Search Results (142)

This study investigates the dynamic response mechanisms of discharge capacity in the Han River Estuary to hydrological process changes at the Yangtze–Han River confluence. By constructing a one-dimensional hydrodynamic model for the 265 km Xinglong–Hankou reach, we quantitatively decouple the synergistic effects of riverbed scouring (mean annual incision rate: 0.12 m) and Three Gorges Dam (TGD) operation through four orthogonal scenarios. Key findings reveal: (1) Riverbed incision dominates discharge variation (annual mean contribution >84%), enhancing flood conveyance efficiency with a peak flow increase of 21.3 m³/s during July–September; (2) TGD regulation exhibits spatiotemporal intermittency, contributing 25–36% during impoundment periods (September–October) by reducing Yangtze backwater effects; (3) Nonlinear interactions between drivers reconfigure flow paths—antagonism occurs at low confluence ratios (R < 0.15, e.g., Cd increases to 45 under TGD but decreases to 8 under incision), while synergy at high ratios (R > 0.25) reduces Hanchuan Station flow by 13.84 m³/s; (4) The 180–265 km confluence-proximal zone is identified as a sensitive area, where coupled drivers amplify water surface gradients to −1.41 × 10⁻³ m/km (2.3× upstream) and velocity increments to 0.0027 m/s. The proposed “Natural/Anthropogenic Dual-Stressor Framework” elucidates estuary discharge mechanisms under intensive human interference, providing critical insights for flood control and trans-basin water resource management in tide-free estuaries globally. Full article

Non-Native Tree Species (NNTs) play crucial roles in global and European forests. However, in the Czech Republic, NNTs represent a tiny fraction of the forested areas due to limited research on their potential use. The country is actively afforesting abandoned agricultural lands; NNTs which are already tested and certified could enhance the country’s forestry system. This study aimed to evaluate the initial growth of Castanea sativa, Platanus acerifolia, and Corylus colurna under three soil treatments on abandoned agricultural soil, evaluate the survival and mortality of the tree species, and further compare the soil dynamics among the three ecosystems to describe the initial state and short-term changes in the soil environment. The research plot was set in the Doubek area, 20 km East of Prague. Moreover, soil-improving materials, Humac (1.0 t·ha⁻¹) and Alginite (1.5 t·ha⁻¹), were established on the side of the control plot at the afforested part. The heights of plantations of tree species were measured from 2020 to 2024. Furthermore, 47 soil samples were collected at varying depths from three ecosystems (afforested soil, arable land, and old forest) in 2022. A single-factor ANOVA was run, followed by a post hoc test. The result shows that the Control-C plot (Castanea Sativa + Platanus acerifolia + Corylus colurna + agricultural soil without amendment) had the highest total growth (mean annual increment in the year 2024) for Castanea sativa (KS = 40.90 ± a21.61) and Corylus colurna (LS = 55.62 ± 59.68); Alginite-A (Castanea Sativa + Platanus acerifolia + Corylus colurna + Alginite) did best for Platanus acerifolia (PT = 39.85 ± 31.52); and Humac-B (Castanea Sativa + Platanus acerifolia + Corylus colurna + Humac) had the lowest growth. Soil dynamics among the three ecosystems showed that the old forest (plot two) significantly differs from arable soil (plot one), Humac and Platanus on afforested land (plot three), Platanus and Alginite on afforested land (plot four), and Platanus without amendment (plot five) in horizon three (the subsoil or horizon B) and in horizon four (the parent material horizon or horizon C). Results document the minor response of plantations to soil-improving matters at relatively rich sites, good growth of plantations, and initial changes in the soil characteristics in the control C plot. We recommend both sparing old forests and the afforestation of abandoned agricultural soils using a control treatment for improved tree growth and sustained soil quality. Further studies on the species’ invasiveness are needed to understand them better. Full article

Climate change poses a significant threat to the persistence of rear-edge populations, which are located at the margins of a species’ distribution range and are particularly vulnerable to environmental shifts. This study focuses on Yew (Taxus baccata L.) in the Iberian Peninsula, representing the southernmost extent of its range, where warming temperatures and decreasing moisture may compromise its survival. Our research aims to assess the climate sensitivity and habitat variability of Yew, addressing the hypothesis that future climate scenarios will significantly reduce the species’ climatic suitability, particularly in southern and low-altitude regions, and that this reduction will negatively impact individual growth performance. We used species distribution models (SDMs) based on ecological niche modeling (ENM) to project the current and future distribution of suitable habitats for Yew under two climate scenarios (SSP126 and SSP585). The models were calibrated using bioclimatic variables, and the resulting suitability maps were integrated with field data on individual growth performance, measured as basal area increment over the last five years (BAI5). The ensemble model showed high predictive performance, highlighting precipitation seasonality and annual mean temperature as the most influential variables explaining the climatic suitability distribution in the Iberian Peninsula. Our results indicate a substantial reduction in suitable habitats for Yew, especially under the high-emission scenario (SSP585), with southern populations experiencing the greatest losses. Furthermore, individual growth was positively correlated with climatic suitability, confirming that populations in favorable habitats exhibit better performance. These findings highlight the vulnerability of rear-edge populations of Yew to climate change and underscore the need for targeted conservation strategies, including the identification of climatic refugia and the potential use of assisted migration. Full article

Despite the climate crisis, a significant barrier to sustainability is limitations to the current accounting and reporting system. These deficiencies, mean the global financial system continues to invest trillions of dollars annually in environmentally sub-optimal projects. To catalyze the economic transition away from fossil-fuel and plastic configurations to more sustainable ones, sustainability accounting and reporting (SAR) is imperative. However, theoretical contention, pragmatic concerns, and costs stoke strong resistance to SAR. The research used ablative thematic analysis to apply hermeneutic phenomenology. First, it scanned the backdrop to the SAR problem and identified a corpus of recent literature from key associated institutions. The initial interpretation of the texts disentangled SAR’s conflicting threads and generated three themes of ‘climate crisis’ and ‘conservative’ or more ‘radical’ SAR reform paradigms. Iteratively harnessing these thematic lenses, the investigation re-examined the SAR literature corpus. The textual ‘dialogue’ generated understanding of the fragmented SAR responses to the climate crisis. Accordingly, the research reformulated its first theme to ‘dystopic climate crisis fragmentation’ and refined the other themes to take account of materiality and the split between Anglo-Saxon (IFRS, SSAB) or global (UN) and continental European accounting institutions (EU, GRI). Conservatives retain a single materiality investor-focus and concede only incremental standard improvements. Radicals seek to implement double materiality with a broader spectrum of stakeholders in mind. Both approaches have theoretical as well as pragmatic advantages and disadvantages, so the SAR contention rumbles on. Whilst the standard-setting landscape is evolving, disagreements remain. Its roots of contention are philosophical and pragmatic. Philosophically, radicals strive to temper libertarian anarcho-capitalist proclivities and broaden firm responsibility. Pragmatically, social, or environmental externalities are problematic to assign or measure. Given vested interests in the destructive status quo, it would be naïve to expect a harmonious SAR Ithaca to emerge anytime soon. Yet the challenges impel an intensification of SAR dialogue and concrete actions. Rather than a scientifically nomothetic contribution, the paper provides a qualitative, artful interpretation of a complex, contentious but crucial field. Full article

The present study analyzed the growth pattern of the stingray Urotrygon chilensis caught as bycatch by the shrimp fishery in the southeastern Mexican Pacific. From January to December 2012, the thoracic vertebrae of 491 females and 205 males were collected. Female ages ranged from 0 to 14 years, whereas male ages ranged from 0 to 12 years. The marginal increment and edge analyses suggested the annual formation of growth bands in the vertebrae. The size-at-age data were analyzed using the multimodel inference approach; six candidate growth models were compared, including models with a theoretical age-at-zero total length, mean size-at-birth, and generalized models. Based on Akaike’s information criterion, the best statistical fit to the size-at-age data was the two-phase Gompertz growth model (k = −0.13, G = 1.59, $L_0$ = 10.40) for males and the two-parameter Gompertz growth model (k = 1.42, α = 0.15, $L_0$ = 10.90) for females. In this study, we compare the growth parameters among batoid species, finding that U. chilensis has a relatively short lifespan, slower growth, and that females are larger than males. Full article

Forest carbon sinks have faced significant challenges with the accelerating warming trend in the 21st century. Net primary productivity (NPP) serves as a critical indicator of the carbon cycle in forest ecosystems and is intricately influenced by both human activities and climate change. This study focuses on the subtropical Southern Forests of China as the research object, using the Wuyi Mountains as a representative study area. The positive and negative contributions of ecologically oriented human activities driven by China’s forestry construction over the past few decades were investigated along with potential extreme climate factors affecting the forest NPP from an altitude gradient perspective and regional-scale forest NPP changes from a novel viewpoint. MODIS NPP, climate, and land use data, along with a vegetation type transfer matrix and statistical methods, were utilized for this purpose. The results are summarized as follows. (1) From 2000 to 2022, NPP in the Wuyi Mountains exhibited a high distribution pattern in the northeastern and southern areas and a low distribution pattern in the central region, with a weak overall increase and an average annual growth increment of only 0.11 gC·m⁻²·year⁻¹. NPP increased with altitude, with a mean growth rate of 5.0 gC·m⁻²·hm⁻¹. Notably, the growth rate of NPP was most pronounced in the altitude range below 298 m in both temporal and vertical dimensions. (2) In the context of China’s long-term Forestry Ecological Engineering Projects and Natural Forest Protection Projects, as well as climate warming, the transformation of vegetation types from relatively low NPP types to high NPP types in the Wuyi Mountains has resulted in a total NPP increase of 211.58 GgC over the past 23 years. Specifically, only the altitude range below 298 m showed negative vegetation type transformation, leading to an NPP decrease of 119.44 GgC. The expansion of urban and built-up lands below 500 m over the 23-year period reduced NPP by 147.92 GgC. (3) The climatic factors inhibiting NPP in the Wuyi Mountains were extreme nighttime high temperatures from June to September, which significantly weakened the NPP of evergreen broadleaf forests above 500 m in elevation. This inhibitory effect still resulted in a reduction of 127.36 GgC in the NPP of evergreen broadleaf forests within this altitude range, despite a cumulative increment in the area of evergreen broadleaf forests above 500 m over the past 23 years. In conclusion, the growth in NPP in the southern inland subtropical regions of China slowed after 2000, primarily due to the significant rise in nighttime extreme high temperatures and the expansion of human-built areas in the region. This study provides valuable data support for the adaptation of subtropical forests to climate change. Full article

Southwest China’s karst region represents a global hotspot for ecological restoration, with natural succession on abandoned farmland emerging as a pivotal mechanism under recent land-use transitions. Despite its ecological significance, empirical data remain scarce regarding tree growth characteristics in this fragile ecosystem. This seven-year study (2018–2024) at Puding Karst Ecosystem Research Station quantified the spatiotemporal patterns of tree growth through monthly diameter at breast height (DBH) measurements for dominant species, coupled with microhabitat characterization (rock exposure, competition indices, and canopy architecture). Key findings revealed that the mean annual DBH increment was 5.74 mm/a, while biomass accumulation averaged 9.38 kg/a; growing-season drought duration significantly modulated interannual growth variation; and microhabitat heterogeneity and tree size significantly influenced the spatial variance of tree growth. These results substantiate natural succession as an effective carbon sequestration strategy, particularly in nutrient-depleted karst terrains. We advocate for the policy prioritization of passive restoration over active afforestation in marginal croplands. Full article

Nonstructural carbohydrates (NSCs) are key storage molecules that can be used for tree growth and metabolism. The trade-off between NSC storage and biomass production has been long reported on. However, the carbon source limitation (indicated by NSC storage) to biomass production remains poorly quantitively assessed. The seasonal whole-tree NSC pool dynamics of 12 temperate tree species were quantitatively evaluated across seven seasonal sampling points. The ratio of seasonal variation in whole-tree NSC pool to annual biomass increment (the ΔNSC/ABI ratio) and the linear relationship of annual biomass increment to NSC storage were used to assess the coupling of NSC storage to annual biomass production. Whole-tree NSC pools were consumed in early summer when structural growth peaked and recovered in the nongrowing season, indicating a short-term trade-off between storage and growth. The ΔNSC/ABI ratio was on average 0.59, with a large interspecific variation. Notably, there was a significant positive correlation between the storage of NSC and the 10 yr mean annual biomass increment, indicating a storage–growth coupling and the source limitation of growth in the long term. However, the storage cost of biomass production decreased along the slow-growth-to-fast-growth species continuum, mirroring the spectrum from conservative to acquisitive NSC use strategies. These findings highlight the critical role of time scale in understanding the relationship between storage and growth, which should be considered in the framework of simulation and conceptual models. Full article

Background: Carotid intima-media thickness (IMT) is a noninvasive surrogate marker of subclinical atherosclerosis and cardiovascular disease risk. This study explored IMT distribution across three carotid artery segments in a large cohort of healthy individuals and identified the key factors associated with increased IMT. Methods: This study utilized data from the Kangbuk Samsung Health Study, a cohort of South Korean adults aged ≥ 18 years who underwent comprehensive annual or biennial health examinations. The analysis included 86,351 healthy individuals, excluding those with known carotid disease. IMT was measured using high-resolution B-mode ultrasonography across the three segments: common carotid artery (CCA), carotid bulb, and internal carotid artery (ICA). An increased IMT was defined as a measurement of ≥1.5 mm in any segment. Multivariable linear regression analyses were conducted to identify independent predictors of increased IMT. Results: The study population had a mean age of 46.7 years and was predominantly male (69.7%). The prevalence of thickened IMT was the highest in the carotid bulb, followed by the ICA and CCA. IMT increased progressively with age and was higher in males across all segments, with the disparity becoming more pronounced after 65 years of age. The carotid bulb displayed the largest absolute IMT values, whereas the ICA exhibited a sharper age-related increment. Increased CCA IMT was strongly linked to hypertension (beta, 0.11; p < 0.001) and diabetes mellitus (beta, 0.12; p < 0.001). Both CCA and ICA IMT showed a weak but significant association with dyslipidemia (beta, 0.03; p < 0.001). Conclusions: The IMT distribution and its determinants vary across carotid segments. CCA is a robust marker of systemic vascular health, whereas the carotid bulb is the most sensitive marker for detecting early atherosclerotic changes. This study provides novel insights into segment-specific IMT patterns and their association with cardiovascular risk factors in a large, healthy Asian population. Full article

Poplar is an important tree species for timber supply and ecological protection in northern China. Cultivating and selecting high-quality varieties and germplasm resources suitable for cultivation are key factors in enhancing the quality and productivity of poplar plantations in the arid and semi-arid northern regions with shorter growing seasons. This study conducted a field cultivation experiment on 10 progeny clones from the direct cross (D × M) of imported Populus deltoides ‘DD-109’ with Populus maximowiczii and 7 progeny clones from the reciprocal cross (M × D) using one-year-old rooted cuttings planted at a 4 m × 8 m spacing. Based on 17 years of annual growth observations, the study systematically compared growth characteristics, age of quantitative maturity, path relationships between traits, and early selection efficiency in the hybrid offspring. The results indicated that the D × M population had superior diameter at breast height (DBH), tree height (H), and volume (V) compared to the M × D population, while the height-to-diameter ratio (HDR) was lower. The growth rate of the 17 clones peaked from 10 to 14 years, with annual volume growth increments (PAIs) higher than mean annual volume increments (MAIs) during the early growth stages; the quantitative maturity age ranged between 12 and 16 years. The D × M population generally reached quantitative maturity earlier than the M × D population, with the fastest clone maturing in 12 years. Four clones (DM-9-17, DM-9-18, DM-9-14, and MD-61) showed values for V, DBH, H, and HDR above the hybrid group average. Path analysis demonstrated that DBH had the most significant direct and indirect effects on V, suggesting it as the best predictor for V. Using DBH as a reference, correlation and early selection efficiency analysis showed a strong relationship between growth characteristics at planting years 4–5 and later-stage performance, indicating this as the optimal period for early selection. These findings contribute to evaluating the production potential of P. deltoides ‘DD-109’ and P. maximowiczii germplasm in northern China and provide valuable guidance for selecting poplar clones suitable for local cultivation, accelerating breeding processes, and informing management planning for poplar plantations. Full article

Monitoring land use/land cover (LULC) dynamics facilitates effective management and mitigation measures by providing timely and accurate information on the landscape. This study investigates LULC dynamics in Sagarmatha National Park (SNP), one of the most popular destinations for mountain tourism, and Khaptad National Park (KNP), which are emerging destinations, though popular among domestic tourists. A random forest classification algorithm was employed to generate LULC dynamics using Landsat data. High-resolution Planet Scope images and Google Earth images were used for accuracy assessment. Archived tourist and climatic data were analyzed to explore the impacts on LULC change. Cellular automata–artificial neural network (CA-ANN)-based LULC predictions were employed to predict future LULC. LULC dynamics of SNP revealed an increase in bare land, grassland, shrubland, glacial lakes, agriculture, and water bodies; however, snow/glacier and forest cover experienced substantial decreases of 140.25 km² and 15.36 km², respectively, from 1989 to 2021. In KNP, LULC dynamics showed an increasing trend in grassland, agriculture, water bodies, and bare land; however, forest and shrubland experienced a decrease of 18.63 km² and 10.48 km². The forest loss (19.33 km²) in the buffer zone of KNP was greater compared to the buffer zone of SNP (13.45 km²). The increment in built-up area was 0.80 km² in SNP and 1.11 km² in KNP, indicating escalating tourist activities and population growth. For SNP, the mean annual precipitation and temperature data from 1994 to 2023 showed decreasing and increasing patterns, respectively. However, the mean annual precipitation and temperature trends in KNP demonstrated an increasing pattern. Under the business-as-usual scenario, the estimated forest loss will be 1.61 km² in SNP by 2032 and 23.8 km² in KNP by 2030. A significant decline in snow/glaciers is projected for the core zone of SNP, with a loss of 22.84 km² expected by 2032. This study provides a baseline information on LULC changes in SNP and KNP. Further, it showcases the necessity of diversified national park policies as per the requirement. Full article

By the end of the decade, the world population is expected to increase by nearly one billion people, posing challenges to meeting global food demand. In this scenario, soybean production is projected to increase by 18% within this decade. Despite being the largest soybean producer, responsible for over 40% of soybeans produced worldwide, drought events often impair Brazilian production. The goals of the present research were to quantify soybean yield losses related to drought in Brazil from 1973 to 2023 at national, state, and municipal levels and to assess the spatial distribution of losses across the production areas. The hypothesis investigated is that year-to-year variations in soybean yield are closely related to water availability, considering that crop management practices are constant from year to year, while increments in soybean yield across time (more than five years) relate tightly to better crop management practices and breeding improvements. Thus, quantifying year-to-year yield losses might demonstrate the effects of water availability on soybean yield. Yield data from the 1976/1977 to 2022/2023 crop seasons from the 26 states and the Federal District came from the National Supply Company, while the Brazilian Institute of Geography and Statistics supplied yield data for the 1973/1974 to 2020/2021 crop seasons from 1998 municipalities with more than 14 crop seasons. Soybean drought yield losses were calculated for each cropping season individually at the municipal, state, and national levels, based on the deviation in the observed yield to the corresponding maximum yield in the five-year window, considering that crop management practices and genetics represent a regular increment in soybean yield, which means that production practices improved over time and deviations from year to year are mainly related to drought occurrence. Annual soybean yield loss (expressed in tons, USD, and percentage), frequency of yield loss, and severity of yield loss were calculated at national, state, and municipal levels for each cropping season. The Standardized Precipitation Index (SPI), acquired from the Brazilian Weather Forecast and Climate Studies Center at the National Space Research Institute, was used as a qualitative indicator to corroborate the assessed soybean yield losses related to drought. The results demonstrate yield losses in more than 50% of crop seasons at the national level, with a similar frequency across the five decades, albeit with lower severities in the last 30 years. The Central–West region was more stable than the South region, with yield losses of up to 74%. In five decades, yield losses related to drought events stand at 11.65%, corresponding to 280 million tons or USD 152 billion (considering the average soybean price in 2022 at the Chicago Board of Trade). At the municipal level, analogous behavior was observed across time and space. The outcomes from the present research might subsidize public and corporative policies related to agricultural zoning, farm loan programs, crop insurance contracts, and food security, contributing to higher agricultural, environmental, economic, and social sustainability. Full article

There is an unexplored knowledge gap regarding the relationship between soil quality and mean annual increment (MAI) in forest plantations in Tanzania. Therefore, this study aimed to identify soil quality indicators and their impact on the mean annual increment (MAI) of Pinus patula at Sao Hill (SHFP) and Shume forest plantations (SFP) in Tanzania. The forests were stratified into four site classes based on management records. Tree growth data were collected from 3 quadrat plots at each site, resulting in 12 plots in each plantation, while soil samples were taken from 0 to 40 cm soil depth. Analysis of variance examined the variation in soil quality indicators between site classes at two P. patula plantation sites. Covariance analysis assessed the differences in MAI and stand variables across various site classes, taking into account the differing ages of some stands, with stand age serving as a covariate. Linear regression models explored the relationship between soil quality indicators and MAI, while partial least squares regression predicted MAI using soil quality indicators. The results showed that, at SHFP, sand, organic carbon (OC), cation exchange capacity, calcium (Ca), magnesium (Mg), and available P varied significantly between site classes, while silt, clay, and available P varied significantly at SFP. At SHFP, sand and clay content were positively correlated with MAI, while at SFP, silt content, available P (Avail P), potassium (K), Ca, and Mg showed significant positive correlations. Soil quality indicators, including physical and chemical properties (porosity, clay percentages, sand content, and OC) and only chemical (K, Mg, Avail P, and soil pH) properties were better predictors of the forest mean annual increment at SHFP and SFP, respectively. This study underscores the importance of monitoring the quality of soils in enhancing MAI and developing soil management strategies for long-term sustainability in forests production. Full article

Open-grown trees in cities can improve environmental conditions by providing sustainable ecosystem services. Reliable data are necessary for assessing the functions of urban trees. The diameter at breast height (DBH), diameter increment, and annual ring measurements are the main parameters in the development of reliable models. To model periodic mean diameter increments calculated for different time periods (5, 10, 15, 20, and 25 years), a total of 43 open-grown stone pines (Pinus pinea L.) of different diameter classes were sampled in several urban parks in Istanbul, Türkiye. The DBH was measured, and increment cores were extracted from each tree at 1.30 m stem height using an increment borer. Tree age at breast height was determined by counting annual rings, and periodic mean diameter increments were calculated for different periods based on the measured tree-ring widths. The periodic mean increments of different periods were related to the inside-bark diameter at breast height and tree age. Since there was no significant relationship between tree age and periodic mean increments for each period’s length, as shown in the correlation analysis, models used to estimate the periodic mean increments of inside-bark DBH were developed using the least squares regression and quantile regression (QR) techniques. As the period length increased, the estimation success of the diameter increment models increased while the mean absolute percentage error (MAE) values decreased from 40 to 32%. The best model was the one used for the last 25-year period with the quantile value q = 0.50 which estimated the diameter increment with an RMSE = 1.391 mm/year and MAE = 32.27%. Full article

The increasing demand in structural engineering now extends beyond collapse prevention to encompass business continuity planning (BCP). In response, energy dissipation devices have garnered significant attention for building response control. Among these, buckling-restrained braces (BRBs) are particularly favored due to their stable hysteretic behavior and well-established design provisions. However, BCP also necessitates the prevention of furniture overturning—an area that remains quantitatively underexplored in the context of buckling-restrained braced frames (BRBFs). Addressing this gap, this research designs BRBFs using various design criteria and performs incremental dynamic analysis (IDA) with artificially generated seismic waves. The results are compared with previously developed fragility curves for furniture overturning under different BRB design conditions. The findings demonstrate that the fragility of furniture overturning can be mitigated by a natural frequency shift, which alters the threshold of critical peak floor acceleration. These results, combined with hazard curves obtained from various locations across Japan, quantify the mean annual frequency of furniture overturning. The study reveals that increased floor acceleration in stiffer BRBFs can lead to a 3.8-fold higher risk of furniture overturning compared to frames without BRBs. This heightened risk also arises from the greater hazards at shorter natural periods due to stricter response reduction demands. The probabilistic risk analysis, which integrates fragility and hazard assessments, provides deeper insights into the evaluation of BCP. Full article