Search Results (179)

Ecological stoichiometry offers a powerful framework for linking the elemental composition of ecosystems to their biogeochemical functions. However, whether soil stoichiometry directly controls greenhouse gas (GHG) emission ratios remains largely unexplored. This study provides a case study investigating the link between the soil carbon-to-nitrogen (C:N) mass ratio and the gaseous C:N molar emission ratio in three distinct temperate island-like forests (Larix gmelinii forest, LGF; Betula platyphylla forest, BPF; and a Populus-Betula mixed forest, PBMF) in the Qixing River Wetland. Using the static chamber–gas chromatography method, we measured soil fluxes of CO₂, CH₄, and N₂O throughout the growing season. Our results revealed a strong, significant positive linear relationship (R² = 0.99, p < 0.001) between the soil C:N ratio and the gaseous C:N emission ratio across all forest types. The LGF, possessing the highest soil C:N ratio, exhibited the highest gaseous C:N emission ratio, driven by substantial CO₂ emissions (mean flux of 512.45 mg·m⁻²·h⁻¹). Furthermore, the Larix gmelinii forest (LGF) exhibited the highest total Global Warming Potential (GWP), primarily driven by its significant CO₂ emissions. In contrast, the PBMF was the strongest CH₄ sink (−25.82 μg·m⁻²·h⁻¹) and a N₂O emission hotspot (15.24 μg·m⁻²·h⁻¹), corresponding to its low soil C:N ratio. These findings provide strong evidence that soil elemental stoichiometry is a key driver regulating the functional signature of GHG emissions. This case study highlights the potential of using stoichiometric theory to develop predictive tools for assessing ecosystem sustainability and informing sustainable forest management strategies under climate change. Full article

Rapid urban growth in South Indian coastal cities such as Chennai has intensified the Urban Heat Island (UHI) effect, with paved parking lots, walkways, and open spaces acting as major heat reservoirs. This study specifically compares conventional construction materials with natural and low-thermal-inertia alternatives to evaluate their relative ability to mitigate Surface Urban Heat Island (SUHI) effects. Unlike previous studies that examine isolated materials or single seasons, this pilot provides a unified, multi-season comparison of nine urban surfaces, offering new evidence on their comparative cooling performance. To assess practical mitigation strategies, a field pilot was conducted using nine surface types commonly employed in the region—concrete, interlocking tiles, parking tiles, white cooling tiles, white-painted concrete, natural grass, synthetic turf, barren soil, and a novel 10% coconut-shell biochar concrete. The rationale of this comparison is to evaluate how conventional, reflective, vegetated, and low-thermal-inertia surfaces differ in their capacity to reduce surface heating, thereby identifying practical, material-based strategies for SUHI mitigation in tropical cities. Surface temperatures were measured at four times of day (pre-dawn, noon, sunset, night) across three months (winter, transition, summer). Results revealed sharp noon-time contrasts: synthetic turf and barren soil peaked above 45–70 °C in summer, while reflective coatings and natural grass remained 25–35 °C cooler. High thermal-mass materials such as concrete and interlocked tiles retained heat into the evening, whereas grass and reflective tiles cooled rapidly, lowering late-day and nocturnal heat loads. Biochar concrete performed thermally similarly to conventional concrete but offered co-benefits of ~10% cement reduction, carbon sequestration, and sustainable reuse of locally abundant coconut shell waste. Full article

Addressing land use carbon emissions (LUCE) is critical for mitigating climate change. Using multi-source heterogeneous data from 2010 to 2020, with Land use transition matrix and Kaya-LMDI model, this paper analyzes the spatiotemporal evolution and driving factors of LUCE on Hainan Island. The results indicate the following: (1) The study period witnessed significant land use transitions relevant to carbon stocks. Forest area (a key carbon sink) decreased substantially by 2188.74 km², while construction land (a major emission source) expanded by 182.10 km². (2) Consequently, total net LUCE increased by 54% over the decade. This growth was overwhelmingly driven by a 60.8% increase in carbon emissions from the expansion of construction land. (3) The driver analysis indicates that LUCE growth was significantly promoted by land finance dependence and economic development, with these effects exhibiting significant spatial heterogeneity. This study provides a scientific basis for optimizing low-carbon land use policies and offers critical insights for sustainable development in island areas. Full article

Expansive soils undergo significant volume changes with moisture fluctuations, posing persistent challenges for infrastructure due to heave, settlement, and loss of bearing capacity. Stabilization is a common mitigation strategy, though traditional binders, such as cement and lime, are associated with high energy consumption and considerable CO₂ emissions. In this context, identifying low-carbon alternatives is essential. This study evaluates the short-term behavior of expansive marly clays from southern Spain stabilized with volcanic ash generated during the 2021 Tajogaite eruption (La Palma, Canary Islands, Spain). Volcanic ash was incorporated in different proportions to assess its performance as a natural pozzolan, while natural hydrated lime was used both as a direct stabilizer and as an activator to enhance ash reactivity. A key methodological contribution of this research is the monitoring of lime reactivity throughout storage, using XRD and TGA to quantify portlandite loss and partial carbonation before mixing—an aspect seldom addressed in stabilization studies. The experimental program included chemical and mineralogical characterization, compaction, Atterberg limits, free swelling, unconfined compressive strength, and direct shear tests on natural and stabilized mixtures. The results show that volcanic ash, particularly when lime-activated, substantially improves volumetric stability. Free swelling decreased from 11.9% in the natural soil to values as low as 1.7%, while dry density increased and plasticity decreased. Strength gains were modest under short-term conditions, consistent with the limited time for pozzolanic reactions to develop. The combined use of volcanic ash and lime reduced the lime demand required to achieve equivalent volumetric control, offering an eco-efficient and technically viable alternative for stabilizing expansive marly clays. Full article

Rapid urbanization in China has exacerbated the dual challenges of urban heat islands (UHIs) and air pollution, threatening urban sustainability. We conducted a national-scale analysis of the spatiotemporal dynamics and synergy between the surface UHI intensity, distinguished as daytime (DUHI) and nighttime (NUHI), and major air pollutants (PM_2.5, PM₁₀, NO₂) in 370 Chinese cities (2000–2019). Using multi-source remote sensing, ground-based monitoring, and urban data, we applied coupling coordination and correlation analyses to quantify these interactions. Key findings reveal distinct patterns: (1) The annual mean land surface temperature (LST) rose, with the nighttime LST (NLST) increasing faster than the daytime LST (DLST). Conversely, the UHI intensity showed an overall decline, with the DUHI decreasing more than the NUHI. (2) Air pollutants displayed strong seasonality; while PM10 concentrations decreased slightly over the long term, NO₂ levels rose significantly. (3) Monthly, pollutants correlated negatively with LST (R² > 0.92 for PM_2.5), suppressing the DUHI but intensifying the NUHI. Long-term, the correlation trend revealed a strengthening synergy, particularly between particulate matter and NUHI (trend R² = 0.50). (4) Spatially, over 90% of cities exhibited high UHI–particle coordination. Key associated factors include anthropogenic activities, urban morphology, and natural mitigation factors. We conclude that disrupting the heat–pollution synergy requires integrated strategies, namely reducing emissions at the source, optimizing the urban form, and enhancing ecological regulation. This is essential for advancing low-carbon, climate-resilient urban development. Full article

Under the environment of globalized energy restructuring and achieving the goal of “peak carbon and carbon neutrality”, this paper proposes an optimal scheduling method based on the improved cosine algorithm for island microgrids, which relies on diesel generators, resulting in high carbon emissions and high operating costs. First, an optimal scheduling model for island microgrids is established with the objective of minimizing the system operating cost, which comprehensively considers the carbon emission penalty, power balance constraints, equipment operation constraints, and the volatility of renewable energy sources. Secondly, the traditional sine–cosine algorithm is improved by introducing an adaptive adjustment factor, elite retention strategy and chaotic mapping initialization population in order to solve its shortcomings of falling into local optimums and insufficient convergence accuracy when solving high-dimensional complex problems. Finally, the effectiveness of the proposed method is verified by simulation experiments. The results show that the method in this paper reduces the total system cost to 2994.2 yuan (6.5% lower than the baseline scenario), reduces the carbon emission to 968.8 kg (55.1% lower), and improves the wind and light consumption rate to 98.84%, which is an obvious advantage and provides a theoretical basis and technical support for the realization of the low-carbon and economic operation of island microgrids. Full article

Viticulture in insular and volcanic environments faces mounting pressures from land abandonment, limited mechanization, and climate-related stress on soil and water resources. This study develops an integrated framework combining Life Cycle Assessment (LCA) and soil diagnostics to evaluate the environmental and agronomic performance of vineyards on the island of Tenerife (Canary Islands, Spain). Fifteen representative vineyards located between 100 and 1000 m a.s.l. within the Tacoronte–Acentejo Denomination of Origin were assessed using the ReCiPe 2016 Midpoint (H) method and the Ecoinvent 3.8 database. The average carbon footprint reached 1.40 kg CO₂-eq kg⁻¹ of grapes, with diesel use for field access and transport contributing over 50% of total impacts and 64% of human toxicity. Copper-based fungicides accounted for ~11% of impacts, underscoring their environmental persistence. Soil analyses revealed widespread Ca/Mg imbalances and sporadic K deficiencies, while organic matter and pH levels were generally adequate. Importantly, vineyards with balanced nutrient ratios exhibited both higher yields and lower environmental burdens, suggesting that improved soil health can enhance eco-efficiency, primarily by supporting higher yields under similar input regimes. Targeted strategies—such as magnesium supplementation, reduced copper inputs, and low-carbon mobility practices—can therefore mitigate emissions while improving productivity. The proposed LCA–soil integration provides a replicable model for sustainable resource management and climate-resilient viticulture in other fragile and topographically constrained agricultural systems. Full article

As global warming and the greenhouse effect become increasingly evident, and in response to the “Carbon Peak” and “Carbon Neutrality” policies, extensive research has been conducted on “blue carbon” sinks in marine and coastal zones. Due to their low cost and flexibility, hydro-eco coupled numerical modeling has emerged as a prominent method for studying carbon sequestration. This study employs a two-dimensional NPZD (Nutrient-Phytoplankton-Zooplankton-Detritus) framework coupled with tidal flow dynamics to analyze changes in flow fields, ecological benefits, and carbon sequestration effects before and after the restoration project in Sanya Bay. Additionally, the impact of planting seagrass seedlings near the artificial island on carbon sequestration is investigated. The seagrass restoration achieved approximately 0.57 Mg C sequestration within one month. The project has achieved remarkable benefits. According to different working condition examples, the annual carbon sink of the artificial island and the sand replenishment restoration has increased by 83.83 Mg compared with that before the restoration. Full article

The world is far from meeting the goals of the Paris Agreement of limiting the rise of global temperature to below 1.5 °C, with dire consequences for Small Island Developing States (SIDS) in particular. If SIDS are to address their climate vulnerabilities through policy-induced resilience building, they need to have a robust governance framework in place that coherently addresses climate change adaptation and disaster risk reduction. What would such a governance framework look like? To address this question, we carried out a systematic literature review of papers published between 1992 and 2023. Our review reveals that the governance around climate change adaptation and disaster risk reduction is relatively weak in SIDS. However, the analysis of barriers and enablers unveils the contours of a proposed three-tiered governance framework, the application of which needs to be contextualised: Tier 1 comprises three key pillars: Policy Planning, Institutional Arrangements, and Laws and Regulations; Tier 2 identifies the principles of transparency, accountability, equity, legitimacy, and subsidiarity; the core pillars and the principles are nested within a broader Tier 3 comprising democratic processes (rule of law), religious and cultural values, and political commitment. In order for SIDS to fight the existential threat of climate change, the proposed framework will allow SIDS to better understand their climate governance framework and deliver low-carbon, climate resilient development within the broader ambit of sustainable development. This framework also addresses the weakness in previous studies, which consider dimensions, principles, and enabling an environment of good governance on equal footing. We illustrate this framework using the analogy of the lotus flower. Full article

The rapid expansion of island and reef infrastructure has intensified the demand for sustainable concrete materials, yet the scarcity of conventional aggregates and freshwater severely constrains their supply. More critically, the fundamental bonding mechanism between steel reinforcement and coral aggregate concrete (CAC) remains poorly understood due to the highly porous, ion-rich nature of coral aggregates and the complex interfacial reactions at the steel–cement–coral interface. Moreover, the synergistic effect of polyoxymethylene (POM) fibers in modifying this interfacial behavior has not yet been systematically quantified. To fill this research gap, this study develops a C40-grade POM-fiber-reinforced CAC and investigates the composition–property relationship governing its bond performance with steel bars. A comprehensive series of pull-out tests was conducted to examine the effects of POM fiber dosage (0, 0.2%, 0.4%, 0.6%, 0.8%, and 1.0%), protective layer thickness (32, 48, and 67 mm), bar type, and anchorage length (2 d, 3 d, 5 d, and 6 d) on the interfacial bond behavior. Results reveal that a 0.6% POM fiber addition optimally enhanced the peak bond stress and restrained radial cracking, indicating a strong fiber-bridging contribution at the micro-interface. A constitutive bond–slip model incorporating the effects of fiber content and c/d ratio was established and experimentally validated. The findings elucidate the multiscale coupling mechanism among coral aggregate, POM fiber, and steel reinforcement, providing theoretical and practical guidance for the design of durable, low-carbon marine concrete structures. Full article

Structural applications that use High-Strength Low-Alloy (HSLA) steels require detailed microstructural analysis to manufacture welded components that combine strength and weldability. The balance of these properties depends on both the chemical composition and the welding parameters. Moreover, in multi-pass welds, thermal cycling results in a complex Heat-Affected Zone (HAZ), characterized by sub-regions with a multitude of microstructural constituents, including brittle phases. This study investigates the influence of Vanadium addition on the microstructure and performance of the HAZ. Multi-pass welded joints were manufactured on 15 mm thick S355 steels with different Vanadium contents using a robotic GMAW process. A steel variant containing both Vanadium and Niobium was also considered, and the results were compared to those of standard S355 steel. Moving through the different sub-regions of the welded joints, the results show a heterogeneous microstructure characterized by ferrite, bainite and martensite/austenite (M/A) islands. The presence of Vanadium reduces carbon solubility during the phase transformations involved in the welding process. This results in the formation of very fine (average size 11 ± 4 nm) and dispersed precipitates, as well as a lower percentage of the brittle M/A phase, in the variant with a high Vanadium content (0.1 wt.%), compared to the standard S355 steel. Despite the presence of the brittle phase, the micro-alloyed variants exhibit strengthening without loss of ductility. The combined presence of both hard and soft phases in the HAZ provides stress-damping behavior, which, together with the very fine precipitates, promises improved resistance to crack propagation under different loading conditions. Full article

This study aims to establish an energy assessment system and provide low-carbon design strategies for block-scale science and technology industrial parks in the Yangtze River Delta region of China. To investigate low-carbon design strategies for these parks, the impact of solar energy utilization potential and heat island effect on the energy consumption of buildings is taken as the entry point. Through an analysis of the spatial characteristics of twenty block-scale science and technology industrial parks in the Yangtze River Delta region of China, two types of idealized park models comprising a total of eighteen variations were established. The simulation process involved six key morphological parameters to describe the specific shape of the parks quantitatively. The Ladybug Tools 1.6.0, Radiance 5.4a, and URBANopt v0.9.2 software were used to simulate the potential for photovoltaic power generation and the energy consumption of the parks. Net Energy Use Intensity (NEUI) and Potential Utilization Ratio of Renewable Energy (PURRE) were selected as the final evaluation indexes to represent the integrated energy performance of the park. The results show that for the park with a circular layout, the optimal integrated energy performance is achieved when the building density is between 35% and 40%; the average building height is designed with lower values within the range of 20 m to 24 m, and the height-to-depth ratio is around 0.3. Finally, based on the results of the analysis, four major low-carbon design strategies were proposed: high-density development, courtyard layout, supporting-function centralized layout, and carbon sink enhancement. Full article

Antarctic research stations require reliable low-carbon power under extreme conditions. This study compiles a synchronized PV-meteorological time-series data set on Horseshoe Island (Antarctica) at 30 s, 1 min, and 5 min resolutions and compares four PV module types (monocrystalline, polycrystalline, flexible mono, and semitransparent) under controlled field operation. Model development adopts an interpretable, multi-objective framework: a modified SPEA-2 searches rule sets on the Pareto front that jointly optimize precision and recall, yielding transparent, physically plausible decision rules for operational use. For context, benchmark machine-learning models (e.g., kNN, SVM) are evaluated on the same splits. Performance is reported with precision, recall, and complementary metrics (F1, balanced accuracy, and MCC), emphasizing class-wise behavior and robustness. Results show that the proposed rule-based approach attains competitive predictive performance while retaining interpretability and stability across panel types and sampling intervals. Contributions are threefold: (i) a high-resolution field data set coupling PV output with solar radiation, temperature, wind, and humidity in polar conditions; (ii) a Pareto-front, explainable rule-extraction methodology tailored to small-power PV; and (iii) a comparative assessment against standard ML baselines using multiple, class-aware metrics. The resulting XAI models achieved 92.3% precision and 89.7% recall. The findings inform the design and operation of PV systems for harsh, high-latitude environments. Full article

This study aims to elucidate the geochemical reactions between CO₂-saturated water and rocks in CO₂-enhanced geothermal system (CO₂-EGS) reservoirs by focusing on andesite found in island arc regions, such as Japan. Laboratory flow tests of CO₂-saturated water (3 wt.% CO₂) and rocks (particle size: 0.14–1 mm) were conducted under varying temperature (150–250 °C) and flow rate (0.3 and 1.0 mL/min) conditions using a flow-through reactor. Elevated temperatures enhanced the dissolution of silicate minerals, reflected by increased Na⁺, K⁺, Ca²⁺, and Si concentrations, whereas those of Fe²⁺ and Al³⁺ remained low, suggesting secondary mineral precipitation. The dissolution process was dominant at 150 °C. Al-bearing minerals, such as gibbsite and boehmite, as well as clay minerals, including beidellite and kaolinite, were predominant at higher temperatures (200–250 °C). Carbonate minerals were not observed, attributable to low pH and limited availability of divalent cations. Flow rate substantially influenced Si dissolution rates, with lower flow rates promoting longer residence times and higher Si dissolution rates. These results indicate that the test conditions simulate the environment around the injection well, where the fluid is acidic and dissolution is the main reaction in the rock. Although a small amount of secondary minerals precipitated and the Si dissolution rates were of the same order of magnitude as those for labradorite, it may be considered that andesite has less impact on permeability variations than basalt near the injection well in CO₂-EGS reservoirs. Full article

Fusarium wilt, caused by Fusarium oxysporum f. sp. cubense (FOC), remains a major constraint to global banana (Musa spp.) production, especially in tropical regions. Although soil conditions are known to modulate disease expression, the specific physicochemical drivers of FOC prevalence under field conditions are not well understood. This study investigated the relationships between soil properties and the Fusarium wilt incidence across 47 banana farms on Hainan Island, China, a tropical region dominated by highly weathered tropical soil (latosols). The disease incidence (%PDI) and FOC abundance were quantified, alongside key soil parameters, including the pH, organic carbon, cation exchange capacity, and macro- and micronutrient availability. The soils were predominantly acidic (mean pH 4.93), with low levels of organic carbon and exchangeable calcium (Ca) and elevated levels of available phosphorus (P), potassium (K), and magnesium (Mg). The Fusarium wilt incidence ranged from 1% to 78%, with significantly higher levels observed in younger plantations (<5 years old). Statistical analyses revealed strong negative correlations between the PDI and the soil pH, exchangeable Ca and Mg, and available K. Principal component analysis further confirmed the suppressive role of the pH and base cations in the disease dynamics. Farms older than five years exhibited better soil fertility indices and lower disease pressure, suggesting a temporal improvement in soil-mediated disease suppression. These findings underscore the critical role of soil acidification and nutrient imbalances, particularly Ca, Mg, and K deficiencies, in promoting FOC pathogenicity. Enhancing soil health offers a promising and sustainable strategy for managing Fusarium wilt in tropical banana production systems. Full article