Earth and Environmental Sciences

Current challenges in the construction field emphasize the need for compatible and durable materials for heritage interventions. Traditional lime-based mortars often exhibit limitations under environmental exposure, particularly in terms of water absorption and freeze–thaw resistance. This article investigates the performance of hydroxyapatite (HAp)-modified lime mortars applied in a real-scale heritage context, namely a student built micro-museum developed within the Apoș Architecture Summer School. Following the premature degradation of a conventional lime mortar layer applied at roof level, HAp-modified formulations were introduced as a protective and consolidating solution. The experimental approach combines laboratory testing and in situ evaluation, including compressive strength measurements, water absorption, capillarity tests, chromatic analysis, and freeze–thaw assessment. The results indicate a reduction in water absorption from approximately 22% to 12%, an increase in compressive strength from 6.57 MPa to 19.95 MPa and a significant improvement in freeze–thaw resistance, reflected by a decrease in gelivity from 61.2% to 5.73%, compared to traditional lime mortars. In addition, the contact angle increased from 36° to 82°, indicating enhanced hydrophobic behavior. These improvements are associated with pore structure refinement, reduced capillary uptake, and enhanced interfacial bonding within the mortar matrix. The study also highlights the role of real-scale educational environments in validating sustainable material solutions.

Abstract

Abstract Despite increasing emphasis on sustainability, existing instruments for assessing recycling behavior often rely on single indicators or attitudinal measures, limiting their ability to capture the multidimensional nature of responsible recycling practices. Addressing this gap, this study aims to develop and validate the Responsible Recycling Behavior Scale (REBES), a theory-driven, multidimensional instrument to assess responsible recycling behavior among university students. A mixed-method design was employed. Item generation was based on a literature review and qualitative data, followed by expert evaluation. The scale was tested using data from three independent samples of university students (N=1105). Exploratory factor analysis (EFA) and confirmatory factor analysis (CFA) were conducted to examine the factor structure, and reliability and validity analyses were performed. The findings support a 24-item, five-factor structure consisting of ecomanagement/physical action, consumer/economic action, individual/public persuasion action, political action, and legal action. The model demonstrated good fit indices, along with satisfactory reliability, convergent validity, and discriminant validity. These results indicate that responsible recycling behavior is multidimensional, extending beyond routine practices to include social, economic, and institutional forms of engagement. The study contributes to the literature by providing a behavior-focused, multidimensional measurement tool that enables a comprehensive assessment of responsible recycling behavior among university students.

Against the backdrop of ocean governance that increasingly emphasizes cross-border coordination, institutional coherence, and implementation linkage, high seas marine protected areas (MPAs) have emerged as an important governance tool for advancing the “30×30” target and strengthening biodiversity conservation in areas beyond national jurisdiction (ABNJ). However, the main challenge of high seas MPAs lies not only in their limited coverage, but also in the difficulty of translating conservation designations into sustained and coordinated implementation within a fragmented cross-sectoral governance structure. Existing practice and research show that high seas MPA implementation has long been constrained by dispersed institutional mandates, weak scientific data and monitoring, unclear management and enforcement arrangements, poor data sharing, and persistent participation and capacity gaps. A significant divide therefore remains between MPA designation and effective protection. Drawing on existing high seas MPA practice and the Agreement under the United Nations Convention on the Law of the Sea on the Conservation and Sustainable Use of Marine Biological Diversity of Areas beyond National Jurisdiction (BBNJ Agreement), this article combines doctrinal legal analysis with comparative institutional analysis to identify the principal governance obstacles to high seas MPA implementation and to evaluate both the potential and limits of the new Agreement in addressing them. The article argues that the BBNJ Agreement provides an important global institutional foundation for improving high seas MPA governance by promoting greater procedural coherence, coordination, and transparency, but it has not yet produced a sufficiently clear operational implementation system. Effective governance of high seas MPAs under the BBNJ framework requires moving beyond formal designation toward more substantive protection. This includes establishing a dedicated implementation coordination mechanism, further specifying implementation and enforcement rules, embedding monitoring, control, and surveillance (MCS) into the management framework, strengthening targeted proposal support, long-term scientific and technical cooperation networks, and data-sharing arrangements.

Lakshadweep islands are coral atolls islands which are characterized by complex wave transformation patterns due to their unique geomorphological features, such as reef flats, lagoons, and steep fore-reef slopes. Coastal erosion and high wave events in Lakshadweep islands located in Arabian Sea have become more common in recent days, especially during every monsoon and during cyclonic storms. Lakshadweep islands, with a tiny land area, the erosion of even a small portion of the land can be a significant loss to habitat and livelihood. This research aims to investigate the spatial variability of wave climate around the highly populated Androth island of Lakshadweep, which is oriented in east west direction. The numerical model was employed to simulate the long-term nearshore wave climate for the period of 40 years from 1981 to 2020, which examines the interannual variability and seasonal variability of wave climate at various zones of the Androth island. The study also examines the extreme wave climate around the Androth island using long-term hindcast wave data for various return periods. The analysis reveals that the western zone of the Androth island experience high intensity of waves due to high steepness in bathymetry and configuration of island. The western zone of the Androth island is characterized by annual mean significant wave height in the range of 1.2 m to 1.5 m and with high coefficient of variation values for significant wave height. During 1981 to 2020, a statistically significant positive trend of 0.24 cm/year is observed in the annual mean significant wave height in the southern zone of Androth island. The extreme value analysis of wave height reveals that the 100-year return period of significant wave height ranges between 3.32 m and 4.92 m around Androth island. The combined analysis of wave variability and extreme values supports better site selection, optimal design and resilient planning of coastal and offshore infrastructure.

Mounting evidence highlights the critical role of silicate-melt−mediated refertilization in lithospheric evolution, yet chalcophile element behavior during this process remains contentious. Integrating Pyrenean peridotite geochemistry (of the Lherz massif) with quantitative modeling reveals that platinum-group elements (PGEs), due to their extreme sulfide compatibility, are primarily controlled by initial partial melting, and largely unaffected (or net addition strictly localized at the reaction interface) by refertilization. Conversely, moderately incompatible Cu and Au are systematically enriched overall in the mantle column during refertilization. This decoupling is globally corroborated, where pervasive Au-Cu enrichment characterizes both subcontinental lithospheric mantle (SCLM) and oceanic lithospheric mantle (OLM), while systematic platinum-palladium depletion in SCLM versus primitive mantle−like ratios in OLM reflect distinct sulfide exhaustion during their partial melting. Crucially, the eastern North China craton exemplifies how extensive refertilization transforms ancient, barren SCLM into a fertile Au-Cu and volatile-rich source, directly supplying the ingredients for giant Au deposits. This provides a quantitative framework linking mantle processes to lithospheric metal fertility.

Rare-metal granites and pegmatites are commonly interpreted to form either by extreme fractionation of granitic magmas or by low-degree crustal melting. Despite renewed interest in the anatectic model, the mechanisms governing Li release into melts and whether crustal melting alone can concentrate Li to ore-grade levels remain debated. Here, we present the first comprehensive database of Li concentrations in anatectic melt inclusions, providing direct constraints on the Li budget of primary melts formed under typical mid- to lower-crustal pressure-temperature (P-T) conditions and compositions. The dataset shows that Li release into anatectic melts is optimized during early, fluid-absent equilibrium melting of biotite at 750−800 °C in cordierite-free rocks, reaching up to ∼600 μg/g Li. Although these concentrations exceed those of S-type granites, they overlap the range of barren pegmatites, indicating that extreme fractionation is required to produce hard-rock Li ores. Integration of natural constraints with petrological modeling suggests that direct generation of ore-forming Li enrichments (3000−20,000 μg/g Li) requires strongly pre-enriched sources (600−2000 μg/g Li, i.e., >20 times ordinary crustal abundances). Given the lack of compelling evidence that such sedimentary sources retain Li anomalies up to anatectic conditions, the formation of hard-rock Li ores of anatectic origin likely reflects the convergence in space and time of favorable melting mechanisms, P-T conditions, and tectonic controls enabling rapid melt extraction and extensive fractionation—a convergence that, although rare, is preferentially achieved during the waning stages of orogenic cycles.

Biodiversity, as the foundation of life on Earth, sustains the balance of ecosystems and supports human sustainable development. However, the current accelerated decline in biodiversity poses ecological threats that require urgent attention. This research based on the perspective of ethnic ecological wisdom, explores the customary practices of biological conservation among the Miao ethnic group in Southwest China, the Tao ethnic group on Orchid Island (Lanyu), Taiwan, and the Maasai ethnic group on the East African Plateau. By conducting in-depth case studies, combined with literature review and data validation, it investigates their practical value and implementation pathways in biodiversity conservation. By analyzing the ecological conservation wisdom models of the Miao, Tao and Maasai ethnic groups, it is found that the core species populations in each region have shown a positive growth trend since the gradual integration of traditional ethnic customary laws with modern ecological protection systems and practices. Drawing on the extensive experience accumulated in integrating customary law into ecological governance across the three cases, this study proposes a three-dimensional optimization pathway: at the policy level, construct a mechanism integrating customary law and diversified ecological compensation; at the community level, implement a model featuring benefit sharing, patrol mediation and digital management; and at the cultural level, strengthen the development and dissemination of ethnic ecological conservation wisdom through multidisciplinary talent training and IP-based communication of exemplary customary law outcomes. We aspire to slow the rate of global biodiversity loss and achieve a bright future of harmonious coexistence between humans and nature.

When finished with an electronic device, consumers choose between storing, recycling, giving away, trading-in, reselling, or throwing it away. This choice has environmental and data privacy implications, e.g., reuse of devices is generally environmentally preferable to recycling, which is better than throwing away in the trash. Through a survey of 4000 U.S. consumers and regression analysis, this study analyzes how stated attitude and knowledge connect to consumers’ previous and planned disposition choices. The binomial regression model (pseudo-R2=13%) models the decision to store or not store a device. Important factors leading to increased likelihood of storing are data security concerns when recycling (+14%) or reselling (+9%), lack of knowledge of recycling (+10%), and wanting a backup of data (+11%). Notably, data security concerns when recycling or reselling were significant for past behavior, but not for intended behavior. This suggests consumers take data security more seriously when faced with the actual disposition decision. Multinomial regression (pseudo-R2=15%) is used to model which non-storage option is chosen. Knowledge of (+47%) and perceived convenience (+9%) of recycling programs were important in consumers choosing to recycle, reselling of devices was strongly influenced by knowledge of reuse markets.

Assessing environmental flows downstream of reservoirs under changing climate and increasing water demand remains a critical challenge in catchment management. This study presents an integrated framework for optimizing environmental flow releases by explicitly linking reservoir operation with climate change and population growth. The key novelty lies in the development of a modified objective function that incorporates environmental flow requirements alongside evolving hydrological and demand conditions. Reservoir inflows were simulated using an artificial intelligence-based rainfall–runoff model, employing a neuro-fuzzy inference system to capture nonlinear relationships between climate variables and runoff. Future rainfall projections were derived from four general circulation models (ACCESS1.0, CanESM2, MIROC5, and NorESM-M1) across four-time horizons (2021–2040, 2041–2060, 2061–2080, and 2081–2100). The simulated inflows were coupled with a reservoir operation model to optimize environmental flow releases, with system performance evaluated using reliability and vulnerability metrics. Results show that climate change alone has a limited impact on environmental flow supply; however, when combined with population-driven increases in water demand, significant reductions in system performance occur. In the worst-case scenario, the reliability of meeting environmental flow requirements drops below 20%, accompanied by a marked increase in system vulnerability. These findings demonstrate that water demand pressures play a dominant role in shaping future environmental flow availability. The proposed framework provides a robust and adaptable approach for integrating hydrological variability and socio-economic drivers into reservoir management, supporting more informed decision-making for balancing water supply and ecosystem sustainability under future uncertainty.

Research traditionally examines the spatial distribution of urban parks through the lens of spatial equity, overlooking the intricate interaction between the physical foundation of park construction and historical processes. Grounded in the theory of material geography, we investigate the mechanisms underlying the spatio-temporal evolution of urban parks in Shenzhen. We conduct topographical analysis and examine relevant historical policy texts to explore the ‘production of nature’ in China’s post-Mao urbanisation. We find that the distribution of urban parks in Shenzhen is not merely a result of social choice but a product of the interplay between material natural endowments—centred on topography—and urban spatial policies across historical stages. During rapid urbanisation, government-led spatial policies functionally reorganised and assigned symbolic meanings to diverse topographical features, such as plains, hills, and coastal areas, transforming them into urban parks that support capital accumulation and urban upgrading. The proposed ‘topography–policy’ synergistic framework transcends neutral spatial descriptions, revealing the nexus between the commodification of nature and urban governance. We clarify the rationale for the creation of contemporary urban green spaces in China and offer novel theoretical and empirical insights into sustainable urban transformation worldwide.