Search Results (573)

Soil organic carbon (SOC) constitutes the largest terrestrial carbon pool and plays a crucial role in climate regulation, soil fertility, and ecosystem functioning. Understanding its spatiotemporal dynamics is particularly important in semi-arid regions, where fragile environments and extensive ecological restoration may alter carbon cycling. The Loess Plateau, the world’s largest loess accumulation area with a history of severe erosion and large-scale vegetation restoration, provides a natural laboratory for examining how environmental gradients influence SOC storage over time. This study used a random forest model with multi-source environmental data to quantify soil organic carbon density (SOCD) dynamics in the 0–100 cm soil layer of the Loess Plateau from 2005 to 2020. SOCD showed strong spatial heterogeneity, decreasing from the humid southeast to the arid northwest. Over the 15-year period, total SOC storage increased from 4.84 to 5.23 Pg C (a 7.9% rise), while the annual sequestration rate declined from 0.046 to 0.020 kg·m⁻²·yr⁻¹, indicating that the regional carbon sink may be approaching saturation after two decades of restoration. Among soil types, Cambisols were the largest carbon pool, accounting for over 44% of total SOC storage. Vegetation productivity emerged as the dominant driver of SOC variability, with clay content as a secondary factor. These results indicate that although ecological restoration has substantially enhanced SOC storage, its marginal benefits are diminishing. Understanding the spatial and temporal patterns of SOC and their environmental drivers provides essential insights for evaluating long-term carbon sequestration potential and informing future land management strategies. Broader generalization requires multi-regional comparisons, long-term monitoring, and deeper soil investigations to capture ecosystem-scale carbon dynamics fully. Full article

Drought stress is a major constraint to cassava productivity, especially in drought-prone regions. Although cassava is considered drought-tolerant, prolonged or severe water scarcity significantly reduces tuber yield, carbon assimilation capacity and overall plant growth. The development, selection and deployment of cassava genotypes with enhanced drought tolerance and water use efficiency (WUE) will help to achieve food security. The ability of cassava genotypes to maintain productivity under drought stress is enhanced by drought-responsive genes that regulate stress-related proteins and metabolites, contributing to stomatal closure, osmotic adjustment, antioxidant defense, and efficient carbon assimilation. Therefore, this comprehensive review aimed to document: (i) the effects of drought stress on cassava’s physiological, biochemical and agronomic traits, and (ii) the mitigation strategies and breeding technologies that can improve cassava yield production, drought tolerance and WUE. The key traits discussed include stomatal regulation, chlorophyll degradation, source–sink imbalance, root system architecture and carbon allocation dynamics. In addition, the review presents advances in genomic, proteomic and metabolomic tools, and emphasizes the role of early bulking genotypes, drought tolerance indices, and multi-trait selection in developing cassava cultivars with enhanced drought tolerance, drought escape and drought avoidance mechanism. Therefore, the integration of these strategies will accelerate the development, selection and deployment of improved cassava varieties, which contribute to sustainable productivity and global food security under climate change. Full article

Accessible datasets of greenhouse gas (GHG) concentrations help define long-term trends on a global scale and also provide significant information on the characteristic variability of emission sources and sinks. The integration of stable carbon isotope measurements of carbon dioxide (CO₂) and methane (CH₄) can significantly increase the accuracy and reliability of source apportionment efforts, due to the isotopic fractionation processes and fingerprint that characterize each mechanism. Via isotopic parameters such as δ¹³C, the ratio of ¹³C to ¹²C compared to an international standard (VPDB, Vienna Pee Dee Belemnite), it is in fact possible to discriminate, for example, between thermogenic and microbial sources of CH₄, thus ensuring a more detailed understanding of global balances. A number of stations within the Italian consortium of atmospheric observation sites have been equipped with Picarro G2201-i CRDS (Cavity Ring-Down Spectrometry) analyzers capable of measuring the stable carbon isotopic ratios of CO₂ and CH₄, reported as δ¹³C-CO₂ and δ¹³C-CO₂, respectively. The first dataset (Lamezia Terme, Calabria region) of the consortium resulting from these measurements was released, and a second dataset (Potenza, Basilicata region) from another station was also released, relying on the same format to effectively standardize these new types of datasets. This work provides details on the data, format, and methods used to generate these products and describes a framework for the format and processing of similar data products based on CRD spectroscopy. Full article

Karst landscapes, characterized by ecological constraints such as thin soil layers, severe rock desertification, and fragile habitats, require a clear understanding of the mechanisms regulating carbon storage and the impacts of ecological restoration measures. However, current research lacks detailed insights into the specific effects of ecological restoration measures. This study integrates multi-source remote sensing data and adjusts InVEST model parameters to systematically reveal the spatiotemporal evolution of carbon storage and its driving mechanisms in typical karst plateau regions of southwest China under ecological restoration measures. The results indicate: (1) From 2000 to 2020, the carbon stock in the study area increased by 6.09% overall. However, from 2020 to 2025, due to the rapid conversion of forest land into building land and grassland, the carbon stock decreased sharply by 7.69%. (2) Severe rock desertification constrains carbon stock, and afforestation provides significantly higher long-term carbon sink benefits. (3) The spatial heterogeneity of carbon storage is primarily influenced by the combined effects of natural factors (rock desertification, elevation, NDVI) and human factors (POP). Based on the research findings, it is recommended that measures to promote close forests be prioritized in karst regions to protect and restore forest ecosystems. At the same time, local habitat improvement and the establishment of ecological compensation mechanisms should be implemented, and the expansion of building land should be strictly controlled to enhance the stability of ecosystems and their carbon sink functions. These research findings provide a solid scientific basis for enhancing and precisely regulating the carbon sink capacity of fragile karst ecosystems, and are of great significance for formulating scientifically sound and reasonable ecological protection policies. Full article

In the current context of the international climate agenda, understanding both the sources of greenhouse gas (GHG) emissions and the mechanisms for their mitigation is a fundamental requirement for low-carbon development strategies. Kazakhstan has pledged to reduce its GHG emissions by 15–25% by 2030, relative to 1990 levels, and to achieve carbon neutrality by 2060. However, there is no unified methodology for comprehensively assessing the national carbon balance, particularly at the regional scale. This study addresses this gap by analyzing GHG emissions and carbon sequestration capacities across Kazakhstan’s regions using a sectoral disaggregation approach and scenario-based modeling aligned with IPCC methods. Emission hotspots were identified in the energy sector (328 MtCO₂-eq), agriculture (118 MtCO₂-eq—primarily from pasturelands), and transport (7 MtCO₂-eq). In contrast, current carbon sinks—mainly forest ecosystems and abandoned pasturelands—account for only 3.97 and 13.9 MtCO₂-eq, respectively. The research evaluates the technical potential for emissions reduction through the best available technologies (BAT), livestock management, partial transition to gas-powered vehicles, and reforestation. A geoengineering scenario combining all measures suggests that Kazakhstan could meet its 2030 climate targets, although full carbon neutrality by 2060 would remain out of reach under current policy trajectories. The Akmola region is examined as a representative case study, demonstrating a possible 35% reduction in net emissions by 2035. This work contributes a regionally nuanced, data-driven framework for integrating ecosystem services into national climate policy and identifies nature-based solutions—especially forest management—as essential components of Kazakhstan’s decarbonization pathway, offering insights for other carbon-intensive economies. Full article

To mitigate climate change, achieving net-zero carbon dioxide (CO₂) emissions across all sectors is essential. In the floricultural and landscaping industries, a key concern is whether the production and use of landscape plants contribute to CO₂ reduction. However, few studies have assessed the greenhouse gas (GHG) budgets of landscape plant production. This study quantified all major components of GHG budgets to determine whether herbaceous plant production acts as a GHG sink or source. Kentucky bluegrass sod and three herbaceous plants (Hedera canariensis, Liriope muscari, and Tagetes patula) were investigated for their GHG (CO₂, CH₄, and N₂O) budgets. For Kentucky bluegrass sod production, the total GHG budget was calculated as −17.764 t-CO₂e ha⁻¹ year⁻¹, comprising carbon sequestration (23.014 t-CO₂/ha), GHG fluxes (0.049 t-CO₂e/ha), and GHG emissions from energy and resource consumption (5.201 t-CO₂e/ha). These results indicate that Kentucky bluegrass sod production functions as a GHG sink. In contrast, the total GHG budgets for potting production of the three herbaceous plants were positive, primarily due to higher GHG emissions from the use of potting soil and granular pesticides. To reduce net CO₂ emissions in herbaceous plant production, using biochar as a growth medium and minimizing granular pesticides is an effective approach. Full article

Ship Shoal, a large transgressive sand body on the Louisiana continental shelf, is a critical sediment source for coastal restoration. This study evaluates spatial and temporal variability in sediment grain size, percents organic matter (%OM), and carbonate (%CO₃) across the shoal crest (REF), Caminada Dredge Pit (CAM), and Terrebonne Dredge Pit (TER). Sediment samples were collected between 2020 and 2022 using box cores and analyzed for grain size, %OM, and %CO₃, with temporal and spatial patterns assessed through statistical comparisons, correlation analyses, and random forest regression models. Results show that dredged areas act as sinks for fine-grained, organic-rich sediments, with CAM consistently exhibiting the smallest median grain sizes and highest %OM, while REF maintained coarse, well-sorted sands. Carbonate enrichment reflected long-term depositional regimes, with REF exhibiting the highest %CO₃ due to the absence of dredging disturbance. Grain size and %CO₃ were identified as the strongest predictors of %OM, while %CO₃ was only weakly correlated with other sedimentary variables. Collectively, these findings demonstrate that dredge pits function as persistent repositories, with implications for benthic habitat resilience, sediment management, and coastal restoration planning. Future integration of hydrodynamic modeling with sediment transport and biogeochemical processes is needed to enhance predictive capability for managing dredged environments. Full article

Arctic warming is expected to alter permafrost landscapes and shift tundra ecosystems from greenhouse gas sinks to sources. We quantified plant biomass and necromass, carbon stocks, and microbial activity across five Low-Arctic tundra sites in the Yana–Indigirka Lowland (Chokurdakh, NE Siberia) during the 2024 growing season. Above- and below-ground plant biomass was measured by harvest adjacent to 50 × 50 m permanent plots; total C and N were determined by dry combustion on an elemental analyzer. Total organic carbon (TOC) stocks were calculated by horizon from TOC (%), bulk density, and thickness. Microbial basal respiration (BR), substrate-induced respiration (SIR), microbial biomass C (MBC), and the metabolic quotient (qCO₂) were assessed in litter/organic (O), peat (T), and mineral gley horizons. Mean above-ground biomass was 15.8 ± 1.5 t ha⁻¹; total living biomass averaged 43.1 ± 1.6 t ha⁻¹. Below-ground biomass exceeded above-ground by 1.73×. Carbon in above-ground, below-ground, and necromass pools averaged 7.8, 12.2, and 12.5 t C ha⁻¹, respectively. Surface organic horizons dominated ecosystem C storage: litter–peat stocks ranged from 234 to 449 t C ha⁻¹, whereas 0–30 cm mineral layers held 18–50 t C ha⁻¹; total (surface + 0–30 cm) stocks spanned 258–511 t C ha⁻¹ among sites. Key contributors to biomass and C storage were deciduous shrubs (Salix pulchra, Betula nana), bryophytes (notably Aulacomnium palustre), and the graminoids (Eriophorum vaginatum). BR and MBC were highest in O and T horizons (BR up to 21.9 μg C g⁻¹ h⁻¹; MBC up to 70,628 μg C g⁻¹) and declined sharply in mineral soil; qCO₂ decreased from O to mineral horizons, indicating more efficient C use at depth. These in situ data show that Low-Arctic tundra C stocks are concentrated in surface organic layers while microbial communities remain responsive to warming, implying high sensitivity of carbon turnover to thaw and hydrologic change. The dataset supports model parameterization and remote sensing of shrub–tussock tundra carbon dynamics. Full article

Qilian Mountain National Park, an important forest ecosystem in northwest China, plays a crucial role in achieving the national “dual carbon” goals and advancing sustainable forest management. This study focuses on the systematic assessment of forest carbon storage and its market economic value, employing multi-source data fusion and the GARCH-M(1,1) model to integrate forest carbon storage data from 2000 to 2020 with historical trading records from the EU and Chinese carbon markets (2017–2025). The study utilizes three dynamic carbon pricing scenarios—low, medium, and high—to assess the carbon storage capacity and economic value of the park’s forest ecosystems. Results show that forest carbon storage increased by approximately 4.0 × 10⁷ tons, with an average annual growth rate of 0.27%. Under the high carbon pricing scenario in 2025, the forest carbon sink value in the EU market reaches CNY 518.2 billion, approximately 12.5 times that of the Chinese market, highlighting the differences in market maturity and volatility persistence. Through Monte Carlo simulations and dynamic pricing analysis, this research reveals the substantial market potential of Qilian Mountain’s forest carbon sinks, providing data-driven support for regional carbon trading optimization, ecological compensation mechanisms, and sustainable forest management, while contributing to the global carbon trading system and international cooperation in forest-based climate mitigation. Full article

Against the backdrop of intensified governance of territorial spatial planning, investigating carbon emissions from the perspective of territorial spatial planning for transport-land use integration holds significant academic and practical value. Taking Cangnan County as the case study, this research first dissects the reciprocal feedback mechanism between regional transport and land use at the territorial spatial planning level, while exploring transport-influencing factors. Subsequently, it constructs an integrated reciprocal feedback system for regional transport and land use by integrating accessibility drivers, cost matrices, and neighborhood weights through land use simulation–prediction models and the four-stage transport model. Finally, based on critical land use factors, diverse development scenarios under this integrated system are formulated; carbon emissions from transport and land use under each scenario are quantified; and their interrelationships are analyzed across multiple dimensions to explore the nexus of carbon emissions in transport–land use integration. Results indicate the following: (1) Integrated feedback enhances model accuracy (Kappa: 0.795→0.893; overall accuracy: 0.893→0.915), facilitating more precise land use simulation. (2) The county’s core construction area demonstrates the highest carbon emissions across all scenarios, meriting prioritized attention. (3) As deduced from the analysis of territorial spatial land use patterns, the significantly higher transport carbon emissions under the ecological protection priority scenario, compared to other scenarios, originate from over-concentrated construction land and imbalanced planning of carbon source land. These findings offer insights for regional planning; policy recommendations for Cangnan County include expanding carbon sink land, scientifically planning carbon source land, optimizing transport structures, and promoting new energy vehicles to advance carbon emission reduction and sustainable development. Full article

Chinese forest ecosystems are key carbon sinks that significantly contribute to lowering carbon emissions. Accurate Net Ecosystem Productivity (NEP) estimations are essential for evaluating their carbon sequestration capabilities and overall health. This study employed the Physiological Principles Predicting Growth-Satellites (3-PGS) and soil heterotrophic respiration models to simulate China’s forest carbon sinks and sources distribution from 2013 to 2023. Then, climatic factors influencing NEP changes were examined through the application of a geographical detector model. The net carbon sequestered was 1.71 ± 0.09 PgC with an annual average of 0.156 ± 0.0071 PgC, signifying a substantial carbon sink in China’s forest. The annual NEP was highest in evergreen broadleaf forests (352.12 gC m⁻²) and lowest in deciduous needleleaf forests (148.31 gC m⁻²). NEP in China’s forests increased by a rate of 1.67 gC m⁻² annually, with most regions exhibiting a 275.32 gC m⁻² annual carbon sink. The geographical detector model analysis showed that solar radiation, precipitation, and vapor pressure deficit were the main drivers of NEP change, while temperature and frost days had a secondary influence. Furthermore, the interaction between solar radiation and temperature variables showed the greatest impact. This study can enhance the understanding of carbon sink and source distribution in China, serve as a reference for regional carbon cycle research, and provide key insights for policymakers in developing effective climate strategies. Full article

To elucidate shade adaptation mechanisms in Pinus yunnanensis seedlings across different ages, this study established five light gradients (100% full sunlight as control or CK, 80% as L1, 45% as L2, 30% as L3, and 5% as L4) for experimental treatments on one- and three-year-old seedlings. By analyzing dynamic changes in non-structural carbohydrates (NSCs) and their components within needles, stems, and roots—combined with a phenotypic plasticity assessment, a correlation analysis, and a principal component analysis—we explored the carbon metabolic adaptations under shade stress. The key results demonstrate the following: (1) Increasing shade intensity significantly reduced the NSCs in the needles and roots of both age groups. The stem NSCs markedly decreased under L1 and L2, indicating “carbon limitation.” However, under severe shade (L3 and L4), the stem NSCs stabilized while the stem soluble sugars gradually increased. In three-year-old Pinus yunnanensis seedlings under the L3 treatment, the ratio of soluble sugars to starch in the stems reached as high as 5.772 g·kg⁻¹, yet the stem NSC content showed no significant change. This pattern exhibited “growth stagnation-carbon enrichment” characteristics. This reveals a physiological strategy for maintaining stem carbon homeostasis through a “structure–metabolism” trade-off under carbon limitation. (2) Shade adaptations diverged by age: one-year-old seedlings employed a short-term “needle–root source–sink reallocation” strategy, whereas three-year-old seedlings developed a “root–stem–needle closed-loop homeostasis regulation” mechanism. (3) Age-specific shade thresholds were identified: one-year-old seedlings required >80% full light to maintain a carbon balance, while three-year-old seedlings exhibited enhanced root carbon storage under moderate shade (45–80% full light). This study clarifies the physiological mechanisms by which P. yunnanensis seedlings of varying ages optimize shade adaptation through organ-specific carbon allocation, providing a theoretical foundation for shade management in artificial forests and understory seedling conservation. Full article

Continental ecosystems are crucial constituents of the worldwide carbon process, and their carbon source and sink processes are highly sensitive to human-induced climate change. However, the spatiotemporal changes and principal determinants of carbon source/sink in Shandong Province remain unclear. This study constructs six dominant control modes of carbon sources/sinks based on three carbon sink indicators (gross primary production (GPP), net primary production (NPP), and net ecosystem productivity (NEP)) and three carbon source indicators (autotrophic respiration (Ra), heterotrophic respiration (Rh), and total ecosystem respiration (Rs)), revealing the main control characteristics of the spatiotemporal dynamics of carbon source/sink in the continental ecosystems of Shandong Province. Additionally, the principal determinants of carbon sources and sinks are quantitatively analyzed using cloud models. The research findings are as follows: (1) From 2001 to 2020, the continental ecosystem of Shandong Province demonstrated a weak carbon sink overall, with both carbon sinks and sources showing fluctuating growth trends (growth rate: GPP, NEP, NPP, Rs, Ra, and Rh consist of 15.55, 6.14, 6.09, 9.59, 9.47, and 0.07 gCm⁻²a⁻¹). (2) The dominant control characteristics of carbon source/sink in Shandong Province exhibit significant spatial differentiation, which can be classified into absolute carbon sink cities (Jinan, Zibo, Rizhao, Jining, Liaocheng, Zaozhuang, Binzhou, Dezhou, Tai’an) and relative carbon source cities (Weifang, Yantai, Weihai, Linyi, Qingdao, Heze, and Dongying). GPP is the dominant control factor in carbon sink areas and is widely distributed across the province, while Rs and GPP are the dominant control factors in carbon source fields, focused on the eastern coastal and southwestern inland sites. (3) Landscape modification and rainfall are the main driving elements influencing the carbon sink and source variations in Shandong Province’s continental ecosystems. (4) The spatial differentiation of the driving factors of carbon producers and reservoirs is significant. In absolute carbon sink cities, land-use change and vegetation cover are the dominant factors for carbon sinks and sources, with significant changes in both range and spatial differentiation. In relative carbon source cities, land-use change is the leading factor for carbon source/sink, and the range of changes and spatial differentiation is most notable. The observations from this study supply scientific underpinnings and reference for enhancing carbon sequestration in continental ecosystems, urban ecological safety management, and achieving carbon neutrality goals. Full article

Biodiversity conservation has been identified as an important climate change mitigation tool. Healthy ecosystems act as natural carbon sinks while also strengthening resilience, making them essential for climate change adaptation. Climate change effects have led to various negative impacts, including biodiversity loss and food insecurity. The loss of forest biodiversity threatens vital wild fruits and vegetables that sustain rural communities, disrupting natural food sources and constituting a form of social injustice for poor, vulnerable, and previously marginalised groups in rural and semi-urban communities. Therefore, this study aimed to investigate the relationship between previous biodiversity conservation outcomes, ecosystem services, highly utilised wild vegetables and fruits, food and nutritional security, climate change effects, and climate resilience. We identified gaps in African biodiversity conservation and developed a conceptual framework to highlight integral principles required for the effective biodiversity conservation of wild forests in Africa. The integral principles are active community engagement, a strong network of stakeholders, sustainable plant resources management practices, legal reforms, and the creation of awareness through various platforms. Conservation policies should prioritise African indigenous wild, drought-tolerant vegetables and fruits that serve as an interface between food and medicine; play various roles in human survival in the form of ecosystem services; and act as carbon sinks to ensure a food-secure future with reduced climate change effects. The African indigenous community’s efforts in biodiversity conservation engagements are key to successful outcomes. Full article

Soils act as sources or sinks for three major greenhouse gases (CO₂, CH₄, and N₂O). Approximately 20% of global CO₂ emissions are released from soils through the soil respiration process. Soil respiration (soil CO₂ emission) can account for over 85% of ecosystem respiration. The aim of this study was to compare managed and unmanaged stands of pedunculate oak (Quercus robur L.) in order to investigate the impact of forest management on soil CO₂ emissions. We selected one managed and two unmanaged stands. The first stand (S1) represents a managed middle-aged stand, which is the optimal stage of development. The second stand (S2) belongs to the over-mature stage of development in an old-growth oak forest, while the third stand (S3) belongs to the decay stage of development in an old-growth oak forest. The closed chambers method was used for air sampling and the air samples were analyzed using gas chromatography (GC). Multiple regression models that include soil temperature (ST), soil moisture (SM), and their interaction provide a better explanation for variation in soil CO₂ emission (SCDE) (higher R² values) compared to regression models that only involve two variables (ST and SM). The study showed that SCDE in the decay stage of old-growth forest (S3) was significantly lower (p < 0.001) compared to the other two stands (S1 and S2). S3 is characterized by very low canopy cover and intensive natural regeneration, unlike S1 and S2. However, there were no significant differences in SCDE between the managed middle-aged stand (S1) and the over-mature (old-growth) stand (S2). Over a long-term rotation period in pedunculate oak forests, forest management practices that involve the periodic implementation of moderate silvicultural interventions can be deemed acceptable in terms of maintaining the carbon balance in the soil. Full article