Sink Enhancement Research Articles

Characteristics of Spatial Distribution of Soil Organic Carbon and Its Seasonal Change of Different Vegetation Buffer Zones in Duliujian River

Different vegetation types may affect the accumulation and transformation of soil organic carbon （SOC）, but it is unclear whether the organic carbon fixation is realized by litter input and/or root control of environmental factors and dissolved organic matter （DOM） of soils. In this study, the spatial distribution characteristics of easily oxidizable organic carbon （EOC）, dissolved organic carbon （DOC）, particulate organic carbon （POC）, mineral-bound organic carbon （MAOC）, and their seasonal variations in the surface soil （0-10 cm） were studied in different vegetation zones of the arbor forest （at the upper position）, the mixed forest of arbor and shrub （at the middle position）, and the waterfront vegetation （at the bottom position） in the ecological embankment of Duliujian River, Tianjin, China. The spatial distribution characteristics of soil DOM components and their seasonal changes were also analyzed by combining UV-visible spectroscopy and 3D fluorescence spectroscopy. The results showed that： ① The accumulation of SOC was significantly higher in the waterfront vegetation than in the arbor forest and the mixed forest of arbor and shrub in summer, whereas the opposite was true during the spring season. It was indicated that the root input of the soil was the key driving factor for determining the accumulation of SOC in summer, whereas the input quality of above-ground litters was more important for the sequestration of SOC in spring. ② Differences in DOM fractions explained the fixation and transformation pathways of SOC in different seasons, with humus-derived DOM in spring promoting the transformation of DOC to POC and MAOC and microbial-derived DOM in summer advancing the transfer of EOC to MAOC under the action of microorganisms. ③ Soil physicochemical properties had less direct influences on SOC, which preferentially affected SOC accumulation by regulating the composition as well as the chemical structure of soil DOM. ④ The structural equation modeling indicated that water content （MC） and total phosphorus （TP） were directly involved in SOC transport and transformation, whereas ammonium nitrogen （NH4+-N）, nitrate nitrogen （NO3--N）, electrical conductivity （EC）, available phosphorus （AP）, pH, K+, and Na+ indirectly affected SOC accumulation mediated by DOM from humus and microbial sources. In summary, the present study elucidated that the trade-off mechanisms affecting SOC sequestration in the critical functional zone along the land-river ecotone, and the results can provide theoretical support for further exploring the constructive methods of ecological corridors and the pathways of carbon sequestration and sink enhancement in the "watershed-estuary-offshore" system of the coastal rivers.

Vegetation and carbon sink response to water level changes in a seasonal lake wetland.

Water level fluctuations are among the main factors affecting the development of wetland vegetation communities, carbon sinks, and ecological processes. Hongze Lake is a typical seasonal lake wetland in the Huaihe River Basin. Its water levels have experienced substantial fluctuations because of climate change, as well as gate and dam regulations. In this study, long-term cloud-free remote sensing images of water body area, net plant productivity (NPP), gross primary productivity (GPP), and Fractional vegetation cover (FVC) of the wetlands of Hongze Lake were obtained from multiple satellites by Google Earth Engine (GEE) from 2006 to 2023. The trends in FVC were analyzed using a combined Theil-Sen estimator and Mann-Kendall (MK) test. Linear regression was employed to analyze the correlation between the area of water bodies and that of different degrees of FVC. Additionally, annual frequencies of various water levels were constructed to explore their association with GPP, NPP, and FVC.The results showed that water level fluctuations significantly influence the spatial and temporal patterns of wetland vegetation cover and carbon sinks, with a significant correlation (P<0.05) between water levels and vegetation distribution. Following extensive restoration efforts, the carbon sink capacity of the Hongze Lake wetland has increased. However, it is essential to consider the carbon sink capacity in areas with low vegetation cover, for the lakeshore zone with a higher inundation frequency and low vegetation cover had a lower carbon sink capacity. These findings provide a scientific basis for the establishment of carbon sink enhancement initiatives, restoration programs, and policies to improve the ecological value of wetland ecosystem conservation areas.

Understanding and estimating the role of large-scale seaweed cultivation for carbon sequestration on a global scale over the past two decades

Seaweeds, as marine photosynthetic organisms, are harvested by humans from the wild or through cultivation for various production purposes and to provide a range of marine ecosystem services, including nutrient removal, oxygen production, and carbon sequestration. The potential use of cultivated seaweed in mitigating carbon dioxide (CO2) has been extensively proposed in conjunction with commercial seaweed production worldwide. This study aims to assess the annual potential and benefits of cultivated seaweed in reducing and fixing anthropogenic CO2. Over the past two decades (2000–2019), global seaweed production has seen significant growth. The total output of cultivated seaweed reached 407.4 × 107 tons (t), with coastal mariculture removing 4.26 × 107 t of carbon annually and wild capture removing 2.24 × 106 t. The recalcitrant dissolved organic carbon (RDOC, 549.88–621.60 × 104 t) plays a significant role in the carbon sinks of seaweed cultivation. The substantial benefits of carbon sink resulting from the formation of RDOC from seaweed make up a considerable proportion in the calculation of carbon sequestration and sink enhancement benefits in large-scale seaweed cultivation. The sizable carbon sink base of seaweed cultivation (8631.90–9567.37 × 104 t) results in significant carbon fixation benefits. The total economic value of carbon sequestration and oxygen production was estimated at $70.36 ± 1.52 billion, with an annual average benefit of $3.52 ± 1.70 billion. Increasing the area and yield available for cultivated seaweed has the potential to enhance biomass production, carbon accumulation, and CO2 drawdown. It is crucial to emphasize the need for improved communication regarding the essential criteria for the feasibility of CO2 removal (CDR), with a focus on conducting life cycle assessments (LCA) when utilizing marine processes in the present and future work. The sustainable development of the seaweed cultivation industry not only ensures that Asian-Pacific countries remain leaders in this field but also provides an effective yet overlooked solution to excessive CO2 emissions worldwide.

Multi-Scenario Simulation of Land Use and Assessment of Carbon Stocks in Terrestrial Ecosystems Based on SD-PLUS-InVEST Coupled Modeling in Nanjing City

In the context of achieving the goal of carbon neutrality, exploring the changes in land demand and ecological carbon stocks under future scenarios at the urban level is important for optimizing regional ecosystem services and developing a land-use structure consistent with sustainable development strategies. We propose a framework of a coupled system dynamics (SD) model, patch generation land-use simulation (PLUS) model, and integrated valuation of ecosystem services and trade-offs (InVEST) model to dynamically simulate the spatial and temporal changes of land use and land-cover change (LUCC) and ecosystem carbon stocks under the NDS (natural development scenario), EPS (ecological protection scenario), RES (rapid expansion scenario), and HDS (high-quality development scenario) in Nanjing from 2020 to 2040. From 2005 to 2020, the expansion rate of construction land in Nanjing reached 50.76%, a large amount of ecological land shifted to construction land, and the ecological carbon stock declined dramatically. Compared with 2020, the ecosystem carbon stocks of the EPS and HDS increased by 2.4 × 106 t and 1.5 × 106 t, respectively, with a sizable ecological effect. It has been calculated that forest and cultivated land are the two largest carbon pools in Nanjing, and the conservation of both is decisive for the future carbon stock. It is necessary to focus on enhancing the carbon stock of forest ecosystems while designating differentiated carbon sink enhancement plans based on the characteristics of other land types. Fully realizing the carbon sink potential of each ecological functional area will help Nanjing achieve its carbon neutrality goal. The results of the study not only reveal the challenges of ecological conservation in Nanjing but also provide useful guidance for enhancing the carbon stock of urban terrestrial ecosystems and formulating land-use planning in line with sustainable development strategies.

Temperature and leaf form drive contrasting sensitivity to nitrogen deposition across European forests

Raised emissions of biologically reactive nitrogen (N) have intensified N deposition, enhancing tree productivity globally. Nonetheless, the drivers of forest sensitivity to N deposition remain unknown. We used stem growth data from 62,000 trees across Europe combined with N deposition data to track the effects of air temperature and precipitation on tree growth's sensitivity to N deposition and how it varied depending on leaf form over the past 30 years. Overall, N deposition enhanced conifer growth (until 30 kg N ha−1 yr−1) while decreasing growth for broadleaved angiosperms. Lower temperatures led to higher growth sensitivity to N deposition in conifers potentially exacerbated by N limitation. In contrast, higher temperatures stimulated growth sensitivity to N deposition for broadleaves. Higher precipitation equally increased N deposition sensitivity in all leaf forms. We conclude that air temperature and leaf form are decisive in disentangling the effect of N deposition in European forests, which provides crucial information to better predict the contribution of N deposition to land carbon sink enhancement.

Response Mechanism and Evolution Trend of Carbon Effect in the Farmland Ecosystem of the Middle and Lower Reaches of the Yangtze River

The farmland system in the global terrestrial ecosystem has dual attributes as both a carbon source and a carbon sink, playing a crucial role in controlling carbon emissions and mitigating global warming. Using carbon source and sink accounting of farmland ecosystems, we applied methods such as standard deviation ellipse, Tapio decoupling theory, and Markov chain to analyze the spatiotemporal changes, response mechanisms, and evolutionary trends of regional carbon effects. The results indicated that from 2011 to 2021, the farmland ecosystem in the middle and lower reaches of the Yangtze River consistently acted as a carbon sink. However, the net carbon sink showed slight fluctuations and significant spatial differences. The migration range of the net carbon sink center in the farmland ecosystem of the middle and lower reaches of the Yangtze River was relatively small, ranging from 115.52 to 115.77° E and 30.14 to 30.27° N. The decomposition of the Tapio decoupling index between the net carbon sink of the farmland ecosystem and agricultural output value showed the order of effects on their coupling relationship as follows: agricultural mechanization level &gt; agricultural mechanization efficiency &gt; agricultural output value &gt; planting scale. The probability of maintaining the original state of net carbon sink in various cities in the middle and lower reaches of the Yangtze River (over 77%) was much higher than the probability of transfer, making it difficult to achieve a leapfrog growth in net carbon sink. The net carbon sink at the city scale exhibits the Matthew effect and spatial spillover effect. The above research results clarify the spatiotemporal changes in carbon effects in agricultural production at multiple levels, including city, province, and region. They also provide a theoretical basis for formulating differentiated regional emission reduction and sink enhancement strategies in the middle and lower reaches of the Yangtze River, promoting the rapid development of low-carbon agriculture in China.

Current status and research prospects of terrestrial ecosystem carbon sink in Northeast China.

Increasing the carbon sink capacity of terrestrial ecosystems is a primary strategy to mitigate climate change and achieve the "carbon neutrality" goal. Clarifying the status and future dynamics of carbon sink of terrestrial ecosystems in Northeast China is crucial for achieving "carbon neutrality" as this region is a core contributor to carbon sink in China's terrestrial ecosystems. Here, we systematically summarized current research on carbon sink of terrestrial ecosystems across Northeast China, including the measurements and spatial-temporal patterns of carbon sinks, driving mechanisms of carbon sinks, the assessments of carbon sink potential, and technologies for increasing carbon sequestration. There are substantial uncertainties in quantifying terrestrial ecosystem carbon sink in Northeast China due to differences in data sources and methods, especially for forest carbon sink measurements, ranging from 0.020 to 0.157 Pg C·a-1. Carbon sink function depends on carbon exchange processes across plant-soil-atmosphere interfaces. The key pathways to enhance carbon sequestration in Northeast China under different temporal and spatial scales remains unclear. Improving terrestrial ecosystem quality is the key and core of carbon sequestration and sink enhancement. However, there is an urgent need to develop a multi-ecosystem collaborative carbon sequestration and sink enhancement technology system for the "dual carbon" goal. Future research needs to develop an accurate carbon sink measurement system that integrates multi-source data and multi-scale technologies to accurately assess the function and potential of carbon sink in Northeast China, focus on the multi-scale driving mechanism of carbon sink functions, develop new technical systems for coordinated enhancement of carbon sink for the Northeast terrestrial ecosystems, and carry out demonstrations of carbon sink enhancement technologies. These efforts will provide the scientific and technological supports for achieving the "carbon neutrality" goal.

Dynamics of bio-based carbon dioxide removal in Germany

Bio-based carbon dioxide removal encompasses a range of (1) natural sink enhancement concepts in agriculture and on organic soils including peatlands, and in forestry, (2) bio-based building materials, and (3) bioenergy production with CO2 capture and storage (BECCS). A common database on these concepts is crucial for their consideration in strategies and implementation. In this study, we analyse standardised factsheets on these concepts. We find different dynamics of deployment until 2045: for CO2 removal rates from the atmosphere, natural sink enhancement concepts are characterised by gradually increasing rates, followed by a saturation and potentially a decrease after few decades; forest-related measures ramp up slowly and for construction projects and bioenergy plants, annually constant removal rates are assumed during operation which drop to zero afterwards. The expenses for removing 1 t CO2 from the atmosphere were found to be between 8 and 520 € t CO2−1, which arises from high divergence both in capital and operational expenditures among the concepts. This high variability of expenses seems to suggest the more cost-effective concepts should be implemented first. However, aspects from economics, resource base and environmental impacts to social and political implications for Germany need to be considered for developing implementation strategies. All concepts investigated could be deployed on scales to significantly contribute to the German climate neutrality target.

Enhancing natural carbon sinks: Simulation of land use change under different carbon market scenarios by developing an ANN-ABM model

The carbon market mechanism presents an innovative approach to achieving carbon neutrality, however, its impact on regional carbon sink enhancement remains uncertain. This paper proposes an analysis framework based on an Artificial Neural Network-Agent-Based Model (ANN-ABM) to simulate the potential contribution of carbon market mechanism in enhancing carbon sinks. Taking the case of Chongming, China, the results demonstrate significant economic potential with forest land expansion from 2010 to 2020, equivalent to 30.69 % of eco-compensation. Under scenarios introducing a carbon market, there is an increased probability of converting land to high carbon sink types. Compared to the baseline scenario, carbon prices at 1.34 US$/t and 6.27 US$/t result in additional funds of 8.94 % and 41.46 %, respectively, and increase the carbon sink by 12.52 % and 30.28 %. The findings contribute to an understanding of how the value of carbon sinks can be realized through market mechanism and offer guidance for innovative eco-compensation approaches.

A potential CO2 carrier to improve the utilization of HCO3– by plant-soil ecosystem for carbon sink enhancement

IntroductionImproving the rhizospheric HCO3– utilization of plant-soil ecosystem could increase the carbon sink effect of terrestrial ecosystem. However, to avoid its physiological stress on the crop growth, the dosage of HCO3– allowed to add into the rhizosphere soil was always low (i.e., <5–20 mol/m3). ObjectivesTo facilitate the utilization of relatively high concentrations of HCO3– by plants in the pursuit of achieving terrestrial carbon sink enhancement. MethodsIn this study, the feasibility of directly supplementing a high concentration HCO3– carried by the biogas slurry to the plant rhizosphere was investigated using the tomato as a model plant. ResultsThe CO2-rich biogas slurry was verified as a potential CO2 carrier to increase the rhizospheric HCO3– concentration to 36 mol/m3 without causing a physiological stress. About 88.3 % of HCO3– carried by biogas slurry was successfully fixed by tomato-soil ecosystem, in which 43.8 % of HCO3– was assimilated by tomato roots for the metabolism, 0.5 ‰ of HCO3– was used by microorganisms for substances synthesis of cell structure through dark fixation, and 44.4 % of HCO3– was retained in the soil. The rest of HCO3– (∼11.7 %) might escape into the atmosphere through the reaction with H+. Correspondingly, the carbon fixation of tomato-soil ecosystem increased by 150.1 g-CO2/m2-soil during a tomato growth cycle. As for the global countries that would adopt the strategy proposed in this study to cultivate the tomato, an extra carbon sink of soil with about 1031.1 kt-C per year (i.e., an additional 0.21 tons of carbon per hectare soil) could be obtained. ConclusionThis would be consistent with the goal of soil carbon sink enhancement launched at COP21. Furthermore, the regions with low GDP per capita may easily achieve a high reduction potential of CO2 emissions from the agricultural land after adopting the irrigation of CO2-rich biogas slurry.

Meta-ecosystem Frameworks Can Enhance Control of the Biotic Transport of Microplastics.

The lack of systematic approaches and analyses to identify, quantify, and manage the biotic transport of microplastics (MPs) along cross-ecosystem landscapes prevents the current goals of sustainable environmental development from being met. This Perspective proposes a meta-ecosystem framework, which considers organismal and resource flows among ecosystems to shed light on the research and management challenges related to both abiotic and biotic MP transport at landscape levels. We discuss MP transport pathways through species movements and trophic transfers among ecosystems and sub-ecosystems, and highlight these pathways in the mitigation of MP pollution. The integration of biotic pathways across landscapes prioritizes management actions for MP transport using diverse approaches such as wastewater treatment and plastic removal policies to mitigate contamination. In addition, our framework emphasizes the potential sink enhancement of MPs through habitat conservation and enhancement of riparian vegetation. By considering the mechanisms of meta-ecosystem dynamics through the processes of biotic dispersal, accumulation, and the ultimate fate of MPs, advances in the environmental impact assessment and management of MP production can proceed more effectively.

Estimating terrestrial ecosystem carbon storage change in the YREB caused by land-use change under SSP-RCPs scenarios

Terrestrial ecosystems, as an essential carbon sink of atmospheric CO2, play an important role in balancing the global carbon cycle. Land-use and land-cover changes (LUCCs) are the major factors in terrestrial ecosystem carbon storage (TECS) change. However, they are not yet sure how future LUCCs would affect the TECS in the Yangtze River Economic Belt (YREB) to meet China's carbon-neutral goal. We simulated eight land-use change scenarios and used these to estimate the YREB's TECS and its 2020–2060 variation by coupling the spatially explicit projections of LUCCs under the latest IPCC, combining shared socioeconomic pathways (SSPs) and representative concentration pathways (RCPs) with datasets on terrestrial ecosystem carbon density dataset. Results show that: 1) the total TECS of the YREB in 2020 is ∼28.07 Gt. Spatially, TECS in the YREB focused on Sichuan and Yunnan (∼13.35 Gt), which plays a crucial role in balancing the regional carbon cycle; its losses are in Jiangsu, Zhejiang, and Hunan provinces; Yunnan is the potential region with future carbon sink enhancement in the YREB. 2) Compared to the TECS change under eight land-use scenarios, the low-carbon and sustainable development pathways are the priority chosen by humans. 3) The replacement of vast forest land with cropland and urban expansion are the key factor of TECS change in the YREB. 4) Land management policies (i.e., Cultivated land requisition-compensation balance) should balance the conflicts between food self-sufficiency and the carbon sink rather than only the dynamic balance in quantity. Our study aims to provide data support for the government in planning future development pathways and refining carbon emission reduction strategies to assist in carbon trading and compensation and achieve the YREB's dual-carbon goal.

Key processes of carbon cycle and sink enhancement paths in natural wetland ecosystems in China

Key processes of carbon cycle and sink enhancement paths in natural wetland ecosystems in China

Research on Zoning and Carbon Sink Enhancement Strategies for Ecological Spaces in Counties with Different Landform Types

Ecological carbon sinks, pivotal in mitigating carbon emissions, are indispensable for climate change mitigation. Counties, as the fundamental units of ecological space management, directly impact the achievement of regional dual carbon targets through their levels of carbon sink. However, existing research has overlooked the intricate relationship between terrain features and ecological spaces, leading to a lack of specific guidance on enhancing the carbon sink for counties with diverse landform characteristics. This study focused on Jingbian County (Loess Plateau), Fuping County (Guanzhong Plain), and Chenggu County (Qinba Mountains), each characterized by distinct landform characteristics. This study proposes a comprehensive identification model for ecological space within the context of dual carbon targets. Utilizing this model as a basis, the land use structure, carbon sink potential, and ecological spatial patterns of different counties were systematically analyzed. The results indicated substantial disparities in land use structure, carbon sink capabilities, and ecological space distributions among counties with different landform types. Specifically, Jingbian County was predominantly covered by grassland, exhibiting a moderate overall carbon sink capacity, with baseline ecological spaces playing a significant role. Conversely, Fuping County, dominated by cultivated land and construction land, exhibited the lowest carbon sink capacity, with non-ecological spaces accounting for a staggering 85.93%. Chenggu County, on the other hand, was characterized by the dominance of forestland, with nearly all its carbon sink originating from forestland, and core ecological spaces occupying a leading position. Tailored optimization strategies are recommended based on varying terrain features: Jingbian County should prioritize ecosystem restoration and conservation, while Fuping County should concentrate on optimizing land use structure and promoting urban greening. Reinforcing the carbon sink capacity of existing ecosystems is crucial for Chenggu County. This study broadens the perspective on ecological space optimization and provides scientific guidance and pragmatic insights tailored to regional disparities, which are instrumental in assisting various regions to achieve their dual carbon targets.

Evaluation of innovative thermal performance augmentation techniques in heat sinks & heat pipes: Electronics & renewable energy applications

Heat sinks and heat pipes have vast applications including industrial domains requiring high heat flux. Due to numerous uses of these heat transfer devices, there have been great advancement in this area through innovation. This study focuses use of nanofluids and hybrid nanofluids for thermal performance enhancement of heat pipes and heat sinks. There are five different arrangements finless sintered copper wicked heat pipe, water based TiO2 filled heat pipe, TiO2 and SiO2 based hybrid nanofluid filled heat pipe, water cooled cylindrical pin finned heat sink and Fe2O3 and TiO2 hybrid nanofluid cooled heat sink. There are two test rigs one for testing heat pipe configurations and other for heat sinks. All the five elements are tested at constant heat flux ranging from 900 W/m2 to 3600 W/m2, in four equal steps. It’s observed that nanofluids play a very significant role in thermal performance augmentation, the affect is even more significant in heat pipes compared to heat sinks. Interestingly, nanofluids based heat pipes are proved more significant for high heat flux applications, although, nanofluid cooled heat sinks have slight better performance compared to the said but at a higher expense of weight, auxiliaries, space and cost. At 3600 W/m2 nanofluid based heat pipes have 33 % lower thermal resistance compared to water cooled heat sink. Therefore, nanofluid based heat pipes are primarily significant unless use of heat sink deemed dire. Nusselt number of heat sink is calculated at various heat flux and at variable mass flux conditions and found increasing with both parameter.

Ecological restoration is crucial in mitigating carbon loss caused by permafrost thawing on the Qinghai-Tibet Plateau

Climate change leads to permafrost thawing, accelerating carbon emissions increases, challenges the goal of climate change mitigation. However, it remains unknown whether implementing ecological restoration projects in Alpine areas can offset the adverse effects of permafrost thawing locally. Here we took the Qinghai‒Tibet Plateau as an example to explore this issue based on the improved Biome-BGCMuSo model. We found future climate change-induced permafrost thawing will decrease carbon sink. Projects’ carbon sink enhancement could fully counteract the permafrost thawing-induced carbon loss. Additionally, future warmer and wetter climates will enlarge the suitable area for restoration. If these areas are taken into account, carbon sink attributable to Projects will further increase. These results indicate that ERPs have the potential to combat future permafrost thawing-induced carbon loss, and their contribution will be further amplified by future climate change.

Effects of fertilization applications on soil aggregate organic carbon content and assessment of their influencing factors: A meta-analysis

Fertilizer application plays an important role in agricultural soil organic carbon (SOC) and its sustainable management. However, there is a lack of consensus about the mechanisms regarding fertilizer application in the soil on the procedure of carbon sequestration and sink enhancement in the aggregates. In this study, the extent by which various fertilization treatments, fertilization durations, climate conditions, soil texture, and land-use types affected the organic carbon (OC) content of different particle-size aggregates was quantitatively assessed using a meta-analysis of 696 treatment comparisons from 36 published studies. Based on the meta-analysis results, fertilization enhanced the OC contents of macroaggregates and clay and silt particles, particularly through replenishing organic material. Long-term fertilization increased the OC content of macroaggregates (>0.25 mm), while the OC content of the clay and silt particles (<0.053 mm) reached a maximum at 15.4 years of fertilization, after which it reached carbon saturation. Organic fertilizer effectively increased the OC content of small macroaggregates (0.25–2 mm) and microaggregates (0.053–0.25 mm) at lower temperatures and precipitation. Compared with inorganic fertilization, combined organic–inorganic fertilization increased OC contents of all sizes of aggregates in sandy or clay loam soils, but decreased OC contents of microaggregates and clay and silt particles in silt loam soils. All fertilization treatments increased the OC content of all particle-size aggregates in upland soils. In contrast, inorganic fertilization and mixed organic–inorganic fertilization reduced the OC content of microaggregates (0.053–0.25 mm) and clay and silt particles (<0.053 mm) in paddy field soils. In conclusion, the application of organic fertilizers is more conducive to the accumulation of OC in agricultural soil aggregates. Whereas the limiting factors for the accumulation of OC content in soil aggregates vary under different conditions, organic fertilizer inputs should be given more consideration, especially in dryland and coarse-textured soils.

Assessment of carbon reduction and sink enhancement potential of photovoltaic+mining ecological restoration model

The energy oriented mine ecological restoration mode of photovoltaic+ecological restoration provides a breakthrough for alleviating the dilemma of photovoltaic land development and solving the urgent need for restoration of abandoned mining land. Taking a mining area in central Liaoning Province as an example, we established three photovoltaic+mining ecological restoration modes, including forest-photovoltaic complementary, agriculture-photovoltaic, and grass photovoltaic complementation. Combined with the life cycle assessment method, we calculated and assessed the potential of photovoltaic+mining ecological restoration in carbon reduction and sink enhancement. The average annual carbon reduction and sink increase was 514.93 t CO2·hm-2 under the photovoltaic+mining ecological restoration mode, while the average annual carbon reduction per megawatt photovoltaic power station was 1242.94 t CO2. The adoption of photovoltaic+ecological restoration mode in this mining area could make carbon reduction and sink enhancement 6.30-7.79 Mt CO2 during 25 years. The carbon reduction and sink increment mainly stemmed from the photovoltaic clean power generation induced carbon reduction, accounting for 96.4%-99.4%, while the contribution of ecosystem carbon sink increment was small, accounting for only 0.6%-3.7% of the total. Among different photovoltaic+ecological restoration modes, the carbon reduction and sink increment was the largest in forest-photovoltaic complementary (7.11 Mt CO2), followed by agriculture-photovoltaic (7.04 Mt CO2), and the least in grass photovoltaic complementation (6.98 Mt CO2). Constructing the development mode of "photovoltaic+mining ecological restoration" could effectively leverage the dual benefits of reducing emissions from photovoltaic power generation and increase sinks from mining ecological restoration, which would be helpful for achieving the goal of carbon neutrality in China.

Differentiation of Carbon Sink Enhancement Potential in the Beijing–Tianjin–Hebei Region of China

Carbon sink enhancement is of great significance to achieving carbon peak and carbon neutrality. This study firstly estimated the carbon sink in the Beijing–Tianjin–Hebei Region using the carbon absorption coefficient method. Then, this study explored the differentiation of carbon sink enhancement potential with a carbon sink–economic carrying capacity index matrix based on carbon sink carrying capacity and economic carrying capacity under the baseline scenario and target scenario of land use. The results suggested there was a remarkable differentiation in total carbon sink in the study area, reaching 2,056,400 and 1,528,300 tons in Chengde and Zhangjiakou and being below 500,000 tons in Langfang and Hengshui, while carbon sink per unit land area reached 0.66 ton/ha in Qinhuangdao and only 0.28 t/ha in Tianjin under the baseline scenario. Increasing area and optimizing spatial distribution of arable land, garden land, and forest, which made the greatest contribution to total carbon sinks, is an important way of enhancing regional carbon sinks. A hypothetical benchmark city can be constructed according to Qinhuangdao and Beijing, in comparison with which there is potential for carbon sink enhancement by improving carbon sink capacity in Beijing, promoting economic carrying capacity in Qinhuangdao, and improving both in the other cities in the study area.

Uncovering the world's largest carbon sink-a profile of ocean carbon sinks research.

As the world's largest carbon sink, the oceans are essential to achieving the 1.5°C target. Marine ecosystems play a crucial role in the "sink enhancement" process. A deeper comprehension of research trends, hotspots, and the boundaries of ocean carbon sinks is necessary for a more effective response to climate change. To this end, academic literature in the field of ocean carbon sinks was investigated and analyzed using the core database of the Web of Science. The results show that (1) The ocean carbon sink is a global study. The number of literatures in the field of ocean carbon sinks is growing, and the USA and China are the main leaders, with the USA accounting for 31.19% of the global publications and China accounting for 26.57% of the global publications, and the environmental science discipline is the most popular in this field. (2) Keyword burst detection shows that the keywords "sink, sensitivity, land, dynamics, and seagrass" appear earliest and have high burst intensity, which are the hot spots of research in this field; the keyword clustering shows that the global ocean carbon sinks research mainly focuses on three themes: (i) carbon cycle and climate change; (ii) carbon sinks estimation models and techniques; and (iii) carbon sinks capacity and ocean biological carbon sequestration in different seas. Finally, targeted research recommendations are proposed to further match the ocean carbon sink research.