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As a key parameter for C pool and flux assessments, vegetation carbon (C) content can be used in ecological models to predict climate-induced changes in the C sequestration capacity of vegetation. However, the differences in methods for upscaling C content from the organ to the community scale and their impact on regional C stock estimates have been ignored. Based on a comprehensive community structure survey of 72 typical natural ecosystems in China and 27,905 measured samples of plant organs (leaves, twigs, trunks, and roots), we first quantified the differences among scaling-up methods for vegetation C content. These methods included the community or dominant species-weighted mean, geometric mean, arithmetic mean, and traditional empirical coefficients (45 % and 50 %), and their impact on C storage estimation at the regional scale. Comparing the accuracy, variability, and response patterns of the different scaling-up methods, the dominant C species biomass-weighted mean (C DWM ) method had the highest similarity to the community-weighted C mean (C CWM ) method. Concerning vegetation C storage estimation in China's natural terrestrial ecosystems, the relative errors of the other methods ranged from -2.6 % to 8.22 % compared with that of the C CWM method (18.39 Pg C). The empirical coefficients had the highest uncertainty, with a 45 % empirical coefficient underestimating the vegetation C stock by 2.60 %, and a 50 % empirical coefficient overestimating it by 8.22 %. The C DWM method proposed here has high reliability for C storage estimation (overestimated by only 0.44 %), making it a preferable sampling and scaling-up method for regional C content and stock assessment. Additionally, our study provided the C content of plant organs for China's provinces and typical vegetation types based on the C CWM , which could be used for regional C stock assessment and C cycle models., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

The rapid increase in carbon and other greenhouse gases is likely to change the regional and global temperature, and planning of these gases is needed. The present study focused on National Highway-16 of the Srikakulam district, which was upgraded from 4 to 6 lane standards to facilitate traffic. This study intended to compute the carbon sequestration and storage capacity of above and belowground biomass. This helps in the comparison and impact of the road project on flora and its carbon pool, from where future tree stock changes can be prepared. A total of 1930 plots were constructed of criss-crosses of equal size (2 × 100 m). All woody trees with dbh ≥ 30 cm were considered and their diameters were measured. A total of 29 tree species belonging to 13 families were identified; the quantity of macrobiotic carbon sequestered as a whole, i.e., above and below ground, was 768,890.29 tC and 199,911.48 tC , respectively. The mean sequestration rate of carbon as biomass above ground was 1.19 tC/tree, and that below ground was 0.31 tC/tree . The estimated average C-Stock per tree was 1.5 tC ; however, the mean C-Stock per quadrate was 250.2 tC ., (© 2024. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Forests, the ancient wooden giants, are both symbols of natural beauty and reservoirs of carbon stocks. The current climate crisis has created an urgent need for an in-depth study of forest ecosystems and carbon stocks. Based on forest inventory data from field surveys and four bioclimatic zones [Zone 1 (Z1, humid forest), Zone 2 (Z2, semi-humid forest), Zone 3 (Z3, semi-humid to semi-arid forest-grassland), and Zone 4 (Z4, semi-arid typical grassland)], two methods [Method 1 (M1) and Method 2 (M2)] were used to estimate carbon stocks in forest ecosystems in Shaanxi Province, China, and explored the spatial patterns of carbon pools and potential influences. The total forest ecosystem carbon pool amounted to 520.80 Tg C, of which 53.60% was stored aboveground, 17.16% belowground, and 29.24% in soil (depth of 0-10 cm). Spatially, there were marked north-south gradients in both biomass (Z2 > Z3 > Z1 > Z4) and soil organic carbon densities (Z1 > Z2 > Z3 > Z4). The differences between aboveground and belowground biomass carbon density across broadleaf, needle-leaf, and broadleaf and needle-leaf mixed forest were not pronounced, while soil organic carbon density had the order of broadleaf (18.38 Mg C/ha) > needle-leaf (11.29 Mg C/ha) > broadleaf and needle-leaf mixed forest (10.33 Mg C/ha). Under an ideal scenario that excludes external factors, mainly forest growth, the sequestration potential of forest biomass by 2032 was estimated by M1 as 85.43 Tg, and by M2 to be substantially higher at 176.21 Tg. As of 2062, M1 estimated 155.97 Tg of sequestration potential for forest biomass. The spatial patterns of forest biomass and soil carbon density were closely related to climatic factors, and these relationships allowed the spatial division into two distinct climatic regions. Moreover, biomass carbon density was significantly correlated with the normalized difference vegetation index, soil silt, and elevation. This study provides key information for promoting the strategic shift from light-green to deep-green forest systems in Shannxi Province and updates the estimation methods of forest ecosystems' carbon pools based on field surveys., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Tropical and subtropical forests play a crucial role in global carbon (C) pools, and their responses to warming can significantly impact C-climate feedback and predictions of future global warming. Despite earth system models projecting reductions in land C storage with warming, the magnitude of this response varies greatly between models, particularly in tropical and subtropical regions. Here, we conducted a field ecosystem-level warming experiment in a subtropical forest in southern China, by translocating mesocosms (ecosystem composed of soils and plants) across 600 m elevation gradients with temperature gradients of 2.1°C (moderate warming), to explore the response of ecosystem C dynamics of the subtropical forest to continuous 6-year warming. Compared with the control, the ecosystem C stock decreased by 3.8% under the first year of 2.1°C warming; but increased by 13.4% by the sixth year of 2.1°C warming. The increased ecosystem C stock by the sixth year of warming was mainly attributed to a combination of sustained increased plant C stock due to the maintenance of a high plant growth rate and unchanged soil C stock. The unchanged soil C stock was driven by compensating and offsetting thermal adaptation of soil microorganisms (unresponsive soil respiration and enzyme activity, and more stable microbial community), increased plant C input, and inhibitory C loss (decreased C leaching and inhibited temperature sensitivity of soil respiration) from soil drying. These results suggest that the humid subtropical forest C pool would not necessarily diminish consistently under future long-term warming. We highlight that differential and asynchronous responses of plant and soil C processes over relatively long-term periods should be considered when predicting the effects of climate warming on ecosystem C dynamics of subtropical forests., (© 2023 John Wiley & Sons Ltd.)

We investigated the sediment carbon (C) stocks, sequestration and sources in tidal flats and their adjacent mangroves in two coastal wetlands in Hong Kong (the Mai Po Nature Reserve (MPNR) and Ting Kok (TK)), part of a megacity of ∼20 million. At both locations, the C stock of tidal flats was lower than that of mangroves. In MPNR, tidal flats indicated a higher C burial rate (75.2 g C m -2  yr -1 ) compared to mangroves (64.3 g C m -2  yr -1 ). The C of tidal flats mainly originated from mangroves and riverine sources, while those in deeper sediments (below 60 cm) in the mangroves originated from the tidal flats. In TK, the C of tidal flats was dominated by oceanic sources. Our study indicates that tidal flats are also important in coastal C sequestration. On highly urbanized coasts, tidal flats and their connected mangroves can play a critical role for C mitigation., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Based on datasets from plot survey and bibliographic of Larix olgensis plantations in Maoer Mountain, the CO 2 FIX model was used to quantitatively simulate the effects of different rotations (30, 40, 50, 60 years), site indices (12, 16, 20 m), and initial densities (2500, 3333, 4444 trees·hm -2 ) on the stand level carbon flows among different carbon pools ( i.e. , biomass carbon pool, soil carbon pool, and product carbon pool). The results showed that the CO 2 FIX model had high reliability for simulating the processes of L. olgensis plantation, with the average relative errors of stand biomass and volume between analog and measured values being 6.4% and 3.7%. Under the baseline conditions of initial density of 3333 trees·hm -2 , site index of 16 m and rotation of 40 years, the carbon stock of total and sub-pool of L. olgensis plantation changed periodically with rotation. The total stand carbon stock and volume for L. olgensis plantation increased with the extension of rotation, the improvement of site index, and the increase of initial density. The stand carbon stock and volume would be increased by 12.2% and 31.2%, 36.7% and 67.8%, respectively, when the reference rotation was correspondingly extended by 10 and 20 years. However, if the reference rotation was shortened by 10 years, stand carbon stock and volume would be correspondingly decreased by 20.9% and 40.4%, respectively. When the initial density was set as 3333 and 4444 trees·hm -2 , stand carbon stock and volume were increased by 27.8% and 50.9%, 27.4% and 49.1%, respectively. When the site index was under the range of 12 to 20 m, stand carbon stock and volume could be increased by 36.0% and 40.3%, 39.3% and 44.2%, respectively, with each increase of 4 m in site index. During one rotation, 271.57 t C per hectare could be fixed into L. olgensis plantation. At the end round of the rotation, 27.47 and 56.75 t C were transferred to soil and wood product carbon pools. Therefore, when the site condition was good, the management model with a higher initial density (4444 trees·hm -2 ) and longer rotation (60 years) would be more beneficial to maximizing the carbon sink and timber benefits of L. olgensis plantation.

Forest's ecosystem is changing at an alarming rate and anthropogenic alteration of forests to other land use is a major driver of carbon (C) emission and biodiversity loss. We estimated ecosystem-level C stock and factors affecting C stock in six major forest types; tropical wet evergreen forest, montane subtropical forest, temperate forest, bamboo forest, quercus forest, and jhum land of the eastern Himalayan region (India). We determined ecosystem structure, biodiversity, and plant and soil C stock by laying random plots in each forest site. The average C stock was estimated in the range of 79.0-373.4 Mg C ha -1 and found significantly different among the forest types. Partitioning ecosystem C stocks in plant (24-55%), soils (43-75%), deadwood (1-4.8%) and litter (0.20-1.25%) components varied largely. Pearson correlation analysis shows a significant positive relation of basal area with species diversity, tree density, and ecosystem C stock. Linear mixed-effect model demonstrates the high influence of species density and soil moisture content on the ecosystem C stock. We recommend the inclusion of forest structural attributes and pedological characteristics while predicting synergies between C stock and future climatic conditions. Additionally, conversion of natural forests to jhum land should be minimized because they stored lesser ecosystem C stocks thus plays a minimum role in C accumulation and cycling. The study provides estimates of C stocks in major forests that can be useful in suggesting a path forward to partially fulfill India's commitments to REDD + policy., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Urban green spaces provide manifold environmental benefits and promote human well-being. Unfortunately, these services are largely undervalued, and the potential of urban areas themselves to mitigate future climate change has received little attention. In this study, we quantified and mapped city-wide aboveground carbon storage of urban green spaces in China's capital, Beijing, using field survey data of diameter at breast height (DBH) and tree height from 326 field survey plots, combined with satellite-derived vegetation index at a fine resolution of 6 m. We estimated the total amount of carbon stored in the urban green spaces to be 956.3 Gg (1 Gg = 10 9 g) in 2014. There existed great spatial heterogeneity in vegetation carbon density varying from 0 to 68.1 Mg C ha -1 , with an average density of 7.8 Mg C ha -1 . As expected, carbon density tended to decrease with urban development intensity (UDI). Likely being affected by vegetation cover proportion and configuration of green space patches, large differences were presented between the 95th and 5th quantile carbon density for each UDI bin, showing great potential for carbon sequestration. However, the interquartile range of carbon density narrowed drastically when UDI reached 60%, signifying a threshold for greatly reduced carbon sequestration potentials for higher UDI. These findings suggested that urban green spaces have great potential to make contribution to mitigating against future climate change if we plan and design urban green spaces following the trajectory of high carbon density, but we should be aware that such potential will be very limited when the urban development reaches certain intensity threshold., (© 2019 John Wiley & Sons Ltd.)

Global climate is undergoing significant changes due to extensive release of greenhouse gases (GHGs) such as CO 2 and methane in the atmosphere. These gases are produced and released as a result of anthropogenic activities and fossil fuel burnings which also result in depletion of soil carbon resources. Biochar has various distinctive properties, which contribute to make it an effective, economical, and eco-friendly approach for soil carbon sequestration. The versatility in physicochemical properties of biochar provides an opportunity to optimize its efficacy to obtain desired benefits. A critical review of the literature indicates that biochar and plant growth-promoting microbes have the potential to improve soil organic carbon (SOC). Recent studies have depicted a significant role of the combined application of plant growth-promoting microbes and biochar on SOC dynamics. In future, these areas need to be explored as these have the potential to improve SOC dynamics and it could be a better strategy to sustain natural resources and ultimately mitigation of the climate change.

China's terrestrial ecosystems have functioned as important carbon sinks. However, previous estimates of carbon budgets have included large uncertainties owing to the limitations of sample size, multiple data sources, and inconsistent methodologies. In this study, we conducted an intensive field campaign involving 14,371 field plots to investigate all sectors of carbon stocks in China's forests, shrublands, grasslands, and croplands to better estimate the regional and national carbon pools and to explore the biogeographical patterns and potential drivers of these pools. The total carbon pool in these four ecosystems was 79.24 ± 2.42 Pg C, of which 82.9% was stored in soil (to a depth of 1 m), 16.5% in biomass, and 0.60% in litter. Forests, shrublands, grasslands, and croplands contained 30.83 ± 1.57 Pg C, 6.69 ± 0.32 Pg C, 25.40 ± 1.49 Pg C, and 16.32 ± 0.41 Pg C, respectively. When all terrestrial ecosystems are taken into account, the country's total carbon pool is 89.27 ± 1.05 Pg C. The carbon density of the forests, shrublands, and grasslands exhibited a strong correlation with climate: it decreased with increasing temperature but increased with increasing precipitation. Our analysis also suggests a significant sequestration potential of 1.9-3.4 Pg C in forest biomass in the next 10-20 years assuming no removals, mainly because of forest growth. Our results update the estimates of carbon pools in China's terrestrial ecosystems based on direct field measurements, and these estimates are essential to the validation and parameterization of carbon models in China and globally., Competing Interests: The authors declare no conflict of interest.

Nepal has successfully established more than 370,000 ha of plantations, mostly with Pinus patula, in the last three and a half decades. However, intensive management of these planted forests is very limited. Despite the fact that the Kyoto Convention in 1997 recognized the role of plantations for forest-carbon sequestration, there is still limited knowledge on the effects of management practices and stand density on carbon-sequestration of popular plantation species (i.e. Pinus patula) in Nepal. We carried out case studies in four community forests planted between 1976 and 1990 to assess the impacts of management on forest carbon stocks. The study found that the average carbon stock in the pine plantations was 217 Mg C ha -1 , and was lower in forests with intensively managed plantations (214.3 Mg C ha -1 ) than in traditionally managed plantations (219 Mg C ha -1 ). However, it was the reverse in case of soil carbon, which was higher (78.65 Mg C ha -1 ) in the forests with intensive management. Though stand density was positively correlated with carbon stock, the proportionate increment in carbon stock was lower with increasing stand density, as carbon stock increased by less than 25% with a doubling of stand density (300-600). The total carbon stock was higher in plantations aged between 25 and 30 years compared to those aged between 30 and 35 years., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

More than half of the cultivation-induced carbon loss from agricultural soils could be restored through improved management. To incentivise carbon sequestration, the potential of improved practices needs to be verified. To date, there is sparse empirical evidence of carbon sequestration through improved practices in East-Africa. Here, we show that agroforestry and restrained grazing had a greater stock of soil carbon than their bordering pair-matched controls, but the difference was less obvious with terracing. The controls were treeless cultivated fields for agroforestry, on slopes not terraced for terracing, and permanent pasture for restrained grazing, representing traditionally managed agricultural practices dominant in the case regions. The gain by the improved management depended on the carbon stocks in the control plots. Agroforestry for 6-20 years led to 11.4 Mg ha -1 and restrained grazing for 6-17 years to 9.6 Mg ha -1 greater median soil carbon stock compared with the traditional management. The empirical estimates are higher than previous process-model-based estimates and indicate that Ethiopian agriculture has greater potential to sequester carbon in soil than previously estimated., (© 2016 The Authors. Global Change Biology Published by John Wiley & Sons Ltd.)

Mangroves are the most important coastal blue carbon sinks. The accurate estimation on the carbon sequestration capacity of plant communities would guide the mangrove conservation, afforestation and management. This study investigated the vegetation carbon stocks of dominant mangrove communities, which were Avicennia marina, Kandelia obovata, Sonneratia caseolaris, and Sonneratia apetala in Futian Nature Mangrove Reserve in Shenzhen, Guangdong Province of China. Vegetation carbon stock consisted of living trees (aboveground and belowground biomass), understory, pneumatophore, standing dead trees, fallen dead trees and litter in these communities. The net primary productivity (NPP) was calculated from the litterfall and incremental growth in the same year of each community. Our results showed that the vegetation carbon stocks for A. marina, K. obovata, S. caseolaris, and S. apetala communities were 28.7, 127.6, 100.1, and 73.6 t C·hm -2 , and the NPP were 8.75, 7.67, 9.60, and 11.8 t C·hm -2 ·a -1 , respectively. Therefore, acting as urban forests, Futian mangroves in Shenzhen assimilated about 4000 t CO 2 ·a -1 . These results provided guidance for mangrove blue carbon assessment, and theoretical basis for the construction of coastal carbon sequestration forests in China.

Understanding the responses of lake systems to past climate change and human activity is critical for assessing and predicting the fate of lake carbon (C) in the future. In this study, we synthesized records of the sediment accumulation from 82 lakes and of C sequestration from 58 lakes with direct organic C measurements throughout China. We also identified the controlling factors of the long-term sediment and C accumulation dynamics in these lakes during the past 12 ka (1 ka = 1000 cal yr BP). Our results indicated an overall increasing trend of sediment and C accumulation since 12 ka, with an accumulation peak in the last couple of millennia for lakes in China, corresponding to terrestrial organic matter input due to land-use change. The Holocene lake sediment accumulation rate (SAR) and C accumulation rate (CAR) averaged (mean ± SE) 0.47 ± 0.05 mm yr(-1) and 7.7 ± 1.4 g C m(-2)  yr(-1) in China, respectively, comparable to the previous estimates for boreal and temperate regions. The SAR for lakes in the East Plain of subtropical China (1.05 ± 0.28 mm yr(-1) ) was higher than those in other regions (P < 0.05). However, CAR did not vary significantly among regions. Overall, the variability and history of climate and anthropogenic interference regulated the temporal and spatial dynamics of sediment and C sequestration for lakes in China. We estimated the total amount of C burial in lakes of China as 8.0 ± 1.0 Pg C. This first estimation of total C storage and dynamics in lakes of China confirms the importance of lakes in land C budget in monsoon-influenced regions., (© 2015 John Wiley & Sons Ltd.)

Natural forests in South-East Asia have been extensively converted into other land-use systems in the past decades and still show high deforestation rates. Historically, lowland forests have been converted into rubber forests, but more recently, the dominant conversion is into oil palm plantations. While it is expected that the large-scale conversion has strong effects on the carbon cycle, detailed studies quantifying carbon pools and total net primary production (NPPtotal ) in above- and belowground tree biomass in land-use systems replacing rainforest (incl. oil palm plantations) are rare so far. We measured above- and belowground carbon pools in tree biomass together with NPPtotal in natural old-growth forests, 'jungle rubber' agroforests under natural tree cover, and rubber and oil palm monocultures in Sumatra. In total, 32 stands (eight plot replicates per land-use system) were studied in two different regions. Total tree biomass in the natural forest (mean: 384 Mg ha(-1) ) was more than two times higher than in jungle rubber stands (147 Mg ha(-1) ) and >four times higher than in monoculture rubber and oil palm plantations (78 and 50 Mg ha(-1) ). NPPtotal was higher in the natural forest (24 Mg ha(-1)  yr(-1) ) than in the rubber systems (20 and 15 Mg ha(-1)  yr(-1) ), but was highest in the oil palm system (33 Mg ha(-1)  yr(-1) ) due to very high fruit production (15-20 Mg ha(-1)  yr(-1) ). NPPtotal was dominated in all systems by aboveground production, but belowground productivity was significantly higher in the natural forest and jungle rubber than in plantations. We conclude that conversion of natural lowland forest into different agricultural systems leads to a strong reduction not only in the biomass carbon pool (up to 166 Mg C ha(-1) ) but also in carbon sequestration as carbon residence time (i.e. biomass-C:NPP-C) was 3-10 times higher in the natural forest than in rubber and oil palm plantations., (© 2015 John Wiley & Sons Ltd.)

Bamboo forests provide important ecosystem services and play an important role in terrestrial carbon cycling. Of the approximately 500 bamboo species in China, Moso bamboo (Phyllostachys pubescens) is the most important one in terms of distribution, timber value, and other economic values. In this study, we estimated current and potential carbon stocks in China's Moso bamboo forests and in their products. The results showed that Moso bamboo forests in China stored about 611.15 ± 142.31 Tg C, 75% of which was in the top 60 cm soil, 22% in the biomass of Moso bamboos, and 3% in the ground layer (i.e., bamboo litter, shrub, and herb layers). Moso bamboo products store 10.19 ± 2.54 Tg C per year. The potential carbon stocks reach 1331.4 ± 325.1 Tg C, while the potential C stored in products is 29.22 ± 7.31 Tg C a(-1). Our results indicate that Moso bamboo forests and products play a critical role in C sequestration. The information gained in this study will facilitate policy decisions concerning carbon sequestration and management of Moso bamboo forests in China., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

Global warming is a critical factor driving climate change, impacting every aspect of life on Earth. The escalating concentration of greenhouse gasses in the atmosphere, the primary contributor to global warming, necessitates immediate action through effective climate mitigation strategies. This study aimed to quantify the biomass and blue carbon stocks in the eastern coastal mangrove forests of North Sumatra and Aceh Provinces in Indonesia, focusing on key sites in Langkat, Deli Serdang, Batu Bara, Tanjung Balai, and Aceh Tamiang Regencies. We measured carbon stock in three carbon pools: biomass (above and below ground), necromass, and soil. By analyzing tree stands using parameters such as tree height and diameter at breast height within circular plots (7 m in radius, 125 m apart), we gathered fundamental data on forest structure, species composition, and above- and below-ground biomass. Additionally, we collected soil samples at various points and depths, measuring the amount of wood, stems, or branches (necromass) that fell to or died on the forest floor. Data were collected in plots along a line transect, comprising three transects and six circular plots each. Sixteen diverse mangrove species were found, demonstrating rich mangrove biodiversity. The mangrove forests in the five regencies exhibited significant carbon storage potential, with estimated average above-ground carbon ranging from 96 to 356 MgC/ha and average below-ground carbon from 28 to 153 MgC/ha. The estimated average deadwood carbon varied between 50 and 91 MgC/ha, while soil carbon ranged from 1200 to 2500 MgC/ha. These findings underscore the significant carbon storage potential of these mangrove forests, highlighting their importance to global carbon cycling and climate change mitigation. This research contributes to a broader understanding of mangroves as vital blue carbon ecosystems, emphasizing the necessity of conservation efforts such as forest restoration and rehabilitation to enhance their role in stabilizing coastal areas and improving global climate resilience. [ABSTRACT FROM AUTHOR]

Abstract Background Implementing large-scale carbon sink afforestation may contribute to carbon neutrality targets and increase the economic benefits of forests in rural areas. However, how to manage planted forests in China to maximize the joint benefits of timber production and carbon sequestration is still unclear. Therefore, the present study quantified the effects of different rotation lengths, thinning treatments, site quality (SCI), stand density (SDI), and management costs on the joint benefits of carbon sequestration and timber production based on a stand-level model system developed for larch plantations in northeast China. Results The performances of the different scenarios on carbon stocks were satisfactory, where the variations in the outcomes of final carbon stocks could be explained by up to 90%. The joint benefits increased significantly with the increases of SDIs and SCIs, regardless of which rotation length and thinning treatments were evaluated. Early thinning treatments decreased the joint benefits significantly by approximately 131.53% and 32.16% of middle- and higher-SDIs, however longer rotations (60 years) could enlarge it by approximately 71.39% and 80.27% in scenarios with and without thinning when compared with a shorter rotation length (40 years). Discount rates and timber prices were the two most important variables affecting joint benefits, while the effects of carbon prices were not as significant as expected in the current trading market in China. Conclusions The management plans that promote longer rotations, higher stand densities, and no thinning treatments can maximize the joint benefits of carbon sequestration afforestation and timber production from larch plantations located in northeast China. Graphical Abstract

Tree plantations are an important forest resource that substantively contributes to climate change mitigation and carbon sequestration. As the area and standing volume of tree plantations in China have increased, issues such as unreasonable structure, low productivity, limited ecological functionality and diminishing ecological stability have occurred, which hinder the ability of tree plantations to enhance carbon sequestration. This study outlined the trajectory of carbon sequestration and its associated benefits in tree plantations by examining the current state of tree plantation establishment and growth, elucidated the strategies for advantages of carbon sequestration and climate change mitigation in planted forests, and summarized the existing problems with tree plantations. This paper underscores the pressing need for concerted efforts to boost carbon sequestration within planted forests and proposes management and development strategies for Chinese tree plantations. In the future, it will be necessary to apply scientific theories to practice and develop multi-objective management optimization models for the high-quality development of tree plantations. This will involve establishing a cohesive national carbon trading market, improving the prediction of carbon sequestration, and identifying priority zones for afforestation and reforestation, to better serve China's national strategy for achieving peak carbon and carbon neutrality. [ABSTRACT FROM AUTHOR]

Long-term excessive use of fertilizers and intensive cultivation not only decreases soil organic carbon (SOC) and productivity, but also increases greenhouse gas emissions, which is detrimental to sustainable agricultural development. The purpose of this paper is to identify organic amendments suitable for winter wheat growth in the North China Plain by studying the effects of organic amendments on the economic benefits, carbon emissions, and carbon sequestration for winter wheat fields and to provide a theoretical basis for the wide application of organic amendments in agricultural fields. The two nitrogen rates were N0 (0 kg ha−1) and N240 (240 kg ha−1), and the four organic amendments were straw, manure, mushroom residue (M R), and biochar. The results showed that, compared to N0, N240 significantly increased the yield by 244.1–318.4% and the organic carbon storage by 16.7–30.5%, respectively, but increased the carbon emissions by 29.3–45.5%. In addition, soil carbon stocks increased with all three types of organic amendments compared to the straw amendment, with the biochar treatment being the largest, increasing carbon storage by 13.3–33.6%. In terms of yield and economic benefits, compared to the straw amendment, the manure and biochar amendments increased winter wheat yields by 0.0–1.5% and 4.0–13.3%, respectively, and M R slightly decreased wheat yield; only the economic benefit of the M R amendment was greater than that of the straw amendment, with an increase in economic benefit of 1.3% and 8.2% in the 2021–2022 and 2022–2023 seasons, respectively. Furthermore, according to the net ecosystem productivity (NEP), N0 was the source of CO2, while N240 was a sink of CO2. The TOPSIS results showed that N240 with a mushroom residue amendment could be recommended for increasing soil carbon stocks and economic benefits for winter wheat in the NCP and similar regions. Low-cost M R can increase farmer motivation and improve soil organic carbon, making a big step forward in the spread of organic materials on farmland. [ABSTRACT FROM AUTHOR]

Background: Implementing large-scale carbon sink afforestation may contribute to carbon neutrality targets and increase the economic benefits of forests in rural areas. However, how to manage planted forests in China to maximize the joint benefits of timber production and carbon sequestration is still unclear. Therefore, the present study quantified the effects of different rotation lengths, thinning treatments, site quality (SCI), stand density (SDI), and management costs on the joint benefits of carbon sequestration and timber production based on a stand-level model system developed for larch plantations in northeast China. Results: The performances of the different scenarios on carbon stocks were satisfactory, where the variations in the outcomes of final carbon stocks could be explained by up to 90%. The joint benefits increased significantly with the increases of SDIs and SCIs, regardless of which rotation length and thinning treatments were evaluated. Early thinning treatments decreased the joint benefits significantly by approximately 131.53% and 32.16% of middle- and higher-SDIs, however longer rotations (60 years) could enlarge it by approximately 71.39% and 80.27% in scenarios with and without thinning when compared with a shorter rotation length (40 years). Discount rates and timber prices were the two most important variables affecting joint benefits, while the effects of carbon prices were not as significant as expected in the current trading market in China. Conclusions: The management plans that promote longer rotations, higher stand densities, and no thinning treatments can maximize the joint benefits of carbon sequestration afforestation and timber production from larch plantations located in northeast China. Highlights: A compatible model of stand volume and carbon for larch plantations was developed. Thinning decreased the joint benefits of higher SDIs, but longer rotations enlarged it. Discount rates and timber prices predominated the joint benefits. The effects of carbon prices on the joint benefits were unconspicuous. [ABSTRACT FROM AUTHOR]

In recent years, the "dual carbon" issue has become a major focus of the international community. Changes in land use driven by anthropogenic activities have a profound impact on ecosystem structure and carbon cycling. This study quantitatively assesses the spatiotemporal changes in cropland occupation and supplementation in the Pearl River Delta from 2000 to 2020 using the InVEST model, analyzing the spatial clustering of carbon storage changes caused by variations in cropland area. The PLUS model was employed to simulate land-use patterns and the spatial distribution of carbon storage in four future development scenarios. The results indicate the following: (1) From 2000 to 2020, the net change rate of cropland area in the Pearl River Delta was −0.81%, with a decrease of 16.49 km2 in cropland area, primarily converted to built-up land and forest land. (2) Carbon storage in the Pearl River Delta exhibited a pattern of lower values in the center and higher values in the periphery. The terrestrial ecosystem carbon storage in the Pearl River Delta was 534.62 × 106 t in 2000, 518.60 × 106 t in 2010, and 512.57 × 106 t in 2020, showing an overall decreasing trend. The conversion of cropland and forest land was the main reason for the decline in total regional carbon storage. (3) The area of carbon sequestration lost due to cropland occupation was significantly greater than the area of carbon loss compensated by new cropland, indicating an imbalance in the quality of cropland occupation and supplementation as a crucial factor contributing to regional carbon loss. (4) Under the ecological priority scenario, the expansion of built-up land and the reduction in ecological land such as cropland and forest land were effectively controlled, resulting in the minimal loss of carbon storage. The soil organic carbon pool of cropland is the most active carbon pool in terrestrial ecosystems and has a significant impact on carbon storage. Clarifying the relationship between "cropland protection measures–land use changes–ecosystem carbon storage" will improve cropland protection policies, provide references for regional carbon sequestration enhancement, and support sustainable socio-economic development. [ABSTRACT FROM AUTHOR]

Biomass estimation forms the foundation for tackling global climate issues across diverse land use systems (LUSs). A research initiative was undertaken to identify the maximum biomass allocation using an allometric approach, and to assess the carbon stock, CO2 sequestration, and carbon credit across diverse land use systems (LUSs) in the Vindhyan region of Mirzapur, Uttar Pradesh, India. This study aims to address climate change by identifying land‐use strategies that stabilize income and are easily adoptable by farmers. Tropical dry deciduous forest, agriculture, plantation, horticulture and agri‐horticulture LUSs were investigated using three combinations of custard apple (Annona squamosa), guava (Psidium guajava), bael (Aegle marmelos), mustard (Giriraj) (Brassica nigra), mustard (Pitambri) (Brassica juncea), and lentil (Lens culinaris) in an agri‐horticulture system. Seven treatments with varying carbon stocks were identified: tropical dry deciduous forest (T1) LUS (TDDFLUS); wheat based agriculture (T2) LUS (WBALUS); plantation based on teak (Tectona grandis) (T3) LUS (TBPLUS); horticulture based on karonda (Carissa carandas) (T4) LUS (KBHLUS); bael + lentil (Hul‐57) (T5) LUS (BLBLUS); guava + mustard (Giriraj) (T6) LUS (GMBLUS); and custard apple + mustard (Pitambri) (T7) LUS (CAMBLUS). The results indicate that the lowest and the highest bulk densities (ρb) were recorded in TDDFLUS and WBALUS at the depths of 0–20 cm and 20‐40 cm, respectively. The mean value of the soil organic carbon (SOC) stock ranged from 11.24–18.09 t ha−1. The average value of biomass, biomass carbon stock and biomass CO2 sequestration of seven treatments varied from 9.76–88.49 t ha−1, 4.88–44.25 t ha−1, and 17.91–162.39 t ha−1, respectively. The total carbon stock, CO2 sequestration, and carbon credit for the seven treatments varied from 16.57–64.64 t ha−1, 60.82–237.28 t ha−1 and 3040.821–11 863.89US$ ha−1, respectively. The results demonstrated that different LUSs have specific advantages and their application at farm level can encourage sustainability and increase biomass accumulation, leading to carbon sequestration. Agri‐horticulture‐based LUSs can lead to better livelihoods and can also offer numerous advantages such as increased yields of staple food crops and fruits, improved soil health, reduced soil erosion, and significant contributions to the mitigation of anthropogenic warming through CO2 sequestration. [ABSTRACT FROM AUTHOR]

Economic, social, and ecological aspects of the environment are all impacted differently by mining in different parts of the world. When mining activities end and leave the area bare, rehabilitation and revegetation are required to minimize the impacts of mining in general. By fixing carbon in tree biomass, these interventions have a positive effect on increasing carbon storage. Measuring carbon stock is essential to evaluating the effectiveness of these interventions. This study was conducted in an inactive mining area in Marinduque, Philippines. Plots for sampling were created in areas that were not yet undergoing rehabilitation as well as those that were. The above-ground carbon stock and biomass were estimated using the allometric equation provided by IPCC (Intergovernmental Panel on Climate Change) and Sourcebook for Land Use, Land-Use Change and Forestry Projects as references, respectively. The results for areas undergoing rehabilitation and those that were not indicated 4.297 t/ha and 0.0509 t/ha, respectively. The former has an above-ground carbon stock of 2.1485 t/ha, and the latter has 0.2545 t/ha. This shows a successful increase in biomass and carbon stock in the area undergoing rehabilitation. This comparison suggests that rehabilitation and revegetation should be implemented in mining areas to help mitigate the impacts of mining while also sequestering carbon. Policies and activities that will protect the current rehabilitation efforts and expand this rehabilitation to other inactive mining areas should be incorporated for future research. [ABSTRACT FROM AUTHOR]

The integration of trees into diverse land-use systems holds potential for India to meet nationally determined contribution (NDC) targets under the Paris Climate Agreement. With a target of sequestering 2.5–3 billion tons of CO2 equivalent by 2030, the study focused on the widespread and economically viable eucalyptus-based agroforestry, practiced widely in various planting geometries tailored to meet industrial end-use requirements. In this context, a detailed study was conducted to quantify the influence of five planting geometries [3 m × 3 m, 6 × 1.5 m, 17 × 1 × 1 m (paired row) and two boundary plantations (east–west and north–south directions) at 2 m away from tree to tree] of eucalyptus on intercrops [dhaincha (Sesbania aculeata)—barley (Hordeum vulgare L.) rotation] biomass, soil properties, and carbon stock of the system during 2009–2016. Results revealed that biomass accumulation of different tree components was 62.50%–74.09% in stem; 6.59%–9.14% in branch; 3.18%–5.73% in leaves; 12.20%–20.44% in stump roots; and 1.71%–3.48% in fine roots across the planting geometries. The mean carbon content of the stem, branch, leaves, and roots was 49.00, 47.00, 43.00, and 49.00%, respectively. Over the 8-year period, geometry of 3 × 3 m performed better in terms of total biomass production (344.60 Mg ha− 1 by tree biomass and 62.53 Mg ha−1 by intercrops). The independent parameter, DBH²H (DBH: diameter at breast height and H: tree height), was found to be a very good predictor of dry weight, followed by DBH alone. Among various functions (linear, allometric, logistic, Gompertz, Chapman, and exponential), the best-fit equation was allometric, i.e., B = 300.96 × DBH²H0.93 (adjusted R² = 0.96) for eucalyptus based on universal model adequacy and validation criteria. The carbon sequestration rate was maximum (20.79 Mg C ha−1 year−1) in 3 × 3 m followed by 17 × 1 × 1 m. The total carbon stock of eucalyptus-based system (tree + crop + soil) varied significantly under different planting geometries and sole crop rotation (dhaincha–barley). The higher carbon stock (237.27 Mg ha−1) was obtained from 3 × 3 m spacing and further partitioning carbon stock in trees—166.29 Mg ha−1, crops—25.01 Mg ha−1 and soil—45.97 Mg ha−1. The paired row spacing (17 × 1 × 1 m) yielded higher crop yield and net returns (Rs. 600,475 ha−1), underscoring wide spacing’s role in system productivity and sustainability. Tree-based systems were valuable components of agriculture, advocating for their widespread adoption to reduce CO2 emissions and generate income through carbon credits. These findings will provide crucial insights into sustainable land-use practices and advance India’s commitment toward adaptation of climate change mitigation strategies. [ABSTRACT FROM AUTHOR]

[Objective]In an attempt to increase carbon stock in the agricultural sector, the marginalized and unstable lands were identified as the fallow plots, carbon sinks due to ecological fallowing under future multi-gradient fallowing scenarios were explored to provide an crucial basis for arranging the fallow of marginalised cropland and enriching the theory of carbon sequestration in the northeast black soil region. [Methods]Based on the 2005 and 2020 land use data in the central black soil area of Jilin Province, a multi-gradient fallow scenario was simulated by the PLUS-Markov coupled model and the InVEST model, and the carbon stock and the potential for carbon sequestration and sink enhancement due to ecological fallow in the study area were measured. [Results](1)The natural development scenario and three fallowing scenarios A, B, and C with increasing intensity were set in this study. The marginal unstable farmland fallow in scenarios A, B, and C were 1. 5 × 104 hm², 2. 65 × 104 hm², and 3. 8 × 104 hm², respectively. These scenarios were mainly driv-en by socio-economic factors, accounting for about 30％of the total contribution. In terms of fallow types, the returning-to-forest areas widely distributed, mainly concentrated in the places such as Siping, Dongliao, and Changchun, while the returning-to-grass areas were smaller but exhibited spatial aggregation features, which were mainly located in the places such as Shuangliao and Nong'an. (2)As the simulated fallow intensi-ty increased, the carbon stock in the study area also indicated an increasing trend. Under fallow scenarios A, B, and C, the estimated carbon storage would reach up to 7. 26 × 106 Mg, 7. 27 × 106 Mg和7. 27 × 106 Mg, respectively, which decreased from the southeast and the northwest. The areas with high carbon sinks concentrated mainly in areas such as Shulan, Yongji, and Huadian. (3)Under different fallow scenarios, the carbon sink pattern in the study area remained stable, mainly concentrated in the eastern and southern parts. Considering the factors of food security and agricultural carbon sequestration demand, it is recommended to refer to the fallowing scenario B, and Siping, Dongliao, and Changchun will become the key agricultural carbon sink units in the black soil area of central Jilin Province. It is estimated that carbon stock will increase to 1963. 4 Mg, 806. 48 Mg and 703. 06 Mg, respectively. [Conclusion]The carbon stock increase from the agricultural sector in the black soil region of central Jilin Province depends on the fallow of marginalized croplands in a rolling hilly region. The productivity and the ecological effects arising from cropland use should be balanced in the layout and priority of the fallow projects. Meanwhile, the food production capacity needs to be adjusted in conjunc-tion with comprehensive land reclamation in the entire region in order to achieve the aims of improving the spatial suitability of cropland and the sustainability of the agricultural system in the black soil area. [ABSTRACT FROM AUTHOR]

Urban green spaces have received little attention for climate change mitigation by way of carbon dioxide (CO2) sequestration. The present study explores the diversity and CO2 mitigation value of roadside tree species in Sagar city, India. Various diversity and richness indices were determined to assess the diversity structure of these discontinuous vegetations. The CO2 mitigation value was determined by estimating biomass and carbon stock through a non-destructive method. The study area was found to include 1,130 individuals belonging to 26 families and 66 species. A higher value of diversity indices (Simpson's, 0.95 and Shannon's, 3.42) and lower Simpson's index of dominance (0.05), along with the higher value of species richness (9.25) and evenness (0.82) showed good diversity and uniform distribution of the species. The CO2 mitigation value for the present study area was 66.62 Mg/ha, along with a total biomass value of 36.3 Mg/ha and a carbon stock of 18.15 Mg C/ha. Observations from the study show that these types of vegetations do play a substantial role in carbon sequestration. The results of this study will be useful to give an insight into the significance of these roadside trees to policymakers and the necessity for careful management of them. [ABSTRACT FROM AUTHOR]

Forested areas provide various services, including crucial carbon sequestration for climate change mitigation. The Madhupur Sal Forest (MSF) in Bangladesh was studied extensively for its ecosystem services and carbon sequestration potential. Research conducted from February to August 2023 in Gaira and Dokhola villages assessed local community benefits and biodiversity. Interviews with 50 respondents and analysis of 20 plots were conducted to study carbon sequestration in the MSF. Twenty identified ecosystem services range from fuel and wood to cultural and economic advantages. Eight tree species, totaling 401 trees, were identified, with Ficus hispida being the most effective in annual carbon sequestration. Shorea robusta showed less efficacy in carbon sequestration, resulting in a total forest capture of 12 004 657.8 pounds per year. The study highlights the MSF's significant contribution to global climate change mitigation. Emphasis is placed on the need for enhanced carbon sequestration through forest management, reforestation, and afforestation projects in deforested areas. Despite diverse ecosystem services, the MSF faces threats, necessitating collaborative conservation efforts, sustainable management practices, and community involvement for its vitality. [ABSTRACT FROM AUTHOR]

Assessment of soil organic carbon (SOC) stock and identification of the factors influencing its spatial variation are crucial for adopting appropriate mitigation and adaptation strategies under changing climatic conditions. The present study aims to measure SOC content and stock and identify the factors contributing to SOC variation in India's sub-tropical, dry sub-humid Eastern Plateau Region (EPR). It also aims to recognize the potential land uses for enhancing the C stock in the region. Soil samples were collected from two soil depth layers—0 to 10 cm and 10 to 20 cm, from locations under different soil type, land use, and topographic conditions. The Walkley-Black method was used to determine the SOC content of the samples. Ordinary kriging based on an exponential semi-variogram model was employed to analyze the spatial variability of SOC concentration and its relationship with the sampling strata. The study shows that the topsoil variation in SOC depended mainly on the land use type and the corresponding soil properties viz. pH and texture. Cultivated areas, especially those of the lowland, recorded higher SOC than other land use classes. The findings of the present study are useful for defining agricultural management practices and carbon sequestration strategies for the region in the context of climate change. [ABSTRACT FROM AUTHOR]

Quantifying soil attributes in agroforestry reflects its productivity and carbon dynamics which indicates a healthier ecosystem functioning toward achieving sustainable production of coffee in the Southern region of Chhattisgarh. The present study was carried out in the coffee-based agroforestry system (AFs) of the Darbha Block, Bastar region in Chhattisgarh. The objective of this paper was to analyze soil properties and carbon dynamics of soil under five varietal treatments of coffee-based AFs. Silver oak cultivation was added to the AFs as it protects coffee and helps in sustainable coffee production. The soil was collected randomly using the auger from two different depths viz., 0–15 and 15–30 cm under coffee-based AFs. The value of N, P, K, S, B, Zn, C, Fe, Mn, OC%, and SOC stock were higher in San Ramon (T3) based AFs. The values of bulk density (BD), pH, and EC were recorded as highest under control treatment (To), respectively. Soil organic carbon (SOC) stock ranged between 10.21 (T0)–13.86 (T3) and 0.34 (T0)–0.59 (T3) t ha−1 for surface and sub-soil, respectively. Data analysis revealed the isolation of six PCA (principle component analysis) from the various soil attributes. The first component reflected maximum variability for both layers. Further, correlation studies revealed a strong association between the soil attributes. Therefore, the present work highlights the importance of agroforestry systems towards improving soil quality along with sustainable production of coffee. [ABSTRACT FROM AUTHOR]

This study examines the impact of silvicultural and land-use management practices on carbon sequestration in peri-urban forest ecosystems, with a particular focus on human-induced carbon dynamics. The study area's complex profile spans from a compact native forest to varying degrees of fragmentation. This included areas undergoing secondary succession forest without silvicultural interventions (No-SI) alongside sites subjected to high-intensity (High-SI) and low-intensity silvicultural interventions (Low-SI). The research assessed carbon stocks and sequestration in different carbon pools (living biomass, dead organic matter and soil) using field data, allometric equations and laboratory analysis. Findings reveal a significant correlation between the intensity of anthropogenic interventions and variations in carbon stocks. The CASMOFOR model facilitated the reconstruction of carbon stock and carbon-stock change dynamics over four decades (1980–2022), showing disparities in carbon storage capabilities linked to the structural characteristics of the sites. The Low-SI site had the highest carbon stock in all carbon pools (378 tonnes C ha−1), which is more than double compared to High-SI (161 tonnes C ha−1) or No-SI sites (134 tonnes C ha−1). However, the secondary succession forest (No-SI) demonstrated the highest annual carbon stock change (4.4 tonnes C ha−1 year−1), two times higher than the Low-SI mature stand (2.2 tonnes C ha−1 year−1), emphasising the resilience of forest ecosystems to recover and sustain carbon sequestration capacities after harvesting if forest land use remains unchanged. The study underscores the significant importance of anthropogenic interventions on carbon dynamics, especially for living tree biomass, which has consequences in enhancing carbon sequestration and contributing to emission reduction targets. [ABSTRACT FROM AUTHOR]

Rangelands are important for mitigating climate change and rehabilitating land by storing carbon from woody plants and seeds in the soil. However, there is a lack of empirical data on how traditional rangeland management practices (such as enclosure, communal grazing and prescribed fire) affect the carbon storage of woody species and the conservation potential of soil seed banks. This study evaluates the carbon sequestration and soil seed bank conservation potential of traditional rangeland management practices in the Western Guji zone, Ethiopia. A total of 32 sample plots were established using systematic random sampling, with 12 in each management practice, to measure woody biomass and estimate carbon stock using a nondestructive method. Additionally, 72 soil samples were collected for soil seed bank analysis, with 24 samples taken from each type of rangeland management practice. The study found that enclosures had the highest amount of carbon stocks 63.1 tons per hectare (t ha−1), with a corresponding carbon dioxide equivalent (CO2e) sequestration of 231.58 t ha-1, followed by communal grazing areas that stored 27.05 t ha−1 of carbon with a CO2e sequestration of 99.27 t ha−1. Prescribed fire had the lowest carbon stocks at 19.39 t ha−1, with a CO2e sequestration of 71.16 t ha−1. The study also found that different traditional rangeland management practices significantly influenced the diversity, richness, and density of woody species in soil seed banks. The highest Shannon diversity was recorded in enclosures (3.56 ± 0.09), followed by communal grazing (2.87 ± 0.14) and prescribed fire (1.27 ± 0.08). As a result, enclosure promotes the storage of carbon in woody plants and increases the diversity, density, and richness of woody species seeds in the soil, while prescribed fire reduces it. Therefore, it recommend for pastoralists to expand the use of enclosures as it improves the potential for conserving carbon stocks and soil seed banks of woody species.

Tropical forests play a significant role in climate change by sequestering atmospheric carbon dioxide. However, deforestation and forest degradation adversely affect these forests’ carbon stocks. Reports indicate that anthropogenic activities have led to forest degradation and deforestation in Boabeng Fiema Monkey Sanctuary (BFMS) and Kogyae Strict Nature Reserve (KSNR). This study assessed the effects of these activities on the carbon stocks of BFMS and KSNR. Using satellite imagery, field measurements and allometric models, carbon stocks of the study area were assessed from 1992 to 2023. The assessment revealed significant losses attributed to anthropogenic activities, such as hunting, farming and charcoal burning. BFMS experienced a total loss of 40,236 Mg C, while KSNR lost 272,109 Mg C. The closed forests had the highest carbon stock amongst the different vegetation types, with soil representing the most significant carbon pool in the protected areas, revealing the influence of vegetation structure on carbon sequestration and the need for soil conservation. The substantial carbon sequestration potential observed in the different vegetation types of the study area indicates that the Forest-Savannah Transition Zone is a prospective area for climate change mitigation aligning with the Sustainable Development Goals (Goals 13 and 15) and the National Climate Change Policy of Ghana. These findings provide valuable insights for carbon trading and biodiversity conservation, emphasizing the potential of nature-based solutions in addressing global climate challenges.

ARTICLE HIGLIGHTS - Agroforestry boosts carbon storage, reducing greenhouse gas emissions significantly. - Diverse tree-based farming enhances biodiversity, soil health, and climate resilience. - Carbon sequestration in agroforestry supports sustainable agriculture and environmental balance. - Agroforestry practices mitigate climate change by storing carbon in trees and soil. - Combining trees with crops provides multiple ecological and economic benefits. ABSTRACT One of the processes for compensating greenhouse gas emissions is atmospheric carbon removal and storage in the terrestrial biosphere. Agricultural systems to which trees are returned for careful management alongside crops and animals are thought to be substantial CO2 sinks. People are increasingly realizing the importance of agroforestry because it is good for the environment and farming. In this study, total carbon pools from the aboveground biomass carbon (ABGC), forest floor carbon (FFC), and soil organic carbon (SOC) were investigated and carbon storage data for some agroforestry practices native to Uttaradit in northern Thailand were analyzed. The role of these carbon pools in reducing CO2 concentrations in the atmosphere was also discussed. The results showed differences in the total carbon stock sourced from traditional agroforestry (TAF), applied agroforestry (AAF), and developed agroforestry (DAF). The total carbon store (ABGC + TFFC + SOC) of TAF, AAF, and DAF was 267.05 Mg C/ha, 226.48 Mg C/ha, and 324.70 Mg C/ha, respectively. SOC contributed 47.64%, 54.26%, and 44.81% and ABGC contributed 22.75%, 19.79%, and 23.90% to the total carbon stock in TAF, AAF, and DAF, respectively. The CO2 adsorption was 979.27 Mg CO2/ha, 830.50 Mg CO2/ha, and 1,190.6 Mg CO2/ha in TAF, AAF, and DAF, respectively. It is clear that agroforestry systems serve as carbon sinks in terrestrial ecosystems. Although the comparison of agroforestry practices and other land use types is important for carbon mitigation and the implementation of the “Land Use, Land Use Change, and Forestry” concept for CO2 sinks, it is also crucial to compare the potential of carbon sequestration in different CO2 pools.

Global warming is a critical factor driving climate change, impacting every aspect of life on Earth. The escalating concentration of greenhouse gasses in the atmosphere, the primary contributor to global warming, necessitates immediate action through effective climate mitigation strategies. This study aimed to quantify the biomass and blue carbon stocks in the eastern coastal mangrove forests of North Sumatra and Aceh Provinces in Indonesia, focusing on key sites in Langkat, Deli Serdang, Batu Bara, Tanjung Balai, and Aceh Tamiang Regencies. We measured carbon stock in three carbon pools: biomass (above and below ground), necromass, and soil. By analyzing tree stands using parameters such as tree height and diameter at breast height within circular plots (7 m in radius, 125 m apart), we gathered fundamental data on forest structure, species composition, and above- and below-ground biomass. Additionally, we collected soil samples at various points and depths, measuring the amount of wood, stems, or branches (necromass) that fell to or died on the forest floor. Data were collected in plots along a line transect, comprising three transects and six circular plots each. Sixteen diverse mangrove species were found, demonstrating rich mangrove biodiversity. The mangrove forests in the five regencies exhibited significant carbon storage potential, with estimated average above-ground carbon ranging from 96 to 356 MgC/ha and average below-ground carbon from 28 to 153 MgC/ha. The estimated average deadwood carbon varied between 50 and 91 MgC/ha, while soil carbon ranged from 1200 to 2500 MgC/ha. These findings underscore the significant carbon storage potential of these mangrove forests, highlighting their importance to global carbon cycling and climate change mitigation. This research contributes to a broader understanding of mangroves as vital blue carbon ecosystems, emphasizing the necessity of conservation efforts such as forest restoration and rehabilitation to enhance their role in stabilizing coastal areas and improving global climate resilience.

Aquaculture is one of the main drivers of mangrove loss across Southeast Asian countries. The conversion of mangroves to aquaculture generates substantial loss of carbon stocks and reduces carbon storage capacity. Here, we present total ecosystem carbon stocks (TECS), carbon dioxide (CO2) and methane (CH4) effluxes obtained from mangrove forests (fringe and interior mangroves), silvofishery aquaculture ponds (dense and sparse mangroves), and non-silvofishery aquaculture ponds in Sawah Luhur, Banten, Indonesia. We found no significant difference in TECS across five land uses, ranging from 261 ± 14 Mg C ha-1 in non-silvofishery ponds to 574 ± 119 Mg C ha-1 in fringe mangroves. Most of these stocks were found in the soil carbon pool (87%) in fringe and interior mangroves. However, the conversion of mangroves to aquaculture ponds resulted in soil carbon loss from -6% to 60%. The highest soil CO2 effluxes during dry and wet seasons were observed in interior mangroves (151 ± 12 mg CO2 m-2 h-1). The highest soil CH4 effluxes were found in fringe mangroves with 0.13 ± 0.04 mg CH4 m-2 h-1. The highest aquatic CO2 and CH4 effluxes were found in dense silvofishery ponds, at 118 ±7mg CO2 m-2 h-1 and 0.38 ± 0.04 mg CH4 m-2 h-1, respectively. Our findings suggest that land use that includes mangroves (i.e., mangrove forest and/or silvofishery ponds) tends to have higher carbon stocks, soil, and aquatic CO2 and CH4 effluxes, compared to aquaculture ponds without mangroves. It is therefore crucial to maintain mangroves for natural carbon capture and storage through carbon stock enhancement. [ABSTRACT FROM AUTHOR]

Forests face a variety of threats in the modern era. Agroforestry systems, both traditional and introduced, have a tremendous capacity for providing sustainable resources and combating the impact of global climate change. Indigenous agroforestry and forest land-use systems are important reservoirs for biodiversity conservation and ecosystem services, providing a potential contribution to livelihood security for rural communities. This study aimed to assess the tree diversity and carbon stock of agroforestry and adjoining forests along altitudinal gradients, ranging between 700 and 2200 masl (i.e., lower, middle, and upper altitudes) by laying sample plots randomly of a size of 20 × 20 m2. In the forest land-use system, the maximum Importance Value Index (IVI) included Dalbergia sissoo (71.10), Pyrus pashia (76.78), and Pinus roxburghii (79.69) at the upper, middle, and lower elevations, respectively, whereas, in the agroforestry land-use system, the IVI reported for Ficus semicordata was 43.05 at the upper, while for Grewia optiva it was at 53.82 at the middle and 59.33 at the lower altitudes. The below-ground biomass density (AGBD) was recorded as 1023.48 t ha−1 (lower), 242.92 t ha−1 (middle), and 1099.35 t ha−1(upper), while in the agroforestry land-use system, the AGBD was 353.48 t ha−1 (lower), 404.32 t ha−1 (middle), and 373.23 t ha−1 (upper). The total carbon density (TCD) values recorded were 630.57, 167.32, and 784.00 t ha−1 in forest land-use systems, and 227.46, 343.23, and 252.47 in agroforestry land-use systems for lower, middle, and upper altitudes, respectively. The Margalef's Index values for agroforestry and forests ranged from 2.39 to 2.85 and 1.12 to 1.30, respectively. Soil organic carbon (SOC) stock recorded 45.32, 58.92, and 51.13 Mg C ha−1 for agroforestry and 61.73, 42.65, and 71.08 Mg C ha−1 for forest in lower, middle and upper elevations, respectively. The study suggests that selecting land use patterns can be an effective management system for tree species at different elevations for carbon storage, helping to mitigate climate change and aiding in sustainable management of ecosystems in the Garhwal Himalayas. [ABSTRACT FROM AUTHOR]

Carbon sequestration is obtained from the total accumulation of the element in both soil and plants. The enhancement has the capacity to reduce greenhouse gas emissions and influence soil quality and fertility, thereby affecting plant biomass and crop yield. Therefore, this research aimed to compare the total carbon sequestration in rice field with different farming systems, determine soil characteristics, and identify the correlation between the total carbon sequestration and impact on rice yield. An exploratory-descriptive method was used through field survey and laboratory analysis. The locations were mapped by overlaying the Indonesian landform map of the Girimarto District with various rice field systems, soil types, and slopes. Furthermore, the 12 Land Mapping Units (LMU) with 3-time repetitions resulted in 36 sampling points. Data were processed by calculating total carbon sequestration and statistical tests such as one-way ANOVA and Pearson's correlation. The results showed that rice field farming systems affected the total carbon sequestration. Organic farming had the highest total carbon sequestration value of 72.49 Mg/ha and the increase had a strongly positive correlation with crop yield of paddy. Crop yield in organic farming were higher than in semi-organic and conventional systems by 8.92 tons/ha. Factors that determined total carbon sequestration were soil C-organic and microbial biomass C. The suggested improvement recommendations were the transition of conventional and semi-organic farming as well as adding a variety of organic fertilizers such as biofertilizers. [ABSTRACT FROM AUTHOR]

Savannas constitute a mixture of trees and shrub patches with a more continuous herbaceous understory. The contribution of this biome to the soil organic carbon (SOC) and above-ground biomass (AGB) carbon (C) stock globally is significant. However, they are frequently subjected to land use changes, promoting increases in CO2 emissions. In Uruguay, subtropical wooded savannas cover around 100,000 ha, of which approximately 28% is circumscribed to sodic soils (i.e., subtropical halophytic wooded savannas). Nevertheless, there is little background about the contribution of each ecosystem component to the C stock as well as site-specific allometric equations. The study was conducted in 5 ha of subtropical halophytic wooded savannas of the national protected area Esteros y Algarrobales del Río Uruguay. This work aimed to estimate the contribution of the main ecosystem components (e.g., soil, trees, shrubs, and herbaceous plants) to the C stock. Site-specific allometric equations for the most frequent tree species and shrub genus were fitted based on basal diameter (BD) and total height (H). The fitted equations accounted for between 77% and 98% of the aerial biomass variance of Neltuma affinis and Vachellia caven. For shrubs (Baccharis sp.), the adjusted equation accounted for 86% of total aerial biomass. C stock for the entire system was 116.71 ± 11.07 Mg•ha-1, of which 90.7% was allocated in the soil, 8.3% in the trees, 0.8% in the herbaceous plants, and 0.2% in the shrubs. These results highlight the importance of subtropical halophytic wooded savannas as C sinks and their relevance in the mitigation of global warming under a climate change scenario. [ABSTRACT FROM AUTHOR]

Carbon stock and diversity of species together address the two most pressing concerns for successful ecosystem functioning and management, namely climate change and biodiversity loss. Understory vegetation is a significant indicator of plant biodiversity, contributing to forest carbon storage, sustaining species, and providing many ecological services. However, little research has been done about the contribution of the understory carbon stock in the forests, most likely because these understory components only make up a small portion of the total carbon stock of the forest ecosystem. To fill this knowledge gap, the current study sought to study the baseline understory (shrub and herb) diversity and carbon stock from the Zabarwan Mountain Range. Data on the characteristics of the understory vegetation in five different forest types were gathered using a random sample method. Using the Pearson method, we calculated the correlation coefficient between the diversity parameters and the carbon stock. The calculated average total carbon stock in the understory was determined to be 3.93 Mg C/ha (1.55–9.2 Mg C/ha). The shrub layer contributed a maximum value of 82 % of carbon stock. The increasing trends in total understory carbon were Parrotiopsis forest Broad-leaved forest > Acacia forest > Pinus forest > Parrotiopsis forest. Overall, the data show that coniferous-dominated woodlands had higher understory carbon stocks than other kinds of woodlands. The data acquired highlights the importance of shrub carbon stock storage in the understory layer in this Himalayan region. The current research on understory vegetation provides strong evidence for maintaining forest management practices that enable and encourage the planting of multiple layers of vegetation in landscape restoration as approaches to improve biodiversity while increasing resistance to climate change.

Forests are the potential source for managing carbon sequestration and balancing universal carbon equilibrium between sources and sinks. In view of the importance of biomass, this study makes an attempt to estimate temporal and spatial carbon stock of Godebie National Park, Ethiopia, using Moderate Resolution Imaging Spectro radiometer (MODIS), normalized difference vegetation index (NDVI), enhanced vegetation index (EVI) and the field inventory data through geospatial techniques. A model was developed for establishing the relationship between forest carbon, EVI, and NDVI in the selected study site. The correlation value between estimated carbon stock with EVI were found as 0.69, while with NDVI, the values were obtained as 0.87 respectively. The regression model of measured biomass with NDVI and EVI was developed for the data obtained during the period 2020-2021. The R² values obtained were 0.81 for the regression model between estimated carbon stock and EVI, and 0.77 for the regression model between NDVI and estimated carbon stock. The results indicate that the methodology adopted in this study can help in selecting best fit model for analyzing relationship between carbon stock and NDVI/EVI and for estimating biomass and carbon stock using allometric equation at various spatial scales. The produced output map and allometric equation revealed carbon stock distribution of 5.88 t/ha up to 900 t/ha, with an average value of 406.67. Generally, the approaches used on this study can be used by the forest planners, policy makers, and government officials for conservation and protection of the forest ecosystem. [ABSTRACT FROM AUTHOR]

The impact of the construction and expansion of the highway system on the surrounding soil ecosystem was investigated based on field surveys and experimental analysis during the years 2016 and 2017. In the proposed study, soil available nutrients (N, P, K), heavy metal toxicity, and carbon stock were evaluated spatially by considering horizontal distances of 0–5 m, 5–10 m, and > 20 m and seasonally during pre-monsoon and post-monsoon months. The concentration of soil available N, P, K ranged from 278.22 to 297.64 kg ha−1, 34.93 to 46.73 kg ha−1, and 233.91 to 265.22 kg ha−1 and was observed to be low in the soils adjacent to road construction activities (0–5 m) as compared to control site (> 20 m), which significantly indicated that soils nearby roads were more degraded. Seasonal variation played a significant impact on soil chemical properties; especially, a higher concentration of available macronutrients was observed during the post-monsoon season. The highly disturbed soil at 0–5 m registered higher heavy metal concentrations (Cd, Cr, Pb, Zn, and Fe) as compared to the control site and followed the decreasing order: Fe > Zn > Pb > Cr > Cd. In addition, highway expansion activities decreased soil organic carbon by 30% in the roadside soils in comparison to the control site. A significant loss of soil carbon stock of 1058.82 Mg C ha−1 was observed, leading to a reduction in the carbon sequestration potential of the region. Moreover, the study notices that highway transportation and construction activities are of potential risk for degrading soil quality. [ABSTRACT FROM AUTHOR]

The necessity to identify ecosystems with high carbon sink capacity as an alternative mitigation approach to terrestrial carbon sequestration has increased due to hazards such as global warming from emissions of Green House Gases mainly due to anthropogenic activities. Tea is an intensively managed perennial cash crop planted beneath a canopy of shade trees. They provide a prospect for the reduction of climate change while providing economic incentives so much so that some states and the country are dependent on the plantations and the revenue generated out of the tea gardens. Tea and shade trees together can store a significant quantity of atmospheric CO2 in the plants and the soil. The area of the gardens and the shade trees that grow in them makes it very necessary to estimate the amount of carbon sequestered in tea agroforestry systems and define their role as carbon sinks countering the climatic changes and the mitigation of the same. [ABSTRACT FROM AUTHOR]

Floodplain restoration can enhance the capacity for carbon sequestration by facilitating higher water tables, deposition of fine sediment, and increased input and residence time of organic matter. We measured floodplain soil organic carbon stocks in nine stream restoration projects across the western United States and compared them to nearby degraded and reference condition floodplains. Degraded floodplains had the lowest soil mean carbon stocks in the majority of floodplains measured (range 161–894 Mg C/ha), and reference stocks had the highest stocks (range 391–904 Mg C/ha) of those with statistically significant differences between the three categories. Across all sites measured, stream restoration sites, referred to as treatment sites, had stocks (range 203–1028 Mg C/ha) similar to degraded condition floodplains but the largest range. When modeled under degraded conditions, four out of nine of the treatment sites had significantly higher OC stocks than predicted. Climate and geologic variables are most influential in predicting carbon stocks, and floodplains in the interior western USA have the highest carbon stocks. As the demand for carbon sequestration increases due to climate change, ecologically responsible floodplain restoration provides a significant opportunity for carbon storage. However, despite the statistically significant relationships we observed in this dataset, the variations within the data in relation to degraded/treatment/reference categories illustrate the uncertainties in quantifying the effects of restoration on floodplain carbon stocks. [ABSTRACT FROM AUTHOR]

Forest carbon sinks play an important role in climate change mitigation and adaptation. The Chinese government has demonstrated its proactive approach to addressing climate change by setting development targets for low-carbon transformation and making solemn commitments to peak carbon emissions before 2030 and to achieve carbon neutrality by 2060. In this article, the Chinese Government's Work Reports and Five-Year Plans are used to construct an index named China's Climate Change Policy Attention ( C C P A ), which reflects the government's emphasis on climate change and forestry in China. This article aims to examine the impact of C C P A , the adjusted Climate Policy Uncertainty ( C P U ) index from the U.S., and the Economic Policy Uncertainty ( E P U ) index from China on the Chinese forest carbon stocks ( F C S ) comprehensively. On this basis, we are interested in clarifying the channels by which C C P A promotes the growth of forest carbon sequestration in China. Specifically, panel data from 30 provinces in China from 2000 to 2017 are used for empirical analysis, and the following results are obtained: (1) The baseline regression indicates that C C P A significantly promotes the growth of F C S , while C P U or E P U inhibits its growth. (2) The interactive regression shows that the effect of C C P A on the growth of F C S can mitigate the inhibiting impact of C P U or E P U . (3) Mediation analysis documents that C C P A promotes F C S growth by increasing the forest tending area, expanding the existing forest area, increasing renewable energy consumption, and improving green investment. (4) Heterogeneity analysis reveals a clear differentiation in the effect of C C P A on F C S under different situations. Finally, policy implications are proposed based on the results. This article is expected to provide a theoretical basis for the Chinese government to develop relevant policies from the perspective of promoting F C S growth. [ABSTRACT FROM AUTHOR]

The purpose of this article was to assess the participation of young soils of ash dump forest communities in carbon sequestration by soils of southern taiga forests, considering the physico-chemical properties of the ash substrate and forest litter (pH, TOC, TN, content of P and K mobile compounds, and exchangeable Ca and Mg ions). It was revealed that on three Middle Ural ash dumps (composed of fly ash from various brown coals) over 50–60 years, forest communities spontaneously formed according to the zonal type (with the dominance of Betula pendula Roth and Populus tremula L.) with poorly differentiated young soils—technosols. For the first time, as a result of using an integrated approach to assess the direction of forest ecosystem formation on fly ash dumps, a tendency to increase carbon stocks in technogenic soils that have not reached the level of zonal soils was revealed, as well as the dependence of C accumulation on some physico-chemical characteristics of ash was established. Carbon stocks in Technosols are on average equal to 44 t/ha but vary significantly. It was shown that there is a medium negative relationship between the content and stocks of organic carbon in soils formed on a technogenic substrate and the content of mobile phosphorus compounds in them (the correlation coefficient is −0.58 and −0.53, respectively). The average carbon stocks in the litter of technosols, which is the main source of organic carbon in forest soils, are 3.2 t/ha. It was revealed that the carbon stocks in the litter are most influenced by the content of exchangeable calcium cations and magnesium in it (the correlation coefficients are −0.68 and −0.69, respectively). Any correlation between the studied litter parameters and carbon accumulation in the soils of ash dumps was found. The study revealed that the carbon stocks in the technosols of ash dump forest communities are two times less than the carbon stocks in the zonal forest soils of the Middle Ural southern taiga. The stocks of this element in the litter of young soils are equal to 1/3 of the litter of zonal soils. The composition of the humus substance system formed in the soils of forest areas of ash dumps and zonal soils is similar. The results of this study can serve to fill gaps in the knowledge about carbon sequestration by soils and aim to draw attention to forest communities of technogenic ecosystems to consider the contribution of their components to carbon sequestration. [ABSTRACT FROM AUTHOR]

Land use change has a significant impact on the carbon balance in urban ecosystems. Based on the law of land use change in Taiyuan City from 2000 to 2020, this study uses the CA-Markov model to predict the spatial pattern of land use in different scenarios in 2030, and uses the InVEST model to evaluate the carbon storage of Taiyuan City from 2000 to 2030. The results show that from 2000 to 2020, the construction land increased significantly, an increase of 339.265 km², and the area of forest land increased by 96.707 km²; the area of water, cultivated land, grassland and unused land decreased by 13.333 km², 275.037 km², 146.073 km² and 1.223 km², respectively. From 2000 to 2020, the carbon storage in Taiyuan has decreased by 2 312 591.65 t. Different from the natural development scenario, under the ecological protection scenario, the forest land will increase slightly in 2030 compared with 2020, and the construction land will be effectively limited and expanded, both of which facilitated the generation of ecological effects under the ecological protection scenario. In 2030, the carbon storage under the ecological protection scenario is 1 760 959.397 t more than that under the natural development scenario. From the perspective of land use changes, the increase in forest area is the main reason for the increase in carbon storage in the study area, and the carbon sequestration capacity is enhanced under the ecological protection scenario. This study will provide a scientific basis for land use structure adjustment and management in Taiyuan. [ABSTRACT FROM AUTHOR]

Forest management decisions affect carbon stock and rates of sequestration. One subject of debate is the rotation age that will optimize sequestration over extended periods. Some argue that shorter rotations facilitate greater sequestration rates due to the accelerated growth rates of younger trees compared to mature or old-growth trees. Others maintain that frequent harvesting will not allow forest carbon to rebound after each subsequent rotation, and thus more extended periods between clearcutting is the superior choice. These contrasting viewpoints are mirrored regarding the impact of thinning treatments, in that either thinning will enhance forest carbon uptake by facilitating improved and sustained r growth of residual trees or removing any above-ground biomass will outweigh the yields. This study aims to compare the different suites of management decisions and identify practical combinations of rotation ages and thinning applications that will optimize carbon sequestration while meeting other objectives over a 240-year projection timeframe. Stand development under different harvest rotations and thinning specifications was modeled using a Forest Vegetation Simulator (FVS). We found that site productivity was the primary determinant in stand-above-ground carbon dynamics under various management scenarios. Thus, the optimal rotation age/thinning treatment combinations differed between site classes. High productivity stands were estimated to sequester the most above-ground live carbon with 60-year rotations with a low-intensity thin at age 40. Moderately productive stands performed the best with 80-year rotations when two low-intensity thinning treatments were applied between harvests. For high and moderate productivity stands, estimates of gross carbon increased when two low or moderate-intensity thinning treatments were applied within 80- or 120-year rotations. High-intensity thinning treatments reduced total carbon sequestered over the 240-year projection timeframe for all productivity levels and rotation ages, except for low productivity stands under 120-year rotations. [ABSTRACT FROM AUTHOR]