Forest Sequestration Research Articles

Pathways to a net zero building sector in Colombia: Insights from a circular economy perspective

The rapid urbanization and economic growth in Colombia have made the residential sector one of the largest energy and material consumers in the country. Circular economy (CE) strategies are a promising alternative to decouple the sector from resource depletion and climate change. The analysis shown here is based on the RECC model framework, a dynamic material flow analysis (dMFA) model. Our results suggest that by 2050 without CE strategies, residential building stock will reach 2.5 billion m2 and emit between 13 and 25 Mt CO2/yr, depending on whether carbon forest sequestration is included or not. A complete implementation of CE strategies and lower floor space can reduce 2020–2050 cumulative primary material production, waste generation, and GHG emissions by 48, 5, and 49 %, respectively. There is a potential to achieve net zero emissions by 2050 if, in addition to the measures mentioned above, more wood materials and forest sequestration are considered.

Influence of Climate Change on Carbon Sequestration in Pine Forests of Central Spain

Climate change influences carbon sequestration by forests, either positively or negatively. In the Mediterranean region, this effect is predominantly negative, although it seems to be compensated by the elevation. This study aims to analyse the impact of climate change on carbon sequestration in five pine species—Pinus halepensis, P. nigra, P. pinaster, P. pinea, and P. sylvestris—growing across an altitudinal gradient from 573 to 1743 m a.s.l. in central Spain. Data from 300 forest inventory plots in ten forests were used to first calculate carbon sequestration in 2024. To estimate future carbon sequestration, the expected values of precipitation and temperature for 2100 were determined, based on regionalised climate scenarios for RCP4.5 and RCP8.5. Values from 13 meteorological stations located around the forests, at different elevations, were analysed, conducting a statistical analysis to determine whether variations were significant. A statistically significant variation was detected for temperature and precipitation changes only under the RCP8.5 scenario. Using temperature and precipitation data for 2024 and 2100, net potential productivity in both years was established, considering its variation ratio equivalent as equivalent to that of growth and carbon sequestration. An inflection point was detected in 2100 at 1646 m a.s.l., with a decrease in productivity below and an increase above that elevation. Results reflect a decline in carbon sequestration in all the species, ranging from 6% in P. sylvestris to 28% in P. halepensis, conditioned by the elevation. Regionally, the average decrease would be 16.4%. In temperate and boreal regions, forest growth is expected to increase due to climate change, but the Mediterranean region will experience a significant decrease, except in mountain areas. To maintain current levels of carbon sequestration, it would be necessary to increase the existing carbon sinks through new plantations and the restoration of degraded forests.

Assessing ensemble models for carbon sequestration and storage estimation in forests using remote sensing data

Forests play a crucial role in storing much of the world's carbon (C). Accurately estimating C sequestration is essential for addressing and mitigating the impacts of global warming. While many studies have used machine learning models to estimate carbon storage (CS) in forests based on remote sensing data, this research further examines C sequestration (i.e., the annual carbon uptake by trees; CSE). The objectives of this study are two-fold: firstly, to identify the best models for estimating CSE and CS by testing various methods, and secondly, to examine the effect of climatic data and the canopy height model (CHM) on the estimation of CSE. To achieve the first objective, we will compare the performance of fourteen models, including twelve machine learning models, one deep learning model, and an ensemble model that combines the top four independent models. For the second objective, we study the effect of four input configurations: the first is a baseline configuration based solely on attributes extracted from satellite images (Sentinel-2) and geomorphology; the second combines satellite features with climatic data; the third uses a CHM derived from LiDAR instead of climatic data; and the fourth combines all available features: satellite images, climatic data, and CHM. The results show that adding climatic data does not improve the estimation of CSE and CS. However, adding CHM features significantly improves the models' performance for both targets. The implemented ensemble model demonstrated the best performance across all configurations.

Tree richness increased biomass carbon sequestration and ecosystem stability of temperate forests in China: Interacted factors and implications

Biodiversity loss and forest degradation have received increasing attention worldwide, and their effects on forest biomass carbon storage and stability have not yet been well defined. This study examined 1275 tree plots using the field survey method to quantify the effects of tree diversity, tree sizes, and mycorrhizal symbiont abundance on biomass carbon storages (Cs) and NDVI (Normalized Difference Vegetation Index)-based ecosystem stability (standard deviation/mean NDVI = NDVI_S) during the field survey period from 2008 to 2018. Our data showed Cs and NDVI_S averaged at 31–108 t ha−1 and 32.04–49.28, respectively, and positive relations between Cs and NDVI_S were observed (p < 0.05). Large forest-type and regional variations were found in these two parameters. Broadleaf forests had 74% of Cs (p < 0.05) of the conifer forests, but no differences were in NDVI_S. Cold regions at high latitudes had 71% of NDVI_S in the warm regions at low latitudes, while no differences were in Cs. Moist regions at high longitudes had 2.04 and 1.28-fold higher Cs and NDVI_S (p < 0.05). The >700 m a.s.l. regions had 1.24-fold higher Cs (p < 0.01) than the <700 m a.s.l. regions, but similar NDVI_S (p > 0.05). Nature Reserves had 1.94-fold higher Cs but 30% lower NDVI_S than outside Reserves (p < 0.001). > 40-year-old forests had 1.3- and 2-fold higher Cs and NDVI_S than the young forests. Structural equation modeling and hierarchical partitioning revealed the driving paths responsible for these variations. Tree richness was positively associated with Cs and ecosystem stability, contributing 21.6%–30.6% to the total effects on them; tree sizes significantly promoted the Cs, but had negligible impacts on NDVI_S. MAT's total effects on NDVI_S of conifer forests were 40% higher than that of broadleaf forests, MAP's total effects on Cs varied with forest types; arbuscular mycorrhizal tree dominance exhibited a smaller positive impact on Cs and ecosystem stability in comparison to other factors. Our findings underscore that the significance of climatic-adapted forest management, diversity conservation, and big-sized tree protections can support the achievement of carbon neutrality in China from biomass carbon sequestration and ecosystem stability.

Assessment of Woody Species Biodiversity and Carbon Stock Potentials in the Arboretum of National School of Water and Forests of Mbalmayo, Center Region of Cameroon

Assessing forest biodiversity is crucial for supporting sustainable forest planning. We investigated the potential for biodiversity and carbon sequestration in both artificial and natural forests of the arboretum of the National School of Water and Forests (ENEF) of Mbalmayo. A floristic inventory was carried out in 72 plots measuring 25m x 25m in the artificial forest covering an area of 4.5ha, and in a quadrat measuring 250m x 180m in the natural forest of the arboretum. Carbon stocks were determined by the non-destructive method using allometric equations. The results of the woody biodiversity inventories identified 77 species belonging to 69 genera and 33 families. This species richness varied from 69 species in the natural forest to 58 species in the artificial forest. Tree density was slightly higher in the artificial forest (616 ±339 ind/ha) than in the natural forest (312 ±176 ind/ha), without being significantly different. Basal area was constant in both types of forest studied, with an average of 55.97 ±36.28 m2/ha in the artificial forest and 58.33 ±19.42 m2/ha in the natural forest. The greatest quantity of sequestered carbon was found in the natural forest with 432±146.49 tC/ha compared with 400.69±328.37 tC/ha in the artificial forest. Nevertheless, these rates were not significantly different according to the ANOVA test. Given the importance of this massif in carbon sequestration and the needs of local populations, ENEF should support these populations in agroforestry practices and in the domestication of priority tree species.

Nitrogen availability and its related enzyme activities affect microbial residue nitrogen accumulation during Chinese fir plantation development

Microbial growth, metabolism, and reproductive activities have a significant role in the generation, transformation, and storage of soil nitrogen (N). However, the time-integrated effect of microorganisms on long-term N sequestration in plantation forests remains poorly understood. We investigated the microbial residue N (MRN) and its contribution to soil total N (TN) among the young (8-year), middle (16-year), near-mature (24-year), mature (34-year), and over-mature (106-year) stands of Chinese fir plantation (CFP) in subtropical China. The soil TN content showed a general pattern of increasing with stand age, ranging from 2.61 to 3.42 g kg−1, and was higher in the over-mature and mature stands than in the other three stands (p < 0.001). In addition, soil carbon (C), N, phosphorus (P), and hydrolase stoichiometric ratios indicated that P limitation was widespread during all stages of CFP development. The average ratio of soil fungal residue N (FRN) to bacterial residue N (BRN) was 3.64:1. The MRN content and its contribution to soil TN exhibited a falling and then rising pattern from young to over-mature stands, ranging from 1.24 to 1.70 g kg−1 and 38.8 % to 57.5 %, respectively. Soil N fraction contents and hydrolase activities were higher in the 0–5 cm soil layer than in the 5–30 cm soil layer (p < 0.05). Regression analysis showed that soil MRN content increased with soil N fraction contents, C-N-P stoichiometric ratios, and hydrolase activities (p < 0.001). Redundancy analysis and partial least squares path modeling revealed that soil available N (AN) and N hydrolase were the main factors affecting MRN accumulation. These parameters may partially indicate the dynamics of MRN accumulation. Our study discovered that the long-term development of CFP promotes soil N sequestration, with microbial residues playing a significant role in contributing to N pools.

Shifting wood between material and energy use: Modeling the effects of substitution

AbstractWood as a renewable material is relevant for climate change mitigation: Carbon sequestration in forests and carbon storage in harvested wood products (HWPs) contribute to carbon reduction in the atmosphere, and the substitution of carbon‐intensive products with wood products can reduce greenhouse gas (GHG) emissions. Since wood is a limited resource, it must be used efficiently and sustainably. Shifting wood from one application to another might result in decreased GHG emissions due to substitution effects. However, which wood application will lead to a GHG emission reduction is currently unknown. This study investigates the effects of shifting wood between applications and the resulting substitution effects from a system perspective. A system dynamics model describes the wood utilization system of Austria, including the value chains from the forest to wood‐processing industries and the substitution that takes place in these industries. These value chains are associated with the global warming potential. Seven wood utilization scenarios shifting between material use and use for energy are simulated. The results show that wood shifts lead to both a substitution effect (emission reduction) in industries where wood utilization is increased and a counter effect (emission increase) where wood is replaced. The two effects potentially outweigh each other partly, leading to comparatively small net effects. However, carbon sequestration in HWPs and future changes in substitution effects might lead to additional effects. To substantially contribute to climate change mitigation, alternatives other than shifting wood between material and energy value chains need to be found within the wood utilization system.

Repeated Mild Summer Drought in Crataegus monogyna Jacq. Provokes Compensation Growth in the Following Year

Water limitations will pose significant challenges to forest ecosystems across Europe. To gain a deeper understanding of the potential impacts, we investigated the response of the common shrub Crataegus monogyna to two summer droughts, each followed by rewatering. The experimental design consisted of a common garden with potted saplings from a local Belgian (n = 48), a Swedish (n = 47), and a Spanish-Pyrenean provenance (n = 48). We quantified the effects on growth and leaf phenology, focusing on the legacies in the year following the droughts. Responses were influenced by the severity of the drought and by its timing. Most strikingly, height increment was enhanced by 24% (p = 0.046) in comparison to the controls in the year following the droughts in the group of plants that endured the two drought treatments, each time without developing visible stress symptoms. Only one such mild drought, whether early or late summer, did not lead to this response, suggesting stress memory acting as a growth promoter. A late summer drought that resulted in visible drought symptoms led to a reduced diameter increment in the year following the droughts, independent of the preceding treatment (severe, mild, or no drought), whereas this was not the case for a similar drought in early summer. Minor leaf phenological responses were detected in the year following the droughts. Finally, the non-local provenances did not respond in a deviating way to the droughts compared to the local provenance. Our findings contribute to the prediction of carbon sequestration in forests and other woody vegetations in the temperate regions of Europe.

Forest Stewards Guild position on climate-smart forestry

Climate-smart forestry is an increasingly important topic in forest policy and for practices. However, what does and does not constitute climate-smart forestry is subject of debate. At stake are billions of dollars of investment aimed at encouraging climate-smart forestry practices in the United States. As a leading voice for ecologically, economically, and socially responsible forestry, The Forest Stewards Guild (FSG) has produced a position statement based on the organization's vision, mission, and principles to guide conversations around climate-smart forestry for all interested stakeholders. This forest perspective presents and expands on the findings of the FSG position on climate-smart forestry. There are three common aspects in the multiple co-existing definitions of climate-smart forestry: 1) adapting forests to expected future climate conditions, 2) mitigating climate change by leveraging carbon sequestration and storage functions of forests, and 3) improving social outcomes. There are potential trade-offs with other benefits forests provide if climate-smart forestry is pursued without holistic consideration of forest ecosystems. We suggest that such trade-offs can be minimized if the goals of climate-smart forestry projects are communicated transparently, system boundaries are made as comprehensive as possible, potential trade-offs are assessed along with climate benefits, climate-smart practices are tailored to the social-ecological contexts, and uncertainty is recognized.

Study of Carbon Sequestration in Forest Ecosystems in DRC

Purpose: The aim of the study was to investigate the study of carbon sequestration in forest ecosystems in DRC. Methodology: This study adopted a desk methodology. A desk study research design is commonly known as secondary data collection. This is basically collecting data from existing resources preferably because of its low cost advantage as compared to a field research. Our current study looked into already published studies and reports as the data was easily accessed through online journals and libraries. Findings: Research on carbon sequestration in DRC's forests underscores their crucial role as significant carbon sinks. These forests store substantial amounts of carbon in biomass and soils, contributing significantly to global climate regulation efforts. However, challenges like deforestation and illegal logging threaten this capacity, highlighting the importance of sustainable forest management and conservation. Enhancing carbon sequestration in DRC's forests is essential for mitigating climate change impacts and preserving biodiversity. Unique Contribution to Theory, Practice and Policy: Ecological succession theory, resource allocation theory &amp; social-ecological systems theory may be used to anchor future studies on the study of carbon sequestration in forest ecosystems in DRC. Encourage the adoption of sustainable forestry practices that enhance carbon sequestration while supporting biodiversity conservation and local livelihoods. Align forest management policies with national and international climate change mitigation goals, emphasizing the role of forests as natural carbon sinks.

Canopy and understory nitrogen additions differently affect soil microbial residual carbon in a temperate forest.

Atmospheric nitrogen (N) deposition in forests can affect soil microbial growth and turnover directly through increasing N availability and indirectly through altering plant-derived carbon (C) availability for microbes. This impacts microbial residues (i.e., amino sugars), a major component of soil organic carbon (SOC). Previous studies in forests have so far focused on the impact of understory N addition on microbes and microbial residues, but the effect of N deposition through plant canopy, the major pathway of N deposition in nature, has not been explicitly explored. In this study, we investigated whether and how the quantities (25 and 50 kg N ha-1 year-1) and modes (canopy and understory) of N addition affect soil microbial residues in a temperate broadleaf forest under 10-year N additions. Our results showed that N addition enhanced the concentrations of soil amino sugars and microbial residual C (MRC) but not their relative contributions to SOC, and this effect on amino sugars and MRC was closely related to the quantities and modes of N addition. In the topsoil, high-N addition significantly increased the concentrations of amino sugars and MRC, regardless of the N addition mode. In the subsoil, only canopy N addition positively affected amino sugars and MRC, implying that the indirect pathway via plants plays a more important role. Neither canopy nor understory N addition significantly affected soil microbial biomass (as represented by phospholipid fatty acids), community composition and activity, suggesting that enhanced microbial residues under N deposition likely stem from increased microbial turnover. These findings indicate that understory N addition may underestimate the impact of N deposition on microbial residues and SOC, highlighting that the processes of canopy N uptake and plant-derived C availability to microbes should be taken into consideration when predicting the impact of N deposition on the C sequestration in temperate forests.

Structural changes and enhanced properties of bamboo fibers by controlled pyrolysis

Bamboo has low-cost, fast-growing, good mechanical properties, and its cultivation results in environmental benefits such as CO2 sequestration and preservation of native forests, in addition to being an excellent source for natural fibers. Bamboo fiber presents high mechanical performance, which can be further improved by chemical or physical treatments. Controlled pyrolysis is an important treatment for modifying natural fibers, generating materials with different properties. In the present study, bamboo fibers from the species Dendrocalamus asper were subjected to controlled pyrolysis at 160, 400, and 800 °C and their morphological, thermal, and electric properties were evaluated by thermogravimetric analysis, X-ray diffraction, scanning electron microscopy, molecular absorption test, and electrochemical impedance spectroscopy. Controlled pyrolysis at 160 °C caused few changes to the structure and properties of the bamboo fiber. However, thermal stability, crystalline structure, and fiber morphology were strongly affected during pyrolysis at 400 and 800 °C. A resistive electric behavior was also verified in the fiber pyrolyzed at 800 °C, while for the other treated fibers, a capacitive electric behavior was verified. The controlled pyrolysis of bamboo fibers proved to be viable for producing new fibers with different properties.

Global pattern of organic carbon pools in forest soils.

Understanding the mechanisms of soil organic carbon (SOC) sequestration in forests is vital to ecosystem carbon budgeting and helps gain insight in the functioning and sustainable management of world forests. An explicit knowledge of the mechanisms driving global SOC sequestration in forests is still lacking because of the complex interplays between climate, soil, and forest type in influencing SOC pool size and stability. Based on a synthesis of 1179 observations from 292 studies across global forests, we quantified the relative importance of climate, soil property, and forest type on total SOC content and the specific contents of physical (particulate vs. mineral-associated SOC) and chemical (labile vs. recalcitrant SOC) pools in upper 10 cm mineral soils, as well as SOC stock in the O horizons. The variability in the total SOC content of the mineral soils was better explained by climate (47%-60%) and soil factors (26%-50%) than by NPP (10%-20%). The total SOC content and contents of particulate (POC) and recalcitrant SOC (ROC) of the mineral soils all decreased with increasing mean annual temperature because SOC decomposition overrides the C replenishment under warmer climate. The content of mineral-associated organic carbon (MAOC) was influenced by temperature, which directly affected microbial activity. Additionally, the presence of clay and iron oxides physically protected SOC by forming MAOC. The SOC stock in the O horizons was larger in the temperate zone and Mediterranean regions than in the boreal and sub/tropical zones. Mixed forests had 64% larger SOC pools than either broadleaf or coniferous forests, because of (i) higher productivity and (ii) litter input from different tree species resulting in diversification of molecular composition of SOC and microbial community. While climate, soil, and forest type jointly determine the formation and stability of SOC, climate predominantly controls the global patterns of SOC pools in forest ecosystems.

Response of Soil CO2 Emission to Addition of Biochar and Dissolved Organic Carbon along a Vegetation Restoration Gradient of Subtropical China

Biochar, as a soil amendment, has been widely confirmed to increase soil carbon sequestration. However, how biochar addition affects soil carbon changes during the vegetation restoration process is still unclear, which constrains our ability to explore biochar’s application in the technology of soil carbon sequestration in forests. We conducted an incubation experiment on biochar and dissolved organic matter (DOM) addition to soil at three stages of revegetation (degraded land (DS), plantation forest (PS), and secondary natural forest (NS) in Changting County in Fujian province, China) to investigate the effects of vegetation restoration, biochar, DOM, and their interaction on soil CO2 emission and its relative mechanisms. We found that the accumulative release of CO2-C in the NS and PS soils was 7.6 and 6.8 times higher, respectively, in comparison to that from the DS soil. In the DS, biochar addition significantly increased the accumulative release of CO2-C, soil pH, NH4+-N content, qCO2, phenol oxidase, and peroxidase activities. Peroxidase activities were positively correlated with the accumulative release of CO2-C, and oxidase was the most important direct factor influencing the accumulative release of CO2-C in the DS. However, the accumulative release of CO2-C, soil NH4+-N content, qCO2, β-glucosidase, and N-acetylglucosaminidase activities was significantly reduced after the application of biochar in the PS and NS. These two hydrolases were positively associated with the accumulative release of CO2-C, and hydrolase was the most vital direct factor influencing the accumulative release of CO2-C from the PS and NS soils. The positive effect of DOM addition on CO2 emission under biochar application declined with a vegetation restoration age increase. Our results indicated that biochar could alter microbial physiological processes, inhibit qCO2 and hydrolase activities, and further decrease CO2 emission in relatively fertile soil from the PS and NS; but in the relatively barren soil from the DS, biochar might promote CO2 emission by stimulating microorganisms to enhance qCO2 and oxidase activities.

Balance of Anthropogenic and Natural Greenhouse Gas Fluxes of All Inland Ecosystems of the Russian Federation and the Contribution of Sequestration in Forests

Balance of Anthropogenic and Natural Greenhouse Gas Fluxes of All Inland Ecosystems of the Russian Federation and the Contribution of Sequestration in Forests

Seasonal aridity regulates drivers and temporal variability of wood phenology: A meta-analysis of dendrometer monitoring data across the Northern Hemisphere

The secondary growth phenology of trees, also known as wood phenology, plays a vital role in assessing the timing of carbon sequestration in forests. However, its spatio-temporal variability and determinants in the Northern Hemisphere remain debated. Here, we presented a meta-analysis using secondary growth phenology data based on dendrometer monitoring of 59 tree species and 84 sites to explore the drivers and temporal connections of phenology across seasonal arid and humid regions in the Northern Hemisphere. We found spring temperatures and precipitation co-regulated the start of secondary growth (SOG) in spring arid regions, and SOG advanced with the increase in spring temperatures and precipitation. However, SOG was only influenced by spring temperatures in spring humid regions. The end of secondary growth (EOG) indicated strong correlations with autumn temperatures only in autumn arid regions but not in humid regions. Interestingly, the earlier SOG promoted advancement of the time of maximum secondary growth rate (MOG) and EOG both in seasonal humid and arid regions, while the end of secondary growth in the previous year (prEOG) negatively affected SOG only in seasonal arid regions. The legacy effects of previous phenological events on subsequent ones should be integrated into phenological prediction models to help accurately assess global carbon, water, and energy cycles.

Successional dynamics of carbon sequestration in forests of the eastern United States

AbstractCarbon sequestration in the forests of the eastern United States is an important offset to the country's CO2 emissions. Much of the eastern forestland is the product of reforestation of abandoned agricultural land or recovery following clear‐cutting over a century ago. This has led to concerns that eastern forests are even‐aged and that rates of carbon sequestration will decline as forests increase in carbon. Our objective was to examine the successional dynamics of forest carbon sequestration—using live tree carbon stocks as a proxy for successional status—for the six broadly defined forest types present in the region. We used datasets from the National Forest Inventory (NFI) for the 31 US states from Minnesota south to Louisiana and eastward and analyzed live tree net carbon increment for 2007–2021, the period for which NFI plot remeasurement data were available for all 31 states. Spruce–fir and southern pines were the only forest types for which carbon increment declined even modestly over a significant fraction of the range of live tree carbon observed in the region, and southern pine–hardwood forests were the only forests in which predicted sequestration in live tree carbon declined to zero within the range of carbon stocks observed in the region. Northern hardwood–conifer forests, oak–hickory forests, and lowland forests experienced either no decline or a slight increase in sequestration in live tree carbon across the range of successional status observed in the region. Thus, the average stocks of live tree carbon per unit area increased steadily over the study period. At some point in succession, rates of mortality are expected to increase and balance gross growth, leading to zero net sequestration in live tree carbon. Mature and old‐growth stands, however, are rare in all six forest types, and mortality as a fraction of live tree carbon for all six forest types declined across the range of successional status present in the region. Our results thus provide no support for the hypothesis that the successional dynamics of forests in this region can be expected to lead to near‐term declines in net carbon sequestration.

Assessing preferences for forest carbon credit and co-benefits: A choice experiment case study in Japan

This study investigated corporate preferences for forest carbon credit offsets. The preferences were elicited through a choice experiment by administering a questionnaire to determine the price of credit, location of forest sequestration project offset, social development on local employment, preservation of ecosystem services, and unit of sustainable development goals (SDGs). We also examined stated preferences for credit offset and the willingness to pay. The analysis employed multinomial logit and random parameter logit (RPL) models to account for heterogeneity in preferences. The results showed that small and medium-sized enterprises (SMEs) held a neutral stance regarding offsetting their emissions and were categorized as being in the early stages of engagement with carbon offsetting. As SMEs can decide whether to purchase credit, we assessed their preferences for the type of credit-based forest carbon sequestration. SMEs had a significant preference for the location of the project, SDGs, and credit price when deciding to purchase credit based on the RPL model estimates. They were willing to pay JPY 6,191 (approximately USD 41) for the location of a project to be local rather than overseas, JPY 933 for a higher number of unit SDGs, and JPY 131 for an increase in the number of jobs. These results suggest that SMEs prefer purchasing local credit generated within their prefecture as a carbon offset alternative.

Carbon stocks and sequestration potential of community forests in Bhutan

Community Forestry (CF) is recognized globally as a forest management regime with the potential to address deforestation and forest degradation, provide forest goods and services to local communities and contribute to climate change mitigation. Around 4% of Bhutan's forests are currently under CF management and these forests provide essential goods and services for local communities. However, the potential of CF in Bhutan to contribute to climate change mitigation is not well understood and has not been researched.In this study, we estimated the carbon stock and carbon sequestration of community forests in Bhutan by using data from the 2015 National Forest Inventory (NFI). The total biomass carbon in community forests was 130.3 Mg ha−1 (107.3–153.2) and the soil organic carbon was 52.8 Mg ha−1 (30.4–75.1). Carbon sequestration was 0.7 Mg ha−1 yr⁻¹. Other attributes: basal area, stem density and tree height, were also determined to assess forest condition and the potential to increase carbon sequestration.The values for biomass carbon in Bhutan's community forests as well as the non-community forests (all other forests) were similar to those reported from Forest Resource Assessment and NFI for forests in Nepal and the Indian Himalayan states respectively. Disaggregation of data from 38 research studies across the Himalayan region indicated that biomass carbon in Bhutan's forests was significantly lower than that in well-stocked (non-degraded) forests in the Indian and Nepal Himalayas. It was also much lower than that in Bhutan's Forest Management Units, which were used as an indicator of the potential upper limit of biomass carbon in Bhutan's forest environment. Similarly, basal area, stem density and mean tree height were also lower in Bhutan's community forests than in well-stocked forests in other Himalayan countries.The Bhutan Government is currently exploring the potential to generate revenue from the sale of carbon sequestered in its forests. This study confirms that there is potential to increase carbon sequestration by improving management of existing forests. Currently, the 107,866 ha of community forests in Bhutan store about 19 million Mg of carbon. With improved management by Community Forest Management Groups, which have the institutional capacity to control local management outcomes, the carbon stock could likely be doubled (to 40 million Mg of carbon), thereby demonstrating the potential of Community Forestry to play an important role in climate change mitigation, while not jeopardizing the provision of day-to-day goods and services to local communities.

Carbon storage and sequestration in a eucalyptus productive zone in the Brazilian Cerrado, using the Ca-Markov/Random Forest and InVEST models

Tropical ecosystems in Brazil, particularly Mato Grosso do Sul, possess substantial greenhouse gas (GHG) mitigation potential through carbon sequestration in tree forests. However, the expansion of agricultural activities poses a threat to this potential. Notably, eucalyptus forests could enhance carbon sequestration and reduce GHG emissions. This study focused on Três Lagoas, known as Brazil's cellulose capital, and aimed to evaluate carbon stock and sequestration for 2030 under business as usual (BAU) and protected forest (PF) scenarios. Combining Cellular Automata (CA) and Random Forest models implemented in Patch-Generating Land Use Simulation (PLUS) and the Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST) model, we simulated land use scenarios and assessed ecosystem services generated by carbon sequestration. The results showed that the PF scenario indicated a higher total carbon stock than the BAU scenario, with a difference of 2.48 Tg. Carbon sequestration varied by period and scenario. Between 2010 and 2020, 3.88 Tg of carbon were sequestered. However, in the next period (2020–2030), the BAU scenario estimated 2.45 Tg in total carbon sequestration. In contrast, the PF scenario predicted 4.93 Tg of carbon sequestration for 2020–2030, surpassing the previous decade. Monetarily, carbon sequestration in 2010–2020 amounted to $92.48 million, decreasing to $58.49 million for 2020–2030 in the BAU scenario. In the PF scenario, sequestration for 2020–2030 increased to $ 117.43 million, nearly double that of the BAU scenario. In conclusion, combining the Ca-Markov/Random Forest and InVEST models revealed the spatiotemporal dynamics of carbon stock and sequestration in the municipality with the largest eucalyptus-planted area in Brazil. The results underscore the significant variability in carbon stocks and sequestration based on classes, periods, and scenarios analyzed. This study contributes valuable insights into the potential for carbon mitigation in this critical region.