Search Results (4,221)

Trillium camschatcense, a plant renowned for its ecological and medicinal value, is predominantly found in the temperate forests of East Asia. However, its habitat is increasingly threatened from climate change, habitat fragmentation, and intensified human activities. In this study, the Maxent (Maximum Entropy) model was used to assess the current ecological suitability of T. camschatcense based on historical climate data (1970–2000), and further simulate its potential distribution shifts under multiple future climate change scenarios to predict long-term habitat variation trends across northeast China.All modeling and spatial mapping analyses were performed using MaxEnt and ArcGIS 10.8.1 software. Drawing upon 93 known distribution points and 26 pertinent environmental variables covering climate, soil, and elevation, we built species distribution models for both present and future periods to pinpoint the crucial environmental factors influencing its distribution. Our findings revealed that elevation, soil nitrogen content, seasonal temperatures, annual precipitation, mean temperature during the coldest quarter, and mean diurnal temperature range were the primary factors influencing the distribution of T. camschatcense. Notably, highly suitable habitats were predominantly concentrated in Baishan City and the southwestern region of Yanbian Korean Autonomous Prefecture in Jilin Province. This insight offers valuable scientific guidance for the conservation planning, sustainable utilization, and potential introduction and cultivation of T. camschatcense. Furthermore, targeted conservation strategies can help identify climate refugia and protect climatically stable habitats for the long-term persistence and resilience of the species under continuous global warming. Full article

Climate-driven changes in oceanographic conditions are increasingly affecting the distribution of marine species, particularly vulnerable elasmobranchs. The undulate ray, Raja undulata, is a Near Threatened batoid species distributed throughout the northeastern Atlantic Ocean and parts of the Mediterranean Sea, yet its potential response to future climate change remains poorly understood. This study assessed current and future habitat suitability using species distribution modelling approaches and CMIP6 climate projections under the SSP245 scenario. Species occurrence records were compiled from biodiversity databases and published sources, and environmental predictors were selected following multicollinearity screening. Among twelve evaluated modelling algorithms, MaxEnt showed the highest predictive performance (AUC = 0.99; TSS = 0.95) and was selected for subsequent analyses. Current habitat suitability was concentrated along the Iberian Peninsula, the Bay of Biscay, the English Channel, and parts of the western Mediterranean Sea. Future projections indicated substantial habitat contraction, with habitat loss (57.3%) greatly exceeding habitat gain (2.2%), resulting in a southward redistribution of suitable habitats. Minimum phytoplankton concentration, sea surface temperature, and silicate concentration were identified as the most influential environmental predictors. Areas predicted to remain suitable under both current and future conditions may represent important climate refugia for the species. Overall, the results indicate that R. undulata is highly vulnerable to future environmental change and highlight the need to incorporate climate-driven habitat shifts into conservation planning, fisheries management, and long-term monitoring strategies. Full article

Projecting the spatiotemporal dynamics of the potential distribution of dominant species under climate change is essential for desertification control and vegetation restoration in drylands. Here, we modeled the current (1970–2000) and future (2080–2100) suitable habitats of Caragana korshinskii Kom, an ecologically important shrub species in northwestern China, by constructing an ensemble of eight species distribution models on the Biomod2 platform using three CMIP6 Shared Socioeconomic Pathways (SSP126, SSP370, SSP585) and 40 environmental variables representing climate, soil, topography and drought conditions. Key environmental drivers were identified through variable importance ranking and response curves, while area changes, spatial patterns, and centroid shifts in suitable habitats were quantified. The ensemble model demonstrated good to excellent predictive performance (mean AUC > 0.9, mean TSS > 0.5). Soil base saturation (t-bs) and soil moisture contributed the most (>38%), highlighting the dominant role of edaphic factors. The current total suitable habitat of C. korshinskii is approximately 182.2 × 10⁴ km², with all future scenarios projecting a consistent decline. Under SSP585, habitat loss reached 9.8% with contraction (30.5 × 10⁴ km²) far exceeding expansion (12.6 × 10⁴ km²). The distribution centroid shifted markedly eastward with a minor southward fluctuation, establishing the Ordos–Bayannur region as a stable core habitat. Overall, our findings suggest that the distribution of C. korshinskii is strongly constrained by edaphic and moisture conditions, and future contraction of marginal habitats may compromise ecosystem services. Full article

Seasonal freeze–thaw transitions reorganize lake microbiomes, yet the coupling of environmental filters, biotic interactions, and assembly mechanisms across habitats remains unclear. We profiled bacteria and fungi in the water and sediment of Lianhuan Lake during winter (frozen) and spring (thawed) using amplicon sequencing, co-occurrence networks, and assembly models. Despite sharp physicochemical differences, α-diversity remained stable, while β-diversity was mainly driven by habitat (water vs. sediment), with seasonal turnover detectable, particularly for bacteria. Network analysis revealed a clear winter-to-spring shift: the frozen-water (FW) network was complex with high connectivity and 15% cross-domain edges, while frozen sediment (FS) was less connected but more modular. After thaw, both habitats showed reduced connectivity, with thawed sediment (TS) displaying the strongest modularity and an increase in cross-domain links (~16%). Keystone taxa shifted seasonally and by habitat: FW was dominated by peripheral taxa like Polaromonas, Pseudomonas, and Candidatus Limnoluna; FS had connectors such as the families Comamonadaceae and Ilumatobacteraceae. In spring, Luteolibacter and Rhodoferax dominated water, while Flavobacterium and Sutcliffiella took over sediment. Environmental drivers varied by season and habitat: in winter water, pH was the dominant organising factor, with permanganate index (COD_Mn) and ammonia nitrogen (NH₃-N) as secondary hubs, while NH₃-N became central after thaw. In sediments, sediment total nitrogen (STN) and sediment organic matter (SOM) promoted bacterial links in winter, but SOM had a negative effect after thaw. Assembly analyses suggested selection-driven processes, with dispersal-assisted selection for water bacteria (neutral community model (NCM) R² ≈ 0.76), stronger determinism for sediment bacteria (R² ≈ 0.30), and for fungi, assembly governed jointly by heterogeneous selection and dispersal limitation rather than by a single dominant process. These results highlight how freeze–thaw cycles reshape cross-kingdom networks and microbial assembly, providing insights for monitoring seasonally frozen lakes. Full article

Understanding age and growth in marine bivalves is essential for interpreting population dynamics and environmental responses. The analysis of sclerochronological growth increments within internal shell layers provides a reliable approach for reconstructing age and growth history and preserves long-term records of environmental variability and stress. This study presents the first assessment of age structure and growth history of the pearl oyster Pinctada radiata in Bahrain waters using shell growth-line analysis. Pearl oysters from two contrasting salinity regimes in Bahrain waters, the Northern Area (~40‰) and the hypersaline Western Coast (~55‰), were examined using acetate peel replicas and internal shell growth-line analysis. Age determination was conducted from shell cross-sections, and growth patterns were evaluated through morphometric analysis and von Bertalanffy growth modelling. Oysters from the Northern Area attained larger shell sizes and exhibited estimated life spans of up to 5–6 years, whereas hypersaline populations displayed reduced life spans (3–4 years), thinner shells, and lower asymptotic growth despite rapid early development. A strong correlation between shell height and umbo height supported the reliability of internal growth increments as age proxies. These findings suggest that pearl oysters inhabiting naturally hypersaline habitats may exhibit a dwarf-like growth pattern and reduced life span associated with persistent hypersalinity. The results improve understanding of growth responses and physiological limits of P. radiata under naturally hypersaline conditions in the Arabian Gulf. Full article

Megafires are a growing global phenomenon, with their frequency increasing in recent decades. In 2023, Europe’s largest recorded fire occurred in North-Eastern Greece, burning 94,250 hectares, including the Dadia–Lefkimi–Soufli National Park (DLS-NP). This protected area is of high ecological importance due to its rich biodiversity, hosting 18–20 breeding raptor species. The fire exhibited remarkable spatial heterogeneity, with some patches burning at low to moderate severity while others remained unburned, likely functioning as critical post-fire refugia. In this study, 15 environmental variables were analyzed using Maxent to model pre-fire potential nesting habitat suitability for eight tree-nesting species, including seven raptors and the Black Stork. The models were then used to examine the spatial overlap between historically suitable habitats and unburned, low-, and moderate-severity areas. The results suggest that these patches may represent important spatial remnants of potential nesting habitat for raptor communities after the fire, especially where historically suitable areas coincide with unburned or moderately burned forest structures. Accordingly, post-fire landscape management in Evros should prioritize the protection of unburned refugia and the cautious retention of partially burned forest structures, particularly in areas identified as historically suitable, while avoiding interventions that may unnecessarily simplify habitat structure. Effective management should combine species-specific protection of key habitat islands with landscape-scale strategies that preserve heterogeneity and support prey availability, within an adaptive framework guided by systematic monitoring over the next 3–5 years. Full article

The Qinghai–Tibet Plateau (QTP) is highly sensitive to global climate change, and the stability of its grassland ecosystems is critical for regional ecological security and livestock development. Therefore, investigating future spatial distribution changes of dominant species on the QTP is of great importance for grassland management. In this study, an ensemble model was used to simulate and analyze the potential distribution and centroid migration directions of dominant species in alpine meadow, alpine grassland, desert grassland, and temperate grassland under current and future climate scenarios (SSP2-4.5 and SSP5-8.5). The results show that the ensemble model achieved excellent predictive accuracy for all species (AUC > 0.9, TSS > 0.7, Kappa > 0.6). Elevation is the key factor governing species distribution, while climate drivers differ significantly among species. The distribution of dominant species in alpine meadow and alpine grassland is primarily co-driven by the mean monthly temperature range (MTR), isothermality (ISO), and annual precipitation (AP); desert grassland dominants are mainly influenced by AP and the mean temperature of the driest quarter (MTDQ); and temperate grassland dominants are driven by the precipitation of the coldest quarter (PCQ) and AP. The suitable habitats of dominant species in the future will generally expand towards high-altitude, high-latitude regions in the north and northwest, with centroid migration directions varying markedly among species. Specifically, the centroids of desert grassland dominants and S. bungeana in temperate grassland will migrate northwest under SSP2-4.5 and SSP5-8.5, while N. splendens and S. krylovii in temperate grassland will migrate southwest. For alpine meadow and alpine grassland dominants, the centroids will generally move northwest under SSP2-4.5 but diverge under SSP5-8.5—E. nutans and S. purpurea in alpine grassland will continue to migrate northwest, whereas alpine meadow dominants and P. annua in alpine grassland will migrate east or northeast. This study provides a theoretical basis for grassland conservation, biodiversity conservation, and livestock production in response to climate change on the QTP. Full article

Accurate prediction of the potential habitat distribution of Scomber japonicus, an important target species in China’s distant-water fisheries, is essential for fishing ground forecasting. Using catch data for S. japonicus collected from Chinese large-scale purse-seine and trawl fisheries in the Northwest Pacific Ocean from May to November during 2015–2024, this study applied the maximum entropy model (MaxEnt) and the genetic algorithm for rule-set production (GARP) model to predict the potential habitat distribution of S. japonicus in the Northwest Pacific Ocean. The area under the receiver operating characteristic curve (AUC) and the true skill statistic (TSS) were used to evaluate model performance. The MaxEnt model predicted a relatively concentrated highly suitable habitat, whereas the GARP model identified a broader highly suitable area. To reduce the bias and uncertainty associated with single-model predictions, the outputs of the MaxEnt and GARP models were integrated using a weighted ensemble approach, with the optimal weights for MaxEnt and GARP determined as 0.7:0.3. The ensemble model achieved higher predictive performance, with an AUC of 0.983 and a TSS of 0.840. The highly suitable habitat of S. japonicus was mainly concentrated within 147° E–156° E and 40° N–44° N. Chlorophyll concentration, sea surface temperature (SST), and temperatures at depths of 150 m and 200 m were the main environmental variables affecting the potential habitat distribution of S. japonicus in the MaxEnt model. These findings provide useful information for resource utilization, fishing ground forecasting, and sustainable management of S. japonicus in the high seas of the Northwest Pacific Ocean. Full article

The research analysed the space-use and habitat-preference characteristics of red deer (Cervus elaphus) in the Sopron Mountains, Hungary, utilising high-resolution Global Positioning System (GPS) telemetry data and two distinct land-cover databases. Hourly location data from 10 individuals were processed using the minimum convex polygon (MCP) and kernel home range (KHR) methods. Additionally, a relative stability index (RSI) was developed to describe seasonal shifts in area use. Significant sexual dimorphism was identified in the extent of annual home ranges: the mean space use of stags (3381 ha) significantly exceeded that of hinds (1391 ha). Geomatical analyses highlighted the seasonality of space use: the smallest extent was recorded in June, and shifts in home ranges within a single year were significant, while the winter period exhibited the least seasonal variation. Regarding habitat selection, significant seasonality was observed in hinds, reflecting temporal changes in resource availability, whereas this pattern was not observed in stags. The study concluded that the applied methods are appropriate for gathering baseline information; however, integrating high-precision databases is essential for accurate modelling of deer–forest interactions. Full article

Fish are an important criterion for evaluating the quality of river ecosystems, and water flow characteristics may be the main factor affecting the living environment of fish. As the main component of a river, the topography of the bank slope has a significant impact on the characteristics of nearshore water flow. At the same time, eco-revetment structure has the functions of smoothing water flow, maintaining stable bank slopes, and improving river ecology. It can reset the distribution of nearshore water flow and provide a stable living environment for fish. This study focuses on the middle and lower reaches of the Yangtze River as the research area, with the main research object being grass carp. We construct a generalized model based on river morphology and flow characteristics. A new eco-revetment structure is proposed with the main research area of nearshore waters, aiming to improve the flow state of nearshore water and enhance its ecology. A suitability evaluation model for grass carp habitat was constructed based on Large Eddy Simulation and fuzzy mathematics theory, with water flow as the main habitat influencing factor. We study the distribution pattern of suitability for grass carp habitats near nearshore waters. The results indicate that the nitrogen phosphorus ratio near the top of the revetment structure is close to the Redfield value and can be used as a stable foraging area for fish. The flow rate is the dominant factor for the habitat of juvenile grass carp. When there is no vegetation, the suitability of region A is 0–0.4, the suitability of region B is 0.2–0.6, and the area proportion of the high suitability area (0.4–0.6) is maintained at 10–30% with the increase in the flow rate. Region C is not suitable for the long-term survival of juvenile grass carp. When there is vegetation, the suitability of region A ranges from 0 to 0.6, and the proportion of low-suitability areas decreases. The suitability of region B ranges from 0.4 to 0.6, and the proportion of suitable areas is positively correlated with flow velocity. The suitability of region C is consistent with the absence of vegetation. The dominant factors for fish spawning habitat are flow velocity, vorticity, and kinetic energy gradient. The spawning suitability zone (HSI ≥ 0.6) is located between the spanwise structures, with a proportion positively correlated with flow velocity and higher suitability on the deep-water side. The existence of fish has little impact on the habitat. In the juvenile fish habitat area, the proportion of areas suitable for juvenile fish in region A has slightly decreased, and the suitability of region B has increased. In spawning grounds, an HSI ≥ 0.6 accounts for about 5% of the decrease compared to no-fish conditions, and overall can meet the needs of fish habitat, foraging, and spawning. This article provides ideas and foundations for the design of future new eco-revetment structures and a suitability analysis of living environments for fish. Full article

The analysis of specific habitat conditions involves a systematic assessment of environmental variables such as temperature, hydrology, and vegetation, to clarify species’ ecological requirements and develop conservation strategies. Common approaches include statistical modelling, various Habitat Suitability Index (HSI) models, and GIS-based spatial analyses, which quantify factors like topography, land cover and anthropogenic pressures. Today, machine learning (ML) methods are widely applied across engineering disciplines, including water resources management. In this study, ML methods, particularly model trees, are employed to model and predict key abiotic factors relevant to fish communities. The research focuses on the bioindicator species Barbus balcanicus (brook barbel), which inhabits the middle part of the Sutla River (transboundary river basin between Croatia and Slovenia) and serves as an indicator of ecological conditions in this system. Using ML, models for water depth, water velocity, and water temperature were developed and applied together with SWAT (Soil and Water Assessment Tool) data to determine the HSI for future scenarios to support habitat assessment and water management planning. Full article

Climate change is increasingly reshaping species habitat suitability worldwide. Primula L., the largest genus in Primulaceae, comprises 404 species in China (including 296 endemic species) and is characterized by high endemism and numerous rare and endangered taxa. However, global warming has intensified habitat fragmentation and loss, while its distribution patterns and key environmental drivers remain insufficiently understood. We compiled 7647 occurrence records of 404 wild Primula species in China and integrated 60 environmental variables (climatic, topographic, and soil factors). Using the MaxEnt model combined with ArcGIS spatial analysis, we assessed current and future habitat suitability, identified dominant environmental drivers, and quantified conservation gaps under multiple climate scenarios. Species richness is highly concentrated in Sichuan (186 species), Yunnan (177 species), and Xizang (165 species), with the Hengduan Mountains and eastern Himalayas representing the core distribution area and showing clear peripheral differentiation. The optimized MaxEnt model performed well (AUC = 0.858), identifying temperature seasonality (bio4, 39.8%) and elevation (27.1%) as the main limiting factors. The total suitable habitat area is 268.52 × 10⁴ km², with high-suitability areas mainly distributed in the Hengduan Mountains, southeastern Qinghai–Xizang Plateau, and the Central Mountain Range of Taiwan. Under three shared socioeconomic pathway (SSP) scenarios (SSP126, SSP245, and SSP585), suitable habitat shows a persistent decline, most pronounced under SSP585 in the 2090s (−20.73%), accompanied by a 25.86% reduction in low-suitability areas. Localized expansion of high-suitability habitats suggests that the Hengduan Mountains and southeastern Qinghai–Xizang Plateau may act as potential climatic refugia. Habitat loss consistently exceeds habitat gain, while the distribution centroid shifts westward and northwestward, with migration distances increasing under higher-emission scenarios. Conservation gap analysis indicates that 90.01% of high-suitability habitats lie outside the current protected area network, revealing a strong mismatch between biodiversity hotspots and conservation coverage. These findings highlight the urgent need to expand protected areas and establish micro-reserves in key gap regions (southwestern Sichuan, northwestern Yunnan, southeastern Xizang, and southern Gansu), and to integrate climate-driven migration corridors into conservation planning to support long-term alpine plant persistence under climate change. Full article

Cathaya argyrophylla Chun et Kuang is an endangered relict gymnosperm endemic to China. Its habitat has been severely fragmented due to Quaternary glaciations, a condition further exacerbated by modern, fragmented administrative management. We compiled 98 spatially filtered occurrence records across four provinces and developed a combined analysis framework integrating the Biomod2 ensemble model with the Marxan systematic planning algorithm. Our optimal model (TSS = 0.911, AUC = 0.986) identified mean diurnal range and ultraviolet-B seasonality radiation as the dominant ecophysiological drivers of the species’ distribution. Currently, suitable habitats cover 7.10% of the study area, with highly suitable habitats accounting for only 3.08% (21.76 × 10³ km²). Priority conservation areas account for 2.48% (17.55 × 10³ km²) of the total area. A gap analysis revealed that 76.98% (13.51 × 10³ km²) of the optimized priority conservation areas currently lack formal protection under China’s protected area system and the World Database on Protected Areas. Under four future climate scenarios (2030s–2090s), projections indicated overall habitat contraction, with limited spatial expansion observed only under specific scenarios (SSP1-2.6 in the 2030s and 2090s; SSP5-8.5 in the 2030s), and the population centroid was projected to shift southeastward by an average of 42.67 km in Huaihua City. Twenty-one core habitat patches were identified under current climate conditions. As these core habitat patches are concentrated along interprovincial boundaries, specifically the Dalou Mountains and the Yuecheng Ridge, our findings emphasize the need to bridge local administrative barriers. This spatial framework provides actionable guidelines for establishing transboundary protected areas, optimizing in situ conservation networks, and implementing model-based assisted migration. Full article

As the largest inter-basin water diversion project in eastern China, the Eastern Route of China’s South-to-North Water Diversion Project (ER-SNWDP) plays a crucial role in alleviating water shortages and ensuring regional ecological security. However, large-scale water diversion that uses natural lakes as impounded lakes across different basins has impacted on the structure and function of the original ecosystems. To explore the changes in the food web and ecosystem structure of the impounded lakes during different operation periods of the ER-SNWDP, we constructed Ecopath models for Hongze Lake in 2010–2011 (pre-operation), 2017–2018 (initial operation), and 2023–2024 (operational period). Our results showed that the trophic energy flow in Hongze Lake was dominated by the detrital food chain, with the highest trophic level ranging from 3.06 to 3.50. Energy flows at trophic levels I and II accounted for a high proportion of the total throughput, and the interactions between trophic levels were relatively simple, indicating that Hongze Lake is approaching a mature ecosystem. Compared with the pre-operation period, the average trophic level, food chain length, and energy conversion efficiency of Hongze Lake declined during the initial operation period, but rebounded during the operational period, though still remaining lower than the pre-operation period. Ecosystem stability followed a similar trajectory: the total primary production/total respiration (TPP/TR) and the system omnivory index (SOI) indicated that ecosystem maturity decreased during the initial operation and increased during the operational period. Fishing activities had negative effects on most functional groups during the pre-operation and initial operation periods, whereas the negative effects from zooplankton and non-native species groups increased during the operational period. Based on changes in the food web structure and ecosystem of Hongze Lake across different water diversion periods, we suggest that the management of Hongze Lake should establish precautionary fishing management measures targeting the effects of filter-feeding functional groups and non-native species, optimize the species and quantities of restocking initiatives, prioritize the protection of critical habitat integrity, and implement long-term ecological monitoring. Full article

This study examines the role of circular services in generating economic value within the construction sector, focusing on firms belonging to the Sustainable Habitat Cluster in the Aburrá Valley, Colombia. The research analyzes how circular business model strengthening translates into economic outcomes through the implementation of circular service portfolios. Using a Partial Least Squares Structural Equation Modeling (PLS-SEM) approach, the study evaluates the relationships between circular business model capabilities, circular service implementation, and circular revenue generation. The results confirm a sequential mechanism linking strategic capabilities to economic outcomes, where strengthening circular business models significantly enhances the implementation of circular services, which in turn strongly predicts the generation of circular revenues. The findings indicate that circular strategic orientation is a necessary but insufficient condition for economic value creation, as monetization occurs only when circular principles are translated into concrete service offerings. The study highlights the central role of circular services as the operational bridge between strategic readiness and economic performance, contributing to the literature on circular business models and Product–Service Systems (PSS) by providing empirical evidence of how circular strategies translate into revenue generation within the built-environment sector. Full article