Forests For Carbon Sequestration Research Articles

Blue carbon and the role of mangroves in carbon sequestration: Its mechanisms, estimation, human impacts and conservation strategies for economic incentives

Mangroves, tidal marshes, and seagrasses have been recognized as blue carbon coastal ecosystems as they accommodate large carbon stocks, enable long-term carbon storage, have the capacity to control greenhouse gas emissions and possess the potential to reduce the rise in atmospheric CO2 levels. In the tropical and subtropical intertidal zones, mangroves show significant productivity and rapid deposition rates. Mangroves play an important role in capturing, transforming, and storing CO2 in the atmosphere into coastal sediments for a long time, displacing organic carbon from the coastal zone to the offshores and the ocean. Mangroves also help in preventing storms, hurricanes, coastal erosion, and tidal waves. Recently, mangroves have been threatened by natural and anthropogenic activities such as urbanization, pollution, aquaculture and tourism. They are expected to hamper their essential services, such as coastal defense, breeding grounds for aquatic organisms' seafood supply, etc. Despite the importance of mangrove forests in carbon sequestration and the numerous goods and services they offer humans, wood and non-wood forest products, food, fisheries, medicines, eco-tourism, and recreation. These mangrove ecosystems are deteriorating at alarming rates, necessitating immediate intervention. Thus, the protection, restoration and conservation of this ecosystem are gaining considerable attention from researchers across the globe. This paper provides information on different mangrove adaptations, their mechanisms, roles in the ecosystem, carbon estimation, influencing factors, threats, and conservation strategies for carbon sequestration in this invaluable coastal habitat.

Which Provinces Will Be the Beneficiaries of Forestry Carbon Sink Trade? A Study on the Carbon Intensity–Carbon Sink Assessment Model in China

Carbon emissions pose a significant challenge to sustainable development, particularly for China, which is the world’s largest emerging economy and is under pressure to achieve carbon neutrality and reduce emissions amid escalating human activities. The variation in economic development levels and carbon sequestration capacities among its provinces poses a significant hurdle. However, previous research has not adequately examined this dual discrepancy from the perspective of spatial heterogeneity, resulting in a lack of differentiated management of forest carbon sinks across diverse regions. Therefore, to mitigate this discrepancy, this study presents an assessment methodology that analyzes over 100 types of natural and plantation forests using forest age and biomass expansion factors. This study presents a model that can significantly support the efforts of both China and the whole world to achieve carbon neutrality through the improved management of forest carbon sinks. This approach facilitates the assessment of carbon offsets required to meet reduction targets, the development of a provincial framework for carbon intensity and sequestration, and the exploration of their potential for trading markets. Analysis is conducted using MATLAB. Key achievements of this study include the following: (1) The collection of a comprehensive carbon stock dataset for 50 natural and 57 plantation forest types in 31 provinces from 2009 to 2018, highlighting the significant role of new forests in carbon sequestration. (2) The development of a provincial carbon status scoring system that categorizes provinces as carbon-negative, carbon-balancing, or carbon-positive based on local forest sink data and carbon credit demand. (3) The formulation of the carbon intensity–carbon sink assessment (CISA) model, which suggests that provinces with middle- to upper-middle-level economies may have a prolonged need for carbon sink credits during their peak carbon phase. Furthermore, the results show that carbon trading may benefit Guangxi and Yunnan, but may also bring opportunities and risks to Hunan and Hubei. To address regional imbalances, this study advocates tailored policies: carbon-negative and carbon-balancing provinces should enhance carbon sink management, while carbon-positive provinces must focus on energy structure transformation to achieve sustainable development goals.

Accessible satellite data decision support systems for Yurok Tribe forest management

Local decisionmakers managing forests for sequestering carbon and mitigating disturbance face increasing pressures from climate change, while needing to derive revenue from forests resources and balance diverse stakeholder concerns. Decision support systems (DSS) that use freely available satellite data are effective tools for forest management decision-making, due to the broad spatial coverage and temporal consistency of this data. However, the literature demonstrates that many DSS developed by researchers incorporating satellite data are often not utilized by decision makers. This is in part due to a lack of stakeholder engagement in DSS development. Here, we employ an intentional stakeholder engagement process to develop an accessible DSS incorporating satellite data. This process is applied with the Yurok Tribe – an Indigenous community in California – towards the goal of managing forests for carbon sequestration. We use system architecture framework (SAF) to translate stakeholder objectives into targeted analyses and the environment-vulnerability-decision-technology (EVDT) integrated modeling framework to incorporate contextual local infrastructure and land ownership information alongside satellite data analyses. Satellite data analyses classify tree cover and track Normalized Difference Vegetation Index (NDVI) over time. We compare and show that trends in our analysis agree with independent global tree cover and biomass datasets. These analyses meet the Tribe's objective for tracking forest trends in Yurok carbon sequestration projects, while also detecting undesirable conifer encroachment on culturally-important prairies traditionally managed as open landscapes. Additionally, integration of community infrastructure data alongside satellite-derived drought, forest fire, and smoke density information via EVDT meets another Yurok Tribe objective of identifying negatively impacted Tribal areas for aid allocation. User feedback sessions with participating Yurok Tribe employees assess the prototype DSS and show 80% of users providing high ratings (≥75%) for information accuracy, relevancy, and sufficiency, demonstrating that our DSS development process overcomes previous gaps to DSS use and satellite data accessibility to augment Yurok Tribe forest management decision making.

Bioenergy crops, biodiversity and ecosystem services in temperate agricultural landscapes—A review of synergies and trade‐offs

AbstractThe Paris agreement on climate change requires rapid reductions in greenhouse gas emissions. One important mitigation strategy, at least in the intermediate future, is the substitution of fossil fuels with bioenergy. However, using agriculture‐ and forest‐derived biomass for energy has sparked controversy regarding both the climate mitigation potential and conflicts with biodiversity conservation. The urgency of the climate crisis calls for using forests for carbon sequestration and storage rather than for bioenergy, making agricultural biomass an attractive alternative for fossil energy substitution. However, this calls for comprehensive assessments of its sustainability in terms of consequences for biodiversity and ecosystem services. In this review, we provide a first holistic overview of the impacts on ecosystems of land‐use changes from bioenergy crop production in temperate climates, by synthesizing results on both biodiversity and ecosystem service impacts. We found that bioenergy‐related land‐use changes can have both positive and negative effects on ecosystems, with original land use, bioenergy crop type and scale of bioenergy production being important moderators of impacts. Despite the risk of opportunity cost for food production, perennial crop cultivation on arable land had the lowest occurrence of negative impacts on biodiversity and ecosystem services. Growing biomass for bioenergy on surplus land has been suggested as a way to alleviate competition with food production and biodiversity conservation, but our results demonstrate that utilizing marginal or abandoned land for bioenergy crop production cannot fully resolve these trade‐offs. Furthermore, there is a lack of empirical studies of the biodiversity value of marginal and abandoned land, limiting our understanding of the sustainability implications of biomass cultivation on surplus land. We argue that future research and policies for bioenergy production must explicitly consider biodiversity and ecosystem services in combination to avoid potential trade‐offs between the two and to ensure sustainable bioenergy production.

Sacred groves: a model of Zagros forests for carbon sequestration and climate change mitigation

SummaryForests are the most important carbon pools among terrestrial ecosystems, and ensuring less disturbance of sacred groves might constitute a form of forest management for carbon sequestration and climate change reduction. The carbon contents in Zagros oak sacred groves and silvopastoral lands were compared to determine the carbon sequestration potential of these forests. Using a nested sampling design, we measured total carbon content (tC ha–1; aboveground tree biomass, aboveground sapling biomass, belowground biomass, soil organic carbon, leaf litter, herbs and grasses and dead wood and fallen stumps) in both forest groves and silvopastoral lands. The mean total biomass and mean total carbon content varied between sacred groves (453.8 t ha–1 and 338.79 tC ha–1, respectively) and silvopastoral lands (89.4 t ha–1 and 113.46 tC ha–1, respectively). Mean soil organic carbon was significantly lower (71.44 tC ha–1) in silvopastoral lands than in sacred groves (125.49 tC ha–1). The mean total sequestered carbon dioxide (CO2) was 1243.36 tCO2 ha–1 in the sacred groves and 416.40 tCO2 ha–1 in silvopastoral lands. We conclude that human activities have reduced the CO2 absorption capacity of the forests. The substantial disparities between the landscapes emphasize the need to restore damaged forests, and sacred groves might be a useful model for increasing carbon storage in these forests.

Practical evaluation and prediction based on carbon sequestration forest decision model

A decision model for understanding forest use is developed and the model is applied to selected forests and evaluated in practice.To make a decision model for using forests, we use a meta-analysis method to look at how forest ecosystem services are worth and rank their value impacts. To figure out whether or not the forest can be left uncut and when it should be cut down, we look at carbon sequestration benefits, which is a significant factor in the operator's decision.We applied the forestry model to several forestry sites. We used it to the Sekhangba forest in China and forestry sites throughout New Zealand to predict the amount of CO2 absorbed in 100 years and give the corresponding forest management plan. We answered using the optimal rotation period given in the previous round for the transition strategy.

Role and value of urban forests in carbon sequestration: review and assessment in Indian context

Role and value of urban forests in carbon sequestration: review and assessment in Indian context

Management trade-offs between forest carbon stocks, sequestration rates and structural complexity in the central Adirondacks

Managing forests for carbon sequestration is an emerging objective within forestry sectors, although considerable uncertainty remains about how best to influence forest C dynamics through silviculture. This study tests hypotheses regarding forest C management within the central Adirondacks and assesses management trade-offs between aboveground live tree C relative to forest structural and biological complexity. The effects of management on forest C stocks, sequestration rates and structural complexity were assessed using a multivariate metric of management intensity derived from historical harvest records, combined with forest inventory data collected from Huntington Wildlife Forest (Newcomb, NY) from 1970 to 2011. Management intensity was quantified using a principal component analysis on measures of management inputs (harvest duration, total harvest area, number of harvest entries) and outputs (harvested wood volume). The first principal axis was used as a unitless metric of management intensity, which explained 64.1% of the variation in management activity. As management intensity increased, above ground live tree C stocks significantly declined but C sequestration rates significantly increased. Management intensity was correlated with decreased structural complexity. Active management can increase forest C uptake through the distribution of resources to young tree cohorts within a stand, which is consistent with the hypothesis of the C stock-sequestration trade-off. However, structural complexity was significantly reduced in areas with the highest C sequestration rates. These trade-offs should be considered and balanced when implementing management that aims to improve the C storing potential of central Adirondack forests.

Changes in the intensity of heartwood formation in Scots pine (Pinus sylvestris L.) ontogenesis

Summary An essential stage in woody plant ontogeny (heartwood (HW) formation) determines tree resistance to weather conditions, wood quality (moisture, colour, resistance to biodegradation), and regulates the proportion of functionally active sapwood (SW) in the total trunk biomass. In this study, the patterns of HW formation depending on tree age and cambial age within the same tree were studied in the North-West of Russia in Scots pine in a lingonberry pine forest. It is shown that HW either repeats the trunk profile or shows a maximum proportion on average at the height of 1.5 m. Models using the square root transformation and logarithm transformation have been proposed to predict the number of annual rings in HW depending on the cambial age. Multiple regression is proposed to predict the radial width in HW. Validation of the developed models on random trees gave a good result. HW formation begins at the age of 17–18 years and continues at the rate of 0.3 rings per year for 20–30-year-old trees, 0.4–0.5 rings per year for 70–80-year-old trees, and about 0.7 rings per year for 180-year-old trees. The lifespan of xylem parenchyma cells ranged from 10–15 years in 20-year-old trees to 70 years in 180-year-old trees. At the age of the previous felling (70–80 years) the HW area in the trunk biomass is about 20%, and in 180-year-old pine forests, it increases to 50%. These data can be used to assess the role of old-growth forests in carbon sequestration.

Past Logging and Wildfire Increase above Ground Carbon Stock Losses from Subsequent Wildfire

Background: Wildfire is known to reduce forest carbon stocks, but the influence of antecedent disturbance on wildfire related carbon stock losses is not as well understood. Disturbances such as logging and wildfire may increase the vulnerability of remaining carbon stocks to subsequent wildfire. Conversely, these disturbances may reduce the impact of subsequent wildfire, resulting in lower carbon stock losses. Methods: We measured above ground carbon stocks in productive resprouting Eucalypt dominated forests before and after a mixed severity fire that burned during the 2019/20 ‘Black Summer’ fire season in south-eastern Australia. The initial surveys were stratified by time since logging and time since wildfire, allowing for an assessment of how these disturbance histories influence above ground carbon stock losses caused by subsequent wildfire. Results: Above ground carbon stock losses varied substantially; however, there was a weak decrease in losses associated with time since logging but not time since wildfire. Variance in carbon stock losses associated with logging were greater than that caused by the severity of the 2019/20 wildfire itself. Carbon losses and predicted effects of disturbance may be underestimated in some cases due to the accumulation of carbon at sites between pre- and post-fire surveys. Conclusions: This study presents the largest published dataset of direct carbon stock changes resulting from wildfire in eucalypt forests. Our findings indicate that logging reduces the stability of above ground carbon stocks in resprouting eucalypt forests. This information will be critical for land managers looking to manage forests for carbon sequestration.

Quantification of carbon sequestration by urban forest using Landsat 8 OLI and machine learning algorithms in Jodhpur, India

Urban forests play a significant role in carbon cycling. Quantification of Aboveground Biomass (AGB) is critical to understand the role of urban forests in carbon sequestration. In the present study, Machine learning (ML) based regression algorithms (SVM, RF, kNN and XGBoost) have been taken into account for spatial mapping of AGB and carbon for the urban forests of Jodhpur city, Rajasthan, India, with the aid of field-based data and their correlations with spectra and textural variables derived from Landsat 8 OLI data. A total of 198 variables were retrieved from the satellite image, including bands, Vegetation Indices (VIs), linearly transformed variables, and Grey Level Co-occurrence textures (GLCM) taken as independent input variables further reduced to 29 variables using Boruta feature selection method. All the models have been compared where with RF algorithm, R2 = 0.83, RMSE = 16.22 t/ha and MAE = 11.86 t/ha. For kNN algorithm R2 = 0.77, RMSE = 28.04 t/ha and MAE = 24.24 t/ha and SVM where R2 = 0.73, RMSE = 89.21 t/ha and MAE = 74.22 t/ha and the best prediction accuracy has been noted with XGBoost algorithm (R2 = 0.89, RMSE = 14.08 t/ha and MAE = 13.66 t/ha) with predicted AGB as 0.51−153.76 t/ha. The study indicates that ML-based regression algorithms have great potential over other linear and multiple regression techniques for spatial mapping of AGB and carbon of urban forests for arid regions.

People of the Mangrove: A Lens into Socioecological Interactions in the Ecuadorian Black Pacific

Adapted to survive in the interface between land and sea, mangroves are highly vulnerable to the impacts of climate change. They are also highly adaptive to the imagination, with the theme of the mangrove being differently signified across texts, languages and communities as a place to find death in the tropics, a nature tourism destination, endangered environment, magical wood, refuge for maroons and revolutionaries, and source of livelihoods. The cultural malleability of mangroves mirrors their natural adaptability. It also echoes the varied and rhizomatic identities and imaginaries of the peoples of the tropical Americas. Relevant cultural texts produced in the region support experimentations with mangroves as a raw material susceptible to being worked in order to explain diverse realities. In order to highlight the relevance and malleability of mangrove ecosystems, this paper explores resignifications of socioecological interactions at the Ecological Mangrove Reserve Cayapas-Mataje in Ecuador through the lens of photographer Felipe Jácome. Jácome’s photographic essay Los Reyes del Manglar [The Kings of the Mangrove] provides rich material to study the rhizomatic evolution of the theme of the mangrove and its entanglements with people’s lives, cultures and histories. I argue that cultural representations of mangroves can go beyond their metaphorical recovery to support environmental justice. This essay is also informed by extant research on the important role of mangrove forests for carbon sequestration and climate change mitigation, which locates these socioecological systems at the centre of people’s struggle for climate justice.

Forest soil nutrient stocks along altitudinal range of Uttarakhand Himalayas: An aid to Nature Based Climate Solutions

Understating of forest functioning is crucial for ensuring the sustainable flow of forest ecosystem services. Climate regulation service of a forest ecosystem can be ensured through emission reduction by increasing carbon sequestration in forests. However, understanding about the functioning of forests for carbon sequestration is constrained due to lack of information on nutrient stocks and stoichiometry of soils of forests of India. Present study focuses to examine the stoichiometry of major nutrients; nitrogen (N), phosphorus (P), carbon (C) of forest soil to understand the dynamics of the forests of Uttarakhand, India. The study also attempted to supplement the information about the soil carbon sequestration potential of important tree species of the forest. Soil samples were collected randomly for the evaluation of physico-chemical characteristics and stoichiometry of forest soil at four altitudinal ranges i.e., <1000, 1000–1500, 1500–2000, and >2000 m a.s.l in the Himalayan region of Uttarakhand, India. The analysis shows that total nitrogen, total phosphorous, and soil organic carbon contents in forest soil were 0.35 ± 0.11%, 0.10 ± 0.04% and 3.36 ± 0.84%, respectively, which increases with altitude. The stoichiometric ratios viz., C:N:P, N:P, C:N, and C:P, and N:P were reported of 51.6:5.4:1, 4.30 ± 2.39, 9.60 ± 1.48, and 41.94 ± 23.35, respectively which were invariant with altitude. The low C:N ratio may be attributed to either increase in the nitrous oxide (N2O) emissions with an increase in nitrogen, or low in carbon stock leading to decrease in carbon dioxide (CO2) and methane (CH4) emissions. Moreover, the soil C sequestration potential in the forest tree species follow the order of Abies pindrow > Cedrus deodara > Quercus leucotrichophora > Pinus roxburghii. The information of the study would facilitate for broadening the understanding about the soil properties and stoichiometry of forest ecosystem and would provide an aid to forest management besides contributing to the mitigations strategies of the forests.

Landscape implications of managing forests for carbon sequestration

Abstract We explore the implications of managing forests for the dual purpose of sequestering carbon and producing timber, using a model of the forest sector that includes a Hartman-based representation of forest owners’ behaviour as well as heterogeneity in environmental conditions. We focus on France, where recent policies aim at increasing the carbon sink and where the diversity of forests makes an analysis of spatial dynamics relevant, and we use recent estimates of the shadow price of carbon consistent with the country’s climate commitments. Results suggest that forests may sequester up to 550 MtCO2eq by 2100, driven by changes in harvest levels and species choice, whilst rotation lengths increase overall. A spatial analysis reveals a high spatial variability for these trends, highlighting the importance of considering the local context. Changes in investment patterns affect the spatial distribution of forest cover types: by the end of the century, a majority of regions comprise a larger share of older, multiple-species and mixed-structure forests. Whilst such an evolution may present benefits in terms of biodiversity, ecosystem services provision and resilience, it raises questions regarding the adequacy of such developments with current forest policy, which also aims at increasing harvest levels. An overall mitigation strategy for the forest sector would likely include incentives to energy and material substitution in downstream industries, which we did not consider and may interact with sequestration incentives.

Estimating soil organic carbon stocks under commercial forestry using topo-climate variables in KwaZulu-Natal, South Africa

Commercial forests are expanding globally, with great potential to absorb carbon and mitigate climate change. However, whereas the role of natural forests in carbon sequestration has been widely investigated, there is a paucity in the literature on the role of commercial forests in carbon assimilation. Hence, understanding the role of commercial forests in carbon storage is essential for quantifying local, regional or global carbon balances, which is valuable for climate change mitigation. Soil carbon is known to be the largest pool within any forest landscape, and is controlled by a wide range of physical and climatic factors. However, the relationship between soil organic carbon (SOC) and topo-climatic variables controlling its distribution within commercial forests is still poorly understood. Due to the limitations encountered in traditional systems of SOC determination, particularly at large spatial extents, geospatial techniques have recently emerged as a viable alternative for mapping soil properties. Therefore, this study sought to map SOC stocks variability within the commercial forest landscape, using landscape topo-climatic variables. A total of 81 soil samples was analysed for SOC concentrations and 31 topographic and climatic variables were used as predictors to SOC variability. To reduce multicollinearity, these variables were reduced to 11 using stepwise backward elimination and the maximum entropy (Maxent) algorithm was used for regression analysis to determine the relationship between SOC and the selected topo-climatic variables. Good accuracies were obtained for both training (area under the curve = 0.906) and test (area under the curve = 0.885) data sets, and demonstrate the effectiveness of selected topo-climatic variables and the Maxent algorithm in predicting SOC stocks. This study provides a framework for monitoring the status of soil carbon in commercial forest compartments and provides a viable approach for local, national or regional carbon accounting – valuable for climate change mitigation.&#x0D; Significance:&#x0D; &#x0D; Rainfall and temperature, as well as topographic variables (such as slope, elevation and topographic wetness index) are effective in mapping SOC distribution.&#x0D; The model developed is useful in predicting SOC occurrence and yielded an effective framework for continuous monitoring and assessment of SOC.&#x0D; The method developed in this study is cost-effective and suggests the use of other readily available climatic and topographic information for the prediction of SOC under commercial forestry in South Africa and indeed globally.&#x0D; Results from this study are important to achieve the national carbon accounting objective and are also valuable to forest managers, ecologists and relevant stakeholders in understanding the spatial distribution of SOC.&#x0D;

Research and Exploration of Ecological Highway Carbon Sequestration Forest Methodology

Based on the demand of ecological highway construction, this paper explores the research work of carbon sequestration forest. The introduction of forest carbon sinks and advanced concepts of the forestry carbon sequestration, and for the measurement of the highway in the carbon sink forest carbon sink monitoring and exploration on the aspects, such as, the forest carbon sinks and forestry carbon sink theory knowledge, used in highway transportation, implements the carbon sink forest methodology used in the field of traffic, road area change ever green landscape, the shrub tree species as the main design concept, put forward the concept of carbon sequestration in the road system and based on the neutral roadside greening design forestry carbon sequestration. On the basis of energy conservation and emission reduction, the construction of carbon sequestration forest is adopted to solve the carbon emission problem of the transportation industry from another perspective, so as to improve the quality of planting trees along the transportation lines of Jiangsu province and even the whole country, update the greening concept, enhance carbon sequestration and ecological efficiency, and open up a new path for building a green transportation environment.

Ecosystem carbon stock of a tropical mangrove forest in North Sulawesi, Indonesia

Recent studies have highlighted the valuable role played by mangrove forests in carbon sequestration and storage. Although Indonesia accounts for a large proportion of global mangrove area, knowledge on the carbon stock and sources in the Indonesian mangrove is still limited. In this study, we quantified the ecosystem organic carbon (OC) stock and its spatial variation at an oceanic mangrove in Wori, North Sulawesi, Indonesia. The sources of soil OC were also investigated. The results showed that the mangrove soil had a substantial OC stock containing 15.4 kg/m2 (calculated by carbon) in the top 50 cm soil, and represented the majority of the ecosystem OC stock at the Wori mangrove. The mangrove biomass and ecosystem OC stock were 8.3 kg/m2 and 23.7 kg/m2, respectively. There was no significantly difference in the soil OC stock among the stations with difference distances offshore, while the highest mangrove biomass OC stock was found at the seaward station. Isotope mixing calculations showed that the rich OC in mangrove soils was attributed to the accumulated autochthonous mangrove source while the suspended organic matter in tidal water and the mangrove-adjacent seagrass contributed less than 20% to the soil OC. The results further demonstrated the importances of the oceanic mangrove in carbon storage and the mangrove plants in contributing OC to their soils.

Disturbance ecology benchmarks for Schima–Castanopsis forests in the central Himalayas

ABSTRACTRoughly 2.8 billion people burn wood for basic energy needs, and traditional wood-fuel represents ~55% of global wood harvest. With increasing anthropogenic disturbance of natural forests, the “stability/fragility” paradigm of forest ecology is gradually being replaced by a “disturbance/recovery” paradigm. In order to understand effects of human-induced disturbances on natural forest ecosystems, and to plan for recovery of disturbed forests, appropriate metrics become necessary. Such metrics will aid in assessment and management of forests for carbon sequestration, biodiversity conservation, ecosystem health, and sustainability of natural resources. Such metrics are especially needed in “wood-fuel hotspots” of the world where over 275 million people live and harvest wood-fuel unsustainably. In this article, I provide metrics of human-induced disturbance in Nepal’s Schima–Castanopsis dominated forests and show relationships of disturbance intensity with forest structure and composition, site productivity potential, natural regeneration, and tree species diversity. Benchmark data were collected from survey of two protected reference forests and compared against three other forests representing a disturbance gradient. The Schima–Castanopsis association is a common dominant forest type in the warm temperate zone of the central Himalayas, and the findings from this study should have wider application.

Estimating the aboveground carbon sequestration and its economic value (case study: Iranian Caspian forests)

The aim of the study is to estimate the aboveground carbon sequestration and to determine the economic value of forests in carbon sequestration as a way of mitigating climate change. This research was conducted at Asalem forests in the north of Iran. In order to estimate the amount of annual carbon sequestration, the annual volume growth of stand was determined using the diameter increment data and tariff. The amount of carbon sequestration was estimated based on wood density and using the allometric equation. The carbon model was obtained for each species. The value of sequestrated carbon in stumpage and the net present value of carbon sequestration were determined in order to estimate the economic value of carbon sequestration. Results indicated that the annual volume growth per hectare and the carbon stored are 6.023 m&lt;sup&gt;3&lt;/sup&gt;·yr&lt;sup&gt;–1&lt;/sup&gt; and 2.307 t·ha&lt;sup&gt;–1&lt;/sup&gt;, respectively. Finally, the carbon sequestration value of stumpage and the net present value of carbon sequestration are 11,023.753 and 790.361 (10,000 IRR·t&lt;sup&gt;–1&lt;/sup&gt;·ha&lt;sup&gt;–1&lt;/sup&gt;), respectively. Our results are very useful in estimating the total economic value of Asalem forests and other Iranian Caspian forests in the future.

Agriculture and climate change: Potential for mitigation in Spain

Agriculture and forestry activities are one of the many sources of greenhouse gas (GHG) emissions, but they are also sources of low-cost opportunities to mitigate these emissions compared to other economic sectors. This paper provides a first estimate of the potential for mitigation in the whole Spanish agriculture. A set of mitigation measures are selected for their cost-effectiveness and abatement potential and an efficient mix of these measures is identified with reference to a social cost of carbon of 40 €/tCO2e. This mix of measures includes adjusting crop fertilization and managing forests for carbon sequestration. Results indicate that by using the efficient mix of mitigation measures the annual abatement potential could reach 10 million tCO2e, which represents 28% of current agricultural emissions in Spain. This potential could further increase if the social cost of carbon rises covering the costs of applying manure to crops. Results indicate also that economic instruments such as input and emission taxes could be only ancillary measures to address mitigation in agriculture. These findings can be used to support the mitigation efforts in Spain and guide policymakers in the design of country-level mitigation strategies.