Search Results (5,768)

Monitoring the condition of grasslands is essential given their vital role in food security, carbon sequestration and other ecosystem services. Harvested aboveground biomass (HAB) and aboveground net primary production (ANPP) are among the most important grassland state indicators. However, spatially explicit production estimates are largely lacking, and grassland area estimations also remain uncertain. This study addresses these gaps for drought-prone Central European grasslands over 2017–2024. We synthesized grassland extent data, collected extensive field measurements on biomass (BM), and used remote sensing-based biophysical proxies to build an ensemble of six linear models for spatial extrapolation at 10 m resolution. Bayesian framework was used for the linear model fitting that also considers uncertainty of the observations. The ensemble mean ANPP was 310.7 ± 19 gBM m⁻², with modest interannual variability. Upscaled country-wide mean ANPP was 34.3 ± 13.3 Mt year⁻¹. The results indicate that, within the frame of the present study, the remote sensing-based linear model selection has a larger influence on the country totals than the grassland area database selection. The results highlight that both grassland area uncertainty and model construction are major sources of uncertainty in biomass estimation that have to be addressed in future studies. Full article

Mangrove forests along China’s coastline serve as vital ecological barriers and blue carbon reservoirs. However, pests and diseases have become the primary biotic threats driving stand decline and diminished carbon sequestration capacity. This review synthesizes current knowledge on the major insect pests and plant diseases affecting Chinese coastal mangroves, focusing on their species profiles, characteristic damage symptoms, occurrence dynamics, and integrated control strategies. Fungal pathogens predominate among the diseases, with outbreaks most common during periods of high temperatures and humidity or low temperatures combined with high humidity; these often interact synergistically with insect pests. The dominant insect pests comprise leaf-feeding Lepidoptera, sap-sucking Hemiptera, and wood-boring Coleoptera, which spread through diverse pathways and can rapidly produce extensive “scorched” damage across mangrove stands during epidemic events. Control efforts follow the principle of “prevention first and integrated management,” incorporating cultural practices, chemical interventions, biological control agents, physical trapping methods, and rigorous quarantine-monitoring protocols. When applied in concert, these measures effectively limit damage to acceptably low levels. Recent studies identify pest–disease interactions and climate change as the foremost challenges in current management. Future priorities should include advancing molecular identification techniques, breeding disease-resistant varieties, and developing environmentally friendly biopesticides to establish precision ecological control systems. Such advances will deliver robust scientific support for mangrove conservation and the achievement of China’s dual-carbon goals. Full article

Carbonated water flooding can enhance oil recovery from low-permeability sandstone reservoirs while supporting CO₂ geological sequestration; however, the coupled effects of carbonated water–rock interactions on pore-scale fluid redistribution remain unclear. This study used online nuclear magnetic resonance (NMR), magnetic resonance imaging (MRI), and mineralogical analysis to evaluate wettability-related water redistribution, mineralogical alteration, and oil mobilization in low-permeability sandstone cores exposed to carbonated water for 0, 5, 10, and 15 days, followed by immiscible CO₂ flooding. With increasing exposure duration, NMR-derived water saturation increased from 0.490 to 0.571, indicating an apparent increase in pore-scale water affinity under the same saturation protocol. XRD results showed carbonate and clay/zeolite-related mineral alteration, including calcite falling below the detection or quantification limit and marked decreases in chlorite and laumontite, which were associated with modified pore-wall properties and improved water-phase access. During subsequent immiscible CO₂ flooding, oil was preferentially mobilized from well-connected migration pores, while carbonated water treatment enhanced oil recovery from capillary-controlled percolation pores. The overall recovery factor increased by 2.8 percentage points, reaching 53.8% after 15 days of treatment. These results indicate that carbonated water improves CO₂ flooding performance through coupled mineral alteration, pore-connectivity modification, wettability-related water redistribution, and multi-scale oil mobilization. The study provides NMR-based pore-scale evidence for interpreting carbonated water-assisted CO₂ utilization and enhanced oil recovery. Full article

Territorial space serves as a common platform for both ecosystem carbon sink functions and socioeconomic functions. Rapid urbanization has intensified the competition between carbon source and carbon sink areas, making the measurement of carbon sink conflicts critical for carbon emission reduction and land use optimization. This study takes Hangzhou as its research area and uses districts and counties as the basic evaluation units. Drawing on three dimensions—spatial carbon emission pressure, spatial carbon sequestration capacity, and spatial instability—the study develops a model to assess the intensity of territorial carbon sink conflicts. It systematically evaluates the conflict intensity across Hangzhou’s 13 districts and counties in 2020 and analyzes land use change from 2010 to 2020. The results indicate that (1) from 2010 to 2020, Hangzhou’s built-up areas expanded to some extent, leading to intensified spatial conflicts between carbon sources and carbon sinks; and (2) in 2020, light and general conflict areas were mainly distributed in outlying counties (e.g., Lin’an, Chun’an); moderate conflict areas were in the urban periphery (e.g., Fuyang, Binjiang); and intense to severe conflict areas were in central urban districts (e.g., Shangcheng, Gongshu, Xiaoshan). Overall, carbon sink conflicts exhibited a concentric pattern of “uncontrolled core—periphery on the verge—distant suburbs under control.” This study provides a scientific basis for mitigating future carbon sink conflicts in Hangzhou and offers a perspective for identifying and managing such conflicts in other rapidly urbanizing regions. Full article

Highway corridors are increasingly being discussed not only as zones of ecological disturbance but also as components of regional green infrastructure with potential carbon sequestration functions, yet their long-term evolutionary characteristics and multi-scale associated factors remain insufficiently understood. Using multi-source time-series data from 2000 to 2023, we developed an analytical framework integrating the CASA model, Random Forest, and geographically weighted regression (GWR). To ensure methodological rigor, we implemented a Spatial K-fold Cross-Validation strategy and incorporated Partial Dependence Analysis (PDA) to identify non-linear thresholds. The results indicate that: (1) Vegetation carbon sequestration within Shandong’s highway corridors increased significantly, with total sequestration rising from 5.54 × 10⁶ t in 2000 to 1.55 × 10⁷ t in 2023, representing an average annual growth rate of approximately 5.0%. This growth transitioned from a relatively stable phase to a more rapid growth phase. (2) A clear distance-related ecological pattern was observed. Statistical tests (Kruskal–Wallis H test) confirmed that vegetation carbon sequestration exhibited a significant non-monotonic gradient ($p<0.05$), with a stable peak zone observed 50–100 m from the roadbed. This peak zone is associated with a spatial “trade-off” pattern between the attenuation of traffic-related stressors and roadside ecological management. (3) The observed spatial pattern was associated with a nonlinear coupling of natural background conditions and human disturbance. Precipitation and temperature were the dominant associated factors, while PDA further identified a critical precipitation threshold (~750 mm) and localized tipping points for human interference, with a distinct road-disturbance-sensitive zone evident within 200–500 m. The results suggest that high-standard ecological design and active restoration measures are associated with lower ecological disturbance and higher vegetation carbon sequestration performance in some highway corridors. However, these relationships should be interpreted cautiously, as they may also be influenced by differences in climate background, topography, land-use context, and road construction history. These findings provide empirical evidence to inform differentiated ecological restoration and low-carbon management of traffic corridors. Full article

Anthropogenic CO₂ emissions have perturbed the global carbon cycle and increased atmospheric carbon concentrations to critical levels, making carbon capture and storage (CCS) a key strategy for mitigating climate warming. Natural carbon sequestration has operated continuously in marine environments throughout Earth history. Here, we investigate the growth mechanisms and carbon-sink significance of calcite concretions in the Mesoproterozoic Xiamaling Formation from the Zhaojiashan section and the Zhenzhuquan section in the North China Craton, using petrographic, elemental geochemical and C-O-Re-Os isotopic evidence. The presence of erosional surfaces and local truncation of host-rock laminae suggests that these concretions formed synsedimentarily or during early diagenesis near the sediment-water interface. The δ¹³C values (−5.05‰ to 1.54‰) of samples, together with δ¹⁸O-δ¹³C relationships, indicate a marine carbonate affinity and suggest that dissolved inorganic carbon was the dominant carbon source. In addition, the concretions display initial ¹⁸⁷Os/¹⁸⁸Os ratios as low as 0.136, close to the mantle Os end-member, implying a contribution from mantle-derived material during concretion formation. The middle rare earth element and yttrium (MREYs)-enriched patterns and slight positive Ce anomalies further indicate that concretion growth occurred mainly within the Mn- and Fe-reduction zones. We estimate that the calcite-concretion-bearing interval of the Xiamaling Formation sequestered 70.24 Gt C, equivalent to 257.56 Gt CO₂, serving as an archive of marine carbon burial in the Mesoproterozoic ocean. Microbially mediated carbonate precipitation may represent an effective carbon immobilization mechanism in marine sediments and has potential implications for the development of subseafloor carbon storage strategies, especially where biocatalysts and/or brine could accelerate seawater CO₂ mineral trapping to industrially relevant rates. Full article

Geological carbon sequestration is a critical strategy for reducing atmospheric CO₂ emissions and mitigating climate change; however, its long-term effectiveness depends on a robust understanding of subsurface trapping mechanisms. This review synthesizes recent advances in evidence-based CO₂ trapping by systematically examining four primary mechanisms—structural/stratigraphic, residual (capillary), solubility, and mineral trapping—using insights from experimental studies, field observations, and numerical modeling. The analysis highlights that structural trapping provides immediate containment controlled by caprock integrity and reservoir geometry, while residual trapping immobilizes CO₂ at the pore scale through capillary forces and multiphase flow dynamics. Over longer timescales, solubility trapping enhances storage security via dissolution and density-driven convection, whereas mineral trapping offers the most permanent form of sequestration through geochemical conversion to stable carbonates, albeit with slower kinetics. Recent findings emphasize the strong coupling among trapping mechanisms, the influence of wettability, heterogeneity, and flow regimes, and the growing role of engineered injection strategies and enhanced mineralization approaches. Overall, the review demonstrates that secure and scalable CO₂ storage requires an integrated, multiscale understanding of these interacting processes, supported by improved monitoring, modeling, and experimental validation to reduce uncertainty and optimize storage performance. Full article

In carbon sequestration in saline aquifers, many factors affect multiphase fluid migration and reservoir pressure change. This study developed a high-resolution three-dimensional numerical model to investigate large-scale CO₂ geological storage in the Ordovician carbonate aquifer of the Tarim Basin, China. This study focuses on the quantitative prediction of CO₂ plume migration, multiphase flow interactions between supercritical CO₂ and brine, and formation pressure evolution under coupled injection operations. Injection strategies were compared by constant rate (CR) and variable rate (VR) injection, and two caprock morphology-type selection by placing wells into monocline traps (wells 1/3/5) and anticline traps (wells 2/4) with varying limb dip angles and closure depths. The results demonstrate that both injection speed and caprock morphology strongly control CO₂ trapping evolution and storage security. At the end of the 500-year simulation, the dissolved-CO₂ migration distance followed the order CR > VR, indicating that, under the studied conditions, VR injection most effectively limited the lateral spread of dissolved CO₂ and thereby enhanced dissolved-CO₂ immobilization. In addition, CR and VR injection schedules have a subtle impact on long-term pressure change; Across all cases, formation pressure remained below the caprock breakthrough pressure. CR injection promotes the fastest CO₂ dissolution and pressure dissipation but yields the weakest long-term immobilization, whereas VR injection trades early dissolution rate for more effective plume containment. This result indicates that injection-strategy selection should be matched to dominant site controlled near-term pressure management versus long-term containment and to the trapping behavior imposed by caprock morphology. This study provides a mechanistically grounded optimization framework linking injection-speed control and caprock morphology to the coupled evolution of pressure-buildup safety and long-term CO₂ immobilization, supporting CCUS decision-making in the Tarim Basin. Full article

Young forests are recognized as important contributors to climate change mitigation due to their high productivity. However, their structural simplicity and transitional nature render them ecologically vulnerable to long-term climatic stress. We explored the long-term responses of young forests to climate change by applying the LANDIS-II forest landscape model coupled with a PnET-based physiological model to simulate 200 years of forest succession and carbon dynamics. Simulations were conducted under three climate scenarios (BAU, RCP45, and RCP85) to evaluate changes in aboveground biomass (AGB), carbon storage, and carbon absorption across elevation gradients. The results revealed that climate change significantly altered successional pathways and carbon capacity, with effects varying with elevation and initial species composition. Predominant species such as Quercus mongolica maintained dominance under the RCP45 and RCP85 scenarios across all elevations, whereas shade-tolerant mid and understory species showed suppressed growth. Sub-alpine species showed prominent declines in AGB, particularly in the RCP85 scenario. These divergent responses increased the spatial heterogeneity of forest productivity and reduced the predictability of forest carbon dynamics over time. Our findings emphasize the uncertainty of predicting forest development and carbon sequestration in young forests under future climatic conditions. They highlight the urgent need to plan forest management strategies incorporating site-specific ecological characteristics, promote successional advancement, and maintain functional stability for effective climate adaptation and mitigation. Full article

Urban plant communities are widely regarded as important nature-based solutions for climate mitigation, yet their actual carbon benefits remain uncertain: vegetation growth is accompanied by carbon emissions from construction and long-term maintenance, and existing assessments rarely integrate community succession, interspecific competition, and maintenance-related emissions within a consistent life-cycle framework. To address these limitations, this study developed a dynamic succession-based life-cycle simulation model to project the 50-year carbon source–sink transitions of 150 typical urban plant communities in Tianjin, China. The model updates plant structural attributes—diameter at breast height, crown width, and tree height—iteratively by linking individual plant growth to environmental suitability and neighborhood competition through a Plant Health Index. Simulated structural trajectories were coupled with biomass equations and carbon content coefficients to estimate aboveground carbon sequestration, while construction and maintenance emissions were quantified using life cycle assessment, enabling evaluation of modeled net carbon balance rather than gross carbon sequestration alone. Under the modeled 50-year scenario, most communities were projected to act as carbon sources during the early stage but gradually shifted toward carbon sinks as biomass accumulated; 86.1% of the communities were projected to become net carbon sinks after 50 years (a scenario-based projection under specified growth, maintenance, and emission assumptions). The highest modeled net carbon balance reached 3186.08 kg C ha⁻¹, whereas the weakest community remained a slight carbon source at −81.21 kg C ha⁻¹. Vertical structural complexity and species richness were the strongest positive predictors of modeled net carbon balance, followed by three-dimensional green quantity and canopy closure. Among maintenance processes, fertilization was the dominant emission source, followed by pesticide application and irrigation; comparative scenario analysis showed that resource-saving maintenance consistently improved projected net carbon balance relative to high-maintenance management. These results suggest that low-carbon planting design should prioritize locally adapted species, multi-layered vertical structures, and adaptive maintenance over simply maximizing planting density or minimizing inputs. The results represent scenario-based projections of aboveground vegetation carbon balance; belowground biomass, soil carbon, litter carbon, dead organic matter, and parameter uncertainty were not fully incorporated, and future studies should address these limitations to improve the robustness and transferability of the proposed framework. Full article

Carbonation in CO${}_2$-storage solid-waste backfill materials couples CO${}_2$ transport, mineral reaction, and strength evolution, making carbonation-front prediction and transport–reaction inference important for evaluating sequestration performance. This study proposes an evidence-ranked, physics-guided inverse-learning framework for carbonation-front prediction, auxiliary strength reconstruction, PDE-residual assessment, and practical-identifiability analysis. The framework represents carbonation using group-conditioned latent fields of effective CO${}_2$ concentration and remaining reactive capacity, maps latent carbonation degree to measured depth through a differentiable front operator, and reconstructs unconfined compressive strength through a supervised auxiliary head. Empirical front laws and reaction–diffusion physics-informed neural-network variants were evaluated using held-out ranking, repeated stratified splits, residual-weight sweeps, front-operator threshold and smoothing-coefficient sensitivity checks, profile-likelihood and Fisher-information diagnostics, and controlled synthetic tests. Results show that the grouped Weibull front law achieved the best short-range carbonation-depth interpolation, while the retained constant-diffusion PINN was used as a diagnostic formulation within the physics-guided family to improve auxiliary strength reconstruction and to evaluate residual consistency, front-threshold selection, parameter sharing, and inverse-parameter behavior rather than to replace the empirical depth regressor. Increasing the PDE-residual weight substantially reduced residual magnitudes, but profile-likelihood and Fisher-information diagnostics indicated strong parameter trade-offs; the fitted diffusion, reaction, depletion, and diffusion–decay quantities are therefore interpreted as effective, observation-conditional parameters rather than unique material constants. The proposed framework provides a prediction-first and attribution-aware approach for analyzing carbonation evolution in solid-waste backfill materials and supports coordinated assessment of front advancement, strength response, and transport–reaction behavior, while explicitly delimiting the generalization and physical interpretation that can be supported by sparse literature-derived observations. Full article

Tuberculosis therapy is prolonged partly because dormant subpopulations of Mycobacterium tuberculosis show reduced susceptibility to first-line drugs. Therefore, agents active against both replicating and non-replicating mycobacteria remain important to explore. Here, we investigated secondary metabolites from the Indonesian marine-derived fungus Aspergillus ostianus for activity against Mycobacterium smegmatis, a BSL-1 mycobacterial model, under aerobic and hypoxia-induced non-replicating conditions, and examined the underlying mechanism. Bioassay-guided fractionation and spectroscopic analysis identified three hydroxamate pyrazinones: neohydroxyaspergillic acid (NHAA), hydroxyaspergillic acid (HAA), and neoaspergillic acid (NAA). The MIC values were 1.56 µg/mL for NHAA and 3.13 µg/mL for HAA and NAA under both aerobic and hypoxic atmospheres. Time-kill kinetics showed ≥3-log10 CFU reductions within 24–72 h at 4–8× MIC under aerobic conditions and within 48–96 h at 4–8× MIC under hypoxia, with no regrowth at the final sampling point. Scanning electron microscopy and release of UV-absorbing intracellular material at OD₂₆₀/OD₂₈₀ were consistent with envelope disruption in both atmospheres. Antimycobacterial activity was attenuated in a concentration-dependent manner by exogenous Fe³⁺ and was reversed at 100 µM FeCl₃, whereas isoniazid activity was unaffected, supporting iron-reversible and pyrazinone-specific killing. Together with the established Fe³⁺-binding hydroxamate pharmacophore shared by this compound class, these findings support iron sequestration as a plausible mechanism and identify fungal hydroxamate pyrazinones as scaffolds that retain bactericidal activity against hypoxia-adapted non-replicating mycobacteria, warranting further evaluation in M. tuberculosis models. Full article

Allometric scaling provides a practical framework for predicting human pharmacokinetic (PK) parameters from animal data by relating physiological processes to body size through power-law equations. Despite its simplicity and widespread use in first-in-human (FIH) dose selection, its predictive performance is limited by species-specific differences in absorption, distribution, metabolism, and excretion (ADME). This review summarizes the mathematical foundations, workflows, and diagnostics of allometric scaling, while critically examining where the approach succeeds and where it fails. Core concepts, including clearance, volume of distribution, correction factors, and the rule of exponents, are discussed alongside complementary methods: in vitro–in vivo extrapolation (IVIVE), physiologically based pharmacokinetic (PBPK) modelling, and the Wajima normalized time-course method. Historical clinical failures, including fialuridine, TGN1412, BIA 10-2474, and rofecoxib, illustrate the limits of relying solely on allometry, while thalidomide and the fenfluramine combination exemplify toxicodynamic species-selection failures. Modern advances, including the Extended Clearance Classification System (ECCS), target-mediated drug disposition, FcRn recycling, and emerging artificial intelligence and machine-learning methods, are integrated within a framework. Overall, the review treats allometric scaling as a disciplined starting hypothesis that must be triangulated with mechanistic, experimental, and regulatory evidence to support safer and more reliable human translation. Full article

This study provides a structured operational-to-financial roadmap for soil organic carbon (SOC) sequestration in mineral soils as a specific carbon-farming pathway. It integrates SOC management; Monitoring, Reporting, and Verification (MRV) execution; financial recognition; and farmer adoption barriers. A comparison of carbon farming pathways is first presented to investigate their strengths and limitations, highlighting the specific importance of SOC management in mineral soils. For high-integrity carbon accounting, SOC gains should be assessed not only for quantity, but also for additionality, permanence, uncertainty, leakage, lifecycle emissions, and transparent verification. Credible MRV frameworks operationalize this logic: monitoring quantifies SOC changes, reporting ensures transparency, and verification provides independent assurance for carbon credit issuance and financial recognition. However, MRV execution faces several challenges, including high spatial variability of SOC, slow accumulation rates, methodological uncertainty, and high costs that limit scalability and reduce trust among stakeholders. Financial incentives are available from both public and private sources, supporting long-term soil carbon stabilization, verified carbon removals, and corporate insetting projects. Yet, adoption remains constrained by uncertain payments, poor transparency, contract and permanence concerns, as well as learning and operational costs for farmers. Addressing these bottlenecks is essential for transforming mineral-soil SOC sequestration into a scalable, high-integrity climate and economic opportunity. Full article

Soil salinization represents one of the most severe abiotic constraints on global forest productivity. Populus, the most widely cultivated fast-growing timber tree and a premier model woody plant, exhibits striking intrageneric variation in salt tolerance—from the extremely halophytic Populus euphratica to highly salt-sensitive cultivated clones. Understanding the molecular basis of this variation has profound implications for saline–alkali land reclamation and salt-tolerant variety breeding. This review systematically synthesizes current knowledge on Populus salt-stress responses, covering three primary injury mechanisms (osmotic stress, ionic toxicity, and oxidative damage) and the corresponding physiological countermeasures. We further survey functional genes across four major categories: ion transporters, osmotic-adjustment enzymes, antioxidant-defense components, and transcription factors. Crucially, we extend beyond the herbaceous-plant paradigm by examining salt-tolerance strategies that are specific to the woody architecture of Populus: long-distance radial and axial Na⁺ transport through tall stems, salt sequestration in senescent bark and wood parenchyma, and deep-root ion exclusion strategies. Comparative insights from other woody genera are incorporated to highlight convergent and divergent mechanisms. On this basis, we propose an integrated multi-level regulatory model in which Na⁺ compartmentalization/efflux serves as the core, ROS homeostasis as the key regulatory axis, and osmotic adjustment as the auxiliary strategy. Outstanding challenges—including unresolved primary salt-signal perception, insufficient pathway integration, and limited in planta gene-function verification—are critically assessed, and future research priorities encompassing multi-omics integration, CRISPR-based gene editing, and natural-population genomics are outlined. Full article