Search Results (1,317)

The Azorean livestock system depends strongly on pasture-based feeding, making regional agriculture sensitive to global warming. This study assessed the effects of experimental warming on forage productivity, forage quality, and soil fertility in three pastures along an altitudinal gradient over two years (2020–2021). Open-top chambers were used to create warmer conditions, and soil and forage samples were analysed for chemical and mineral composition. Warming increased net forage productivity by 30% and 70% in the lower-altitude pasture in 2020 and 2021, respectively, and by 56% in the intermediate-altitude pasture in 2021. Responses at the highest altitude were weak or not significant. Effects on forage quality were seasonal. In winter and early spring, warming increased crude protein by 14–45% and ash by 4–13% in the lower- and intermediate-altitude pastures. Later in the season, warming was associated with higher fibre fractions, especially in the intermediate-altitude pasture, indicating faster plant maturation. Soil factors significantly structured forage quality, with phosphorus as the main driver. This study contributes to understanding how climate change may affect the sustainability of pasture-based livestock systems in island environments, supporting the development of adaptive management strategies to safeguard productivity, soil fertility, and ecosystem resilience. Full article

Climate and land-use changes are major drivers of hydrological and water quality dynamics in the Great Lakes Basin. This study investigates recent changes in climate, land use, runoff, and total phosphorus (TP) loading in selected illustrative watersheds within the Canadian Lake Erie Basin and Canadian Lake Ontario Basin during 2009–2022. Results suggest that recent warming and hydroclimatic variability have altered hydrological regimes in southern Ontario, including higher winter temperatures and shifts in seasonal runoff. Land-use changes, including the expansion of row crops and urban areas, have further influenced watershed responses. Variations in TP loading were associated with changes in hydroclimatic conditions and land use. These findings highlight the increasing importance of event-driven nutrient transport under changing hydroclimatic conditions and support adaptive watershed management approaches accounting for seasonal runoff variability and event-driven nutrient transport. This study provides insight into the combined impacts of climate and land-use changes on hydrology and nutrient loading in southern Ontario watersheds. The analysis results enhance understanding of water quality dynamics in the Great Lakes region and support the development of more effective, adaptive, and integrated watershed management strategies under future climate and land-use changes. Full article

Across much of the Arctic, climate warming has reduced the extent of thicker and more persistent sea ice and increased the prevalence of thinner first-year ice. Thin first-year landfast sea ice is ecologically important because reduced ice thickness can increase light transmission to the ice–water interface, while the associated brine conditions, including salinity and permeability, can strongly influence algal biomass accumulation and photophysiology. This thin (0.24–0.55 m), short-lived, seasonal, first-year landfast sea ice already dominates Nuup Kangerlua fjord, southwest Greenland, making it a useful natural example of ice conditions that may become more common in parts of the future Arctic. We focused on late February–early March because this period captures the seasonal transition from very low winter irradiance toward increasing spring light, when sea ice algal communities begin photosynthetic acclimation prior to the main bloom period. Using this site as an example of future Arctic-like conditions, we investigated chlorophyll a (Chl a) concentration and the photobiology of sea ice algal communities during five sampling events between 2017 and 2022. The vertical distribution of Chl a concentration and photobiological parameters measured with variable chlorophyll fluorescence differed between years, as did Chl a concentrations, with integrated biomass ranging from 0.08 to 0.78 mg Chl a m⁻². Direct under-ice PAR measurements showed transmittance values ranging from 0.013 to 0.29. Bottom-ice communities were acclimated to relatively high light intensities, with E_k often exceeding 200 µmol photons m⁻² s⁻¹, and we detected no clear evidence of photoinhibition in the fluorescence data. Boosted regression tree models identified brine salinity as the main predictor of both Chl a concentration, explaining 42.0% of the variation, and, Φ_{PSII_max}, the maximum dark-adapted photosynthetic efficiency, explaining 86.1% of the variation. Both parameters decreased exponentially with increasing sea ice brine salinity (p < 0.0001), indicating that higher brine salinity was associated with reduced algal biomass and lower photosynthetic efficiency. These results show that short-lived first-year landfast sea ice can support physiologically active sea ice algal communities despite relatively low biomass, and suggest that algal performance in this ice type was more strongly associated with brine salinity during the late-winter to early spring sampling period, while light availability also varied substantially among years. As thin and short-lived sea ice conditions become more common in parts of the Arctic, this habitat may represent an increasingly important, though temporally variable, component of Arctic marine primary production. Full article

Global warming is reshaping the climatic suitability of invasive ectotherms. In this study, we used an optimized Maximum Entropy (MaxEnt) model combined with GIS-based centroid tracking to quantify the spatiotemporal changes in the potential climatic suitability of Zeugodacus tau, a major polyphagous quarantine pest, in China. Projections were conducted under the historical baseline climate (1970–2000) and future climate scenarios, including SSP1–2.6, SSP2–4.5, and SSP5–8.5 for the 2050s and 2070s. Here, we projected potential climatic suitability rather than future occurrence or abundance. The model showed high predictive performance (AUC = 0.921). Annual mean temperature (Bio1) and mean diurnal range (Bio2) were identified as the primary environmental variables shaping the species’ climatic suitability. Future projections suggested contrasting spatial changes in climatic suitability, with expansion mainly in northern marginal regions and contraction of the southern highly suitable core area. As winter temperatures increased, the low- and moderate-suitability areas were projected to expand northward into temperate agricultural regions. However, under the extreme warming scenario (SSP5–8.5), the highly suitable core area in southern China was projected to decline by 31.61%, while the centroid of the highly suitable area shifted inland and northwestward by approximately 168 km toward the Wuling Mountains. These spatial patterns may be associated with increasing summer heat stress in low-altitude southern regions, although this mechanism requires further physiological validation. Overall, these findings provide a scientific basis for risk-oriented early warning, quarantine planning, and region-specific pest management under future climate change. Full article

The Indonesian Throughflow (ITF) is a critical conduit connecting the tropical western Pacific Ocean and the Indian Ocean, constituting an essential component of the global ocean circulation and exerting a significant influence on its large-scale balance. Under the backdrop of global warming, both the magnitude of ITF transport and its relationships with El Niño-Southern Oscillation (ENSO) and the Indian Ocean Dipole (IOD) are expected to undergo substantial changes. Using the SODA3.15.2 reanalysis as an observational benchmark, this study evaluates the ability of 14 CMIP6 models to simulate ITF volume transport. Following a systematic performance assessment, four poorly performing models were excluded, and the remaining 10-model ensemble was employed to construct a multi-model ensemble mean (MME). The MME is then employed to investigate the long-term trends in ITF transport during the historical period (1850–2014) and under two future emissions scenarios, SSP2-4.5 and SSP5-8.5 (2015–2100). During the historical period, ITF transport exhibits a transition from a weak strengthening to a weak weakening trend around 1934–1935, detected by both the sliding t-test and the Pettitt test, with relatively modest overall change. Under SSP2-4.5 and SSP5-8.5 scenarios, ITF transport weakens at rates of 0.318 Sv decade⁻¹ and 0.466 Sv decade⁻¹, respectively, with projected declines of approximately 3 Sv (27%) and 4 Sv (36%) by 2100. Reductions during boreal winter and spring exceed those in summer, indicating a pronounced seasonal asymmetry in the ITF response to future warming. The interannual variability of ITF is predominantly driven by ENSO, while the IOD also exerts an independent yet weaker modulating influence. Full article

Substation buildings must achieve energy conservation and carbon reduction, and thereby realize sustainable development, by optimizing envelope structures and adopting systematic design, all while meeting the operational demands of high-precision electrical equipment. This research takes a typical substation building (including switchgear building, main control building, and guard room) in a hot-summer and warm-winter zone as a case study to evaluate the effects of building thermal performance on building energy use. The building cooling load and the energy-saving rate of the air conditioning system are selected as key evaluation metrics. Using building cooling load and energy-saving rate as core indicators, energy simulation software is employed to analyze the thermal parameters of the building envelope of the switchgear building and the main control building. The influence of operational parameters, such as air conditioning setpoint temperature and internal heat gains, on the building cooling load is also investigated in order to explore design solutions that achieve sustainable development. Results indicate that the cooling load per unit area of the switchgear building is significantly higher than that of the main control building. Among the factors analyzed, the air conditioning setpoint temperature has the most substantial impact on the cooling load; increasing it by just 1 °C can reduce the load by 7–8%. When the optimal values of each factor are adopted, the energy-saving rates of the switchgear building and the main control communication building can reach 32.09% and 24.08%, respectively. This research aims to provide valuable references for determining appropriate building thermal performance parameters and operational settings for fully outdoor 220 kV substation buildings in hot-summer and warm-winter zones, thereby contributing to the sustainable development of buildings. Full article

Future volcanic eruptions are largely omitted from CMIP6 simulations, thereby increasing the uncertainty in 21st-century climate projections. We performed an 80-year (2020–2100) 25-member stochastic ensemble simulation with the climate model SOCOL-MPIOM, driven by the SSP3-7.0 forcing scenario, and introduced five stochastically distributed tropical eruptions—three strong, one moderate, and one weak—for each ensemble member (hereafter, SV run). We analyse volcanic influence by comparing the SV run results against a single volcanic-free baseline simulation under the same anthropogenic forcing scenario. Five eruptions over the 80-year simulation period leave the trends of the major climate indicators statistically indistinguishable from those of the volcanic-free baseline at the global and annual mean scales. However, on local and seasonal scales, volcanic activity can substantially alter the results of the volcanic-free simulation. For example, over Northern Europe, volcanic eruptions produce winter temperature warming of up to 1.0 K (about 30% of the warming in the reference run) and an annual precipitation deficit of 36 mm yr⁻¹. This emphasises the need to include volcanic eruptions for more accurate projections of future climate. Probabilistic analysis of the SV ensemble shows that the annual maximum daily temperature (TXx) exceeds +0.5 K over 16% of global land with more-likely-than-not probability, a perturbation absent in standard CMIP6 results. Since our scenario composition targets the upper bound of plausible 21st-century volcanic activity, these exceedance areas represent near-maximum rather than most-probable estimates. Full article

To assess the risk of cross-species transmission of canine parvovirus (CPV) from free-roaming dogs to wild giant pandas in the Foping National Nature Reserve, we collected rectal swabs and serum samples from dogs and fecal samples from giant pandas seasonally (August 2024–August 2025), combined with population surveys and GPS home-range tracking. Vaccination coverage declined from 54.2% to 36.4%, while the proportion of susceptible dogs rose from 8.7% to 29.5%. The CPV nucleic acid positive rate in dogs was 3.9% (4/102, all sub-adults, three deaths), whereas all giant panda samples were negative. Based on individual–seasonal exposure, the serum exposure rate was 30.4%, with immature dogs at significantly higher risk than adults (OR = 5.37). Home-range overlap between dogs and giant pandas (95% KDE: 19.17% in cold seasons vs. 2.61% in warm seasons) and encounter probability were markedly higher in winter and spring. Canine-derived CPV strains possessed the molecular potential to infect giant pandas. In summary, CPV persists long-term in free-roaming dog populations, summer vaccination has not established an effective immune barrier, and winter–spring is a high-risk window for cross-species transmission. We recommend enhanced winter–spring immunization, spatial control measures, and quarantine protocols for incoming dogs. Full article

Birth seasonality in the United States typically peaks in late summer, yet research has rarely examined these patterns in northern mountainous regions or across different hospital obstetric levels. This study investigates the temporal dynamics of maternal healthcare-seeking behavior in Montana, specifically focusing on seasonality in birth volume and obstetric bypassing (delivering at a non-local hospital). We conducted a retrospective analysis of 98,524 birth records (2014–2022) at hospitals with Level 1, 2, and 3 obstetric units, integrating driving distances and monthly county-level climate data. Statistical analyses included calculating observed-to-expected (O-E) ratios to identify seasonality and regression models to test interactions between season, hospital level, and weather. Montana birth volume is distinguished by a peak in June and a trough in January, with seasonality most pronounced at Level 3 hospitals. Obstetric bypassing significantly decreases during winter (O-E ratio 0.95), particularly for Level 1 hospitals, while increasing during warm, high-precipitation months. Over time, bypassing toward Level 3 hospitals has risen from 13.6% to 20%. We conclude that seasonality and weather correlates are associated with significant variation in care-seeking patterns, reflecting the unique challenges facing rural hospitals. Full article

Precipitable water vapor (PWV) is a pivotal parameter in the measurement of atmospheric water vapor content. Interferometric Synthetic Aperture Radar (InSAR) is capable of retrieving PWV with high accuracy and spatial resolution. However, the limitations imposed by factors such as low coherence and phase distortion prevent the monitoring of PWV over the sea surface by InSAR. For this problem, a joint InSAR/Fengyun sea–land cooperative PWV construction method is proposed using constraints from the Global Navigation Satellite System (GNSS) and ERA5 reanalysis data. The Jiaodong Peninsula of China was selected as the research area. The PWV over the land of the Jiaodong Peninsula was obtained by GNSS/ERA5/InSAR. The PWV over the nearby sea was obtained by Fengyun-4A (FY-4A). The PWV reconstruction over the sea and land region is realized by means of unified reference correction and transition processing. The results indicate that InSAR PWV and FY-4A PWV show good agreement with GNSS PWV, with R², MAE and RMSE values of 0.955, 1.86 mm and 2.32 mm for InSAR PWV, and 0.961, 1.90 mm and 2.28 mm for FY-4A PWV, respectively. The fused PWV significantly improves spatial completeness while preserving fine spatial structures, with an annual PWV range of 0.35–59.74 mm and a clear seasonal cycle from 4.16 mm in winter to 33.24 mm in summer. The results effectively capture the coastal moisture transition, with the strongest PWV gradient reaching 0.823 mm/km in the 0–10 km coastal zone during the warm season. PWV also shows the strongest correlation with dew point, with a Spearman correlation coefficient of 0.94. This study overcomes the limitation that PWV is restricted to land areas and provides reliable data support for the analysis of water vapor structures in coastal regions. Full article

Integrated crop–livestock systems (ICLS) that couple crop production, cover crops, and grazing present a promising strategy for soil organic carbon (SOC) sequestration. Long-term assessments of SOC change under ICLS management are limited. This study quantified SOC stocks from management systems typical of the warm, humid southern Midwest, USA, including conventional continuous cereal crop production, permanent pasture, hardwood forest, and decadal-scale ICLS management. The ICLS consisted of no-till production of corn silage with a winter ryegrass cover crop grazed by cattle. We hypothesized greater SOC stocks in the ICLS relative to conventional management, with the greatest increase in surface horizons. Soil cores were collected to a depth of 120 cm, subset into 0–30 cm, 30–60 cm, and 60–120 cm sections, and analyzed for SOC, particulate, and mineral-associated organic matter. Results demonstrated that after 15 years, ICLS SOC stocks were significantly greater than conventionally managed fields and comparable to those of permanent pasture and hardwood forest. The SOC differences were predominantly in the upper 30 cm. Using a space-for-time approach, we calculated an average annual SOC accrual rate of 1.3 Mg C ha⁻¹ yr⁻¹, similar to estimated sequestration rates from biogeochemical model simulations. The majority of additional SOC was allocated to particulate organic matter. Significantly greater mineral-associated organic carbon was also observed. Stable carbon isotope data indicated the ryegrass cover crop was likely the primary source of additional SOC in the ICLS. These findings demonstrate the potential of ICLS to increase SOC and enhance soil health over decadal timescales. Full article

This study investigated the interactive effects of warming and inundation on methane (CH₄) fluxes and soil physicochemical mechanisms in the littoral wetland of Qinghai Lake. Soil samples were collected from the Bird Island littoral wetland. Eight treatments were established: natural control (CK), different inundation depths (S0, S10, S20), warming alone (ZWCK), and warming combined with inundation (ZW0, ZW10, ZW20). CH₄ fluxes were measured over one year using an ABB LGR analyzer. Principal component analysis (PCA) and Mantel tests were used to identify environmental drivers. The main findings are as follows: (1) Under different water level treatments, CH₄ fluxes showed a unimodal seasonal pattern, peaking in autumn. Warming and the interactive treatments shifted the emission pattern to bimodal or multimodal and significantly increased emission intensity. The warming-alone group had the highest annual emission, with anomalously high winter emission (47.683 μg·m⁻²·h⁻¹). Under the ZW20 treatment, emissions were synergistically enhanced in summer and autumn but turned to suppression in winter. (2) PCA showed that the carbon nitrogen pool (70.5%) and the salinity pH gradient (14.9%) were the main drivers of soil variation. The interactive effects on carbon-nitrogen dynamics shifted with season: warming promoted accumulation in spring; warming with shallow inundation retained carbon-nitrogen in summer, but deep inundation caused loss; warming with deep inundation formed a nutrient center in autumn; inundation dominated accumulation in winter, while warming increased loss. (3) Mantel tests showed that carbon-nitrogen components were highly correlated across seasons, but were strongly and positively correlated with CH₄ flux only in autumn (Mantel’s r ≥ 0.4, p < 0.05), indicating autumn as the key window. These findings provide important insights into carbon cycling processes and regulatory mechanisms of alpine wetlands under future climate change scenarios. Full article

Against the backdrop of global warming and the ‘warming and wetting’ trend in north-western China, changes in seasonal snowpack and glacial ice in high-altitude cold regions directly impact water security in inland river basins. At present, there is a paucity of systematic research concerning the long-term evolution of snow and ice cover, multi-scale climate responses and future trends in the source region of the Keriya River on the northern slope of the Kunlun Mountains. To address this, this study utilised Landsat remote sensing imagery and meteorological station data from 2005 to 2024. Employing a multi-model fusion framework that integrates various machine learning and time-series models—including random forests, gradient boosting trees and ARIMA—the research incorporated trend factors, climate cycle identification and probabilistic modelling of extreme events to systematically analyse the spatiotemporal variability of snow/ice coverage and its multiscale coupling relationships with air temperature and precipitation. Given the inherent limitations of optical remote sensing methods in distinguishing between seasonal snow and glacial ice, this study defines the extracted coverage type as snow/ice coverage. Given the inherent limitations of optical remote sensing methods in distinguishing between seasonal snow and glacial ice, this study defines the extracted coverage type as snow/ice coverage. The results indicate that: (1) the annual average snow/ice cover percentage in the study area shows a non-significant decreasing trend (−0.69%/year, p > 0.1); within the year, it exhibits a pattern of accumulation in winter and melting in summer, with a peak in January (average 63.2%) and a trough in August (average 11.6%); (2) snow/ice cover percentage increases significantly with altitude; the annual average SICP in the <2000 m elevation zone is 5.2%; in the 2000–3000 m and 3000–4000 m altitude ranges, this rises to 5.7% and 8.3%, respectively, representing the primary seasonal snow/ice distribution zones; in areas above 6000 m, the annual average reaches 70.3%, constituting a zone of perennial stable snow/ice cover; (3) the relationship between snow/ice and temperature and precipitation exhibits significant time-scale dependence: correlations are weak on an annual scale (temperature R = −0.25, precipitation R = −0.14), but significantly strengthen on a monthly scale and exhibit seasonal differentiation; during the melting season, temperature exerts a dominant negative influence (August R = −0.35), whilst during the accumulation season, solid precipitation provides a positive supplement (February R = 0.34), with the strongest correlation with temperature occurring in September (R = −0.50); (4) it is projected that between 2025 and 2044, snow and ice cover will follow a fluctuating downward trend (averaging an annual decrease of roughly −0.12%), falling to approximately 29% by 2044; at the same time, temperatures are expected to continue rising (+0.035 °C per year), whilst precipitation will increase slightly (+0.4% per year). The results of this study provide a sound scientific basis for formulating sustainable water resource management strategies for the northern flank of the Kunlun Mountains and optimising measures to regulate snowmelt runoff. They are of great importance for safeguarding the stability of the oasis ecological systems in the Keriya River basin and ensuring the sustainable development and utilisation of water resources. Full article

Long-term decarbonization of urban residential buildings in southern China depends on the joint evolution of building stock, end-use efficiency, and electricity carbon intensity. This study develops a dynamic stock-energy-carbon framework for urban residential buildings in China’s hot-summer warm-winter region from 2010 to 2060, using Guangdong, Guangxi, Fujian, and Hainan as case provinces. The model links demographic and housing-space change with stock survival, retrofit of the base-year stock, cohort-specific performance levels for post-2022 new construction, and time-varying provincial grid emission factors. EnergyPlus simulations of seven high-rise residential archetypes show that nearly zero-energy performance reduces province-level EUI by 19.2–26.5% relative to the baseline, with cooling-load reductions forming the dominant part of the improvement in the warmer provinces. Across coupled demand-side scenarios, stricter new-build performance standards reduce 2026–2060 cumulative operational energy by 5.3–10.1% relative to the conservative demand-side setting, while increasing retrofit intensity provides a smaller but consistent additional reduction. Carbon outcomes are more sensitive to electricity-sector assumptions: under the main demand-side setting, moving from the conservative to the accelerated grid pathway advances the operational-carbon peak by 8–15 years across the four provinces and lowers 2060 residual emissions by about 71%. A comparison with available observed provincial household-electricity statistics is added as a plausibility check; it confirms the relevant order of magnitude but also indicates that absolute demand estimates should be interpreted cautiously because of boundary and EUI-representation differences. These results suggest that demand-side efficiency policies must be coordinated with rapid provincial power-sector decarbonization if the residential sector in Hot-Summer Warm-Winter Region is to reach earlier carbon peaks and lower residual operational emissions. Full article

Even under a warming climate, winter sea ice in the Bohai Sea continues to threaten ships and offshore/coastal infrastructure. Reliable pre-season prediction of the overall wintertime sea ice condition in the Bohai Sea, as represented by the Bohai Sea Ice Grade (BSIG), is therefore important for disaster preparedness and mitigation. Based on the 1979–2024 BSIG record, this study compares seven statistical and AI-based seasonal prediction methods: analog year analysis, multiple linear regression, stepwise regression, Principal Component Regression, a cross-correlation-based regression model, support vector regression, and the Bayesian Ensemble Bohai Ice Grade Net (BE-BIGNet). As potential precursors, we considered sea ice extent in 14 Arctic regions together with 114 large-scale atmospheric and oceanic circulation indices. The results suggest substantial differences in predictive skill among the methods. Among the tested approaches, BE-BIGNet, which combines Bayesian regularization with bootstrap median ensembling, achieves strong full-period performance and stable skill during the independent test period, suggesting that it may provide a useful framework for operational BSIG forecasting in the Bohai Sea. Full article