Search Results (4,725)

The watershed boundaries in arid and semi-arid regions are critical zones where ecological vulnerability and socio-economic development are in severe conflict. The upper and middle reaches of the Yellow River basin are a typical example of this dilemma. Intensive land use and human developmental interventions in this region have severely disrupted the integrity and balance of the ecosystem. While spatially designated, networked conservation areas can effectively promote the integrity and balance of regional ecosystems, these areas may fail to capture dynamic changes in vulnerability. This study develops a “functional diagnosis-structural diagnosis-integrated optimization” framework. It integrates various scenarios to diagnose vulnerability under uncertainty and identifies bottlenecks in ecological networks. For functional diagnosis, the coupling of the sensitivity–resilience–pressure (SRP) model and the Ordered Weighted Averaging (OWA) algorithm accurately locates vulnerable areas within the regional ecosystem. In terms of structural diagnosis, the Morphological Spatial Pattern Analysis (MSPA), Minimum Cumulative Resistance model (MCR), and Circuit Theory are integrated to identify structural bottlenecks. The main findings of this study are as follows: (1) Functional Diagnosis: The coupling of SRP and OWA reveals the non-linear vulnerability responses to policy preferences and identifies areas that consistently exhibit functional vulnerability across different scenarios. (2) Structural Diagnosis: The circuit theory combined with MSPA and MCR analysis identifies 72 ecological pinch points. These bottlenecks represent the weakest structural nodes crucial for maintaining regional ecological robustness. (3) Coupled Delineation and Differentiated Restoration Strategies: High vulnerability areas identified by SRP and consistently vulnerable areas identified by OWA are combined to delineate four distinct ecological restoration units: Alpine Fragile Matrix Unit, Loess Hilly Soil Conservation Unit, Anthropogenic Pressure Pinch Point Unit, Key Structural Stepping Stone Unit. Differentiated ecological restoration strategies are proposed based on the varying sensitivity, resilience, and pressure characteristics of these units. The “functional-structural” coupled ecological vulnerability evaluation framework can precisely identify vulnerable areas. The delineated restoration units and their corresponding restoration strategies provide reference and supplementation for the protected areas system, offering transferable tools for enhancing regional ecological efficiency. Full article

Under global climate change, analyzing carbon storage dynamics and their drivers is essential for understanding regional carbon sink capacity. Human activities and land-use change have substantially affected regional carbon storage. However, in China, most existing studies emphasize specific driving pathways, and integrated analyses of the combined effects of climate, natural, human, and landscape factors remain limited. This study aims at clarifying the integrated mechanisms by which multiple driving factors influence regional carbon storage. The InVEST model was used to analyze the carbon storage spatiotemporal changes. OPGD was then applied to evaluate the explanatory power of driving factors and their interactions, quantifying their contributions to carbon storage spatial patterns. Based on PLS-SEM, the direct and indirect effects of LULC, climate, natural, human, and landscape factors were quantified to elucidate the driving pathways of carbon storage. This study focuses on Shaanxi Province, which is a key ecological restoration region in the core area of the Loess Plateau. The main results are as follows: (1) From 2000 to 2020, carbon storage in Shaanxi Province showed a continuous increasing trend, rising from 2.97 × 10¹⁰ Mg C to 3.03 × 10¹⁰ Mg C. (2) LULC was identified as the most important direct and predominantly negative driving factor of carbon storage. (3) Natural factors had a strong positive influence on carbon storage, among which slope and NDVI exhibited the highest explanatory power; in contrast, climate factors showed weaker but still positive effects. (4) Human activities affected carbon storage through both direct and indirect pathways associated with LULC, with positive effects driven by landscape factors and negative effects driven by natural factors, while climate factors exhibited mixed but weak effects. Overall, carbon storage dynamics in Shaanxi Province reflect a hierarchical and path-dependent process shaped by the combined effects of natural constraints, human activities, and policy guidance through LULC pathways, providing important evidence for systematically understanding the driving structure and pathways of regional carbon storage. These findings highlight the importance of aligning land-use policies with regional biophysical constraints to enhance carbon sequestration efficiency. Full article

At present, most plateau-constrained cities worldwide—plateau cities whose spatial form is strictly constrained by topography—have entered the late stage of urbanization. The relationship between urban form and the surrounding geographic spatial pattern has consequently exhibited distinctive new characteristics. However, planning and policy often continue to adopt green-space allocation schemes developed in the mid-stage of urbanization and based on the experience of plain cities, resulting in difficulties in plan implementation, intensified human–land conflicts, and imbalances in both the supply–demand relationship and equity of green public services with severe challenges to urban sustainable development, calling for urgent correction and reconstruction. Through a literature review and comparative case analysis, this study clarifies global trends in the paradigm shift in plateau-city planning and develops an evaluation system comprising “adaptability analysis of originally planned spaces within the built-up area + assessment of the potential for converting ecological value in green spaces outside the built-up area + integrated spatial optimization.” Building on Analytic Hierarchy Process (AHP) weighting and spatial analysis, the study establishes a comprehensive assessment framework and applies it empirically to Kunming as a typical case, with the aim of proposing a correction-and-reconstruction paradigm for green-space allocation tailored to plateau-constrained cities to achieve sustainable development goals. The results indicate a widespread paradigm shift in many cities from “pattern optimization during incremental expansion” and “passive adaptation to ecological patterns” toward “enhancing governance effectiveness during stock-based renewal” and “proactive innovation in governance instruments.” The Kunming case shows that, during the mid-stage of urbanization, numerous parks and green spaces were planned within the built-up area (flat land), yet many of these proposals proved infeasible due to excessive costs and trade-offs. Meanwhile, the adjacent mountainous ecological spaces with substantial scenic and recreational potential were long excluded from the urban public service system. In response, this study proposes a three-dimensional allocation model that combines “optimized adaptation” within the built-up area and “potential conversion” in adjacent peri-urban areas together with differentiated policy instruments and an implementation/transfer assurance mechanism. This approach not only offers practical planning guidance for Kunming but also provides a broadly applicable set of theoretical and practical tools for improving land-use efficiency and promoting green equity in similar cities worldwide. Full article

This study proposes a variable-scale optimization strategy for land-levelling path planning to overcome the limitations of conventional traversal-based operations, including poor coordination, insufficient planning, low operational efficiency, and the computational burden associated with large datasets and constrained earthmoving capacity. For large-scale inter-regional earthwork balancing, an improved ant colony optimization (IACO) algorithm is developed to generate efficient region to region transfer routes. After verifying that inter-regional earthwork balance satisfies the levelling requirement, a field-wide fine-levelling plan is produced at the grid scale using a hybrid method that integrates an improved A* search with ant colony optimization (FIA*ACO). The proposed framework is evaluated through simulation and field experiments using measurement-based indicators, including the maximum elevation difference and the proportion of points within ±5 cm of the target elevation. Field results show that IACO-based inter-regional planning increases the ±5 cm compliant proportion by 14.18 percentage points and reduces the maximum elevation difference by 0.079 m. Subsequent FIA*ACO-based fine-gridded planning further improves the ±5 cm compliant proportion by 20.82 percentage points and decreases the maximum elevation difference by 0.311 m. Overall, the results demonstrate that inter-regional planning rapidly expands the area meeting levelling standards, while grid-level refinement further enhances levelling quality, validating the effectiveness of the proposed variable-scale strategy for land-levelling path planning. Full article

Research designed to reduce or eliminate fishmeal (FM) in trout feeds, for reasons that have changed over time, has been conducted for over a century. Reducing the dependency on FM remains one of the most urgent issues facing the industry. Feed represents the most expensive operational cost of fed aquaculture, and is responsible for ecosystem disturbance following nutrient discharges. Rainbow trout, the second most farmed salmonid globally, can be raised completely without FM or fish oil (FO), with its growth and efficiency not differing from trout fed FM-based feeds. However, ingredient choice and nutrient supplementation strongly influence physiological responses, efficiency, and long-term outcomes. As land animal proteins are increasingly used in place of FM, both with and void of dietary FO, their distinct biological effects warrant focused evaluation. Although numerous studies have synthesized findings across various alternative protein categories including those with insect proteins and animal by-products, this literature is widely disseminated and sometimes difficult to access. The present contribution focuses on terrestrial/aerial animal proteins that have been used to totally replace FM in rainbow trout feeds. Attention is given to their effects on physiological control processes that may influence production efficiency. Areas worthy of future study are identified and include long-term performance and health dynamics, the refinement of nutritional and formulation strategies, and the broader evaluation of biological interactions and system-level outcomes. Full article

Declining birth rates are reshaping higher education across East Asia, accelerating the large-scale underutilization and, in some contexts, partial abandonment of university campus assets. Although adaptive reuse has been widely discussed, campus transformation is often framed primarily as a programmatic or policy problem, with limited attention to the inherited spatial logic embedded in campus morphology. This study revisits Le Corbusier’s concept of unlimited growth as a generative framework for campus transformation. Rather than treating it as a museum-specific historical typology, the research reinterprets unlimited growth as a scalable spatial logic defined by modular continuity, circulation hierarchy, and open-ended sequencing. To enhance reproducibility and operational clarity, the study formalizes a typo-morphological decoding protocol—modules, circulation, and growth sequence—and applies it through plan-, section-, and diagram-based analysis. Through comparative examination of three museum precedents—Sanskar Kendra Museum, the National Museum of Western Art (Tokyo), and the Chandigarh Museum and Art Gallery—the study extracts a set of transferable spatial mechanisms: modular increment, circulation-centered ordering, directional displacement, and fifth-façade ecological continuity. These mechanisms are then translated into an operational right-sizing model and tested through a design-operational demonstrator on a single anonymized Taiwanese campus experiencing demographic contraction. The findings indicate that unlimited growth functions not merely as a formal principle but as a spatial governance logic that supports phased consolidation, adaptive recomposition, and system-level coherence under long-term uncertainty. Importantly, this framework contributes to sustainability by reducing land consumption through spatial consolidation, minimizing unnecessary new construction, enabling adaptive reuse of existing campus assets, and improving long-term resource-use efficiency through phased right-sizing and ecological continuity. This study further advances a reproducible, mechanism-based methodological framework for institutional spatial transformation, providing a transferable approach for large-scale campus restructuring under conditions of long-term demographic and environmental uncertainty. Full article

Monarch butterflies have declined in both eastern and western populations. Conservation initiatives that support this imperiled species are being implemented in lands managed by the energy and transportation sectors. Vegetation management strategies that encourage the presence of milkweed (Asclepias spp.), the larval host of monarch butterflies (Danaus plexippus), or floral resources to support pollinators are being practiced across North America; however, survey methods to evaluate the success of these strategies vary in accuracy and scalability. In this study, we compared five methods to quantify milkweed stem density and land cover estimates: (1) Site al, (2) Transect plot, (3) Square plot, (4) Large transect (informed by the Monarch CCAA methodology), and (5) Machine learning of images collected by UAVs. These methods encompass full coverage ground counts, partial ground counts, and aerial imagery using object-based image analysis. Sites included distribution, transmission, and gas line ROWs, solar arrays, and transportation easements. We found that Site al and Machine learning most consistently quantified milkweed stem density across sites. Partial ground count methods were likely to over or underestimate milkweed populations. Habitat characteristics (woody, broadleaf, grass, and bare ground) estimates were inconsistent across method and site. The intent of this study was to provide land managers with insight as to the most accurate, efficient, and economical approach to quantify milkweed populations and habitat characteristics. Full article

Enhancing urban ecological resilience (UER) is crucial for mitigating soil erosion, improving land use efficiency, and preventing ecological degradation. The digital–real economy integration (DRI) plays a pivotal role in strengthening UER, offering a vital pathway for modernizing ecological governance systems and capabilities in the Yellow River Basin (YRB). Based on ecological resilience theory, this study establishes a three-dimensional evaluation framework centered on “resistance–recovery–adaptation”. Using panel data from 78 cities in the YRB from 2011 to 2023, we empirically examine the impact of DRI on UER. The results indicate that DRI significantly improves UER in the YRB, with notably strong positive effects on recovery and adaptation capacities, although there is no significant effect on resistance capacity. Mechanism analysis reveals that DRI promotes UER primarily through three channels: upgrading the industrial structure, strengthening government governance, and spurring green technological innovation. Heterogeneity analysis further shows that the positive impact of DRI on UER is more pronounced in downstream cities, urban agglomerations, non-resource-based cities, key environmental protection cities, green data center pilot cities, and informatization–industrialization integration pilot cities. Spatial analysis confirms DRI generating positive spatial spillover effects on the UER of neighboring cities. This study provides a theoretical basis for understanding the ecological governance potential of DRI and offers policy insights to support coordinated digital and green transformation in the YRB. Full article

Leaf yellowing seriously affects the sustainability of artificial forest ecosystems. However, it remains unclear whether such chlorosis is driven primarily by soil nutrient deficiency or by internal nutrient reallocation. In particular, the physiological processes underlying the green apices and yellow bases pattern within branches remain poorly understood. This study compared needle carbon (C), nitrogen (N), and phosphorus (P) stoichiometry between apical and basal positions in asymptomatic and symptomatic Pinus sylvestris L. trees within the Otindag Sandy Land, China. Our findings revealed that except for the 80–100 cm layer, soil element concentrations did not differ significantly between healthy and chlorotic trees. In the trees, apical needles maintained stable stoichiometry across all trees, whereas basal needles of symptomatic individuals exhibited significantly higher C:N and C:P ratios, indicating severe localized nutrient stress. Notably, symptomatic trees exhibited exceptionally high N and P resorption efficiencies (79.68% and 71.05%, respectively), which were significantly higher than those of healthy trees (41.73% and 48.09%). The high Stoichiometric Deviation Index (SDI) and weak needle–soil correlations further confirm that needle chlorosis is decoupled from direct soil supply limitations. Instead, this pattern is primarily governed by prioritized internal nutrient reallocation to safeguard apical growth dominance. These findings highlight branch-level nutrient redistribution as a useful adaptive strategy to consider when interpreting early decline symptoms and nutrient stress in sandy-land P. sylvestris plantations. Full article

Salt stress is one of the major environmental constraints in agriculture, significantly limiting crop yield and causing substantial economic loss worldwide. Silicon (Si) and selenium (Se) are widely recognized as beneficial elements for plants, and the application of Si- and Se-based fertilizers is considered a promising strategy for promoting crop growth and sustainable agricultural production under expanding salinization of arable land. In this study, aiming for the targeted application of Si and Se in agricultural production, the individual and synergistic effects of Si and Se on salt stress resistance in tomato when applied via root application or foliar spray were comprehensively investigated. Plant growth parameters, photosynthesis performance, oxidative damage, the activity of the antioxidant system, sodium/potassium (Na/K) content, and the expression of genes related to Na/K homeostasis were determined and further compared using principal component analysis (PCA). The results showed that salt stress markedly inhibited plant growth and photosynthetic performance, while inducing oxidative damage and disrupting Na/K homeostasis in tomato seedlings. In contrast, the application of both Si and Se significantly promoted tomato growth and ameliorated the detrimental effects of salt stress. Moreover, Si and Se exhibited a synergistic effect in promoting salt stress resistance under both root and foliar application. Root application of Si and Se is more effective in enhancing ionic homeostasis, while foliar spray of Si and Se is more effective in promoting photosynthesis performance under salt stress. Overall, considering the convenience and use-cost efficiency of Si and Se application in agricultural practices, the results of this study showed that the synergy application of Si and Se via foliar spray is most effective in promoting salt stress resistance in tomato through modulating photosynthesis performance, antioxidant capacity, and ionic homeostasis. Full article

Seed coating technology is regarded as one of the optimal strategies to promote sustainable agricultural development. It can effectively optimize the physical and physiological characteristics of seeds, improve germplasm quality, and enhance crop resistance to abiotic and biotic stresses. Saline–alkali soils, characterized by high salinity and alkalinity, severely restrict plant growth and development. However, alfalfa, a high-quality leguminous forage, faces substantial challenges in large-scale popularization and cultivation in saline–alkali regions. At present, research on the application of microbial seed coating technology in alfalfa production under saline–alkali conditions remains insufficient, and relevant techniques and formulations still require optimization. Under field conditions, this study used a randomized complete block design with alfalfa as the research material. Different coating treatments combining plant growth-promoting rhizobacteria (PGPR), rhizobia, and extracellular polysaccharides (EPSs) were established to systematically investigate the effects of various coating formulations on alfalfa yield, nutritional quality, root system architecture, and rhizosphere soil properties. Meanwhile, high-throughput sequencing was employed to analyze shifts in rhizosphere soil microbial community structure. The results demonstrated that all microbial coating treatments exerted significant growth-promoting effects on alfalfa grown in saline–alkali soils, among which the T8 treatment (combined coating of rhizobia + PGPR + EPS) performed the best. This treatment not only significantly improved alfalfa yield and nutritional quality but also modified root system architecture and enhanced soil enzyme activities, soil nutrient contents, and soil physical structure, thereby creating a favorable growth environment for plants. Among the single microbial coating treatments, the combined coating of rhizobia and EPS outperformed other single treatments and exhibited favorable application potential. Sequencing results revealed that microbial seed coating treatments significantly increased the relative abundance of beneficial soil bacteria, decreased the abundance of harmful fungi, regulated rhizosphere microbial community structure, and consequently promoted improvements in alfalfa yield and quality by optimizing the plant growth microenvironment. The findings of this study provide important theoretical support for the popularization and application of microbial seed coating technology in crop cultivation in saline–alkali soils, offer a key reference for optimizing alfalfa-specific seed coating formulations for saline–alkali conditions, and are of great significance for promoting the efficient utilization of saline–alkali land resources and the development of ecological agriculture. Full article

With the wave of new campus construction gradually receding, the focus of green campus planning and design is shifting toward the low-carbon retrofitting of the existing built environment. University campuses often face challenges such as dispersed land use, inadequate spatial planning, disorganized road layouts, suboptimal landscape design, and low energy efficiency. Grounded in a review of current research on campus carbon emissions, this study integrates green technology indicators with planning and design approaches to establish a multi-scale, context-adaptive planning framework for carbon control, spanning five dimensions: intensive land use, spatial layout, transportation systems, landscape development, and facility integration. Employing a combined approach of bibliometric analysis and case studies, this research examines and compares typical university campuses both domestically and internationally to validate the effectiveness of the synergistic “technology-system-behavior” pathway in mitigating high-carbon lock-in. Through a systematic comparative analysis of representative low-carbon campuses, the synthesized results indicate that under optimal operational conditions, the clustered reorganization of functional zones demonstrates the potential to reduce transportation carbon emissions by approximately 25%; comprehensive retrofitting of building envelopes can decrease building energy consumption intensity by an estimated 30%; a multimodal coordinated transport system can increase the share of non-motorized travel to around 65%; establishing high carbon-sequestration plant communities can enhance carbon sink capacity by up to 30%; and smart facility integration can reduce overall campus carbon emissions by a projected range of 25–40%. It should be noted that these quantitative outcomes represent high-probability potential ranges, with actual performance subject to behavioral and operational fluctuations. This study provides theoretical support and practical pathways for achieving “near-zero carbon campuses” and underscores the important demonstrative role that higher education institutions can play in addressing climate change. Full article

This study develops and applies an integrated modeling framework to assess the solar-to-hydrogen-to-power potential across Romania’s five hydrogen ecosystems defined in the National Hydrogen Strategy. The methodology couples PVGIS-based photovoltaic yield simulations, based on hourly solar irradiation data and including system losses, with MHOGA-based electrolysis simulation, enabling a quantitative-energetic-environmental (Q-E-E) system-level assessment. A 1 MW photovoltaic plant was simulated under three mounting configurations (15° fixed tilt, optimal tilt, and solar tracking) and interfaced with alkaline (AEL) and proton exchange membrane electrolysers (PEMEL). Specific photovoltaic yields reach up to 360 kWh/m²_PV·year under tracking conditions, producing up to 7.5 kg/m²_PV·year (AEL) and 6.8 kg/m²_PV·year (PEMEL), expressed per unit of photovoltaic surface area to enable consistent comparison across the configurations considered. The modeled round-trip efficiency of the full solar–electricity–hydrogen–electricity chain is 38.32% for AEL and 34.57% for PEMEL. Life-cycle-based emission modeling yields 0.92 kg CO₂/kg H₂ (AEL) and 1.03 kg CO₂/kg H₂ (PEMEL), while avoided emissions exceed 250 g CO₂/kWh relative to grid intensity. Land-use modeling indicates area requirements between 9402 and 18,804 m²/MW, depending on the Ground Coverage Ratio. Results demonstrate that system configuration exerts a stronger influence than regional solar variability in determining hydrogen yield, highlighting the need for integrated techno-environmental optimization for large-scale deployment. Full article

The remediation of large-areas of Cd-contaminated soil, especially agricultural land, remains a major global challenge. Phytoremediation using hyperaccumulators is an effective method for treating Cd-contaminated soils; however, its long-term effectiveness over successive growing seasons has been insufficiently investigated. This study evaluated the sustained phytoremediation capacity of the farmland weed Bidens pilosa L., a known Cd hyperaccumulator, in a three-year pot experiment using contaminated agricultural soil from the Shenyang Zhangshi Irrigation Area (2.08 mg/kg Cd). Two harvest regimes were compared: short-term (harvest at the flowering stage, 70 days) and long-term (harvest at the fruit maturity stage, 108 days). The results showed that although higher total Cd accumulation per harvest was obtained in long-term treatments, short-term experiments resulted in a 14.7% higher net removal rate per day (NR) due to their shorter growth cycle (64.8% of the long-term period). Soil extractable Cd concentrations decreased by an average of 31.2% over three consecutive years of phytoremediation, reducing environmental risk but also limiting subsequent Cd uptake by plants. These findings demonstrate that optimizing harvest timing can substantially improve remediation efficiency per unit of time without the need for soil quality improvement measures. The short growing season characteristic of weeds found in agricultural areas is a practical advantage of phytoremediation. Full article

Landslide hazards occur frequently in the Ya’an region; therefore, accurately identifying and delineating potential landslide areas is crucial for disaster prevention and mitigation. Although deep learning-based detection methods using optical remote sensing imagery are widely adopted, the complex terrain and diverse land cover in this area often result in blurred boundaries and weakened textural features, making it difficult to precisely define spatial extents. To overcome these challenges, this study proposes an improved YOLOv11 model for landslide detection. Building on the YOLOv11 baseline, we designed a novel Multi-Scale Detail Enhancement module and integrated it into the neck network to effectively aggregate shallow-level details with deep-level semantic information, thereby enhancing the model’s ability to represent ambiguous boundaries. Additionally, we incorporated the lightweight SimAM attention mechanism into the backbone network. This mechanism dynamically suppresses background noise based on an energy minimization principle, improving feature discriminability within landslide regions and enabling precise boundary boxes. We conducted validation experiments in the Ya’an region using a custom dataset constructed from high-resolution UAV orthoimagery, comparing our method against mainstream models such as YOLOv8 and YOLOv10. The results show that the proposed improved YOLOv11 model achieves a precision of 90.2%, a recall of 84.8%, and an mAP of 92.7%. This enhanced performance demonstrates the model’s effectiveness in detecting landslides under complex terrain conditions, providing a practical technical reference for efficient hazard screening and dynamic monitoring. Full article