Search Results (746)

In Europe, the most valuable grasslands are semi-natural ecosystems maintained by long-term extensive human management, particularly pastoralism, and therefore do not represent climax vegetation. According to the Natura 2000 habitat interpretation manual (EUR-28), key habitats include xerothermic grasslands of Festuco-Brometalia (code 6210*) on calcareous soils and sandy grasslands of Koelerion glaucae (code 6120*) on poor substrates. Only 10–15% of their area in the EU has favorable conservation status. The main threat is secondary succession and encroachment (83.94%), caused by abandonment of traditional management (81.75%). Without mowing or grazing, dominant grasses replace rare species, followed by shrubs and trees. Other pressures include intensive agriculture (75.18%), habitat loss and fragmentation (69.34%), climate change (37.96%), invasive species (23.36%) and urbanization (14.60%). Multiple threats often co-occur, so cumulative percentages exceed 100%. The most effective conservation method is restoring or maintaining extensive grazing, particularly with local sheep and goat breeds. Grazing limits succession, increases structural diversity and promotes seed dispersal, creating a mosaic of microhabitats that enhances biodiversity. Effective protection requires landscape-scale actions, limiting urban development, and long-term support for farmers under the Common Agricultural Policy. Increasing public awareness of the ecological and cultural value of these ecosystems is also essential. Full article

This study presents the vegetation of a Mediterranean area in Croatia, abandoned by the military three decades ago after two centuries of use. From 2023 to 2025, 97 phytosociological relevés were taken using the Braun–Blanquet approach. Based on numerical classification, we identified seven plant associations, two subassociations, and two communities within nine floristically and ecologically distinct vegetation classes. Military presence shaped the landscape in several ways. Large parts of the peninsula remain near-natural, covered by high maquis with minimal disturbance. Plateau shooting ranges, formerly grasslands, now represent rare habitats due to ongoing succession. Within former barracks, plantings included low-maintenance species providing rapid greening and visual screening. Evergreen conifers were favored for year-round greenery, while deciduous trees and ornamental shrubs provided shade and aesthetic value. Given current neglect and ongoing successional trends, the site requires a carefully planned management program aimed at habitat restoration, control of shrub encroachment, and maintenance of open and semi-open vegetation to preserve biodiversity and landscape heterogeneity. Full article

Adverse weather conditions significantly degrade mobility and safety at rural signalized intersections, where high approach speeds and limited driver expectancy amplify operational and crash risks. While autonomous vehicles (AVs) have the potential to improve traffic performance, it takes a significant duration to penetrate. During this period, mixed traffic with human drivers and AVs will dominate. In this mixed traffic, the impacts of AVs at low penetration levels on adverse weather remain insufficiently understood, particularly in rural contexts. This study presents a simulation-based assessment of the effects of low AV penetration on mobility and safety at a rural signalized intersection under varying weather conditions. A calibrated microsimulation model was developed using PTV VISSIM to represent clear, rain, and snow scenarios with autonomous vehicles introduced at low penetration rates within conventional traffic. Mobility performance was evaluated using delay, travel time, and average speed, while safety impacts were assessed through surrogate safety measures extracted using the Surrogate Safety Assessment Model (SSAM), including time-to-collision and post-encroachment time. Results indicate that low levels of AV penetration of 10% can improve overall mobility performance compared with conventional traffic, particularly under adverse weather conditions. Safety outcomes show a reduction in conflict frequency and severity under low AV penetration, with more pronounced benefits observed during degraded weather scenarios. Further AV penetration from 10% to 25% may not significantly improve in a rural environment. The findings suggest that early-stage AV deployment may offer measurable mobility and safety benefits at rural signalized intersections, even before widespread adoption. This study provides practical insights for transportation agencies and policymakers regarding the potential role of low-penetration AV integration in enhancing rural traffic operations and safety under adverse weather conditions. Full article

Mangroves are crucial for biodiversity conservation, coastal protection, and supporting local livelihoods. Mangroves may also protect coasts from storms and rising sea levels and can play a major role in climate mitigation. Threats to their health include activities such as infrastructural development, urban encroachment, aquaculture and crop farming, and oil and gas exploration. We review the threats and opportunities for the restoration of mangrove ecosystems on the coasts of Africa, which are highly impacted by oil spills. The most important challenge for mangrove restoration identified in this review is the restoration of appropriate hydrologic and salinity regimes prior to natural recruitment or the active planting of propagules. Full article

In this paper, we present a curated dataset derived from continuous multi-object tracking observations over a two-year period from a signalized urban intersection in Salzburg, Austria. The dataset includes time-resolved trajectories of multimodal road users, post-processed object attributes, movement relations, and Post-Encroachment Time values computed for a fixed set of eight predefined multimodal traffic conflict scenarios. Moreover, traffic signal data are included and can be used as contextual information. A temporal six-month subset is published via Zenodo including usage examples written in python. The full dataset can be provided on request. Potential applications include traffic safety analysis, behavioral modeling, method development for interaction detection, and educational use in data-driven traffic research. Full article

Motor vehicle encroachment into non-motorized lanes is a common but hard-to-verify violation in urban intersections, especially when monitored from unmanned aerial vehicles (UAVs) or high-mounted overhead views. Existing rule-based solutions built on horizontal bounding boxes and center-point/line-crossing criteria are sensitive to perspective distortion, occlusion, and frame-to-frame jitter, resulting in unstable decisions and low evidential value. This paper presents a cascaded UAV-view system that closes the loop from perception to evidence output through detection–segmentation–recognition–decision. First, we adopt a two-stage detection cascade: a lightweight vehicle detector localizes vehicles using axis-aligned bounding boxes, and a dedicated YOLOv5n-based oriented bounding box (OBB) license plate detector, constructed via architecture grafting and weight transfer, is then applied within each vehicle region of interest (ROI) to localize rotated license plates under large pose variation and small-target conditions. Second, a U-Net lane region segmentation module provides pixel-level spatial constraints to define an enforceable lane occupancy region. Third, a perspective rectification step is integrated with the PP-OCRv4 optical character recognition (OCR) framework to improve license plate recognition reliability for tilted plates. Finally, an area ratio criterion and an N-frame temporal counter are used to suppress transient misdetections and stabilize alarms. On a representative 100-sample controlled encroachment benchmark, the proposed system improves detection accuracy from 67.0% to 92.0% and reduces the false positive rate from 32.35% to 5.88% compared with a baseline horizontal bounding box (HBB)-based rule. The system outputs both violation alarms and license plate evidence, supporting practical deployment for multi-view traffic governance. Full article

As the largest urban agglomeration and a critical grain production base in northern China, the Beijing–Tianjin–Hebei (BTH) region faces a sharp conflict between rapid urbanization and cropland conservation. Urban expansion inevitably leads to the loss of high-quality agricultural land, posing dual threats to food security and the terrestrial carbon cycle. To accurately assess the ecological costs of this process, this study integrates the CASA model with a time-weighted cumulative model to quantify the spatiotemporal impacts of urban expansion on cropland NPP in the BTH region from 2001 to 2020. Furthermore, a Geographically Weighted Regression (GWR) model was employed to examine the spatially varying effects of key driving factors on cropland NPP loss. The results indicate that urban land in the BTH region expanded by 45.2% over the past two decades, with 91.04% originating from cropland. Despite an overall upward trend in regional cropland NPP driven by climate change and agricultural intensification, the time-weighted cumulative cropland NPP loss attributable to urban encroachment over 2001–2020 reached 29.24 Tg C, which is equivalent to 0.751× the annual total cropland NPP in 2020 (used as a reference benchmark). Crucially, this expansion exhibits distinct ecological selectivity toward high-quality cropland, meaning that urban development has disproportionately encroached upon highly productive land with productivity levels exceeding the regional average. This selective occupation has led to a structural decline in the region’s potential agricultural production capacity. Additionally, GWR results reveal significant spatial non-stationarity in the relationships between cropland NPP loss and its drivers, revealing differentiated response patterns between plains and mountainous areas in terms of socio-economic drivers and physical constraints. These findings expose the hidden threats of urban expansion to food security, providing a crucial scientific basis for formulating differentiated land management policies and coordinating regional urbanization with cropland protection. Full article

Land-use change associated with scattered (isolated) housing in the countryside remains largely underestimated in conventional European land-use datasets due to spatial resolution and minimum mapping unit constraints. This study quantifies low-density urban sprawl at the building level in Cyprus for the period 1993–2022, both within and outside Special Protection Areas (SPAs) of the Natura 2000 network. Situating the analysis within a broader Mediterranean EU planning context, the paper examines how local spatial patterns reflect wider development trajectories, including tourism-driven growth and second-home demand. Results reveal a fivefold increase in isolated housing outside development planning zones, from 2440 units in 1993 to 12,640 in 2022 (+418%). Significant increases occurred within agricultural zones (Γ: +568%) and even in protection zones (Z1: +438%). Within SPAs, isolated houses rose from 341 to 1556 (+356%), while total building premises within these areas increased from 955 to 3649 (+282%), indicating statistically significant encroachment. Although Natura 2000 designation appears to have moderated development rates compared to the broader countryside, it has not prevented sprawl. The findings demonstrate substantial cumulative impacts on landscapes, ecosystems, and land-use planning objectives, highlighting the urgent need for stricter regulation of dispersed houses and auxiliary buildings both within protected and non-protected rural areas. Full article

Species of the genus Thunbergia, native to Africa, Asia, and Australia, are widely cultivated as ornamental plants; however, their ability to escape cultivation and establish themselves in novel environments poses a growing threat to tropical forests. Here, we provide the first nationwide assessment of Thunbergia species occurring in Ecuador, integrating data from citizen science platforms, herbarium collections, and field surveys. We analyzed spatiotemporal patterns of occurrence, evaluated invasion status based on wild persistence and spread, and assessed environmental preferences using climatic niche analyses. Species distributions were further examined across land-cover types, conservation areas, and forest–non-forest interfaces. We confirmed the presence of five Thunbergia species in Ecuador, two of which also occur in the Galapagos Islands. All species were recorded both in cultivation and in the wild, indicating ornamental horticulture as the main introduction pathway for the genus, and occurrences were documented within 24 conservation areas. Thunbergia alata, T. fragrans, and T. grandiflora were categorized as invasive in Ecuador. Among them, T. fragrans exhibited broad environmental tolerance across bioregions. Wild occurrences were predominantly associated with human-modified landscapes but frequently occurred near forest edges, indicating ongoing encroachment into natural forests. These findings highlight the urgent need for preventive and targeted management strategies, particularly against T. alata, which represents an emerging threat to Andean forest ecosystems. Full article

Tipping points of vegetation transitions represent the thresholds beyond which ecosystems can no longer maintain their stable states. Approaching these critical points may result in declined resilience or irreversible vegetation transitions. Detecting and predicting tipping points remains notably challenging, yet it is essential for guiding the preservation and restoration of terrestrial ecosystems. In this study, lag-1 temporal autocorrelation (AC1) derived from the Kernel Normalized Difference Vegetation Index (kNDVI) was utilized as an early warning signal to monitor resilience dynamics. We developed a new tipping-point detection method by combining land-cover changes, time series segmentations and temporal–spatial filters. We revealed a widespread resilience decline in China, with the dominant transition type as shrub encroachment. Then, two machine learning models coupled with temporal cross-validation were employed to predict the probabilities of abrupt shifts in the near future. The results showed that Random Forest models (accuracy > 70%) demonstrated robustness across lead times. High probabilities of transitions in 2024 were concentrated along the 400 mm annual isohyet, mainly affected by decreased water availability, lower soil acidity and degraded vegetation functions. Our study provides an effective methodology to pinpoint hotspots of vegetation vulnerability and to support the conservation of ecosystems for a sustainable future. Full article

Urban expansion presents significant challenges and opportunities for ecological conservation in developing countries, particularly in regions such as the Table Bay Nature Reserve in Cape Town, South Africa, where urban development interfaces with sensitive ecosystems. This article examines the complex dynamics between urban growth and ecological implications in this unique landscape, employing multi-temporal remote sensing techniques to analyze changes over time. By investigating the historical trajectory of urbanization in Table Bay, alongside its impacts on biodiversity and ecosystem services, we aim to underscore the urgent need for sustainable urban planning and conservation strategies. To analyze land use/land cover (LULC) dynamics over a 24-year period, this study leveraged a time series of satellite imagery processed within the Google Earth Engine (GEE) platform. Data can be accessed using their respective collection IDs within the GEE platform. The use of remote sensing tools aligns with Sustainable Development Goal (SDG) 15, which focuses on the protection, restoration, and sustainable use of terrestrial ecosystems. Urban encroachment analysis indicates that approximately 0.324 km² of built-up area expanded directly within the reserve boundary, highlighting a measurable degree of infringement into protected zones. The dominance of built-up and bare land classes highlights the early encroachment of urban infrastructure and anthropogenic disturbance, setting the stage for subsequent land cover transformations observed in later years (2012 and 2024). These findings demonstrate a persistent trend of urban encroachment and ecological alteration within the Table Bay Nature Reserve. With the increase in global population levels, urban expansion into protected conservation areas has become a critical environmental concern, threatening biodiversity globally. This challenge is particularly acute in developing countries as seen in regions like the Table Bay Nature Reserve in Cape Town, South Africa, where urban development is interfaced with sensitive ecosystems. Full article

Urban flood frequency analysis faces unique challenges as land development alters watershed hydrology, producing nonstationary flood records. This study demonstrates nonstationary flood frequency analysis (NSFFA) using RMC-BestFit, an open-source Bayesian software, through two Texas case studies. Brays Bayou at Houston (96 years of record) exemplifies an urbanized watershed with increasing flood trends; a step-logistic model captures both the abrupt increase in mean flood magnitude around 1968 and the progressive decrease in log-space variance as urbanization homogenized runoff response. O.C. Fisher Reservoir (169 years of record) exhibits decreasing trends attributed to brush encroachment and groundwater extraction; despite a sinusoidal model achieving best information criteria, a step function was selected based on physical reasoning, demonstrating that statistical fit alone should not dictate model selection. Results reveal contrasting frequency curve patterns: at O.C. Fisher, stationary and nonstationary curves differ uniformly (53% reduction in 100-year flood), while at Brays Bayou, curves differ substantially for frequent events (48% increase in 2-year flood) but converge in the extreme tail due to opposing trends in location and scale parameters. These findings underscore that NSFFA relevance depends on decision context. Bayesian methods offer key advantages including flexible integration of diverse data sources, comprehensive uncertainty quantification, and principled model comparison. Open-source software democratizes access to these methods, promoting transparency and reproducibility. Full article

Mangrove extent has increased in many regions under strengthened conservation policies and large-scale restoration programs. Nevertheless, mangrove ecosystems continue to face multiple pressures, including limited total area, habitat degradation, biodiversity decline, and biological invasion, and localized deterioration in ecosystem structure and function has been increasingly reported. Despite extensive mapping efforts, the spatiotemporal dynamics of mangrove degradation—particularly in tidally influenced environments—remain insufficiently understood. Focusing on the Nanliu River Delta, the largest deltaic mangrove system in the Northern Beibu Gulf of China, this study integrates long-term Landsat time-series imagery (1990–2025) with deep learning to quantify both mangrove extent change and canopy degradation. To mitigate tidal inundation effects, a NDVI Pseudo-P75 compositing strategy was applied using Google Earth Engine (GEE), enabling consistent observation of mangrove canopies across tidal stages. Global Mangrove Watch v4 (GMW-V4) and HGMF2020 mangrove dataset for China were used as reference labels to train a ResNet34–UNet segmentation framework incorporating Digital Elevation Model (DEM) constraints. The model achieved high classification performance, with an IoU of 0.822 for mangroves and 0.981 for background, yielding a mean IoU of 0.902. The resulting maps, following manual verification, provided a robust basis for spatiotemporal and degradation analyses. Canopy condition was further assessed using the Enhanced Vegetation Index (EVI), which is less prone to saturation in high-biomass mangrove stands. Results show that mangrove area in the Nanliu River Delta expanded from 266 ha in 1990 to 1414 ha in 2025, with the annual expansion rate after 2005 being nearly seven times higher than that before 2005. Despite this net gain, a cumulative loss of 347.45 ha was recorded, primarily during 1990–2000, with approximately 70% converted to aquaculture and coastal engineering. Spatial analysis revealed that mangrove expansion occurred predominantly seaward, whereas both mangrove loss and canopy degradation exhibited an inverse J-shaped relationship with seawall proximity. More than 80% of mangrove loss occurred within 200 m of seawalls, indicating concentrated anthropogenic encroachment, while 75.6% of canopy degradation was observed within 350 m, potentially reflecting landward forest senescence. These results indicate a transition in dominant threats from permanent land conversion in the late 20th century to more subtle, internal functional degradation in recent decades, underscoring the need to complement extent-based assessments with canopy condition monitoring in mangrove conservation and management. Full article

This study comprehensively evaluates the elemental composition of soil and Pinus species needle samples across 25 distinct plots established along the D825 highway in Kahramanmaraş, Türkiye. Located at the confluence of the Mediterranean, East Anatolian, and Central Anatolian regions, this area represents a critical ecological transition zone. A total of 75 soil and 75 needle samples were analyzed in triplicate to assess heavy metal contamination and potential toxicity risks across these elevation gradients. According to the results, the Geoaccumulation Index (I_geo) values for all examined metals remained below zero, categorizing the study area as “unpolluted.” Enrichment Factor (EF) analyses confirmed the lithogenic origin of Cr, Mn, and Ni; however, Lead (Pb) and Cadmium (Cd) exhibited an EF of 1.34. This ‘minimal enrichment’ could potentially be associated with anthropogenic pressures, possibly stemming from traffic emissions on the highway. Although current metal levels fall below global toxicity thresholds (WHO/FAO), the positive skewness and high variation in Pb and Cd distributions suggest a likelihood of localized accumulation, which may warrant systematic monitoring. The original contribution of this study lies in its integrated assessment of plant–soil barrier mechanisms within this unique transition zone, demonstrating how forest ecosystems maintain resilience capacity despite ophiolitic parent material contributions. While soil Cr and Ni levels were elevated due to the geological structure, plant tissue concentrations remained within safe physiological limits, suggesting effective stabilization within the soil-biomass matrix. The findings suggest that these forest ecosystems play a key role in maintaining ecological health and environmental sustainability against potential anthropogenic encroachment in this strategic intersection. Full article

This study examines retailers’ decisions of whether and when to introduce private labels considering the supplier learning effect. We construct a two-period framework including a supplier and a retailer with national brand and private label divisions and elucidate equilibrium results under the decentralized structure. Our analysis shows that the retailer’s optimal choices of private label encroachment are related to the supplier learning rate and product competition intensity. Specifically, the retailer chooses the first-period encroachment of private labels when product competition is weak; when encountering fierce product competition, the retailer’s choices transition from no encroachment to the second-period encroachment and, ultimately, to the first-period encroachment of private labels as the supplier learning effect elevates. Moreover, the retailer’s first-period encroachment of private labels benefits the supplier, consumers and society, but its second-period encroachment and even no encroachment of private labels would be harmful to those firms, especially when product competition intensity is high and the supplier learning rate is relatively low. Our study offers implications for industry participants to make choices of private label encroachment and understand how it influences the supply chain ecosystem in the presence of the supplier learning effect. Full article