural households. Understanding its optimization and reconstruction is essential for promoting the sustainable development of resettled households. This study adopts a spatial perspective to develop a multidimensional measurement framework for livelihood space. Focusing on resettled households in the karst regions of Guizhou, China, we integrate the Optimal Parameter-based Geographical Detector (OPGD) with fuzzy-set Qualitative Comparative Analysis (fsQCA) to systematically analyze the driving mechanisms and equifinal configuration pathways involved in the reconstruction of livelihood space. The key results are as follows: (1) The overall livelihood space is characterized as moderate. Among the various dimensions, institutional and cultural spaces receive the highest scores, followed by social and production spaces, while residential space is rated the lowest. (2) Excluding residential space, there are significant dimensional disparities across different resettlement and livelihood typologies. Households resettled in county towns outperform those in non-county areas. In terms of livelihood types, integrated and off-farm households rank the highest, whereas farming-dependent and subsidy-dependent households rank the lowest. (3) The OPGD analysis indicates that household income and accessibility to public services are primary drivers, exhibiting a bivariate nonlinear synergistic enhancement. (4) The fsQCA findings confirm that the reconstruction of livelihood space is not driven by a single factor; rather, it is influenced by four equifinal pathways formed through nonlinear interactions of multiple conditions, collectively contributing to the enhancement of high-livelihood space. The integration of OPGD and fsQCA moves beyond conventional linear approaches, yielding fresh empirical evidence and new perspectives on livelihood space reconstruction and the sustainability of fragile regions. Full article

Against China’s dual-carbon strategy and watershed ecological high-quality development initiatives, exploring land-use-driven carbon storage variations is crucial for watershed spatial governance, ecological restoration and carbon sink improvement. As the Yellow River’s largest tributary, the Weihe River Basin straddles the ecotone of arid–semiarid Northwest China and the eastern monsoon region, with fragile ecosystems, intense human activities and dramatic land-use evolution. Clarifying its spatiotemporal carbon dynamics and nonlinear factor response patterns can support low-carbon ecological regulation and coordinated watershed sustainability. This study integrates PLUS and InVEST models to quantify the spatiotemporal patterns of land use and carbon storage across 2000–2020 land use data. Four development scenarios are established to predict 2030 carbon storage spatial heterogeneity, and an interpretable XGBoost-SHAP framework was employed to disentangle the nonlinear responses of carbon storage to natural and socioeconomic drivers. The results show that basin carbon storage exhibited an overall increasing trend, with a net increase of 452.29 × 10⁴ t over the 2 decades. Spatially, high-carbon areas presented patchy aggregation in the northeast, sporadic distribution in the west and zonal expansion in the south–central basin, while low-carbon areas were concentrated in the downstream Guanzhong Plain urban agglomeration. Land-use transitions represented a major source of regional carbon variability, with forest expansion driven by the Grain-for-Green Program generating the largest carbon sequestration increments. The 2030 scenario simulations revealed elevated carbon storage under natural development, cropland protection, and ecological protection scenarios, with the ecological protection scenario yielding the most prominent carbon gain. Conversely, unconstrained economic expansion coincided with prominent carbon storage declines, which implies that targeted ecological conservation and restoration could help alleviate carbon depletion across the watershed. NDVI, slope, and population density are the primary determinants of carbon storage, exhibiting typical staged nonlinear influencing effects. This study provides reliable scientific references for refined ecological restoration, spatial optimization, and carbon sink enhancement in ecologically fragile river basins. Full article