Cyanobacterial blooms are increasing in frequency, intensity, and duration in both freshwater and marine environments, potentially enhancing carbon sequestration by producing recalcitrant dissolved organic carbon (RDOC). We conducted monthly analyses of dissolved organic matter (DOM) composition and bacterial community dynamics in Lake Taihu (Meiliang Bay), China, integrating fluorescence DOM and ¹H NMR to quantify carboxyl-rich alicyclic molecules (CRAM) as a molecular proxy for RDOC. Estimated CRAM increased from 51.86 ± 11.22 μM C in the non-bloom period to 60.80 ± 8.21 μM C during blooms (~17% higher). The annual average RDOC was 62.93 ± 10.66 μM C, accounting for ~16% of the total DOC. Bacterial community analysis revealed that labile DOC was actively metabolized and transformed into more recalcitrant compounds through microbial carbon pump mechanisms. Specifically, the CL500-29 marine group and Sphaerotilus contributed to the degradation of protein-like DOM, while the CL500-29 and hgc1 clades played key roles in CRAM formation. The pronounced RDOC enrichment in eutrophic lakes compared to non-eutrophic lakes, rivers, and marine systems underscores the potential of eutrophic lakes to function as significant carbon sinks, highlighting the necessity of integrating bloom-driven RDOC accumulation into carbon budget frameworks to reassess the long-term carbon sequestration potential of these systems.

In the midst of increasing global warming and accelerated urbanization, urban parks, serving as significant carbon sinks, are increasingly recognized for their role in mitigating the urban heat island effect. However, limited research investigating the urban park carbon cycle hinders our full understanding and effective use of their carbon sink potential. This study employed metagenomics sequencing and 16S rRNA gene sequencing to characterize the carbon cycle and its influencing factors within soil and water from collected from nine city parks. Notably, the abundance and alpha diversity of carbon cycle microbes and genes were higher in soil compared to water. Specifically, soil samples exhibited enrichment of carbon cycling genes involved primarily in polysaccharide metabolism, particularly those associated with starch and cellulose metabolism. Conversely, water samples, revealed a greater prevalence of genes associated with chitin metabolism. The most important factor affecting soil carbon cycling genes was bacterial community, followed by non-nutritional factors and nutrient factors, while heavy metals demonstrated no effect on soil carbon cycling genes. The most important factor affecting water carbon cycling genes was only bacterial community. The analysis yielded 381 high-quality metagenomic assembled genomes (MAGs) containing carbon cycling genes, with significant covariation observed between the pta and carbon cycling genes ackA and acyP, which encode cellulose degradation functions. These findings contribute to a better understanding of microbial carbon metabolism within urban parks and offer a foundation for effective carbon emission management strategies.

Urban trees within developed areas provide essential ecosystem services that include carbon sequestration. But growing urban populations put pressure on vegetated urban ecosystem services and biodiversity. This study examined tree diversity, biomass, and carbon storage within the developed areas of the Forestry Research Institute of Nigeria (FRIN). A complete enumeration of 326 trees distributed among 57 tree species and 29 families was conducted. Biodiversity indices were computed using standard procedures, while biomass and carbon storage were estimated using a non-destructive method. Most species (61.4%) were indigenous, while 38.6% were exotic. Pinus caribaea, Khaya senegalensis, Entandophragma angolense, and Gmelina arborea were among the dominant tree species. About 65.6% of the trees were very stable given their low slenderness coefficient. The high biodiversity index values (species richness = 57; Shannon-Wiener diversity index = 3.84; Margalef index = 9.68) suggest that the developed areas of FRIN have good biodiversity conservation status. Total basal area and volume productions were 49.54 m² ha-1 and 660.32 m³ ha-1, respectively, corresponding to 447.90 tons ha-1 of biomass and 223.95 tons ha-1 of carbon. Despite their small land size, the developed areas of FRIN are a significant carbon sink compared to similar institutional landscapes in Nigeria. This study highlights the need for institutional green-space management strategies to be integrated into national climate change adaptation and biodiversity conservation policies for enhanced ecological resilience and sustainability.

Addressing climate change requires both global cooperation and local action. Mountainous rural areas, with their significant carbon sink potential, play a crucial yet under-explored role in achieving carbon neutrality. However, it is not clear how far these villages are from carbon neutrality. This study proposes a novel carbon neutrality assessment framework specifically designed for mountainous villages, integrating carbon emission reduction, sink, and community engagement to assess and guide local carbon neutrality efforts. Case studies in Baizhang Town and its six surrounding villages showed that the town and four villages achieved carbon neutrality, illustrating the framework's effectiveness in reducing emissions and enhancing sink. Theoretical analysis further supports the framework by providing insights into its applicability and scalability for rural communities. The framework offers a practical tool for local communities to manage carbon emissions and implement sustainable practices. This framework can be adapted to other rural areas, offering a model for carbon neutrality efforts across diverse mountainous regions.

The Nilbarahi Community Forest contains the needle leaved tree species Pinus roxburghii (Chir pine) and mixed broad leaved tree species such as Schima wallichii, Engelhardtia spicata, Eurya acuminate, Litsea monopetala and Alnus nepalensis. This community forest’s some part is naturally of mixed broad leaved trees and some part is planted trees of Pinus roxburghii (Chirpine). The SRS method was used to determine the carbon component of the forest to assess the amount of carbon stock and carbon dioxide equivalent (CO2-e) absorption of needle leaved tree and the mixed broadleaved tree of the community forest. The carbon stock of the forest was measured per hectare basis of the biomass contained by the trees. It is very essential to know the type of trees that can absorb much carbon component from the atmosphere through Photosynthesis and store it in their leaves, branches, stems, barks and in the roots. The much carbon retained by the trees would help to mitigate the climate change. The biomass of the trees was determined by the biomass regression model and then the carbon retained in them was obtained by converting the biomass stock of trees into carbon stock by using the IPCC default carbon fraction of 0.47. After then the CO2-e absorption was calculated by multiplying one ton of carbon value to 3.67 tons of carbon dioxide equivalent (CO2-e) which was expressed in metric tons. The total above ground tree biomass was found 188.70 ton/ha at site-3 of mixed broad leaved forest seemed to be the highest biomass followed by the planted forest of Pinus roxburghii (Chir pine) at site-1 which had the biomass of 147.78 ton/ha. The carbon content of above ground tree biomass of the study area was also found to be 88.69 ton/ha followed by 69.45 ton/ha at site-3 and site-1 respectively. The study showed that the needle leaved trees (Pinus roxburghii) had low carbon stock than the natural mixed broadleaved trees in the Nilbarahi Community Forest. The CO2-e was also found to be highest as 295.21MT in the mixed broad leaved trees than the needle leaved conifer trees of 231.18 MT at site-3 and site-1 respectively. The average carbon stock and average CO2e was found to 72.41 t/ha and 241.03 MT in the Nilbarahi Community Forest. The biomass, carbon (C) stock and carbon dioxide equivalent (CO2-e) in the forest ecosystems of Nilbarahi which have been managed and conserved well by the community forest user groups could play an important role in carbon cycle and serve as significant carbon sink to reduce the burning issue of global warming.

Abstract. Accurate estimation and monitoring of forest aboveground biomass (AGB) are essential for understanding carbon dynamics, managing forest resources, and guiding environmental policies. However, the spatial and temporal patterns, dynamics, and driving factors of forest AGB in China over recent decades remain insufficiently understood, hindering ecosystem analysis and forest management strategies. This study combines multi-source remote sensing data with residual neural networks (ResNets) to develop the first 30 m resolution annual China Forest AGB dataset (1985–2023) with uncertainty quantification. Validation results confirm the robustness of the ResNets model, achieving an R2 of 0.91, RMSE of 16.49 Mg ha−1, and Bias of 0.50 Mg ha−1 against GEDI footprint AGBD, and an R2 of 0.63, RMSE of 68.26 Mg ha−1, and Bias of −19.87 Mg ha−1 against independent multi-year ground survey data. The dataset reveals a notable increase in China's average forest aboveground biomass density (AGBD) from 95.74 ± 11.30 Mg ha−1 in 1985 to 122.69 ± 13.94 Mg ha−1 in 2023. During this period, total forest aboveground carbon (AGC) stock rose from 5.50 ± 0.23 PgC to 13.97 ± 0.87 PgC, establishing China's forests as a significant carbon sink over the past four decades, with a net carbon sink of 0.22 ± 0.01 PgC yr−1, offsetting 11.5 %–14.9 % of China's annual fossil fuel and industrial carbon dioxide emissions. Forest growth contributed 65.1 % (5.75 PgC) of the total AGC increase, while forest expansion accounted for 34.9 % (3.09 PgC). This dataset provides critical information for forest carbon accounting in China and offers valuable insights for climate change mitigation, ecosystem conservation, and sustainable land management. The dataset is available at https://doi.org/10.5281/zenodo.12620984 (Part I: 1985–1993, Cai et al., 2025a), https://doi.org/10.5281/zenodo.12637101 (Part II: 1994–2001, Cai et al., 2025b), https://doi.org/10.5281/zenodo.12655492 (Part III: 2002–2008, Cai et al., 2025c), https://doi.org/10.5281/zenodo.12658255 (Part IV: 2009–2015, Cai et al., 2025d), https://doi.org/10.5281/zenodo.12742210 (Part V: 2016–2021, Cai et al., 2025e), https://doi.org/10.5281/zenodo.12747329 (Part VI: 2022-2023, Cai et al., 2025f).

ABSTRACT Forest ecosystems play a critical role in the global carbon cycle. As a significant terrestrial carbon sink, plantations exhibit carbon stock patterns that are shaped by tree species composition, stand structure, and environmental conditions. Here, we investigated typical plantation types in the Mufu Mountain, Hubei Province. Total carbon stock and its distribution across different stand types were quantified by establishing permanent monitoring plots and conducting tree surveys, applying general biomass models to estimate biomass, and employing elemental analysis to measure soil carbon content. Our results indicated that total carbon stock ranged from 37,452.54 to 184,909.38 kg/ha among six forest subplots in the Mufu Mountain. Broadleaf and coniferous stands accumulated substantially more carbon than Phyllostachys edulis (Carrière) J. Houz. forests. Higher soil temperature, illuminance, and increased shrub cover promoted carbon accumulation in trees and shrubs. In contrast, multiple environmental factors regulated carbon stock in herbaceous plants, litter, and soil organic matter, demonstrating clear carbon pool‐specific effects. Our findings clarify key environmental drivers of carbon dynamics in subtropical plantations, and based on these results, we propose concrete management strategies including the selection of high‐carbon stock tree species, maintenance of understory shrub layers, and implementation of strategic canopy thinning to enhance forest carbon sequestration.

In the eastern Hindu Kush, juniper woodlands play a vital role in sustaining montane dryland ecosystems, thereby acting as significant carbon sinks. We investigated the spatial dynamics of both aboveground carbon stock (AGCS) and soil organic carbon (SOC) in relation to environmental variables and disturbance regimes. Cluster analysis identified three distinct woodland types, each exhibiting significant structural diversity, with low to moderate stem densities (318-492 stems ha-1) and basal area (12-20.2 m2ha-1) (ANOVA, p < 0.03). The overall AGCS was low, ranging from 8 ± 2 to 14.2 ± 1Mg C ha-1, with significant variation among the woodland types (ANOVA, p = 0.03), while SOC stock ranged from 19 to 25Mg C ha-1. In total, the amount of CO2 sequestered by the woodlands was estimated at 105-134Mg CO₂ ha-1. Structural attributes, soil silt, phosphorus, and water availability were identified as the primary drivers explaining a substantial portion of AGCS. In contrast, temperature, precipitation, and soil CaCO3 had a secondary influence, followed by negative impacts of soil pH, sand percentage, topography, and geographic coordinates. Similarly, soil electrical conductivity, phosphorus, and potassium were positive determinants of the SOC stock, whereas humidity was negatively correlated. Notably, AGCS was highest in the least disturbed communities and exhibited a robust negative relationship with disturbance intensity (R2 = 0.25, p = 0.005). This study highlights the interconnectedness of socio-ecological and environmental factors in determining carbon density. It also emphasizes the importance of protecting degraded ecosystems through afforestation, woodland conservation, and community-based management to reduce the impacts of climate change.

Climate change is the most serious global environmental issue caused by excessive atmospheric greenhouse gases, primarily carbon dioxide. This study examined the carbon stock potential and the effects of human disturbances on carbon storage in aboveground biomass, belowground biomass, litter biomass, and soil. Forty plots with 20 m x 20 m systematic sampling techniques were laid out to measure the height and DBH of all woody plant species with DBH ≥ 5 cm. Additionally, 200 sub-plots, each measuring 1 m x 1 m, were established within the major plots to gather litter and soil samples. The results indicated that the mean total carbon stock and CO2 equivalent in the Embuli Tahisasdar forest were 172.47 t ha⁻¹ and 633.38 t ha⁻¹, respectively. The estimated average carbon stock in the aboveground, belowground, litter, and soil organic carbon was 43.22 ± 74.13 t ha⁻¹, 11.24 ± 19.27 t ha⁻¹, 2.49 ± 0.86 t ha⁻¹, and 115.52 ± 118.96 t ha⁻¹, respectively. The significant variations in carbon stock were observed across different altitudinal and topographic aspects for aboveground biomass, belowground biomass, litter, and soil (P&lt;0.05). In conclusion, the study area serves as a significant carbon sink, contributing positively to the reduction of greenhouse gas emissions and it has the potential to generate carbon credits, offering financial benefits to the community while supporting biodiversity conservation efforts for the region's forest resources.

Contrasting seasonal variability of net community production between the Southern Yellow Sea and the Northern East China Sea during spring and summer.

Desert ecosystems, once considered biologically inert, are increasingly recognized for their untapped potential in global carbon sequestration (CS). This review addresses a central research question: how do precipitation patterns, vegetation dynamics, and soil processes influence carbon cycling and storage in arid environments, and what is the role of inorganic CS mechanisms in these systems? We synthesize current knowledge on the physicochemical and hydrological processes that regulate carbon dynamics in deserts, with a focus on both organic and inorganic pathways. Key findings reveal that while deserts can function as significant carbon sinks, their CS capacity is highly modulated by sparse rainfall, episodic vegetation growth, and carbonate formation processes in soils. Furthermore, we critically evaluate advanced carbon capture and storage (CCS) technologies and soil carbon enhancement techniques tailored to arid regions, identifying both their potential and limitations. Persistent challenges, such as water scarcity, nutrient limitation, and soil degradation, pose constraints but also present opportunities for innovation in CS strategies. Our synthesis highlights deserts as dynamic, if underutilized, components of the global carbon cycle. We conclude that targeted interventions and integrated land management approaches could substantially improve CS in desert ecosystems, making them valuable assets in climate change mitigation, energy transition planning, and long-term environmental resilience.

ABSTRACT The Huaihe River Eco‐Economic Belt (HREEB), a vital grain‐producing region in China, contributes 11% of the nation's arable land and one‐sixth of its grain output. As an essential indicator of soil health, soil organic carbon (SOC) underpins long‐term productivity and ecological stability. However, the spatiotemporal dynamics of SOC stocks and the relative roles of climate and land management remain poorly quantified. This study investigated spatiotemporal changes in SOC stock in the HREEB (1980s–2020s), identified main SOC sequestration drivers, and proposed strategies for enhancing carbon stocks in sustainable agriculture. SOC stocks increased by 227.73 Tg over four decades, with an average sequestration rate of 220.30 kg C ha −1 year −1 , indicating the region's significant carbon sink potential. Spatially, SOC stocks were higher in the south and lower in the north, with south–north SOC density differences of 0.70, 0.57, and 1.04 kg m −2 in the 1980s, 2010s, and 2020s, respectively. The soil pH, nitrogen input, mean annual temperature, and precipitation were the dominant explanatory variables, contributing 18.46%, 10.67%, 10.37%, and 8.05% to the explained variance in SOC density. Among these, soil pH and annual nitrogen fertilizer input showed highly significant negative correlations ( p &lt; 0.01), as pH regulates SOC stability through mineral interactions, microbial community composition, and enzyme activity. Nitrogen input of 0.072–0.177 Mg ha −1 accelerates SOC decomposition and contributes to carbon input via increased root exudates. Furthermore, both the mean annual precipitation and temperature were positively correlated with changes in SOC density, with the strongest association observed with precipitation ( p &lt; 0.05). Therefore, managing soil pH, optimizing nitrogen use, and adapting to climate change are vital for enhancing the region's soil carbon sink and supporting sustainable agricultural development.

This perspective article synthesises insights from a 2023 interdisciplinary workshop in Kuching, Malaysia, where 26 experts examined how land use and land cover change (LULCC) impacts Blue Carbon Ecosystems (BCE) in Southeast Asia (SEA) and identified pathways for integrated, science-informed governance. BCE in SEA (mangroves, seagrasses and tidal wetlands) are globally significant carbon sinks, critical to biodiversity and the livelihoods of millions, dependant on them for food, income and coastal protection. Yet rapid development and socio-economically driven LULCC threaten BCE resilience and carbon storage capacity. Blue Carbon initiatives risk falling short if they overlook the socio-ecological interconnectivity of these systems. Advances in remote sensing, sediment carbon accounting and ecosystem modelling have improved BCE monitoring, but key gaps persist. These include understanding cumulative upstream effects of LULCC on BCE carbon dynamics, integrating socio-economic with ecological data for robust scenario modelling and evaluating governance effectiveness and equity over time. We frame BCE as dynamic, interconnected socio-ecological systems and call for the advancement of systems thinking in coastal and climate policy. We underscore the need for transdisciplinary, nested governance models operating across ecological scales and political boundaries and argue for a systems-based management approach that links land-sea processes, addresses upstream-downstream dynamics and balances carbon market incentives with local needs. Recommendations include improved monitoring and carbon accounting; alignment between science and policy; regionally coordinated governance; and diversifying finance to reflect the full value of BCE beyond carbon. Together, these actions chart a path for resilient, science-based, socially inclusive BCE conservation in SEA.

Mangrove forests provide a wide range of ecosystem services that benefit both people and nature. While many countries have lost nearly 50% of their mangroves in the past 50 years, Aotearoa New Zealand’s mangroves are rapidly expanding in many locations due to increased sediment inputs from land-use changes and urbanisation. In the Auckland region, where mangrove extent has increased 4.5-fold since 1940, we quantified the blue carbon sequestration benefits from seven mangrove expansion sites. Our results indicate that New Zealand’s mangroves sequester 86,000 t CO 2 annually, with an additional 3,400 t CO 2 sequestered in 2020 due to mangrove expansion. Specifically, mangrove carbon sequestration in the Auckland region has risen from 7,700 t CO 2 yr -1 in 1940 to 34,600 t CO 2 yr -1 in 2020 - equivalent to 50% of the region’s current emissions from forestry, fishing, and mining. Although the expansion of New Zealand’s mangroves may impact perceived coastal amenity values, their role as significant carbon sinks is critical for mitigating global carbon emissions and supporting the country’s commitments to the Paris Agreement. However, like many other countries, New Zealand has yet to include mangrove carbon sequestration in its national policies and management strategies. To move forward, we recommend: 1) integrating blue carbon into the national greenhouse gas inventory; 2) monitoring mangrove expansion and its likely drivers; and 3) working with local communities to better understand conflicting socio-ecological values of expanding mangrove forests. • New Zealand’s mangroves are expanding due to climate and human enablers • Auckland's annual mangrove carbon sequestration increased fivefold from 1940 to 2020 • Mangroves colonising muddy, high-sediment areas sequester the most carbon • Expanding mangroves can have rapid carbon accumulation at 212 g C m -2 yr -1 • Mangrove arrival may lower coastal aesthetic value but increases climatic benefits

Spatiotemporal dynamics of multi-kingdom microbiome interactions drive CNPS cycling in landfills.

"Environmental Policy, Digitalization, and Low-Carbon Development in China"The following ten scientific articles have provided robust, data-driven insights into how China can achieve its "dual carbon" goals (carbon peak and neutrality).They highlight that:• Digital infrastructure, green innovation, and policy experimentation are critical drivers.• Policies must be regionally differentiated and technology-driven.• Effective climate action depends on multi-level coordination, integrating local, regional, and national strategies. In summary, these studies suggest that China's environmental transition must be smart, digital, inclusive, and tailored to local contexts, leveraging both market-based tools and technological advancement to build a sustainable future.Specifically, the papers in this Research Topic can be clustered as follows:The study by Qian et al. (2025) examines the impact of China's "Zero-Waste City" pilot policy on corporate green transformation. Using double machine learning methods on firm-level data (2016)(2017)(2018)(2019)(2020)(2021)(2022)(2023), they find that the policy significantly accelerates corporate environmental upgrading. This happens through three main channels: (1) increased green technology innovation; (2) stronger government oversight; and (3) growing investor environmental awareness. Notably, the policy impact is stronger for non-state-owned firms, non-heavypolluting sectors, and traditional industries, providing valuable evidence for targeted environmental policy effectiveness.Digital transformation plays a central role in environmental governance, as highlighted in multiple studies.Hu & Song (2025) show that greater government digital attention at the city level helps reduce carbon emissions. This is achieved by improving public low-carbon awareness, enhancing governance capacity, and encouraging corporate low-carbon transitions. The effect is stronger in eastern China and in cities with more developed markets.Li & Diao (2025) focus on digital infrastructure, showing that it supports simultaneous reductions in pollution and carbon emissions, with a significant synergistic effect. It facilitates labor, capital, and innovation flows across cities. A nonlinear U-shaped relationship was found, suggesting that digital infrastructure must be optimized to maximize environmental gains.• Sun et al. (2024) analyze how the digital economy influences urban carbon emissions. The effect is nonlinear: initially, digital development increases emissions, but once a certain threshold is crossed, it facilitates technological innovation, which offsets those emissions. Thus, green tech R&D is key to aligning digital growth with climate goals.Land use and demographic changes significantly affect carbon outcomes.• Zhang et al. (2025) examine land use carbon emissions (LUCE) in shrinking counties in the Beijing-Tianjin-Hebei (BTH) region. They find that although shrinking areas emit less overall, their emissions grow faster, mainly due to inefficient urban land expansion. Severe shrinkage areas have the fastest per capita emission growth, stressing the need for differentiated carbon control strategies in shrinking urban regions.• Gao et al. (2024) focus on county-level emissions in the Guanzhong region of Shaanxi. Industrial and residential sectors are the largest contributors. The spatial pattern shows a core-edge structure, with urban centers emitting more, while rural areas (like Qinling National Park) have significant carbon sink potential. This highlights the importance of localized strategies for rural low-carbon development.

Soil organic carbon (SOC) is vital for ecosystem health, improving soil quality, enhancing productivity, and acting as a significant carbon sink for climate change mitigation. Understanding the distribution of SOC across various land uses is essential for developing effective land management strategies that enhance soil health and carbon sequestration. This study aimed to evaluate the sensitivity of SOC fractions, including readily oxidizable carbon, total organic carbon (TOC), carbon stocks, and carbon management index (CMI), across different land use systems (LUSs) in Tripura, India. Soil samples were collected from horticultural and agricultural LUSs (oil palm, litchi, citrus, guava, rubber, ginger, rice–fallow, vegetable cowpea–rice–maize, vegetable cowpea–rice–lentil, vegetable cowpea–rice–mustard, and uncultivated), at five soil depths: 0–15, 15–30, 30–60, 60–75, and 75–100 cm. The samples were analyzed for various physical and chemical properties, SOC fractions, carbon stock, and CMI to assess the role of LUSs in managing soil carbon content. Significant differences were observed in SOC fractions, carbon stock, and CMI across the LUSs. Litchi LUSs exhibited the highest organic carbon content (16.6 g kg−1) and TOC (22.2 g kg−1) at 0–15 cm, while uncultivated land recorded the lowest values. SOC fractions showed a significant decrease with increasing soil depth from 0 to 100 cm. Litchi orchards had the highest average SOC stock (41.2 Mg ha−1) and readily oxidizable carbon (1.72 g kg−1), followed by rubber and oil palm. Rubber showed the highest lability index, followed by litchi and oil palm with values of 1.47, 1.41 and 1.39, respectively. Litchi and rubber exhibited the highest carbon pool index values, indicating substantial carbon retention. Furthermore, litchi, rubber, and oil palm exhibited significantly higher CMI values, with 245, 238, and 222, respectively. The study emphasizes the significant role of different LUSs, particularly horticultural land use, in enhancing SOC fractions and carbon sequestration. The findings suggest that integrating such LUSs, like litchi and rubber, can contribute significantly to improving soil quality and implementing effective climate change mitigation strategies.

Winter climate change is outpacing our conceptual understanding of how winter conditions regulate soil biogeochemical cycling and ultimately impact vital ecosystem services like soil carbon and nutrient retention. In seasonally snow-covered ecosystems like northern temperate forests, increasingly inconsistent winters lead to less precipitation falling as snow, frequent midwinter snow melting, and the loss of a stable, insulative snowpack. These changes leave soils vulnerable to freezing, freeze/thaw cycling, and increasing dry/wet cycles from added snowmelt and rainwater. To uncover how these new winter soil climate conditions alter soil biogeochemistry, we introduce the DeFR❆ST (Determining Forest Responses to Snowmelt Treatments) experiment, a novel approach where we melt snow insitu throughout the winter and monitor changes to soil climate, gas exchange, and biogeochemical cycling. We installed DeFR❆ST in a New England temperate forest, an ecosystem that is part of the most significant global carbon sink and is also in the epicenter of winter climate change in the US. Experimental snow melting drove soil moisture fluctuations in addition to deep and persistent soil freezing. In turn, soils in melted plots exhibited blocked gas diffusion and lower soil oxygen availability. Oxygen limitation may have driven shifts in soil processes from high redox potential metabolisms like aerobic decomposition and nutrient mineralization towards low redox potential metabolisms like iron reduction and the dissolution of iron and carbon from organo-mineral associations. As these changes snowball, altered soil properties and shifts in soil microbial community structure and function could reshape forest biogeochemical cycling, both in these forests and more broadly across seasonally snow-covered ecosystems.

Abstract Seagrass meadows are a significant global carbon sink. Most of the carbon sequestered in these ecosystems is found as sedimentary organic carbon, which can vary spatially across seagrass meadows and can be derived from a variety of sources. Here, we investigate intra‐ and inter‐meadow spatial variability in sediment organic carbon storage and quantify potential organic matter sources in three Zostera marina seagrass meadows spanning three estuaries across California (USA). Seagrass sediment organic carbon storage varies as much intra‐meadow as it varies across regions. At the intra‐meadow scale we find significant correlations between organic carbon content and mud content (fraction of sediment grains &lt;63 μm, %), C/N ratios and δ13C values in surface sediments across two meadows. At the regional scale greater organic carbon storage in the presence of seagrass compared to adjacent unvegetated sediments. Additionally, we find that mud content is the best predictor of sediment organic carbon content at the regional scale, indicating an enhanced role for mineral interaction in organic carbon preservation, but not consistently at the localized meadow scale. Approximately one fourth of organic carbon preserved in seagrass sediments is derived from seagrass. This research provides insights into the variability of organic carbon storage in seagrass meadows in California at multiple spatial scales. We demonstrate the need to account for small‐scale variation of organic carbon storage in seagrass meadows to better estimate the capacity for these ecosystems to serve as effective long‐term carbon sinks.

The agriculture sector encounters the dual challenge of ensuring food security for the growing world population while mitigating its significant contribution to greenhouse gas (GHG) emissions. Regenerative agriculture offers a system-wide approach intended to address this predicament by transforming farming from a carbon source to a significant carbon sink. Regenerative agriculture (RA) can be a promising strategy that focuses on replenishing soil health, structure, and biodiversity lost to degradation, mainly through practices that augment carbon sequestration. In this review, the current understanding of agriculture's contribution to climate change, the principles and practices of RA, and its potential for mitigation are integrated from various literature sources. The essence of regenerative agriculture is the enhancement of soil organic carbon (SOC) through practices that reinforce natural carbon capture and storage mechanisms. The major principles include reducing soil disturbance, maximizing crop diversity, sustaining living roots in the soil, covering the soil throughout the year, and integrating livestock. These practices aid in preserving soil structure (reduces carbon flux), continuous carbon capture through photosynthesis and provisioning of organic matter to the soil web. In addition, this review analyses methodologies for the natural fixation and long-term carbon sequestration. These includes the application of biochar, a soil amendment which helps in reduction of nitrous oxide emissions, cultivation of soil microbial communities (nitrogen fixing bacteria in root nodules of legumes – energy consuming utilizing more carbon from the plants) and promoting arbuscular mycorrhizal fungi (AMF) which improves binding of soil aggregates (ensuring long-term storage). In addition, this review also examines the scope of emerging scientific interventions in regenerative agriculture such as data-driven precision regenerative agriculture, remote sensing, use of sensors and monitoring, using robotics and automation, all which enables farmers in decision making, reducing reliance in manual labor, as well as identifying areas of concern, and optimize management practices. Incorporating practices like no-till farming, cover cropping and rotational grazing, regenerative agriculture offers a scientifically sound pathway to reduce agricultural emissions, regenerate soil health and actively sequester atmospheric carbon. These methods position it as a crucial solution in the global effort against climate change.