Carbon Sequestration Potential Research Articles

Assessment of Ecosystem Characteristics and Fishery Carbon Sink Potential of Qianxiahu Reservoir Based on Trophic Level and Carbon Content Methods

Optimizing biological carbon sequestration has become a primary strategy in global low-carbon-emission initiatives. Freshwater fisheries in reservoirs play an important role in aquatic biological carbon sequestration. However, a standard method for evaluating the carbon sink capacity of inland fisheries has not been developed. Therefore, this study aimed to assess and compare the carbon sequestration potential of the Qianxiahu Reservoir’s fisheries using the trophic level and mass-balance methodologies. The Ecopath model was employed to determine the trophic levels of aquatic organisms within the Qianxiahu Reservoir ecosystem, with input parameters sourced from in situ surveys and the literature on reservoirs. The model includes 21 functional groups, with trophic levels ranging from 1.000 to 3.281. The key species identified are silver carp, bighead carp, and crucian carp. The indices of Finn’s cycling index (FCI), connectivity index (CI), system omnivory index (SOI), and total primary production/total respiration (TPP/TR) for the Qianxiahu Reservoir are 11.35, 0.27, 0.196, and 1.540, respectively. These values indicate a high degree of material recycling and complex interconnections among functional groups. The fishery carbon sink potential of the Qianxiahu Reservoir, calculated using the trophic level and carbon content methods, yielded values of 261.8362 tons/km2 and 66.6818 tons/km2, respectively. The trophic level method showed a notable increase of 195,1544 tons/km2 compared to the carbon content method, underscoring significant differences in results between the two methods. The study concludes with recommendations for research on methods to assess the carbon sink capacity of freshwater fisheries, aiming to establish a scientific framework for this evaluation.

Potential Distribution and Carbon Sequestration of Rhizophora mangle L. in El Vizcaíno Biosphere Reserve, Baja California Sur, Mexico

Mangroves are a type of vegetation distributed in warm areas of the planet. Despite their importance, this flora is seriously threatened by both human activities and climate change. One of the main benefits provided by mangroves is carbon capture and storage, which is key for climate change mitigation. The main objective of this study was to identify the potential distribution and carbon sequestration potential of Rhizophora mangle L. in El Vizcaíno Biosphere Reserve. Potential distribution models were obtained for Baja California Sur, Mexico, using the MaxLike algorithm. For each projection, we used bioclimatic variables from the WorldClim project for current and future conditions (2050 and 2070), two Shared Socioeconomic Pathways (SSP2-4.5 and SSP5-8.5) and three General Circulation Models (ACCESS-CM2, EC-Earth3-Veg and MPI-ESM1-2-HR). The potential distribution models were developed within the perimeter of El Vizcaíno Biosphere Reserve as a case study to establish the potential for carbon sequestration under different climate change scenarios. Our results show a possible future carbon sequestration from 10,177,174 Mg of CO2 and up to 14,022,367 Mg of CO2 for the ACCESS-CM2 SSP5-8.5 to 2070 and MPI-ESM1-2-HR SSP2-4.5 to 2070 projections, respectively. Mangrove species such as Rhizophora mangle can be an important part of climate change mitigation and adaptation.

Future Scenarios of Forest Carbon Sink in a Typical Subtropical County

In the context of achieving global carbon neutrality, forests play a pivotal role in sequestering atmospheric CO2, particularly in China, where forest management is central to national climate strategies. This study evaluates the forest carbon sink capacity in Zixi County, a subtropical region, under varying climate scenarios (SSP2-4.5 and SSP5-8.5). Using the Forest-DNDC (Denitrification–Decomposition) model, combined with high-precision climate data and a random forest model, we simulate forest carbon density and forest carbon sink under different management strategies. The results indicate that under the baseline scenario, forest carbon density in Zixi County increases by 31% over 42 years under the SSP2-4.5 climate scenario and by 28.6% under SSP5-8.5. In the enhancing economic scenario, carbon density increases by 8.5% under SSP2-4.5 and by 7.2% under SSP5-8.5. For the natural development scenario, a significant increase of 130% is observed under SSP2-4.5, while SSP5-8.5 shows an increase of 120%. Spatially, forest carbon sinks in Zixi County total 843,152 T C in 2020, 542,852 T C in 2030, and 877,802 T C in 2060 under the baseline SSP2-4.5 scenario; under SSP5-8.5, these values are 841,321 T C in 2020, 531,301 T C in 2030, and 1,016,402 T C in 2060. In the enhancing economic scenario, the total carbon sink is 34,650 T C in both 2020 and 2030, increasing to 427,351 T C in 2060 under SSP2-4.5, while under SSP5-8.5, it is 46,200 T C in 2020, 34,650 T C in 2030, and 415,801 T C in 2060. The natural development scenario shows the total carbon sink under SSP2-4.5 as 11,157,332 T C in 2020, 3,441,910 T C in 2030, and 1,409,104 T C in 2060, and under SSP5-8.5, it is 10,903,231 T C in 2020, 3,337,960 T C in 2030, and 1,131,903 T C in 2060. Spatial analysis reveals that elevation and forest type significantly affect carbon density, with high-altitude areas and forests dominated by Chinese fir and broadleaf species showing higher carbon accumulation. The findings highlight the importance of targeted forest management, prioritizing species with higher carbon sequestration potential and considering spatial heterogeneity. These strategies, applied locally, can contribute to broader national and global carbon neutrality efforts.

Soil carbon sequestration potential of different land use systems: evidence from sub-humid southern plains and Aravalli hills of Rajasthan, India.

This study has assessed total soil organic carbon (TOC) fractions, carbon management index (CMI), and carbon sequestration economic value under diverse land use systems (LUSs) of sub-humid Southern plains of Rajasthan, India. The study dealt with six LUSs: barren land (BL), agricultural land (AL), agri-horticulture (AH), horticultural land (HL), grassland (GL), and natural forest land (FL) were selected for the study. FL contained the highest TOC (13.04 ± 0.74gkg-1), particulate organic carbon (POC) (2.2 ± 0.19gkg-1), mineral-associated organic carbon (MAC) (10.84 ± 0.54gkg-1), and CMI (230.36 ± 4.13), whereas BL had the lowest amount of TOC (3.53 ± 0.4gkg-1), POC (0.47 ± 0.06gkg-1), MAC (3.06 ± 0.32gkg-1), and CMI (54.60 ± 4.2). The impact of LUSs on soil carbon lability index (LI) was minimal in all LUSs except FL exhibited statistically insignificant variations in LI. TOC stock showed the highest decline in BL (71.04%), AL (55.29%), AH (44.38%), and HL (25.92%) uses compared with the FL system. Different LUSs result in varying amounts of carbon stocks, representing the relative carbon credit gain. The maximum carbon credit was achieved by FL, which was roughly US $49,303 and 245% higher than BL. These results indicate the reinstatement of BL and AL towards HL and AH systems, and effective recycling of residues could improve the TOC storage in the study region.

The restoration of karst rocky desertification has enhanced the carbon sequestration capacity of the ecosystem in southern China

The control of rocky desertification is the largest ecological restoration project in southwestern China, but its impact on the carbon sequestration capacity of karst ecosystems is not clear. Therefore, in this paper selects typical subtropical karst areas in Guangxi are selected as the research object, the carbon sequestration potential of the terrestrial ecosystems are quantified, including karst inorganic carbon sinks, and the response of the terrestrial ecosystem carbon sink to rocky desertification restorationis discussed. The results show that (1) the karst inorganic carbon sink flux (CCSF) is 42.75 t CO2/km2/yr, with a total CCS of 491.12 × 104 t CO2, accounting for only 2.5 % of the country's land area and contributing 7.6 % of the karst inorganic carbon sink. (2) The flux of the vegetation organic carbon sink is 380.44 t CO2/km2/yr, and the total amount is 4403.55 × 104 t CO2/yr., Overall, the spatial distribution exhibits a pattern of high in the northwest and low in the northeast. (3) With decreasing rocky desertification area, the magnitude of the terrestrial ecosystem carbon sink has exhibited a corresponding increasing trend. In particular, during 2010–2020, the rocky desertification area decreased by about 0.868 × 104 km2, and the terrestrial ecosystem carbon sink increased by 114.04 t CO2/km2/yr. This article provides a systematic spatial diagnosis of the carbon sequestration potential of terrestrial ecosystems, including karst inorganic carbon sinks, in the karst areas of Guangxi, and reveals their responses to the restoration of karst rocky desertification. This work has strong reference value and significance for the diagnosis and analysis of the carbon neutrality capacity at the national and global levels.

Modelling the Effects of Forest use Change on Brownification of Finnish Rivers under Atmospheric Pressure.

Browning of surface waters due to increased terrestrial loading of dissolved organic matter (DOM) is observed across the Northern Hemisphere. The effects influence several ecosystem services from freshwater productivity to water purification. Brownification is often explained by changes in large-scale anthropogenic pressures and ecosystem functioning (acidification, climate change, and land cover changes). This study examined the effect of forest use changes on water browning in Finland, considering the effects of global pressures. Our goal was to find the ecosystems and geographic areas that are most sensitive to environmental pressures that increase the loading of DOM. We were also looking for land use strategies that decrease browning. We combined mathematical watershed modelling to scenarios of climate change, atmospheric deposition, and forest use change. Changes included scenarios of forest harvest and protection on forest, that were derived from European Union's regulation. The study area covered 20 watersheds from south to north of Finland. In northern Finland brownification continue. In southern Finland global influence (atmospheric deposition, climate change) seem to weaken, giving more space for local forest use change having an influence on brownification. Forest use change was more influential in river basins dominated by organic soils than in mineral soils. Extending forest protection decreased brownification especially in areas where the influence of atmospheric pressure is decreasing. When forest protection is planned to provide a carbon storage and sequestration potential and to favor biodiversity, it has favorable effect on surface water quality as well.

Evaluation of Carbon Sequestration and Oxygen-Release Potential of Six Mulberry Tree Varieties During Summer

Human activities lead to an increase in greenhouse gases in the environment, among which carbon dioxide (CO2) is one of the most prominent, giving rise to global warming and climate change. Climate change, along with the resulting environmental degradation, is one of the most challenging difficulties faced by humanity in the twenty-first century. The forest ecosystem, with plants being its most important component, plays a pivotal role in regulating climate. Carbon sequestration and oxygen release (CSOR) by plants are major ecological service functions that play an important role in mitigating the negative impacts of the greenhouse effect and help to achieve carbon peaking and neutrality. The CSOR of mulberry (Morus spp.), a species of economic and ecological significance, is not yet understood. Six mulberry tree varieties were selected to evaluate their CSOR potential during summer. We took into consideration whole-plant diurnal assimilation amounts (P), carbon sequestration per unit leaf area (WCO2), oxygen release per unit leaf area (WO2), carbon sequestration per unit land area (PCO2), and oxygen release per unit land area (PO2). Zhongsang 1302 showed the greatest potential for CSOR among the six mulberry varieties. The PCO2 value of the Zhongsang 1302 variety was 1531.84 g·m−2 during summer, followed by Suhu 16 (1380.12 g·m−2), Husang 32 (1005.63 g·m−2), Zhongsang 9703 (990.01 g·m−2), Yu 711 (940.43 g·m−2), and Jin 10 (848.29 g·m−2). Moreover, the Pearson correlation and path analyses showed that photosynthetic rate (PN) and leaf area index (LAI) mainly affect the overall CSOR potential in mulberry. These findings not only enrich theoretical research on CSOR in mulberry, but also serve as an important reference for the use of different mulberry tree varieties in improving climate conditions and achieving carbon peaking and neutrality.

Soil-Based Emissions and Context-Specific Climate Change Planning to Support the United Nations (UN) Sustainable Development Goal (SDG) on Climate Action: A Case Study of Georgia (USA)

Soil-based emissions from land conversions are often overlooked in climate planning. The objectives of this study were to use quantitative data on soil-based greenhouse gas (GHG) emissions for the state of Georgia (GA) (USA) to examine context-specific (temporal, biophysical, economic, and social) climate planning and legal options to deal with these emissions. Currently, 30% of the land in GA has experienced anthropogenic land degradation (LD) primarily due to agriculture (64%). All seven soil orders were subject to various degrees of anthropogenic LD. Increases in overall LD between 2001 and 2021 indicate a lack of land degradation neutrality (LDN) in GA. Besides agricultural LD, there was also LD caused by increased development through urbanization, with 15,197.1 km2 developed, causing midpoint losses of 1.2 × 1011 kg of total soil carbon (TSC) with a corresponding midpoint social cost from carbon dioxide (CO2) emissions (SC-CO2) of USD $20.4B (where B = billion = 109, $ = U.S. dollars (USD)). Most developments occurred in the Metro Atlanta and Coastal Economic Development Regions, which indicates reverse climate change adaptation (RCCA). Soil consumption from developments is an important issue because it limits future soil or forest carbon (C) sequestration potential in these areas. Soil-based emissions should be included in GA’s carbon footprint. Understanding the geospatial and temporal context of land conversion decisions, as well as the social and economic costs, could be used to create incentives for land management that limit soil-based GHG emissions in a local context with implications for relevant United Nations (UN) initiatives.

Analysis of Spatiotemporal Predictions and Drivers of Carbon Storage in the Pearl River Delta Urban Agglomeration via the PLUS-InVEST-GeoDetector Model

Land use and land cover change (LUCC) significantly influences the dynamics of carbon storage in thin terrestrial ecosystems. Investigating the interplay between land use alterations and carbon sequestration is crucial for refining regional land use configurations, sustaining the regional carbon balance, and augmenting regional carbon storage. Using land use data from the Pearl River Delta Urban Agglomeration (PRDUA) from 2010 to 2020, this study employed PLUS-InVEST models to analyze the spatiotemporal dynamics of land use and carbon storage. Projections for the years 2030, 2040, and 2050 were performed under three distinct developmental scenarios, namely, natural development (ND), city priority development (CPD), and ecological protection development (EPD), to forecast changes in land use and carbon storage. The geographic detector model was leveraged to dissect the determinants of the spatial and temporal variability of carbon storage, offering pertinent recommendations. The results showed that (1) during 2010–2020, the carbon storage in the PRDUA showed a decreasing trend, with a total decrease of 9.52 × 106 Mg, and the spatial distribution of carbon density in the urban agglomeration was imbalanced and showed an overall trend in increasing from the center to the periphery. (2) Clear differences in carbon storage were observed among the three development scenarios of the PRDUA between 2030 and 2050. Only the EPD scenario achieved an increase in carbon storage of 1.10 × 106 Mg, and it was the scenario with the greatest potential for carbon sequestration. (3) Among the drivers of the evolution of spatial land use patterns, population, the normalized difference vegetation index (NDVI), and distance to the railway had the greatest influence on LUCC. (4) The annual average temperature, annual average rainfall, and GDP exerted a significant influence on the spatiotemporal dynamics of carbon storage in the PRDUA, and the interactions between the 15 drivers and changes in carbon storage predominantly manifested as nonlinear and double-factor enhancements. The results provide a theoretical basis for future spatial planning and achieving carbon neutrality in the PRDUA.

The conversion of biomass to biochar decreases soil organic and inorganic carbon-derived CO2 emissions under different water conditions in karst regions

Due to the unique geological background and climatic condition, karst soils in southwest China are mainly developed on carbonate rocks and accompanied by frequent dry-wet alternations. Therefore, the effects of biomass (BS) and biochar (BC) on the soil carbon pools (especially inorganic carbon) in karst regions are different from those in non-karst regions. In order to understand the responses of soil organic carbon (SOC) and soil inorganic carbon (SIC)-derived CO2 emissions to BS and BC amendments under different water conditions in karst regions, a microscopic study under dry-wet alternate (DW) and constant moisture (CM) conditions was established to investigate the stability of BC, BS, and their effects on SOC and SIC pools by isotope double-labeling methods. Results showed that the contribution rates of SOC and SIC to soil CO2 emissions were 51.55 %–99.52 %, 0.48 %–48.45 % and 60.55 %–97.72 %, 2.28 %–39.45 % under DW and CM conditions, respectively. Compared with the control, BS application under different water conditions increased SOC and SIC-derived CO2 emissions by 929.78˗1443.39 % and 169.69˗335.71 %, respectively. However, BC amendment significantly decreased SOC and SIC-derived CO2 emissions, especially in the DW condition. The mean residence time (the inverse of the decomposition rate) of BC in karst soils under different conditions ranged from 657 to 3105 years, which was much higher than those of BS (7˗18 years). Therefore, the conversion of BS to BC in karst regions enhances carbon sequestration due to its stability of recalcitrant carbon, the decrease of SOC and SIC- derived CO2 emissions. This study is helpful to understand the quantification of CO2 sources from calcareous soils and elucidate the environmental behaviors and carbon sequestration potentials of BC or BS amendments in karst regions.

Enhancing highland ecosystems in East Hararge, Ethiopia: evaluating intervention strategies for species diversity, soil organic carbon stock, and carbon sequestration

Forest loss and soil degradation pose significant challenges globally, particularly in developing nations like Ethiopia. Various intervention strategies have been implemented to rehabilitate degraded ecosystems. However, research gaps exist in understanding the most effective approaches, particularly in highland ecosystems. This study aimed to evaluate the effectiveness of different intervention strategies on species diversity and carbon stock in the West Hararghe zone, specifically at the Doba district Hades site. The data was collected from 5 February 2022 to 10 December 2022. The study area was characterized by systematic plots and transects to assess vegetation diversity and soil properties across four intervention categories: (physical; only soil and water conservation structures were used, enclosure; only animal and human interaction was restricted, biological; only different tree species were planted, biophysical; both soil water conservation and tree planting were used). Soil samples were collected at different depths, and biomass estimation was conducted using established formulas. Statistical analyses, including one-way ANOVA and post-hoc tests, were performed to test the level of significance. Biophysical interventions exhibited the highest species diversity index (SDI) (4.65 ± 1.21), followed by enclosure interventions (1.68 ± 0.58), while physical interventions recorded the lowest SDI (0.63 ± 0.18). Enclosure interventions led to the highest soil organic carbon (SOC) stocks at 40.13 t C ha−1, followed by biophysical interventions at 39.26 t C ha−1. Physical interventions resulted in the lowest SOC stocks at 23.9 t C ha−1, underscoring their potential for carbon sequestration. Biophysical interventions, which include both above-ground and below-ground biomass, showed significant carbon stock accumulation, totaling 173.8 t C ha−1 (39.26 t C ha−1 from SOC and 114.6 t C ha−1 from biomass), highlighting their effectiveness in enhancing ecosystem resilience. Other studies support these findings, underscoring the importance of context-specific approaches and long-term monitoring for sustainable land management. Enclosure and biophysical interventions emerge as promising strategies for enhancing species diversity and soil health, as well as promoting carbon sequestration in highland ecosystems. These findings emphasize the need for informed decision-making and community involvement in ecosystem restoration efforts to achieve meaningful and lasting impacts.

Variability in soil organic carbon pools in different land use systems in the north-eastern region of India

The current study was carried out during 2020 to 2022, at Horticulture Research Centre (HRC), Nagicherra, Agartala, Tripura to assess and compare the effects of various land use systems, including bamboo, tea, mango, lemon, rice-rice, wheat-millet, okra-onion and uncultivated soils, on soil organic carbon (SOC) dynamics. SOC is a critical component of terrestrial ecosystems, influencing soil health, fertility and carbon sequestration potential. The NEH region of India, Tripura characterized by its diverse agro-ecological zones and land use systems (LUS), presents a unique opportunity to investigate the various land use regimes' effects on SOC pools. Walkley and Black carbon (WBC) significantly vary among the selected LUS, ranging from 7.14–12.48 g/kg, with the maximum values in tea LUS. In 0–30 cm depth, very labile C (CVL) pools are very variable among the selected LUS (2.04–5.35 g/kg), which is the highest in tea and mango compared to the uncultivated system. The C pools in selected LUS indicated the deviation depth and land use pattern. Lability index (LI) varies from 1.50–1.63 and 1.40–1.74 in 0–30 cm and 30–60 cm depth, respectively. Carbon pool index (CPI) assessed highest in tea LUS, 1.78 and 2.1 from 0–30 and 30–60 cm, respectively. Carbon management index (CMI) was higher in selected LUS compared to uncultivated system.

Soil organic carbon and total nitrogen stocks related to land use and basic environmental properties − assessment of soil carbon sequestration potential in different ecosystems

Soil organic carbon (SOC) and total nitrogen (TN) stocks are crucial for the development of wild plants and crops. This paper examines the current SOC and TN stocks and their variability within land uses under different environments, assessing the relationships between SOC and TN stocks with basic environmental properties and quantifying the magnitude of SOC sequestration potential for a better land use management. We studied 991 soil profiles, from steppe to wet mountain-soils. The land use was essential in influencing soil organic C and total N stocking, with the forestland showing the significantly highest SOC stocks specifically in mountain soils, followed by grassland and cropland. Altitude, clay content, pH and plant available phosphorous and potassium were other influencers of SOC and TN stocks. The best predictive multiple linear regression model explained 68 % of the 0.5 m depth SOC stock variability for forest, 61 % for grassland and 37 % for cropland, while Random Forest model explained 70 %, 65 %, and 28 % for the same land uses. The obtained models rank factors contribution and may be useful in management. Lands having the highest C sequestration potential occurred within fine-textured soils, mainly in croplands. The most favorable soil depth for further C sequestration is below C-saturated topsoil and this could be achieved by deep-rooting crops and conservative technologies. Additionally, changing some low-fertile soils of cropland into forestland or grassland would improve SOC sequestration. These measures might contribute to sequester additional C amounts in soils, in order to bolster initiatives for climate-change mitigation and adaptation.

Geoinformatics and Modeling Approaches for Estimating Above-Ground Biomass in the Moist Deciduous Forests of Uttara Kannada, Karnataka, India

The present study aims to estimate Above-Ground Biomass (AGB) in the moist deciduous forests of Mundgod Taluk, Uttara Kannada district, Karnataka, India using a combination of field sampling and remote sensing techniques. AGB was assessed using Sentinel-2A satellite imagery with a spatial resolution of 10 meters. Field data were collected using the Point-Centered Quarter (PCQ) method, it includes measuring tree girth at breast height (GBH), tree height, and canopy density. AGB was calculated using artificial form factor and specific gravity of tree species and further modelled using the Normalized Difference Vegetation Index (NDVI) derived from satellite data. The results showed a significant correlation between canopy density and biomass, with very dense forests exhibiting the highest AGB values. The field-measured AGB was 436.96 t/ha for very dense forests, 259.89 t/ha for moderately dense forests, and 161.67 t/ha for open forests. A linear regression model developed between AGB and NDVI showed a high R² value of 0.91 for open forests, 0.87 for moderately dense forests, and 0.85 for very dense forests. The total area-weighted biomass for the study area was estimated at 8.87 million tons, with 4.79 million tons in very dense forests, 3.44 million tons in moderately dense forests, and 0.76 million tons in open forests. The regression model validation indicated low Root Mean Square Error (RMSE) values, with the moderately dense forests 8.81 t/ha and the in very dense forests 7.54 t/ha. This study highlights the effectiveness of integrating field measurements with remote sensing for rapid, reliable AGB estimation. The approach offers valuable insights into biomass distribution and carbon sequestration potential, providing a scalable method for carbon inventories at state and national levels, contributing to forest management and climate change mitigation efforts.

Estimation, Spatiotemporal Dynamics, and Driving Factors of Grassland Biomass Carbon Storage Based on Machine Learning Methods: A Case Study of the Hulunbuir Grassland

Precisely estimating the grassland biomass carbon storage is vital for evaluating grassland carbon sequestration potential and the monitoring and management of grassland resources. With the increasing intensity of climate change (CC) and human activities (HA), it is necessary to explore spatiotemporal variations in biomass carbon storage and its response to CC and HA. In this study, we focused on the Hulunbuir Grassland, utilizing sample plots data, MODIS data, environmental factors (terrain, soil, and climate), location factor, and texture characteristics to assess the performance of four machine learning algorithms: random forest, support vector machine, gradient boosting decision tree, and extreme gradient boosting in estimating grassland aboveground biomass (AGB). Based on the optimal model combined with root-shoot ratio data, grassland distribution data, and carbon content coefficients, the spatiotemporal characteristics and driving factors of biomass carbon storage from 2001–2022 were analyzed. The results showed that (1) the random forest achieved the highest prediction accuracy for grassland AGB, making it appropriate for AGB estimation in the Hulunbuir Grassland. (2) The spectral indices were the key variables of the grassland AGB, especially the enhanced vegetation index and difference vegetation index. (3) The 22-year average total biomass (TB) of the study area was 1037.10 gC/m2, of which the 22-year average AGB was 48.73 gC/m2 and 22-year average belowground biomass was 988.37 gC/m2, showing a spatial distribution feature of gradual increase from west to east. (4) From 2001–2022, TB carbon storage showed an insignificant growth trend (p > 0.05). The 22-year average carbon storage of TB was 72.34 ± 18.07 gC. (5) Climate factors were the main driving factors for the spatial pattern of grassland TB carbon density, while the combined effects of CC and HA were the main contributors to the interannual increase in grassland TB carbon density.

Calculating carbon: The value of information in precision for blue carbon restoration projects

Coastal wetland restoration projects can receive payments for ecosystem services but often occur in regions with limited data, and additional data collection can be financially prohibitive. Value of Information analysis can quantify the difference between the expected value of an action before and after new information has been collected, aiming to understand how much data is required to make decisions that balance the costs of implementation versus the benefits of the project. The Australian carbon market provides a method that uses reintroduction of tidal flows to restore coastal wetland ecosystems for their carbon sequestration functions. The method requires a hydrological assessment of prospective sites, which is employed to estimate carbon sequestration potential. This research investigates how different amounts of data collection and different levels of complexity in the hydrological assessment influence the carbon abatement emissions estimated using the method. The results indicate that tidal restoration for blue carbon credits on grazing land may not be financially viable. We found that tidal data collected onsite were important for decision-making while complex hydrological models have low value compared to more simplistic approaches. While investing in data collection provides more value than increasing the complexity of modelling approaches, the value of information was still low. Additionally, restoration of coastal wetlands is unlikely to be financially attractive at current carbon prices, and the land would have to be unsuitable for cattle to become profitable for restoration. This work provides a framework for evaluating the financial benefit of collecting on-site data and using robust methods for estimating inundation, that can be used to guide decision-making to achieve optimal income.

Triple impact: Biochar, no-tillage, and cover crops for soil carbon enhancement and climate resilience in soybean farming

With the dissemination of conservation agriculture, no-tillage (NT) and cover crops have widely been adopted globally. However, their effects on greenhouse gas (GHG) emissions are controversial. Biochar is posited to mitigate climate change by increasing carbon (C) sequestration and decreasing GHG emission in soil. To investigate the comprehensive effect of NT, cover crops, and biochar on soil organic carbon (SOC) sequestration and net global warming potential (GWP), a split-split-plot experiment was conducted. The experiment involved various combinations of two tillage methods (NT; Moldboard plowing, MP), two cover crop treatments (Fallow, FA; Rye, RY), and two biochar treatments (with biochar application, WB; no biochar application, NB). NT and RY demonstrated a trend of increasing N2O emission, while WB tended to reduce the N2O emission in NT plots. NT–RY–WB increased the SOC stock (0–30 cm) by 23.2% in 2020 and 30.2% in 2021 compared with MP–FA–NB, indicating that this combination promoted C sequestration. Due to the heightened SOC stock, the net carbon dioxide (CO2) retention effectively compensated the GWP arising from non-CO2 emissions. Consequently, the triple combination of NT, RY and WB positively contributed to a decreased net GWP in the soybean field (−1231 kg CO2 equivalent ha−1 year−1 in 2020 and −2767 kg CO2 equivalent ha−1 year−1 in 2021). These findings highlight the considerable potential of the combined NT–RY–WB for SOC sequestration and net GWP decrease, positioning it as an environmentally beneficial agricultural system for mitigating climate change in Asia’s long-term food production.

Seaweed sinking has great potential for climate mitigation in China

With the intensification of the greenhouse effect, the climate-mitigation role of marine carbon sequestration (blue carbon) is gaining more attention. Seaweed aquaculture, as an important nature-based solution that provides various ecosystem services while as a food source, have become the main way of marine biological carbon sequestration. As an emerging carbon dioxide removal strategy, sinking seaweeds to the deep sea for additional CO2 sequestration to contribute to Paris Agreement temperature goal have attracted much attention. Currently, the ecological value assessment of sinking seaweeds is immature, and there is also a conflict between with traditional food values. However, in the long term, the value of carbon sequestration will continuously rise as global emission reduction advance, and rapidly growing seaweed production will be able to fully satisfy food demand in the future. Therefore, sinking surplus seaweeds to convert excess food value into higher ecological value is more compatible with development prospects, and long-term planning for sinking seaweed is particularly important. As the largest seaweed farming country, China accounted for more than half of the world’s production in 2021, possessing a huge potential for carbon sequestration. Incorporating factors such as food requirements, emission reduction demands and population changes, this paper explored the feasibility and planning of sinking seaweeds to serve the achievement of climate goals under five SSP-RCP scenarios in 2020–2050. The results indicate that with the slowdown in population growth and increasing demand for climate mitigation, the ecological value of seaweeds has more development potential than the edible value, and thus the sunken seaweed task should be placed more in the later period (2041–2050 phase) to maximize the ecological benefits of seaweed farming. Sinking seaweed is able to serve the SSP1-2.6 and SSP2-4.5 scenarios relatively well, while the realization of the SSP1-1.9 scenario presents some challenges.

Timber and carbon sequestration potential of Chinese forests under different forest management scenarios

Developing forestry action plans with the goal of carbon neutrality is a critical task to identify carbon sink potential and balance the pathways of China's forests. Current research that predicts forest biomass carbon stock and sink potential has shortcomings, such as an incomplete assessment of China's forest carbon sink range, assumptions based on unchanged forest area in the base year and insufficient consideration of natural and human disturbance factors. This study utilised the national forest inventory (NFI) data to construct a model of forest growth and consumption using a machine learning algorithm (i.e. random forest), identified suitable areas for future forest expansion by integrating multi-source data, and set up three future forest management scenarios: business as usual (BAU), enhanced policy scenario (EPS) and maximum potential scenario (MPS). In addition, changes in the area, volume stock and biomass carbon stock in China's forests between 2020 and 2060 were predicted under three forestry activities (i.e. existing forest, afforested/reforested (AR) forest and forest conversion) and three climate scenarios (i.e. SSP126, SSP370 and SSP585) based on the 9th NFI (2014–2018). According to China's relevant planning goals and suitable forest space, the area of AR forests is predicted to be 55.55 × 106 hm2 by 2060, and the forest coverage rate is predicted to increase from 23% in 2018 to 28% by 2060. Biomass carbon sequestration (BCS) between 2020 and 2060 in AR forests is predicted to be 36.00 TgC per year. By 2060, the average BCS is predicted to be approximately 140.00–287.56 TgC per year in China's forests, which is mainly owing to arbor forest management. Under the BAU and EPS scenarios, BCS in China's forests is expected to decline from 2020 to 2060. However, under the MPS, BCS in China's forests is projected to increase and be maintained at 322 TgC per year or above by 2060, with wood production reaching 4.71 × 108 m3 per year. China's forests are predicted to experience an increase in biomass carbon stock in the future and play a role as a carbon sink. By taking measures to achieve the maximum growth potential of all forest types, China's forests will achieve a win‒win situation between carbon sinks and timber production.

Relationship Between Evolutionary Diversity and Aboveground Biomass During 150 Years of Natural Vegetation Regeneration in Temperate China.

While the link between plant species diversity and biomass has been well-studied, the impact of evolutionary diversity on community biomass across long timescales or ongoing change remains a subject of debate. We elucidated the association between evolutionary diversity and community aboveground biomass (AGB) using an ideal experimental system with over 150-year history of natural vegetation regeneration. Higher phylogenetic diversity facilitated the sampling effect under the influence of environmental filtering, and caused an increase in AGB. Phylogenetic structure varied from aggregation to dispersion during the later period of vegetation recovery (70-150 years), which was correlated with increases in niche complementarity and increasing AGB. Woody plant evolutionary diversity was used as a key to predict the relationship between vegetation recovery and AGB, with a total explanatory power of ~84.7%. Mixed forests composed of evergreen conifers and deciduous broadleaf forests had higher carbon sequestration potential than that of pure forests, which is advantageous for increasing top-stage AGB. This research expands our knowledge of the causes and effects of biodiversity and ecosystem function dynamics over time and space, which is important for accurately predicting future climate change effects.