Mountainous Regions Research Articles

Multi-Scenario Simulation of Land-Use/Land-Cover Changes and Carbon Storage Prediction Coupled with the SD-PLUS-InVEST Model: A Case Study of the Tuojiang River Basin, China

Land-use and land-cover changes (LUCCs) significantly impact carbon sequestration by modifying the structure and function of terrestrial ecosystems. This study utilized GIS and remote sensing techniques to forecast future LUCC patterns and their influence on regional carbon budgets, which is essential for sustainable development. We devised a coupled system dynamics (SD) model integrated with a patch-generating land-use simulation (PLUS) model to simulate LUCCs under diverse future scenarios using multisource environmental data. Additionally, the InVEST model was employed to quantify carbon storage in terrestrial ecosystems. By establishing three scenarios—ecological priority (EP), highly urbanized (HU), and coordinated development (CD)—this study’s aim was to predict the LUCC patterns and carbon storage distribution of the Tuojiang River Basin (TRB), China, up to 2035. The results showed that (1) from 2000 to 2020, significant LUCCs occurred in the TRB, primarily involving the conversion of cultivated land into construction areas and forestland; (2) LUCCs had a substantial impact on carbon storage in the TRB, with the EP scenario demonstrating the highest carbon storage by 2035 due to extensive forest expansion, while the HU scenario indicated a decline in carbon storage associated with rapid urbanization; and (3) the mountainous regions of the TRB, dominated by forestland, consistently exhibited higher carbon storage, whereas the Chengdu Plain region in the upper basin displayed the lowest. In conclusion, we recommend prioritizing the CD scenario in future development strategies to balance economic growth with ecological protection while simultaneously enhancing carbon storage. Our findings offer valuable insights to shape future LUCC policies in the Tuojiang River Basin, underscoring the adaptability of the coupled model approach to a wide range of geographic scales and contexts.

Resilient roads in challenging terrain: a case study of Siddhartha highway in Nepal

Nepal is a country known for its diverse and challenging topography, and it relies heavily on a robust road infrastructure network to connect its remote regions and urban centers. This study addresses the critical need for enhanced road safety and infrastructure resilience on the Siddhababa road section of the Siddhartha Highway, Nepal, notorious for its high accident rates and susceptibility to landslides. Given the road's strategic importance in connecting remote regions and its challenging topographical conditions, our research aimed to identify the most suitable pavement type to mitigate these issues. Through a detailed examination incorporating eight different soil tests, alongside evaluations of traffic loads, weather conditions, and existing pavement performance, we adopted a comparative analysis methodology to assess the viability of flexible versus rigid pavements within this unique context. Results revealed that the soil composition and environmental conditions of the Siddhababa section significantly influence pavement performance, with specific gravity, moisture content, and California Bearing Ratio (CBR) tests indicating a nuanced suitability for both pavement types under varying circumstances. Our analysis concluded that, despite the economic and staged reinforcement benefits of flexible pavements, the durability, safety, and maintenance considerations favor the adoption of rigid pavement for the Siddhababa road section. However, acknowledging the economic constraints, a hybrid approach is recommended, emphasizing rigid pavements for the most vulnerable sections and flexible pavements elsewhere. This study contributes to the pavement engineering field by providing a model for pavement type selection in mountainous regions, aiming to enhance road safety and durability amidst challenging environmental conditions.

Impact of Typical Land Use Expansion Induced by Ecological Restoration and Protection Projects on Landscape Patterns

Land use and land cover (LULC) changes driven by ecological restoration and protection projects play a pivotal role in reshaping landscape patterns. However, the specific impacts of these projects on landscape structure remain understudied. In this research, we applied geographically weighted regression (GWR) to analyze the spatial relationships between typical land use expansion and landscape pattern characteristics in the Lesser Khingan Mountains–Sanjiang Plain region between 2017 and 2022. Our results indicate three key findings: (1) Significant spatial heterogeneity exists in the relationship between landscape patterns and land use expansion, which varies across geographic locations; (2) Ecological restoration projects generally reduce fragmentation, dominance, and heterogeneity while enhancing connectivity, particularly in forest and farmland regions. However, excessive land use expansion in certain areas may reverse these positive effects; (3) Landscape complexity increases in high-altitude mountainous regions due to land use expansion but decreases in plains, particularly in forest-to-farmland conversions. These findings provide new insights into how landscape patterns respond to ecological restoration efforts and offer actionable guidance for improving future land use planning and policy decisions. Our study highlights the need to consider local geomorphological factors when designing ecological projects, ensuring that restoration efforts align with regional landscape dynamics to maintain landscape integrity.

Women in mountain tourism: exploring the links between women tourism entrepreneurship and women empowerment in Hunza Valley

ABSTRACT Tourism entrepreneurship is crucial to boosting household income and fostering gender equality in Pakistan. However, the involvement of women in mountain tourism entrepreneurship remains rather limited. This study examines the experiences of women entrepreneurs in the Hunza Valley of Pakistan, highlighting their transformative journey into the tourism market despite facing various obstacles. Through qualitative research involving 24 women-led tourism enterprises, the study illuminates the positive outcomes these women have achieved, including greater control over finances, enhanced decision-making power, boosted self-confidence, expanded networks, and overall societal empowerment. The study also identifies internal and external constraints faced by these entrepreneurs, emphasising the need for immediate policy interventions to support women's entrepreneurship in the region. Recognising the catalytic role these women play in promoting gender equality and social innovation, the study advocates for greater recognition and appreciation of their contributions to inspire other women in the region. Based on the study's findings, a framework for women's tourism entrepreneurship is proposed, emphasising the potential of such initiatives to empower women, drive social change, and foster gender equality in remote mountain regions.

The dual lens of diversity: Seasonal variability of avian community structure in urban hills

Urbanization has significantly increased the environmental intricacy of low mountainous and hilly urban landscapes, exacerbating the need for biodiversity conservation in these ecosystems. This study involved comprehensive bird surveys across four seasons from July 2022 to April 2023 along 64 transects in the low mountainous terrain of Jiangsu Province. Adopting a dual lens of taxonomic and functional dimensions, our research explored seasonal fluctuations and assembly mechanisms governing avian community diversity (both α and β) on these urban hills. The results showed that species richness and functional diversity (FD) were higher in spring and lower in autumn, whereas functional mean pairwise distance (MFD) and mean nearest functional distance (FD.MNTD) were higher in summer and winter. Although the standardized effect sizes for MFD were not significantly different from zero in any of the four periods, those for FD.MNTD were significantly less than zero in summer, autumn, and winter, indicating a propensity for functional trait clustering within avian communities during these seasons. Taxonomic variations were found to be chiefly governed by species turnover, whereas functional dynamics were principally shaped by nestedness. A marked disparity emerged, with functional β-diversity and its turnover components consistently registering lower values than their taxonomic counterparts, accompanied by a higher level of functional nestedness versus taxonomic nestedness. This study underscores the intricate seasonal dynamics of avian communities in urbanized low mountainous regions and provides crucial insights to devise conservation strategies aimed at preserving avian biodiversity within these ecologically complex urban landscapes.

Elachistadimicatella sensu auctt.-a complex of neglected species diversity (Lepidoptera, Elachistidae) from European mountain systems.

Elachistadimicatella Rebel, 1903, has so far been considered a species in Europe with restricted distribution from Ukraine to western France. The species occurs on mountainous regions. However, the in-depth analysis of a taxonomically uncertain species of Elachista from the Cottian Alps (Italy), especially through DNA barcoding and subsequent morphological studies, led to the realization that individuals previously identified as E.dimicatella from the Cottian Alps and the Pyrenees were misidentified. According to our research, a total of three species can be differentiated: E.dimicatella from Carpathians and its former junior synonym E.niphadophanes Meyrick, 1937, sp. rev., from the Pyrenees, as well as the newly described E.cottiella sp. nov. from southwestern Alps, hitherto incorrectly identified as E.dimicatella. Diagnostic features of the three species are discussed and illustrated. Elachistadimicatella and E.niphadophanes are redescribed.

Rice Yield Estimation Using Machine Learning and Feature Selection in Hilly and Mountainous Chongqing, China

To investigate effective techniques for estimating rice production in hilly and mountainous areas, in this study, we collected yield data at the field level, agro-meteorological data, and Sentinel-2/MSI remote sensing data in Chongqing, China, between 2020 and 2023. The integral values of vegetation indicators from the rice greening up to heading–filling stages were determined using the Newton–trapezoidal integration method. Using correlation analysis and importance analysis of permutation features, the effects of agro-meteorological variables and vegetation index integrals on rice yield were assessed. The chosen characteristics were then combined with three machine learning techniques—random forest (RF), support vector machine (SVM), and partial least squares regression (PLSR)—to create six rice yield estimate models. The results showed that combined vegetation indices were more effective than indices used in separate development phases. Specifically, the correlation coefficients between the integral values of eight vegetation indices from rice greening up to heading–filling stages and rice yield were all above 0.65. By introducing agro-meteorological factors as new independent variables and combining them with vegetation indices as input parameters, the predictive capability of the model was evaluated. The results showed that the performance of PLSR remained stable, while the prediction accuracies of SVM and RF improved by 13% to 21.5%. After feature selection, the inversion performance of all three machine learning models improved, with the RF model coupled with variables selected during permutation feature importance analysis achieving the optimal inversion effect, which was characterized by a coefficient of determination of 0.85, a root mean square error of 529.1 kg/hm2, and a mean relative error of 5.63%. This study provides technical support for improving the accuracy of remote sensing-based crop yield estimation in hilly and mountainous regions, facilitating precise agricultural management and informing agrarian decision making.

Impact of Human Resource Management on Innovation of Higher Education Lecturers: A Case Study at Local Universities in the Northern Midlands and Mountainous Region of Vietnam

The study was conducted to measure the impact of human resource management on the innovation of higher education lecturers in Vietnam. The research data were collected through surveys of 223 lecturers working at local universities in the Northern Midlands and Mountainous region of Vietnam. The quantitative results indicated that 8 groups of HRM practices, including recruitment, training, career development, job assurance, performance-based appraisal, job description, financial compensation, and participation, have a positive influence on lecturers' innovation. Knowledge sharing and organizational commitment have been proven to be the mediators in the relationship between HRM and individual innovation results. Based on the research results, the authors proposed recommendations to improve HRM practices to motivate lecturers' innovation among lecturers for the development of the university and national higher education.

Future projection of extreme precipitation using a pseudo-global warming method: A case study of the 2013 Alberta flooding event

The June 2013 extreme precipitation event in Alberta resulted in devastating flash floods that caused significant economic losses and societal disruption. In this study, two high-resolution experiments were conducted using the Weather Research and Forecasting (WRF) model to study the change of the 2013 Alberta extreme precipitation event in a warmer climate. The control experiment was forced with 6-hourly ERA-Interim reanalysis data, while the sensitivity experiment was forced with perturbed ERA-Interim reanalysis data with climate change signals derived from ten global climate models under the Representative Concentration Pathway 8.5 emission scenario. The results indicate that the 2013 Alberta extreme precipitation event is projected to exhibit two significant characteristics in a warming climate. First, precipitation is expected to increase over the Canadian Rocky Mountain region and eastern British Columbia. Second, the precipitation is expected to decrease over the Alberta and Saskatchewan Prairies. Future changes in the extreme precipitation event are associated with changes in the cyclone evolution, moisture transport, and atmospheric stability change caused by climate change. We also found that the increase in atmospheric stability due to the decrease of relative humidity in the lower atmosphere cause less precipitation to form over the plains and later enhance the orographic precipitation in the Canadian Rockies. In addition to the general increase of precipitable water under global warming, this mechanism causes the storm's precipitation to be more concentrated near the Canadian Rockies. The findings from this study could be beneficial for understanding future changes in extreme precipitation events that share similar characteristics.

A Green Laboratory Approach to Medical Sample Transportation: Assessing the Carbon Dioxide (CO2) Footprint of Medical Sample Transportation by Drone, Combustion Car, and Electric Car

In response to escalating climate change concerns, this study evaluates the ecological impact and efficiency of medical sample transportation using drones, combustion cars, and electric cars across various terrains and weather conditions in Liechtenstein and Switzerland. Through a comparative analysis, we found that combustion cars emit the highest average CO2 at 159.5 g per kilometer (g/km), while electric cars significantly reduce emissions to an average of 3.43 g/km, representing just 2.15% of the emissions from combustion vehicles. Drones emerged as the most environmentally sustainable option, with an average CO2 emission of 0.09 g/km, which is only 0.07% of combustion car emissions and 2.6% of electric car emissions. Drones also demonstrated superior transport efficiency, covering routes that were, on average, 17% shorter in flat terrain and 24% shorter in mountainous regions compared to cars. Additionally, drones achieved substantial time savings, ranging from 13% to 80% faster delivery times depending on the terrain and traffic conditions. These findings highlight the potential of drone technology to revolutionize healthcare logistics by significantly reducing carbon footprints, optimizing transport routes, and improving delivery efficiency. Integrating drones into healthcare transportation networks offers a promising pathway toward a more sustainable and resilient healthcare system.

Utilization of Tunnel Waste Slag for Cement-Stabilized Base Layers in Highway Engineering.

The rapid expansion of highway infrastructure in the mountainous regions of China has led to a significant increase in tunnel construction, generating substantial amounts of tunnel waste slag. Concurrently, the development of transportation infrastructure has created a critical shortage of natural aggregates, necessitating the exploration of alternative sustainable sources. This study aimed to conduct a comprehensive evaluation of the physical and mechanical properties of tunnel waste slag and explore its potential for utilization in cement-stabilized base courses for highway engineering applications. The uniaxial compressive strength of the parent rock (tunnel waste slag) ranged from 81 MPa to 89 MPa in the desiccated state, indicating its suitability for use as a construction material. This study also determined the maximum dry density (2.432 g/cm3) and optimal moisture content (5.4%) of cement-stabilized mixtures incorporating recycled aggregates derived from tunnel waste slag. The splitting tensile strength of these mixtures at 28 days varied from 0.48 MPa to 0.73 MPa, demonstrating robust mechanical performance. Moreover, the unconfined compressive strength of these mixtures escalated from 7.0 MPa at 7 days to 11.0 MPa at 90 days, signifying a substantial enhancement in strength over time. These results validate the viability of utilizing tunnel waste slag in highway engineering and furnish valuable insights for designers, concrete manufacturers, and construction firms engaged in the development of cement-stabilized aggregate base courses.

Slope stability analysis of colluvial deposits along the Muketuri-Alem Ketema Road, Northern Ethiopia

Slope failures are a significant natural geohazard in hilly and mountainous regions, often resulting in loss of life and infrastructure damage. The Muketuri-Alem Ketema road in Ethiopia is particularly vulnerable to landslides due to colluvial deposits on steep slopes from the higher northeastern plots to the lower Jemma River valley. This study investigates the characteristics of colluvial soil and evaluates the stability of slopes prone to landslides. It combines geophysical data, penetrometer tests, laboratory analyses, Google Earth images, and detailed field visits to assess the soil and bedrock composition and structure. Numerical methods, including limit equilibrium (Bishop, Janbu, Spencer, and Morgenstern-Price methods) and finite element methods, were used to analyze slope sections under various saturation conditions and simulate different rainfall patterns. The results indicate that the Bishop, Morgenstern-Price, and Spencer methods produce similar safety factors with minimal differences (<0.3%), while the Janbu method shows more significant variation (1.5%–5.6%). Safety factor differences for sections A-A and B-B range from 5.26% to 9.86% and 3.5%–4.7%, respectively. Simulations reveal that short-term saturation significantly reduces the stability of the upper slope layer by 20%–46.76%, and long-term saturation decreases the entire slope section by 26.81%–46.76% compared to dry conditions due to increased pore water pressure and self-weight. Long-term saturation effects, combined with dynamic loads, can further reduce colluvial soil stability by over 50% compared to a dry static state. The finite element method predicts larger failure zones than limit equilibrium methods, emphasizing the need for accurate predictions to characterize slope behavior during failure and inform stabilization decisions. This study provides crucial data for maintaining and planning the Muketuri-Alem Ketema Road, highlighting slope performance over time and the effectiveness of stabilization techniques.

Between Transcendental and National: Wooden Churches of Slovakia

ABSTRACT The Eastern Carpathian Mountain region is home to Slavic peoples, who celebrate the bringing of Christianity by Saints Cyril and Methodius in the ninth century. The mountainous region retains small village churches, some dating from the eighteenth century, each established within agrarian communities by Roman Catholic, Greek Catholic, Protestant, or Orthodox denominations. Despite village subjugation under the Austro-Hungarian Empire, Nazi occupation, Russian “liberation” and Socialist-era suppression of non-Orthodox denominations, these exquisite vernacular structures have remained and illustrate the continuing transcendental experience for worshipers but also now shared with those who celebrate them as symbols of national resistance, as well as tourists who come to experience them as UNESCO World Heritage sites. Sharing a common church object, traditional typological and formal aesthetic approaches that have been established by researchers for these structures are contrasted against a phenomenologically rooted set of embodied modes for meaning across examples from extant structures within Slovakia. Embodied approaches provide, via modes of lived experience, a deep offering into what each church shares with their ecological landscape, village, and history; a holistic visceral tapestry key to their appreciation complimenting the typological and differently affirming their continuing value.

Impact of Model Spatial Resolution on Global Geophysical Satellite-Derived Fine Particulate Matter.

Global geophysical satellite-derived ambient fine particulate matter (PM2.5) inference relies upon a geophysical relationship (η) from a chemical transport model to relate satellite retrievals of aerosol optical depth (AOD) to surface PM2.5. The resolution dependence of simulated η warrants further investigation. In this study, we calculate geophysical PM2.5 with simulated η from the GEOS-Chem model in its high-performance configuration (GCHP) at cubed-sphere resolutions of C360 (∼25 km) and C48 (∼200 km) and satellite AOD at 0.01° (∼1 km). Annual geophysical PM2.5 concentrations inferred from satellite AOD and GCHP simulations at ∼25 km and ∼200 km resolutions exhibit remarkable similarity (R 2 = 0.96, slope = 1.03). This similarity in part reflects opposite resolution responses across components with population-weighted normalized mean difference (PW-NMD) increasing by 5% to 11% for primary species while decreasing by -30% to -5% for secondary species at finer resolution. Despite global similarity, our results also identify larger resolution sensitivities of η over isolated pollution sources and mountainous regions, where spatial contrast of aerosol concentration and composition is better represented at fine resolution. Our results highlight the resolution dependence of representing near-surface concentrations and the vertical distribution of chemically different species with implications for inferring ground-level PM2.5 from columnar AOD.

A geospatial approach to identifying and mapping areas of relative environmental pressure on ecosystem integrity

The influence of increasing anthropogenic pressure on ecosystem integrity, such as land use change, is resulting in many ecosystems experiencing a decline in their ability to maintain balanced functions and services. Identifying and quantifying these pressures over different scales is challenging and thus impacting the achievement or maintenance of key environmental outcomes. In this study, a GIS-based and scalable tool was developed, the Relative Environmental Pressure (REP) Tool, to address these challenges. The REP tool combines an ecosystem integrity conceptual framework with a weighted linear combination analysis to quantify and rank relative environmental pressure across the scale of interest. The REP Tool was developed as an automated Python-based model in a PyCharm working environment using ArcGIS Pro Arcpy scripting. The REP Tool was applied to spatially contiguous geospatial data for the Province of Alberta, Canada and dynamically scaled relative to Hydrologic Unit Codes at level 8 (HUC8) along with regional and sub-regional scale sub-watersheds. Both cumulative and individual relative pressure levels were calculated and mapped for specific ecosystem integrity framework-derived Environmental Pressure Groups (EPGs) including Atmospheric Alteration, Sedimentation, Habitat Alteration, Hydrologic Alteration, and Social Pressure. Data driven Jenks natural breaks were then applied to classify the relative environmental pressures into a nine-level ranking system. The resulting visualization and data outputs from the REP Tool clearly show that the highest cumulative relative environmental pressure values align with the distribution of major population centres, zones of intense agriculture and major industrial activity. These regions reflect the physiography of Alberta with the Rocky Mountain and Boreal natural regions dominated by low relative environmental pressure. As scales become smaller and more refined, the location of the higher relative environmental pressure levels typically become more subdivided with greater spatial precision where higher pressured areas are located. These patterns are repeated when looking at individual EPGs but with enhanced differentiation of pressure as scales are refined. The framework and geospatial science driven approach behind the REP Tool can be universally applied to support enhanced understanding of relative environmental pressures in, or between regions, as well as informing adaptive environmental resource management and monitoring activities.

Impacts of moisture transport on extreme precipitation in the Central Plains Urban Agglomeration, China

In recent decades, the Central Plains Urban Agglomeration of China (CPUA) has faced recurring extreme precipitation events (EPEs), leading to severe floods, endangering residents, and causing significant property damage. This study examines the spatiotemporal patterns of summer EPEs in the CPUA from 1961 to 2022. We used the Hybrid Single-Particle Lagrangian Integrated Trajectory model to trace the water vapor trajectories associated with these events, identifying atmospheric circulations linked to various moisture sources. Summer EPEs in the CPUA have become more frequent and intense. Urban regions typically experience stronger EPEs, while mountainous regions encounter more frequent but milder precipitation. The moisture contributing to these events comes from sources including Eurasia (9.94 %), the northern and southern Western North Pacific (48.39 %), and the Bay of Bengal and South China Sea (41.67 %). Notably, contributions from Eurasia and the northern Western North Pacific have increased, whereas those from the Bay of Bengal and the South China Sea have decreased. Events driven by Western North Pacific moisture have stronger impacts on urban areas, influenced by abnormal anticyclonic patterns and the development of the Huang-Huai cyclone, which triggers intense convective activity over the CPUA. The strengthening of the Western North Pacific subtropical high promotes the transport of warm air, which merges with colder inland air, leading to extreme precipitation.

Plant species diversification in the Himalaya-Hengduan Mountains region: an example from an endemic lineage of Pedicularis (Orobanchaceae) in the role of floral specializations and rapid range expansions.

The c. 270 endemic species of Pedicularis in the Himalaya-Hengduan Mountains (HHM) region exhibit high diversity in geographic distribution, elevational range and floral morphology. Many of these, including the species with the longest corolla tubes and beaked galeas, are monophyletic and represent a putative in situ radiation. In this study, we focus on the representative Clade 3 within the HHM region. We integrate the plastid phylogeny of this clade with environmental data and species distributions to infer environmental correlates of species diversity. We estimate macroevolutionary rates and reconstructed ancestral states for geographic ranges and corolla traits, and analyse patterns of range overlap and niche evolution to assess drivers of diversification in the HHM region. Our results show that the region from northwest Yunnan to southwest Sichuan is the centre of diversity for this clade of Pedicularis. Rates of diversification are associated with precipitation and multiple environmental factors. Multiple range expansions from the Sanjiang (Three Parallel Rivers) region, followed by allopatric speciation across the HHM region, contributed to early rapid diversification. Corolla traits are not significantly associated with species diversification. This study highlights the importance of integrated evidence for understanding species diversification dynamics and contributes to our understanding of the origins of the remarkable richness of plant species in the HHM region.

Addressing poverty and inequality in the mountains of Pakistan

This paper examines poverty and inequality in Pakistan's mountains, using nationally representative data. Our analysis reveals that, despite a slight decline in poverty rates, overall rates remain alarmingly high, with significant variations across provinces and regions. Rural and mountain areas exhibit higher poverty rates (31% in rural areas, 13% in urban areas in 2015/16) compared to urban centers. The national incidence of multidimensional poverty in 2014/15 was 41%, surpassing monetary poverty rates. Notably, rural areas (47%) experienced significantly higher multidimensional poverty than urban centers (12%), with Balochistan’s mountainous province recording the highest rates (63%). The four provinces display significant heterogeneity in multidimensional poverty, with district-level variations ranging from 10 to 90% in Khyber Pakhtunkhwa and Balochistan. The majority of districts with high poverty incidence are situated in mountainous regions, where people face multidimensional challenges in accessing basic facilities such as health and education, cooking fuel, and housing. To address this issue, Pakistan needs to prioritize mountain areas and implement targeted programs aimed at improving access to basic services, addressing gender inequalities, and promoting sustainable development.

Evaluation of retrofitting effect of concrete filling in hollow RC columns using XFEM

Hollow RC columns are widely utilized in the construction of high piers in mountainous regions. Recently, precast hollow RC columns have been increasingly used to enhance transportability and ease of handling, aiding Accelerated Bridge Construction. This paper evaluated the effectiveness of concrete-filling retrofitting measures for hollow RC columns using eXtended Finite Element Method (X-FEM). Our focus was particularly on instances where original hollow sections and post-filled concrete sections don't behave as unified structures. The proposed X-FEM model's reliability was validated through simulations replicating compressive strength tests on molded concrete specimens and previous static loading tests on hollow RC columns conducted to evaluate the efficacy of concrete-filling retrofitting for hollow RC columns. The proposed X-FEM model successfully represents the compressive softening and fracture behavior of concrete under uniaxial compression. It also successfully replicated the lateral load capacity and the crack patterns of hollow RC columns observed in the previous experiments. When comparing the component ratios of bending and shear deformation of the columns, the shear deformation component of the hollow RC column retrofitted with the concrete filling was about 1.5 times larger than that of the solid RC column at each displacement. This result indicates that concrete-filling retrofitting might not enhance the shear capacity of hollow RC columns to the anticipated level in scenarios where the pre-existing hollow portion and the post-filled concrete portion fail to function as unified structures. Based on these findings, this study investigated the efficacy of anchor reinforcement in hollow RC columns filled with concrete to enhance the structural unity of existing and filled portions. The results indicate that anchor reinforcement improved the shear resistance properties by enhancing the structural unity between the pre-existing hollow portion and the post-filled concrete portion.

Surviving the extinction vortex? Discovering remnant stands of Senecio hercynicus (Compositae, Senecioneae) evading genetic swamping by its congener S. ovatus in the Bavarian and Bohemian Forest region

Genetic swamping by introgressive hybridisation threatens diversity, caused by climate warming particularly in mountainous regions worldwide. Recent studies resulted in a threatening perspective for Senecio hercynicus in the Bavarian Forest due to genetic swamping by introgressive hybridisation with its cogener S. ovatus. To examine the situation more closely, the distribution and hybridization of S. hercynicus and S. ovatus in high elevation regions of the Bavarian and Bohemian Forest was analyzed by restriction enzyme digestion of nrDNA ITS1 (PCR-RFLP; PCR restriction fragment length polymorphism). For a total of 706 samples from 94 different sample localities a hybrid index was inferred from the fragment band intensities after PCR-RFLP digestion. Boxplot diagrams of the hybrid indices show a tendency of western populations towards S. ovatus genotypes and for populations to the east towards S. hercynicus genotypes. When the hybrid index data was subjected to a regression analysis with nine factors (five habitat patterns inferred during sampling and four bioclimatic variables), only geographical longitude and latitude seemed to describe the observed distribution of S. hercynicus and S. ovatus significantly, arguing for the distribution and hybridisation patterns being shaped rather due to historical than to eco-climatological determinants. While a broad zone of hybridisation between the two species in the Bavarian and Bohemian Forest region was inferred, our study demonstrates that purebred S. hercynicus still exists and remnant stands of this species should be the target of species conservation measures.