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Natural regeneration is critical for sustaining mangrove ecosystems, particularly the Sundarbans, the world's largest mangrove forest. This study assessed the impacts of biotic and abiotic factors on regeneration dynamics, examining spatial variations across salinity zones and temporal changes (2010–2020) using data from 30 permanent sample plots (PSPs) established by the Mangrove Silviculture Division, Bangladesh Forest Research Institute. We found that the biodiversity of the Sundarbans remained relatively stable over time, with a high Müeller-Dombois Similarity Index and low Bray-Curtis Dissimilarity Index across years and zones. However, salinity variations influenced species composition. The study also revealed a decline in the dominance of Heritiera fomes and an increase in the abundance of Excoecaria agallocha (showed habitat expansion) over time while both species maintained a high importance value. The total biomass growth from living (77.84 Mg/ha) and newly established trees (14.39 Mg/ha) was low, while the biomass loss (81.79 Mg/ha) from the dead trees was significant. Furthermore, our analysis indicated that abiotic factors, including salinity, siltation, and soil pH, had minimal influence on plant functional traits, but changes in basal area notably affected biomass dynamics. These findings provide insights into the regeneration trends of the Sundarbans and guide the formulation of policies to manage this unique ecosystem sustainably.

The growing demand for land for slash-and-burn cultivation, driven by human population growth, has led to the creation of scattered cultivated fields and a mosaic of fallow areas in various stages of regeneration. While tropical forests have demonstrated the ability to rebound regarding tree species diversity and forest structure following disturbances, the extent of recovery in coastal vegetation in southern Africa remains uncertain and poorly understood. To address this knowledge gap, our study collected biophysical data from smallholder fields, fallow land, and forests to evaluate the structure and functioning of coastal vegetation in Gaza province, southern Mozambique. We established 90 sample plots of 0.1 ha each at different stages of plant succession using opportunistic sampling approach. Within these plots, we recorded the diameter at breast height, total height, and species name of all trees and shrubs. Litter and soil samples were collected in 1 m² quadrats embedded within the main plot. Our findings indicate a high capacity for regeneration following the disturbance caused by slash-and-burn cultivation. Species composition varied significantly across different stages of succession, with 52 species identified in forests (FL), 34 in old fallow (OF), 29 in middle fallow (MF), 28 in initial fallow (IF), and 15 in cropland (CL). Richness and diversity increased over time after the practice of slash-and-burn cultivation, with a noticeable enhancement from the initial fallow stage. We observed a gradual recovery of soil carbon stocks in young fallow areas, while litter biomass decreased throughout the recovery phase of the fallow lands. Our study highlights that areas abandoned after agriculture can regenerate in terms of structure, floristic composition, and tree carbon content.

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.

Abstract Natural forests are crucial for climate change mitigation and adaptation, but deforestation and degradation challenges highly reduce their value. This study evaluates the potential of natural forest carbon stock and the influence of management interventions on enhancing forest carbon storage capacity. Based on forest area cover, a study was conducted in nine purposely selected forest patches across various forest ecosystems. Data on diameter, height, and environmental variables from various forest management approaches were collected and analyzed with R Ver. 4.1. The findings revealed a substantial difference (p .029) in carbon stock between environmental variables and management interventions. The findings revealed a strong connection between environmental variables and the overall pool of carbon stock within forest patches (p .029). Carbon stocks were highest in the Moist‐montane forest ecosystem (778.25 ton/ha), moderate slope (1019.5 ton/ha), lower elevation (614.50 ton/ha), southwest‐facing (800.1 ton/ha) and area exclosures (993.2 ton/ha). Accordingly, natural forests, particularly unmanaged parts, are sensitive to anthropogenic stresses, decreasing their ability to efficiently store carbon. As a result, the study highlighted the importance of sustainable forest management, particularly area exclosures and participatory forest management, in increasing forest carbon storage potential.

The plant biodiversity status of many village land forest reserves is little known to support meaningful implementation of sustainable forest management objectives in Tanzania. This study was conducted to assess the status of Litwang’ata village land forest reserve in Ludewa district, Southwest Tanzania through 20 square sample plots of 10 × 10 m. A total of 20 woody plant species belonging to 12 families and 19 genera with DBH ≥ 5 cm were identified in the study forest. The most important species with their importance value index were Brachystegia spiciformis (78.02), Brachystegia boehmii (22.05), Faurea saligna (15.18), Uapaca kirkiana (14), Acacia amythethophylla (13.07), Pseudolachnostylis maprouneifolia (12.76) and Gardenia ternifolia (10.36). The forest had a Shannon diversity index (H´) of 2.27, indicating medium diversity. Stand structure comprised 1,330 ± 523 stems ha–1, basal area of 18.97 ± 6.81 m2 ha–1 and stand volume of 142.36 ± 52.17 m3 ha–1. The mean above- and belowground carbon stocks were 46.97 ± 17.23 Mg ha–1 and 23.90 ± 8.58 Mg ha–1 respectively. The higher tree densities, basal area, stand volume and carbon stocks recorded in this study compared to other Miombo woodlands indicate that Litwang’ata forest is still in good condition, and managment efforts should be strengthened to bolster biodiversity conservation for present and future generations.

Global warming is a significant challenge, and carbon stocks in terrestrial ecosystems are crucial for reducing the greenhouse effect and increasing sinks. A study was conducted in Zhengzhou City from 2000 to 2020 using Landsat image spectral reflectance to analyze changes in carbon stock. Environmental variables such as surface moisture, salinity, vegetation index, brightness, and soil texture were constructed. Multiple linear regression (MLR), support vector machine regression (SVR), random forest regression (RFR), and long short-term memory (LSTM) models were used to invert the carbon stock. The results showed that the NDCS index, constructed using Landsat's blue band and NIR band, was the best inversion variable for carbon stock, with the clay index (CI) playing a primary role. The LSTM algorithm had the best fitting effect on carbon stock, with an R2 of 0.84 and RMSE of 3.56. The carbon stock in Zhengzhou City decreased by 13.93% between 2000 and 2020, possibly due to the large-scale reduction of arable land. Future land-use planning should focus on protecting arable land, optimizing land-use patterns, and enhancing the ecosystem's carbon sequestration capacity.

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.

Synergies and trade-offs among land use and land covers (LULCs) pose considerable uncertainties in achieving the dual carbon goals for China's Loess Plateau (CLP). In this context, we unraveled the carbon stock dynamics induced by land use and land cover change (LUCC) in the CLP over the past 40 years using the satellite-derived annual LULC maps and the InVEST model. Then, mixed measures were employed to quantify the global and local responses of the carbon stock dynamics to both natural and anthropogenic factors. We found that approximately a total of 5.58 × 109 Mg of carbon was stored in the CLP's ecosystems in 2019. Chronologically, the total carbon stock showed a slight decrease in the CLP from 1980 to 2019 due to the extensive LUCCs linked to socioeconomic activities. Specifically, the total carbon density loss rate accelerated in urban–rural-wild continuum (RUWC) types with higher human activity intensity, such as villages and urban, while it decelerated in woodlands, and croplands, where the human activity intensity is lower. Moreover, the total carbon density gain rate in wildlands was accelerating. Finally, we revealed that the carbon stock dynamics in the CLP over the past 40 years were primarily influenced by socioeconomic variables and have responded diversely to the drivers in space.

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 ± 7 mg 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.

Accurate estimations of biomass and its temporal dynamics are crucial for monitoring the carbon cycle in forest ecosystems and assessing forest carbon sequestration potentials. Recent studies have shown that integrating process-based models (PBMs) with remote sensing data can enhance simulations from stand to regional scales, significantly improving the ability to simulate forest growth and carbon stock dynamics. However, the utilization of PBMs for large-scale simulation of larch carbon storage distribution is still limited. In this study, we applied the parameterized 3-PG (Physiological Principles Predicting Growth) model across the Mengjiagang Forest Farm (MFF) to make broad-scale predictions of the biomass and carbon stocks of Larix olgensis plantation. The model was used to simulate average diameter at breast height (DBH) and total biomass, which were later validated with a wide range of observation data including sample plot data, forest management inventory data, and airborne laser scanning data. The results showed that the 3-PG model had relatively high accuracy for predicting both DBH and total biomass at stand and regional scale, with determination coefficients ranging from 0.78 to 0.88. Based on the estimation of total biomass, we successfully produced a carbon stock map of the Larix olgensis plantation in MFF with a spatial resolution of 20 ​m, which helps with relevant management advice. These findings indicate that the integration of 3-PG model and remote sensing data can well predict the biomass and carbon stock at regional and even larger scales. In addition, this integration facilitates the evaluation of forest carbon sequestration capacity and the development of forest management plans.

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.

The global interest in increasing the world's carbon stocks is skewed towards perennial woody ecosystems. But a continuous shortage of land stands in the way of achieving the goal. We must therefore aim to explore viable alternatives. The banana as a potential carbon sequester attracted little attention from researchers. Therefore, this study aimed at estimating the potential of bananas in different states of India as potential carbon sequesters. Data was collected from twelve major banana producers between January 2021 and December 2022. One hundred banana gardens were sampled in each of the 12 banana-producing states, covering the major bananas grown (AAA, AAB, and ABB). The above-ground (AGB) and below-ground (BGB) biomass were calculated using the allometric equation with pseudostem volume as the allometric parameter. The dry weight obtained from the allometric equations was then converted to carbon using a dry weight to carbon conversion factor. Sequestered carbon varied with the AAA, AAB, and ABB of bananas. Banana plant carbon stock was also found to be very small, ranging from 2.573 to 6.407 t/ha, compared with very high soil carbon ranging from 39.55 to 77.14t. In all the banana-cultivating states, the proportion of carbon contained in the plant to that in the soil was only 8.286 percent, and that of soil carbon accounted for 91.714%. At the national level, the banana crop sequestered 48.627 million metric tonnes of carbon, with soil carbon accounting for 44.798 metric tonnes and plant carbon accounting for only 3.828 metric tonnes per year. Despite these small amounts of plant carbon, the banana cropping system enriches the soil by enabling much more carbon to be sequestered into the soil in amounts comparable to other perennial plantations.

Mangroves are one of the coastal vegetation that can mitigate carbon (carbon sink and carbon storage). This study aimed to determine the potential for soil carbon stock found under stands of mangroves in Lembar Bay, West Lombok, and West Nusa Tenggara. The research began with the identification of the species and then proceeded toa sampling of the soil, which was then analyzed using the Walkley and Black method. The results showed that there were ten species of mangroves, namely, Rhizophora stylosa, Avicennia lanata, Avicennia marina, Bruguiera gymnorrhiza, Ceriops decandra, Excoecaria agallocha, Lumnitzera racemosa, Scyphiphora hydrophyllacea, Thespesia populnea, and Xylocarpus maluccensis. The highest soil carbon content percentage was found in the lower soil of the A. lanata (1.43 %C) mangrove, and the lowest was found in the lower-stand soil of E. agallocha (0.21 %C). Meanwhile, the carbon sinks per meter were 0.002-0.066 gC/m2, with an average of 0.020±0.020 gC/m2. The estimated total soil carbon sink in 10 mangrove stands was 0.20-6.60 tons C/ha, with an average of 2.18±2.010 tons C/ha. The average total estimated soil carbon stock found in 20.49 ha of the mangrove area studied was 44.67 tonsC, which is equivalent to 263.69 tonsC in a mangrove area of ​​120.96 ha in Lembar Bay.

A growing number of initiatives at global, regional and national scales propose to plant millions, billions or even trillions of trees as a simple solution to resolve complex environmental problems. However, tree planting is much more complicated than it seems. We summarize the multifaceted decision‐making process needed and offer guidelines to increase the success of the proposed ambitious efforts to increase tree cover world‐wide. Given the varied definitions of and motivations for tree planting, it is critical that stakeholders work together to clearly define the biophysical and socioeconomic goals of each project. Then a series of questions must be addressed about where and how (e.g. planting trees vs. allowing for natural forest regrowth) to most effectively achieve these goals and minimize unintended negative consequences, as well as how, when and by whom success of efforts will be evaluated. Key guidelines to successfully increase tree cover include: (a) first addressing the underlying drivers of deforestation; (b) integrating decision‐making across scales from local to global; (c) tailoring tree planting strategies to clearly stated project goals and planning, adaptively managing and evaluating success over a sufficiently long timeframe; (d) focusing on the forest ecosystem as a whole, and not just the trees; (e) coordinating different land uses and (f) involving stakeholders at all stages of the planning process. Synthesis and applications. Tree planting, along with other strategies to increase tree cover in appropriate locations and contexts, can make a valuable contribution to ensuring the ecological and social well‐being of our planet in coming decades, but only if these efforts are considered as one component of multifaceted solutions to complex environmental problems and are carefully planned, implemented and monitored over a sufficiently long time‐scale with stakeholder engagement and broader consideration of socio‐ecological complexities.

Under the background of global climate change, the role of carbon storage in mitigating the increase of atmospheric CO2 concentrations is of paramount importance. However, land use and land cover change (LULC) resulting from urban sprawl disturbs the level and distribution of carbon storage. This study aims to explore the spatiotemporal variability of carbon storage and the correlations between that and urban development for China’s 369 cities in 2000, 2010, and 2020. The InVEST model and several multiple linear regression models are employed and the results show that: (1) Cities in western China sequester a large amount of carbon (maximum greater than 2000 TgC) and only some of them, from 2010 to 2020, can maintain a positive change in carbon storage. The rest of China shows a negative change, but a higher carbon storage per area (maximum greater than 0.01 TgC/km2 in the east). Moran's I shows that such variability has a significant spatial autocorrelation. (2) The intensification of the population, the growth of economy, and urbanization are the main factors influencing carbon storage, which are not only reflected on the national scale but also have different local characteristics in different regions. Cities in China's inland regions (e.g., western, some central, and northeastern China), most of which are developing cities, show more diversified impacts of their urban development on carbon storage. However, in developed cities, mostly concentrated in the eastern region, such impacts and variations show a more unified trend. Considering that environmental policy is often a national action, therefore, to strengthen the carbon sequestration capacity of cities, it is necessary to formulate not only a unified leading policy from the national level but also the practical policies of local governments of cities that match their development stages.

Karst ecosystems serve as a vital part of the Earth’s ecosystem and have a substantial influence on the worldwide carbon cycle. Revealing the features and driving factors of the spatiotemporal evolution of Carbon (C) stock in karst watersheds is critical for the in-depth exploration of the regional carbon cycle and carbon sources/sinks, as well as in regional ecological restoration. In this study, the Nanming River Basin, a representative karst basin in southwest China, was used as the subject region. Based upon data on land use change from 2000 to 2020, an Integrated Valuation of Ecosystem Services & Tradeoffs (InVEST) model was applied to calculate the C stock from 2000 to 2020 and identify the driving factors of the regional change of C stock using an optimal parameters-based geographical detector (OPGD) model. The findings indicate that: (1) the cumulative reduction of C stock in the basin from 2000 to 2020 was 3.16 × 105 t; the center of gravity of C stock increase has shifted to the southwest by 2434.16 m, and the center of gravity of the reduction has shifted to the southwest by 7260.53 m. (2) The transition of forest land into construction land had the highest contribution to the decrease of C stock (60.91%); the transition of cultivated land and grassland into forest land was conducive to a rise in the C stock, and these conversions contributed 45.93% and 35.00%, respectively, to the increase of C stock. (3) The normalized difference vegetation index (NDVI), population density, intensity of human activity, slope, and lithology all have annual average q-values greater than 10%, meaning they are the primary factors driving the spatial differentiation of C stock. The contribution of the NDVI ∩ slope direction to the regional heterogeneity of C stock was the largest among the interactive driving factors, with an explanatory power close to 30%. The interactive combinations of drivers all showed nonlinear enhancement or two-factor enhancement effects. To some extent, this study deepens the study of changes in C stock and related driving mechanisms in karst areas, intending to provide a scientific foundation for the recovery of fragile ecosystems and to support a regional low-carbon economy.

Social Forestry (SF) in Indonesia has emerged as a keystone strategy for Sustainable Forest Management. By allocating 12.7 million ha of forest to be managed by local communities, the government has set in motion an ambitious plan for SF to reduce poverty, empower local people, and improve forest conditions. More recently, SF is framed for its opportunity to contribute to climate change mitigation and adaptation. This study focused on examining the contribution of SF to the Nationally Determined Contribution (NDC) goals in Yogyakarta and Lampung. By analyzing spatial data of SF areas and land cover changes using ArcView 10.8, the study assessed the carbon stock potential in SF areas. Carbon stock calculations were based on the 2022 National Forest Reference Level (FRL) for the periods before and after SF implementation. The finding of the study indicated that the carbon stock of SF areas in Yogyakarta and Lampung ranged from 9,214,381 to 9,923,420 ton CO2eq prior to SF, while the current carbon stock ranges from 8,703,489 to 9,393,706 ton CO2eq, representing a decrease (around 5.4%) rather than an increase. Overall, the changes in carbon stock were relatively small and localized, and the magnitude of the increase was insufficient to offset the overall decrease. To achieve the objectives of SF, such as meeting emission targets and achieving sustainable land use, it is crucial to carefully manage forest edges and fragmented forests, as they can contribute to carbon stock losses. Additionally, further studies and research are needed to improve the accuracy of carbon stock calculations, particularly for non-forest categories, which have higher uncertainty in the reference levels

Abstract Background Temperate forests are major carbon sinks because of their high storage potential and low decomposition processes. We quantified tree carbon (TC) storage from 143 plots distributed across three major forest types of Kashmir Himalaya, relative to differences in ecological factors. Combined regression and Random Forest (RF) analysis were used to examine the distribution of TC stock along ecological gradients and recognize the role of driving factors on TC stocks. Results Among the three forest types, sub-alpine (SA) forest was the primary TC sink, accounting for 228.73 t ha−1 of carbon, followed by mixed conifer (MC; 181.29 t C ha−1) and blue pine (BP; 133.04 t C ha−1) forests. The distribution of TC stocks among the three forest types differed significantly (χ 2 = 18.87; P = 0.000). Relative carbon stock analysis demonstrated that Abies pindrow and Pinus wallichiana accounted 91% of TC stocks across the landscape. Basal area, mean diameter at breast height (DBH), elevation, disturbance and precipitation had significant effects on TC stocks in bivariate regression models. The RF model explained 86% of the variation; basal area interpreted 30.15%, followed by mean DBH (17.96%), disturbance complex (10.64%), precipitation (8.00%) and elevation (7.34%). Conclusions Kashmir Himalayan forests are significant carbon sinks as they store a substantial quantum of carbon in trees. Forest carbon, an essential climatic indicator, is determined by a complex interaction of other ecological variables, particularly stand structural features. The study provides insights into the role of these natural forests in climate change mitigation and in REDD+/national commitments to offset the carbon.

Carbon dioxide (CO2) is one of the greenhouse gases that causes global warming with the highest concentration in the atmosphere. Mangrove forests can absorb CO2 three times higher than terrestrial forests and tropical rainforests. Moreover, mangrove forests can be a source of Indonesian income in the form of a blue economy, therefore an accurate method is needed to investigates mangrove carbon stock. Utilization of remote sensing data with the results of the above-ground carbon (AGC) detection model of mangrove forests based on multispectral imaging and vegetation index, can be a solution to get fast, cheap, and accurate information related to AGC estimation. This study aimed to investigates the best model for estimating the AGC of mangroves using Sentinel-2 imagery in Benoa Bay, Bali Province. The random forest (RF) method was used to classified the difference between mangrove and non-mangrove with the treatment of several parameters. Furthermore, a semi-empirical approach was used to assessed and map the AGC of mangroves. Allometric equations were used to calculated and produced AGC per species. Moreover, the model was built with linear regression equations for one variable x, and multiple regression equations for more than one x variable. Root Mean Square Error (RMSE) was used to assess the validation of the model results. The results of the mangrove forests area detected in the research location around 1134.92 ha, with an Overall Accuracy (OA) of 0.984 and a kappa coefficient of 0.961. This study highlights that the best model was the combination of IRECI and TRVI vegetation indices (RMSE: 11.09 Mg/ha) for a model based on red edge bands. Meanwhile, the best results from the model that does not use the red edge band were the combination of TRVI and DVI vegetation indices (RMSE: 13.63 Mg/ha). The use of red edge and NIR bands is highly recommended in building the AGC model of mangrove forests because they can increase the accuracy value. Thus, the results of this study are highly recommended in estimating the AGC of mangrove forests, because it has been proven to be able to increase the accuracy value of previous studies using optical images.

Abstract Background National and international institutions periodically demand information on forest indicators that are used for global reporting. Among other aspects, the carbon accumulated in the biomass of forest species must be reported. For this purpose, one of the main sources of data is the National Forest Inventory (NFI), which together with statistical empirical approaches and updating procedures can even allow annual estimates of the requested indicators. Methods Stand level biomass models, relating the dry weight of the biomass with the stand volume were developed for the five main pine species in the Iberian Peninsula (Pinus sylvestris, Pinus pinea, Pinus halepensis, Pinus nigra and Pinus pinaster). The dependence of the model on aridity and/or mean tree size was explored, as well as the importance of including the stand form factor to correct model bias. Furthermore, the capability of the models to estimate forest carbon stocks, updated for a given year, was also analysed. Results The strong relationship between stand dry weight biomass and stand volume was modulated by the mean tree size, although the effect varied among the five pine species. Site humidity, measured using the Martonne aridity index, increased the biomass for a given volume in the cases of Pinus sylvestris, Pinus halepensis and Pinus nigra. Models that consider both mean tree size and stand form factor were more accurate and less biased than those that do not. The models developed allow carbon stocks in the main Iberian Peninsula pine forests to be estimated at stand level with biases of less than 0.2 Mg∙ha− 1. Conclusions The results of this study reveal the importance of considering variables related with environmental conditions and stand structure when developing stand dry weight biomass models. The described methodology together with the models developed provide a precise tool that can be used for quantifying biomass and carbon stored in the Spanish pine forests in specific years when no field data are available.

Mangrove forests provide important ecosystem services to the human society and nature including mitigation of climate change. The quality and quantity of ecosystem services offered by mangrove forests are however at risk when mangroves are degraded. The restoration of mangrove areas is considered as a natural solution to recover lost ecosystem services such as securing of carbon stocks. This study was set to assess the extent to which mangrove planting activities compensate for the loss of biomass carbon stocks and other structural attributes in Rufiji Delta-Tanzania through analysis of biomass carbon loss and gain as a result of conversion of mangroves forest into rice farms and planting of mangroves respectively. Circular sampling plots were established in good, degraded and restored mangrove areas where total tree heights and Diameter at Breast Height (DBH) of all standing trees were measured and recorded by species and used to compute biomass carbon stock. The mangrove species composition changed from 7 in 1989 to 2 species in degraded plots in 2016. The species dominance changed from Avicennia marina in 1989 to Rhizophora mucronata in 2016 in good mangrove plots and from A. marina and Sonneratia alba to an invasive Baringtonia racemosa in degraded plots. Bruguiera gymnorrhiza was the only mangrove species used for restoration through planting in the delta and the overall survival rate was 37%. The above-ground carbon (AGC) and below-ground carbon (BGC) for the good natural mangrove plots ranged from 28.18 to 299.43 and 16.00–164.51 Mg C ha−1 respectively compared to 0–150.88 and 0–967.01 Mg C ha−1 in the degraded plots. The total biomass carbon stock in the good natural mangrove plots ranged from 44.14 to 463.94 Mg C ha−1 while for the degraded plots the range was 0–247.89 Mg C ha−1. The carbon stocks in 5, 10 and 15 year old planted mangroves were 13.65, 20.13 and 57.53 Mg C ha−1 respectively. The biomass loss of 172.91 Mg C ha−1 was estimated in a period of 25 years (1989–2016), equivalent to an annual loss rate of 6.9 Mg C ha−1year−1, demonstrating that degradation has a significant contribution to loss of carbon stocks. Nevertheless, an average of 3.8 Mg C ha−1year−1 was stocked by 15 years old planted mangroves, demonstrating that there is potential for the planted mangroves to compensate for the lost carbon if the anthropogenic drivers such as rice farming is controlled. These findings call for urgent collective actions among stakeholders to consider and improve the integrated management of the delta.

Abstract Background Sustainable land management interventions were introduced in Geda watershed in 2012 to reduce soil erosion, improve water infiltration, and increase plant-carbon inputs into the soil. This study explored the impact of the interventions on biomass production, carbon stock, and carbon sequestration. Stratified sampling was employed in the main and the dry seasons in the treated and untreated sub-watersheds that are found adjacent to each other. Above- and below-ground plant biomass, soil bulk density and organic carbon in 0–15- and 15–30-cm depths, and soil moisture content in 0–20- and 20–40-cm depths were collected from the crop, grazing, and tree lucerne plots. All analyses were performed based on standard procedures. Results Plant biomass production, carbon stock, and carbon sequestration varied highly significantly (P ≤ 0.001) among sub-watersheds, landscape positions, and land uses. Higher mean values were observed for treated sub-watershed, lower landscape position, and tree lucerne plot. The higher mean values in the lower landscape position of the treated sub-watershed were due to tree lucerne plantation. Similarly, topsoil (0–15 cm) carbon stock was statistically higher (P ≤ 0.001) in the treated sub-watershed and at tree lucerne plot (P ≤ 0.05). In addition, carbon stock by sub-surface soil (15–30 cm) was significantly higher (P ≤ 0.001) in the treated sub-watershed under crop and grazing lands but the higher value was in cropland and in the upper position. This could be due to the decomposition of organic materials from biomasses of crops and biological supporting measures (tree lucerne and Phalaris) facilitated by tillage. Six years of sustainable land management interventions led to the sequestration of 12.25, 7.77, and 13.5 Mg C ha−1 under cropland, tree lucerne, and grazing plots, respectively. Conclusion Sustainable land management interventions revealed auspicious ecological impacts in Geda watershed in terms of improving plant biomass production, carbon stock, and correspondingly capturing higher carbon dioxide equivalent taking untreated sub-watershed as a baseline. Prohibition of free grazing was the key element of the intervention to reduce biomass export and increase carbon sequestration in the treated sub-watershed. Thus, sustaining tree lucerne plants as a conservation measure and the prohibition of free grazing practices are principally essential.

In India, reforestation programs with native indigenous tree species are a recent activity. Information on experiences comparing mono- and mixed-species plantations is limited. This study aims to estimate growth, aboveground biomass, and carbon sequestration between the mixed-species plantation and mono-species plantation. The growth, survival, height, aboveground biomass, and carbon sequestration of 82 native mixed species plantations were compared with Casuarina equisetifolia an exotic species planted in this region after over a decade (2006–2016). In the mixed species plantation, 7 species showed 100% survival rate and 19 species were not survived after over a decade intervals. While in the mono plantation, C. equisetifolia showed 92% of the survival rate. The growth rate of mixed species when compared to mono plantation, it showed highly significant differences (P

Deadwood is an important structural and functional component of forest ecosystems and biodiversity. As deadwood can make up large portions of the total aboveground biomass, it plays an important role in the terrestrial carbon (C) cycle. Nevertheless, in tropical ecosystems and especially in Africa, quantitative studies on this topic remain scarce. We conducted an aboveground deadwood inventory along two environmental gradients—elevation and land use— at Mt. Kilimanjaro, Tanzania. We used a huge elevation gradient (3690 m) along the southern slope of the mountain to investigate how deadwood is accumulated across different climate and vegetation zones. We also compared habitats that differed from natural forsts in land-use intensity and disturbance history to assess anthropogenic influence on deadwood accumulation. In our inventory we distinguished coarse woody debris (CWD) from fine woody debris (FWD). Furthermore, we calculated the C and nitrogen (N) content of deadwood and how the C/N ratio varied with decomposition stages and elevation. Total amounts of aboveground deadwood ranged from 0.07 ± 0.04 to 73.78 ± 36.26 Mg ha–1 (Mean ± 1 SE). Across the elevation gradient, total deadwood accumulation was highest at mid-elevations and reached a near-zero minimum at very low and very high altitudes. This unimodal pattern was mainly driven by the corresponding amount of live aboveground biomass and the combined effects of decomposer communities and climate. Land-use conversion from natural forests into traditional homegardens and commercial plantations, in addition to frequent burning, significantly reduced deadwood biomass, but not past selective logging after 30 years of recovery time. Furthermore, we found that deadwood C content increased with altitude. Our study shows that environmental gradients, especially temperature and precipitation, as well as different anthropogenic disturbances can have considerable effects on both the quantity and composition of deadwood in tropical forests.

Non-native Sonneratia apetala plantations have been widely recommended as part of China’s mangrove reforestation and afforestation plans, partly due to their rapid carbon accumulation in biomass and sediments. Nonetheless, reviews of the available data estimating carbon dynamics in the S. apetala plantations reveal a lack of monitoring data concerning carbon dynamics for the mature planted mangroves. This study sought to quantify how biomass and SOC stocks of the mature S. apetala plantations varied with mangrove growth between 2012 (aged 19 years old) and 2019 (aged 26 years old) using a continuous monitoring method. The results show that total biomass, as well as tree height and stem diameter at breast height (DBH), increased significantly between 2012 and 2019, while tree densities of both mangrove canopy and understory layers decreased. However, there was no significant difference in SOC content/stocks between 2012 and 2019. This result about SOC change may be partly attributable to the relatively shorter monitoring time span and the slower accumulation rate of SOC in comparison with biomass. In addition, fine root biomass was positively correlated with SOC content and regulated the vertical distribution of SOC content. Regression analysis for China’s S. apetala plantations found that biomass, tree height and DBH, and SOC stocks all increased with forest age. Moreover, SOC stocks were significantly positively correlated with biomass. This suggests that mangrove afforestation and reforestation can offer carbon-sink potential, but this should be confirmed by longer-term monitoring to further evaluate the SOC accumulation of S. apetala plantations over time.

This is an analysis of the tree community’s composition and structure of Bukit Badindiang sacred forest in Nagari Simpang, Pasaman West Sumatera. The study aims to (1) to obtain a representative account of the structure and composition of tree community of the sacred forest, (2) to estimate the Aboveground Carbon Stock (C-Stock) accumulated on it. A one-hectare plot was divided into 25 subplots of 20 m × 20 m each for tree and debris data collection. In each subplots, there would be a 5m x 5m sapling subplots and 1m x 1m seedling, understorey plant and litter subplots were nested inside. A total of 446 trees were recorded, representing 139 species from 49 families with a total basal area of 38.59 m2. The most dominant tree species was Campnosperma auriculata [Importance Value (IV) of 19.19]. The other prevalent species were Ficus benjamina (IV =16.50) and Mallotus caudatus (IV =14.78). A total of 62 species (44.6%) was considered locally rare with density of 1 tree/ha. Mallotus caudatus had the highest density (37 trees/ha) and Ficus benjamina had the highest Basal Area (BA) (5.61 m2 = 14.51% of the total). Euphorbiaceae (IV= 37.40) was the dominant family. The richest families were Euphorbiaceae (10) and Lauraceae (10). The total estimated Aboveground C-Stock was 190.62 MgC/ha, with the highest C was contributed by trees (178.85 MgC/ha or 93.8% of total). Trees with diameter class of 10 – 69.99 cm stored 62% of total tree carbon. The species richness, tree density and C-Stock of Bakit Badindiang sacred forest were relatively higher than those in several disturbed lowland forests in Sumatera.

Abstract Exclosures are used to regenerate native vegetation as a way to reduce soil erosion, increase rain water infiltration and provide fodder and woody biomass in degraded grazing lands. Therefore, this study assessed the impact of grazing exclosure on carbon sequestration and soil nutrients under 5 and 10 years of grazing exclosures and freely grazed areas in Tigray, northern Ethiopia. Carbon stocks and soil nutrients increased with increasing grazing exclusion. However, open grazing lands and 5 years of grazing exclosure did not differ in above‐ and belowground carbon stocks. Moreover, 10 years of grazing exclosure had a higher (p

Climate change has adversely affected the tree species growth throughout the globe. In Indian Himalayas, Celtis australis is an important agroforestry tree species which is highly exploited for domestic use (fuel wood, fodder, and small timber), and thus the growth and biomass production linked to the species bears importance. However, growth, biomass, and carbon stock of C. australis can be improved if genetically superior planting material is used under agroforestry programmes. Therefore, seed source (SS) variation studies in C. australis were initiated to identify potential germplasm for improving the species productivity and climate resilience. Experimental results showed that genotypic variation for height, collar diameter, and total biomass were found higher than corresponding environmental variance after four years. In the field environment, highest plant growth was recorded in Tehri SS (Height: 4.88 m; Diameter: 9.69 cm) and Solan SS (Height: 4.81 m; Diameter: 8.64 cm), compared to rest of the seed sources. In contrast, least plant growth (Height: 3.46 m; Diameter 5.19 cm) was observed in Dehradun SS. Likewise, biomass production was assessed maximum (207 t ha−1) in Tehri SS and it was minimum (44 t ha−1) in Dehradun SS. In different seed sources, the estimated carbon stock and carbon sequestration was ranged between 33 103 t ha−1 and 99–381 t ha−1, respectively. Overall, growth, biomass, carbon stock, and carbon sequestration confirmed the superiority of Tehri SS over rest of the SS, after four years of field experiment. Moreover, Tehri SS showed better mitigation and adaptation potential for changing climate compared to rest of the SS, because of its superiority in term of the growth performance, biomass production, carbon stock, and carbon sequestration. The results indicated that SS induced genetic variation has the tremendous potential to improve the productivity and climate change mitigation and adaptation in C. australis. Therefore, selection of genetically diverse seed sources and evaluation of their potential (adaptive and mitigate) could be one of the futuristic strategies for climate change related fine-tuning of agroforestry practices.

Climate change and human activities have continuously decreased productivity, carbon storage and soil fertility of global plantations under continuous planting. However, this situation can be largely reversed through appropriate planting density and thinning management. We evaluated the effects of initial planting density and selective thinning management on biomass accumulation and carbon stocks in different plantation compartments, on soil carbon stocks in different stand stages of a chronosequence of evergreen (Cunninghamia lanceolata) plantations in typical hilly and mountainous areas of Jiangxi Province, Southeast China.The result showed that biomass components and carbon storage of tree, understory and the whole ecosystem in C. lanceolata plantations were significantly higher with than without selective thinning treatment, in the low (1150 trees ha−1) than in the high (2460 trees ha−1) initial density in our study. Aboveground vegetation biomass and carbon storage in C. lanceolata plantations increased with stand stages. However, carbon storage of 0–10 cm and 20–40 cm soil depth decreased with stand stages, which indicated certain degraded characteristics of soil carbon in the C. lanceolata plantations. Interestingly, low initial density increased the biomass and carbon storage of trees, shrubs, herbs and 0–20 cm soil depth greater in the pre-mature and mature stands compared to high initial density. Furthermore, these positive effects of low density increased with selective thinning. According to regressions and Detrended Correspondence Analysis (DCA), increment in carbon of trees and 0–10 cm soil with the stand age were significantly higher in the low initial density and with selective thinning than in other three treatments.Therefore, selected thinning and relatively appropriate density might have a significantly positive role in carbon storage of the ecosystem in different stand ages, especially showing a increasing trend of soil carbon. Our results provide the important evidence for selective thinning management of C. lanceolata plantations with regeneration, which plays an important role in improving the carbon storage of degraded C. lanceolata plantations.

Until recently, peatlands in Cambodia were relatively unknown despite numerous efforts to locate and identify them. In 2012–2014, mangrove vegetation on the south-western coast of Cambodia was found to be growing on top of a peat layer underlain by marine clay. Believing that more mangrove peat might remain to be discovered, additional surveys were conducted in 2015, focusing on part of the east coast of Botum Sakor National Park and the riverine mangroves outside the National Park boundary. A total area of 4,768 ha of mangrove peat was confirmed to be present. Overall, the peat layer within this mangrove area is not very thick, with about half of all measurements in the range 50–100 cm and the deepest record 135 cm. In total, 26 mangrove species were recorded during the survey, including 20 tree species. Most were typical (either true or associate) species and very similar to those found in other mangrove forests in Cambodia and elsewhere in Southeast Asia. Although the mangrove peat area confirmed is small, it nevertheless contributes to the total peatland extent and carbon stock of the ASEAN region. Mangrove peat ecosystems, such as the one studied here, are not common in Southeast Asia and deserve more detailed and in-depth studies.

Abstract Background Tropical forests play a crucial role as source and sink in global carbon cycle. Development and other anthropogenic activities have led to degradation of forest land, and ultimately, it results in loss of biodiversity and increases concentration of CO2 in atmospheres. Therefore, there is urgent need to estimate regional and national level carbon stock for making forest-based policies and strategies for mitigation of CO2. Patchy and sporadic information is available on biomass and carbon stock of Indian forests. The paper presents a systematic review and comprehensive account of studies conducted in different forest types in India. Result There are six major forest types found in India consisting of 15 groups and other subgroups with peculiar characteristics. Methodologies used by researchers for biomass/carbon stock estimation are destructive, nondestructive, tree inventories data, species-specific biomass estimation, and remote sensing. Majority of estimates are based on nondestructive allometric equation approach. Studies showed positive correlation between tree species, diameter at breast height, and biomass/carbon stock. Small- and medium-sized growing trees, invasive species, mixed forest, Agroforestry, and Agrosilviculture also play an important role in atmospheric carbon assimilation. The results of diverse forest carbon stock studies are broadly categorized in North, Central, and Southern India. Present review will be helpful for developing conservation policies and decision to increase carbon stock and also REDD+ program for particular forest ecosystem. Conclusion The systematic literature review was carried out to gather and summarize information from different studies conducted on forest ecosystems and quantification methods used for biomass estimation and carbon stock in different forests types and states of India. In general, great variability occurs in aboveground biomass and carbon stock on account of climatic and geographic differences. To obtain good and accurate estimations, following nondestructive approach, species-specific density-based equations are required from different habitats and also in relation to degradation status of forests. As such regional volume equations would increase error of estimations. The comprehensive account of data would be helpful to formulate strategies based on carbon sequestration in Indian forests for CO2 mitigation.

Ecosystem services values play a vital role in evaluating the economic benefits of ecosystems and for drawing up the vegetation restoration policy. The change of ecosystem services values in sand dune succession, especially in China, is little reported. This study was conducted in the Wulanaodu region, southeastern of the Horqin Sandy Land, one of the largest sandy lands in China. Here, we used quantitative methods including marketing value method, the alternative market method, the carbon tax method, the industrial oxygen method, the opportunity cost method, the water balance method, and the shadow engineering method. We evaluated ecosystem services values in fixed sand dunes, semi-fixed sand dunes, and mobile sand dunes. These sand dunes constitute a sand dune succession. The results showed that ecosystem services values in mobile sand dunes, semi-fixed sand dunes, and fixed sand dunes were 6206.58 CNY·hm−2·a−1, 9986.28 CNY·hm−2·a−1, and 31466.56 CNY·hm−2·a−1 separately. The ecosystem services values in fixed sand dunes were five times to these in mobile sand dunes. It suggests that ecosystem services values increase along with the sand dune succession. Moreover, in fixed sand dunes, the main categories contributing to ecosystem services values were gas regulation (17748.11 CNY·hm−2·a−1), and soil formation and retention (6461.80 CNY·hm−2·a−1). Meanwhile, gas regulation (3696.61 CNY·hm−2·a−1), and soil formation and retention (3124.74 CNY·hm−2·a−1) were also the main categories contributing to ecosystem services values in semi-fixed sand dunes. The main categories contributing to ecosystem services values were gas regulation (2760.10 CNY·hm−2·a−1) and water regulation (2278.00 CNY·hm−2·a−1) in mobile sand dunes. This study provides evidence that an increase in ecosystem services values in sandy lands is consistent with the aim of the combat of desertification.

The regional/national carbon (C) stock of peatlands is often poorly characterised, even for comparatively well-studied areas. A key obstacle to better estimates of landscape C stock is the scarcity of data on peat depth, leading to simplistic assumptions. New measurements of peat depth become unrealistically resource-intensive when considering large areas. Therefore, it is imperative to maximise the use of pre-existing datasets. Here we propose that one potentially valuable and currently unexploited source of peat depth data is palaeoecological studies. We discuss the value of these data and present an initial compilation for Scotland (United Kingdom) which consists of records from 437 sites and yields an average depth of 282 cm per site. This figure is likely to be an over-estimate of true average peat depth and is greater than figures used in current estimates of peatland C stock. Depth data from palaeoecological studies have the advantages of wide distribution, high quality, and often the inclusion of valuable supporting information; but also the disadvantage of spatial bias due to the differing motivations of the original researchers. When combined with other data sources, each with its own advantages and limitations, we believe that palaeoecological datasets can make an important contribution to better-constrained estimates of peat depth which, in turn, will lead to better estimates of peatland landscape carbon stock.

This article argues that the practice of agroforestry provides ecological contributions to the smallholder farmers cultivating in the watershed areas. Specifically, this farming system provides contribution to carbon sequestration potential of the woody perennials and the biodiversity conservation of the other components of the system.  This argument is based on the research conducted in Molawin-Dampalit Sub-Watershed, Mt. Makiling Forest Reserve in the Philippines and Way Betung Watershed in Indonesia. The research involved an interview session of 106 and 261 smallholder farmers and an assessment of 27 and 14 agroforesty plots for carbon stock assessment and biodiversity assessment, respectively. Results indicated that the total carbon found among the crop components was 52.32 MgC/ha in Molawin-Dampalit Sub-Watershed­ and 244.26 MgC/ha in Way Betung Watershed­, which suggested the high carbon sequestration potential of the woody perennials and understory crops in an agroforestry system. The farm lots being cultivated by the smallholder farmers were found to contribute to biodiversity conservation having a moderate biodiversity index of 2.59 and 2.53, respectively. With these findings, promotion of desired agroforestry systems in suitable portions of the watershed areas should be intensified and heightened to contribute to ecological balance across the landscape. Agroforestry should always be an integral part of all initiatives toward ecological restoration with the cultivators/smallholder farmers as potential partners. The agroforestry system should consider all the technical and socioeconomic considerations toward having diverse components and ensure food security among the smallholder farmers throughout the year.