Carbon Sequestration Research Papers - Academia.edu (original) (raw)

There is a need to accurately estimate the carbon sequestration potential of many of our agricultural and horticultural industries now that the Australian Government has introduced the Carbon Farming Initiative and is planning to... more

There is a need to accurately estimate the carbon sequestration potential of many of our agricultural and horticultural industries now that the Australian Government has introduced the Carbon Farming Initiative and is planning to introduce an emissions trading scheme in 2015. This study estimates that the carbon sequestration of macadamia plantations is around 3t CO 2 e/ha/yr, and provides a methodology to assess the carbon footprint of the Australian Macadamia Industry. This study attempts to estimate the growth rate, and subsequently the sequestration rate of plantation grown Macadamia spp. through regression analysis of stem characteristics of destructively sampled Macadamia integrifolia var. 344. A volume increment curve was also derived using three common genetic varieties (A4, A16 & A42). This curve is used to extrapolate a carbon sequestration rate for the national macadamia plantation estate. Once volume estimates and sequestration rates are deter-mined, an economic benefit of the carbon sequestration can be estimated by auditing the amount of carbon produced by activities such as ''on farm'' fuel use, fuel used in transport, and energy used in producing the product. In this way, a life cycle carbon budget can be developed that will aid the sustainable development of the macadamia and horticultural industries in Australia through the production of carbon credits from the carbon stored in the trees.

Carbon capture and storage (CCS) is vital to reduce CO 2 emissions to the atmosphere, potentially providing 20% of the needed reductions in global emissions. Research and demonstration projects are important to increase scientific... more

Carbon capture and storage (CCS) is vital to reduce CO 2 emissions to the atmosphere, potentially providing 20% of the needed reductions in global emissions. Research and demonstration projects are important to increase scientific understanding of CCS, and making processes and results widely available helps to reduce public concerns, which may otherwise block this technology. The Otway Project has provided verification of the underlying science of CO 2 storage in a depleted gas field, and shows that the support of all stakeholders can be earned and retained. Quantitative verification of long-term storage has been demonstrated. A direct measurement of storage efficiency has been made, confirming that CO 2 storage in depleted gas fields can be safe and effective, and that these structures could store globally significant amounts of CO 2 . carbon storage | geosequestration | carbon dioxide | climate change | energy policy

Carbon sequestration is promoted as a practice to offset the negative consequences of greenhouse gas emissions. The aim of this study was to estimate carbon sequestration in silvopastoral systems established with Pinus radiata D. Don and... more

Carbon sequestration is promoted as a practice to offset the negative consequences of
greenhouse gas emissions. The aim of this study was to estimate carbon sequestration in
silvopastoral systems established with Pinus radiata D. Don and Betula pubescens Ehrh. The
soil compartment proved the most significant carbon sink, and carbon sequestration tended to
be higher under P. radiata due to the higher growth rate of this species compared to B.
pubescens.

Nowadays, livestock production is strongly dependent on inputs produced from outside the farm, such as fertilizers and concentrates. The combination of low-density trees and grasslands allows the feeding of animals in a cheap way, as tree... more

Nowadays, livestock production is strongly dependent on inputs produced from outside the
farm, such as fertilizers and concentrates. The combination of low-density trees and
grasslands allows the feeding of animals in a cheap way, as tree branches can be used as
fodder during periods of forage shortage. Moreover, increased productivity is ensured, as the
land-equivalent ratio of 1 ha of silvopasture is between 1.2 and 1.6 ha of forest and crop
monocrops, to produce the same amount of products. The presence of trees in grasslands at
low density will promote biodiversity, carbon sequestration and nutrient recycling; therefore,
a promotion of efficiency in the use of the resources is definitively enhanced. This paper
reviews results from a series of experiments to show how silvopasture could promote
production and environmental services to provide more sustainable land use options in
livestock production.

Agroforestry, a combination of a woody (shrub/tree) with an herbaceous component (crops/pasture) is considered an important tool to mitigate and adapt agrarian systems to global climate change. This fact is based on the capacity that AGF... more

Agroforestry, a combination of a woody (shrub/tree) with an herbaceous component (crops/pasture) is considered an important tool to mitigate and adapt agrarian systems to global climate change. This fact is based on the capacity that AGF systems have to preserve C already accumulated in the woody component but also to increase C sequestration in a tree-less system when trees are planted. Nitrate and CO2 emissions can be reduced by the consumption of the biomass of the understory in forests with high fire risk, but also for the better use of fertilizers in more open systems that will contribute to mitigate the negative effects of this fertiliser inputs on GHG atmosphere release. Resilience is also improved as biodiversity in AGF systems is usually higher than in tree-less systems.

The latest advances in bioregenerative strategies for long-term life support in extraterrestrial outposts such as on Mars have indicated soil-based cropping as an effective approach for waste decomposition, carbon sequestration, oxygen... more

The latest advances in bioregenerative strategies for long-term life support in extraterrestrial outposts such as on Mars have indicated soil-based cropping as an effective approach for waste decomposition, carbon sequestration, oxygen production, and water biofiltration as compared to hydroponics and aeroponics cropping. However, it is still unknown if cropping using soil systems could be sustainable in a Martian greenhouse under a gravity of 0.38g. The most challenging aspects are linked to the gravity-induced soil water flow; because water is crucial in driving nutrient and oxygen transport in both liquid and gaseous phases, a gravitational acceleration lower than g = 9.806 m s À2 could lead to suffocation of microorganisms and roots, with concomitant emissions of toxic gases. The effect of Martian gravity on soil processes was investigated using a highly mechanistic model previously tested for terrestrial crops that couples soil hydraulics and nutrient biogeochemistry. Net leaching of NO À 3 solute, gaseous fluxes of NH 3 , CO 2 , N 2 O, NO and N 2 , depth concentrations of O 2 , CO 2 and dissolved organic carbon (DOC), and pH in the root zone were calculated for a bioregenerative cropping unit under gravitational acceleration of Earth and for its homologous on Mars, but under 0.38g. The two cropping units were treated with the same fertilizer type and rate, and with the same irrigation regime, but under different initial soil moisture content. Martian gravity reduced water and solute leaching by about 90% compared to Earth. This higher water holding capacity in soil under Martian gravity led to moisture content and nutrient concentrations that favoured the metabolism of various microbial functional groups, whose density increased by 5-10% on Mars as compared to Earth. Denitrification rates became substantially more important than on Earth and ultimately resulted in 60%, 200% and 1200% higher emissions of NO, N 2 O and N 2 gases, respectively. Similarly, O 2 and DOC were consumed more rapidly in the Martian soil and resulted in about 10% increase in CO 2 emissions. More generally, Martian cropping would require 90% less water for irrigation than on Earth, being therefore favourable for water recycling treatment; in addition, a substantially lower nutrient supply from external sources such as fertilizers would not compromise nutrient delivery to soil microorganisms, but would reduce the large N gas emissions observed in this study.

The reports map the flow of carbon through the Swedish Food and Agriculture System, all the way from net primary productivity to human waste and sewage. Animal feed and metabolism, food industries, import and exports, losses etc are all... more

The reports map the flow of carbon through the Swedish Food and Agriculture System, all the way from net primary productivity to human waste and sewage. Animal feed and metabolism, food industries, import and exports, losses etc are all included.

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The feasibility study found that Zambia has a number of features that are compatible with successful biogas production and use. For example, integrated farming, where agricultural production and livestock production are mostly combined,... more

The feasibility study found that Zambia has a number of features that are compatible with successful biogas production and use. For example, integrated farming, where agricultural production and livestock production are mostly combined, is very common in Zambia, therefore agricultural production could benefit from bioslurry application. Furthermore, the cattle are kept in stables or kraals (corrals) close tothe homestead for at least the night in most areas, so there is manure available near the kitchen. Water is generally available close by and the average temperature is high enough for good biogas production.
The technical potential for biogas is great, with an estimated 80,000 cattle holders with five cattle or more, and 10,000 commercial pig farmers who own eight pigs or more. There is also an emerging dairy sector consisting of at least 2,500 dairy farmers connected to milk collection centres. Building materials are readily available.
Zambia’s experience with biogas so far has been very limited and there is little awareness and related knowledge available to build on. Considerable attention must therefore be paid to promoting and marketing the technology.
Quality biodigesters will not be cheap in Zambia, although the price is not much higher than for one good dairy cow or three ordinary cattle, on average. Taking into account cost savings alone, a simple payback period was calculated at 3.25 to 3.75 years. Thus, biodigesters are considered to be affordable for most farmers who have a technical potential of more than five cows or eight pigs. The availability of credit
to purchase a biodigester would greatly enhance demand. Unfortunately, rural credit provision is poorly developed still in Zambia, so any proposed biogas programme will have to find appropriate solutions to that problem.
Zambia does not have a big building sector with many small contractors that could take up the work ofbuilding digesters. Considerable training will be necessary, both on the technical side and also on the business and marketing side, to fill the gap. The government has a far-reaching extension service that would greatly benefit biodigester promotion and dissemination, and support from several rural NGOs could also be instrumental for the sector.
The political environment is stable and favours an energy policy that promotes renewable energy development and biogas, in particular.
For all of these reasons, it was concluded that there is scope for a medium-sized domestic biodigester programme (7,500 units in five years) in Zambia. The five highest ranking provinces, based on cattle density, access to water, (lack of) access to electricity, and population density are Southern, Eastern, Western, Central and Lusaka.
Hivos and SNV aim to promote the creation of a biodigester sector, where maximum participation is soughtfrom existing organisations, each fulfilling a function in the programme and carrying out its core business. Many organisations were contacted in the course of this feasibility study and many expressed interest inparticipating in such a programme.
It is hoped that the programme could start in 2013.

Forest ecosystems are fundamental for the terrestrial biosphere as they deliver multiple essential ecosystem services (ES). In environmental management, understanding ES distribution and interactions and assessing the economic value of... more

Forest ecosystems are fundamental for the terrestrial biosphere as they deliver multiple essential ecosystem services (ES). In environmental management, understanding ES distribution and interactions and assessing the economic value of forest ES represent future challenges. In this study, we developed a spatially explicit method based on a multi-scale approach (MiMoSe-Multiscale Mapping of ecoSystem services) to assess the current and future potential of a given forest area to provide ES. To do this we modified and improved the InVEST model in order to adapt input data and simulations to the context of Mediterranean forest ecosystems. Specifically, we integrated a GIS-based model, scenario model, and economic valuation to investigate two ES (wood production and carbon sequestration) and their trade-offs in a test area located in Molise region (Central Italy). Spatial information and trade-off analyses were used to assess the influence of alternative forest management scenarios on in...

A comparison was made of annual net ecosystem productivity (NEP) of a closed canopy Sitka spruce forest over 2 years, using either eddy covariance or inventory techniques. Estimates for annual net uptake of carbon (C) by the forest varied... more

A comparison was made of annual net ecosystem productivity (NEP) of a closed canopy Sitka spruce forest over 2 years, using either eddy covariance or inventory techniques. Estimates for annual net uptake of carbon (C) by the forest varied between 7.30 and 11.44 t C ha À1 year À1 using ecological inventory (NE-P eco ) measures and 7.69-9.44 t C ha À1 year À1 using eddy covariance-based NEP (-NEE) assessments. These differences were not significant due to uncertainties and errors associated with estimates of biomass increment (15-21%) and heterotrophic respiration (12-19%). Carbon-stock change inventory (NEP DC ) values were significantly higher (27-32%), when compared to both NEP eco -and -NEE-based estimates. Additional analyses of the data obtained from this study, together with published data, suggest that there was a systematic overestimation of NEP DC -based assessments due to unaccounted decomposition processes and uncertainties in the estimation of soil-C stock changes. In contrast, there was no systematic difference between NEP eco and eddy covariance assessments across a wide range of forest types and geographical locations.

Hybrid poplar plantations offer opportunities for enhancing carbon sinks, but accurate assignment of carbon credits requires accurate estimation of the amount of carbon stored in poplar biomass. Here we present individual-tree bole and... more

Hybrid poplar plantations offer opportunities for enhancing carbon sinks, but accurate assignment of carbon credits requires accurate estimation of the amount of carbon stored in poplar biomass. Here we present individual-tree bole and branch biomass equations derived for Populus trichocarpa Torr. and Gray  P. deltoides Marsh. hybrids from plantations in coastal British Columbia, Canada. Trees ranged in age from 4 to 13 years old and were planted at a density of 1111 stems ha À1 . Equations were applied to similar short-rotation intensive-culture plantations near or at rotation age to derive estimates of aboveground leafless biomass production and amount of carbon sequestered. After 12 years, predicted aboveground leafless biomass accumulation ranged from 9.2 to 13.6 Mg ha À1 year À1 ; predicted bole biomass accumulation ranged from 7.5 to 11.3 Mg ha À1 year À1 . Total carbon in aboveground leafless biomass at age 12 ranged from 51.2 to 75.7 Mg ha À1 . Three of the stands reached 14 years of age prior to harvest. Predicted carbon content of aboveground leafless biomass at 14 years of age ranged from 73.7 to 88.7 Mg ha À1 .

Ensuring acceptance of dedicated biomass feedstocks by landowners, agricultural communities, environmental and public interest groups, requires that the environmental benefits, concerns, and risks associated with their production be... more

Ensuring acceptance of dedicated biomass feedstocks by landowners, agricultural communities, environmental and public interest groups, requires that the environmental benefits, concerns, and risks associated with their production be quantified. Establishment and management measures to benefit soil and water quality are being identified by ongoing research. Field studies are showing that nutrients are retained within the rooting zone of dedicated feedstocks, subsurface herbicide transport does not occur, and off-site chemical transport is minimal compared with traditional agricultural crops. The amounts and timing of fertilizer application were critical to minimizing off- site transport of nutrients. Maintaining soil cover decreased runoff, sediment losses, and nutrient transport compared with traditional agricultural crops. Conversion of traditional croplands to biomass and no-till crop production improved soil quality and soil carbon storage. Subsurface nutrient losses were less fr...

To mitigate global climate change, a portfolio of strategies will be needed to keep the atmospheric CO 2 concentration below a dangerous level. Here a carbon sequestration strategy is proposed in which certain dead or live trees are... more

To mitigate global climate change, a portfolio of strategies will be needed to keep the atmospheric CO 2 concentration below a dangerous level. Here a carbon sequestration strategy is proposed in which certain dead or live trees are harvested via collection or selective cutting, then buried in trenches or stowed away in above-ground shelters. The largely anaerobic condition under a sufficiently thick layer of soil will prevent the decomposition of the buried wood. Because a large flux of CO 2 is constantly being assimilated into the world's forests via photosynthesis, cutting off its return pathway to the atmosphere forms an effective carbon sink. It is estimated that a sustainable long-term carbon sequestration potential for wood burial is 10 ± 5 GtC y-1 , and currently about 65 GtC is on the world's forest floors in the form of coarse woody debris suitable for burial. The potential is largest in tropical forests (4.2 GtC y-1), followed by temperate (3.7 GtC y-1) and boreal forests (2.1 GtC y-1). Burying wood has other benefits including minimizing CO 2 source from deforestation, extending the lifetime of reforestation carbon sink, and reducing fire danger. There are possible environmental impacts such as nutrient lock-up which nevertheless appears manageable, but other concerns and factors will likely set a limit so that only part of the full potential can be realized. Based on data from North American logging industry, the cost for wood burial is estimated to be 14/tCO2(14/tCO 2 (14/tCO2(50/tC), lower than the typical cost for power plant CO 2 capture with geological storage. The cost for carbon sequestration with wood burial is low because CO 2 is removed from the atmosphere by the natural process of photosynthesis at little cost. The technique is low tech, distributed, easy to monitor, safe, and reversible, thus an attractive option for large-scale implementation in a worldwide carbon market.

Life-history variation in annuals is known to be caused by size requirements for photoinduction of flowering, but the importance of germination date and injury was overlooked so far even though they may play an important role in disturbed... more

Life-history variation in annuals is known to be caused by size requirements for photoinduction of flowering, but the importance of germination date and injury was overlooked so far even though they may play an important role in disturbed habitats. To test the effect of germination date and timing of injury on life-history variation of an annual plant, we performed a 2-year pot experiment with the root-sprouting herb Rorippa palustris. Plants belonging to six different cohorts, and sown at monthly intervals from April to September, were injured (all stem parts removed) in three ontogenetic stages: vegetative rosettes, flowering plants and fruiting plants. Plants from the April, and partly from the May, cohort behaved as summer annuals: they started to bolt at the same time, resprouted and overwintered poorly. Plants from the June cohort flowered in the first season as well, but they entered the bolting stage a month later than the preceding cohorts, produced the least fruits, but overwintered successfully and flowered again the second year (polycarpic perennials).

Oxygen minimum zones (OMZs), also known as oceanic "dead zones", are widespread oceanographic features currently expanding due to global warming and coastal eutrophication. Although inhospitable to metazoan life, OMZs support a thriving... more

Oxygen minimum zones (OMZs), also known as oceanic "dead zones", are widespread oceanographic features currently expanding due to global warming and coastal eutrophication. Although inhospitable to metazoan life, OMZs support a thriving but cryptic microbiota whose combined metabolic activity is intimately connected to nutrient and trace gas cycling within the global ocean. Here we report time-resolved metagenomic analyses of a ubiquitous and abundant but uncultivated OMZ microbe (SUP05) closely related to chemoautotrophic gill symbionts of deep-sea clams and mussels. The SUP05 metagenome harbors a versatile repertoire of genes mediating autotrophic carbon assimilation, sulfur-oxidation and nitrate respiration responsive to a wide range of water column redox states. Thus, SUP05 plays integral roles in shaping nutrient and energy flow within oxygen-deficient oceanic waters via carbon sequestration, sulfide detoxification and biological nitrogen loss with important implications for marine productivity and atmospheric greenhouse control.

AbstractÐIncreased atmospheric CO 2 , caused partly by burning fossil fuels, is assumed to elevate the risk of global warming, while nitrate contamination of surface runo and groundwater from fertilizer and agricultural wastes constitutes... more

AbstractÐIncreased atmospheric CO 2 , caused partly by burning fossil fuels, is assumed to elevate the risk of global warming, while nitrate contamination of surface runo and groundwater from fertilizer and agricultural wastes constitutes a serious environmental hazard on a regional scale. Switchgrass (Panicum virgatum L.) grown as an energy crop could reduce atmospheric CO 2 accumulation by replacing fossil fuels and sequestering C. It could also improve soil productivity by C sequestration, and reduce xy À1 3 contamination of water by absorbing N lost from fertilizer and agricultural waste if planted in ®lter strips on adjacent land. The objective of this study was to assess potential impacts of switchgrass on C and N balances by reviewing and synthesizing information from current literature, unpublished data and on-going research. Replacing fossil fuels with switchgrass, or any other biomass, will have a much greater eect on atmospheric CO 2 than C sequestration. This is because replacing fossil fuels provides a cumulative eect, while C sequestration oers only a one-time bene®t. Furthermore, switchgrass will provide net gains in C sequestration only if it replaces annual row crops, but not if it replaces grazed pasture. Nitrogen recovery by switchgrass in an Alabama study was 65.6%, which compares favorably with the 50% recovery frequently quoted as the norm for wheat (Triticum aestivum L.) and corn (Zea mays L). #

The vision of the Gulf Coast Carbon Center is to seek to impact global levels of GHG in the atmosphere by doing science and engineering studies that will support reduction of CO2 emissions and enable the development of an economically... more

The vision of the Gulf Coast Carbon Center is to seek to impact global levels of GHG in the atmosphere by doing science and engineering studies that will support reduction of CO2 emissions and enable the development of an economically viable, multifaceted, CO2 sequestration industry in the Gulf Coast. This industrial-academic consortium is investigating issues related to assessing the pathways that would make capture and pipeline transportation economically feasible and environmentally effective within a specific regional context. Key issues considered are capture in the context of the current market, pipeline infrastructure, the role of enhanced oil recovery, and permanence in a basin with many wells. .

A comparative analysis of soils and vegetation from cultivated areas reseeded to native grasses and native prairies that have not been cultivated was conducted to evaluate restoration of southern mixed prairie of the Great Plains over the... more

A comparative analysis of soils and vegetation from cultivated areas reseeded to native grasses and native prairies that have not been cultivated was conducted to evaluate restoration of southern mixed prairie of the Great Plains over the past 30 to 50 years. Restored sites were within large tracts of native prairie and part of long-term grazing intensity treatments (heavy, moderate, and ungrazed), allowing evaluation of the effects of grazing intensity on prairie restoration. Our objective was to evaluate restored and native sites subjected to heavy and moderate grazing regimes to determine if soil nutrients from reseeded cultivated land recovered after 30 years of management similar to the surrounding prairie and to identify the interactive influence of different levels of grazing and history of cultivation on plant functional group composition and soils in mixed prairies. For this mixed prairie, soil nitrogen and soil carbon on previously cultivated sites was 30 to 40% lower than in uncultivated native prairies, indicating that soils from restored sites have not recovered over the past 30 to 50 years. In addition, it appears that grazing alters the extent of recovery of these grassland soils as indicated by the significant interaction between grazing intensity and cultivation history for soil nitrogen and soil carbon. Management of livestock grazing is likely a critical factor in determining the potential restoration of mixed prairies. Heavy grazing on restored prairies reduces the rate of soil nutrient and organic matter accumulation. These effects are largely due to changes in composition (reduced tallgrasses), reduced litter accumulation, and high cover of bare ground in heavily grazed restored prairies. However, it is evident from this study that regardless of grazing intensity, restoration of native prairie soils requires many decades and possibly external inputs to adequately restore organic matter, soil carbon, and soil nitrogen.

The atmospheric CO 2 concentration is increasing, due primarily to fossil-fuel combustion and deforestation. Sequestering atmospheric C in agricultural soils is being advocated as a possibility to partially offset fossil-fuel emissions.... more

The atmospheric CO 2 concentration is increasing, due primarily to fossil-fuel combustion and deforestation. Sequestering atmospheric C in agricultural soils is being advocated as a possibility to partially offset fossil-fuel emissions. Sequestering C in agriculture requires a change in management practices, i.e. efficient use of pesticides, irrigation, and farm machinery. The C emissions associated with a change in practices have not traditionally been incorporated comprehensively into C sequestration analyses. A full C cycle analysis has been completed for agricultural inputs, resulting in estimates of net C flux for three crop types across three tillage intensities. The full C cycle analysis includes estimates of energy use and C emissions for primary fuels, electricity, fertilizers, lime, pesticides, irrigation, seed production, and farm machinery. Total C emissions values were used in conjunction with C sequestration estimates to model net C flux to the atmosphere over time. Based on US average crop inputs, no-till emitted less CO 2 from agricultural operations than did conventional tillage, with 137 and 168 kg C ha −1 per year, respectively. Changing from conventional tillage to no-till is therefore estimated to both enhance C sequestration and decrease CO 2 emissions. While the enhanced C sequestration will continue for a finite time, the reduction in net CO 2 flux to the atmosphere, caused by the reduced fossil-fuel use, can continue indefinitely, as long as the alternative practice is continued. Estimates of net C flux, which are based on US average inputs, will vary across crop type and different climate regimes. The C coefficients calculated for agricultural inputs can be used to estimate C emissions and net C flux on a site-specific basis. Published by Elsevier Science B.V.

Trees in urban areas store carbon directly through photosynthesis, but they also provide the added benefit of reducing carbon emissions produced by fossil-fuel burning power plants, by means of energy conservation from... more

Trees in urban areas store carbon directly through photosynthesis, but they also provide the added benefit of reducing carbon emissions produced by fossil-fuel burning power plants, by means of energy conservation from strategically-planted trees near buildings, as well as by area-wide reductions in the urban heat island effect. Quantifying the role of urban forests is an important prerequisite to managing the vegetation to optimize benefits, and also serves to assign value to the important ecosystem services provided by urban trees. Decisions by policymakers regarding the management and use of urban trees requires accurate and precise information about the state of the resource. This paper creates a methodology for conducting a carbon inventory in an urban forest in the Washington, DC area, one that requires a minimum of data gathering. The methodology could serve as a tool for other similar high-density urban areas to measure carbon resources in urban forests and to serve as the b...

Projects in the forestry sector, and land-use change and forestry projects more generally, have the potential to help mitigate global warming by acting as sinks for greenhouse gasses, particularly CO2. However, concerns have been... more

Projects in the forestry sector, and land-use change and forestry projects more generally, have the potential to help mitigate global warming by acting as sinks for greenhouse gasses, particularly CO2. However, concerns have been expressed that participation in carbon-sink projects may be constrained by high costs. This problem may be particularly severe for projects involving smallholders in developing countries. Of particular concern are the transaction costs incurred in developing projects, measuring, certifying and selling the carbon-sequestration services generated by such projects. This paper addresses these issues by reviewing the implications of transaction and abatement costs in carbon-sequestration

With respect to carbon sequestration in soil, attempts have been made to identify soil organic matter (SOM) fractions that respond more rapidly to changes in land-use than bulk SOM, which could thus serve as early indicators for the... more

With respect to carbon sequestration in soil, attempts have been made to identify soil organic matter (SOM) fractions that respond more rapidly to changes in land-use than bulk SOM, which could thus serve as early indicators for the overall stock change. We used a combination of physical fractionation (size and density separation) and chemical characterisation (C-to-N ratios, CuO lignin signature, 13 C NMR spectroscopy) to identify sensitive SOM fractions in an agricultural system with sandy dystric cambisols in Bavaria, Germany, 7 years after a land-use change. Land-use types included long-term arable land and grassland, and conversion from one system to the other. Soil carbon and nitrogen contents in 0 -3 cm increased from 14 to 39 mg organic carbon g À 1 soil, and from 1.7 to 3.9 mg nitrogen g À 1 soil in the following order: permanent arable, conversion grassland to arable, conversion arable to grassland, and permanent grassland. Wet sieving and ultrasonic dispersion with 22 J ml À 1 released < 5% and 60% to 80%, respectively, of the amount of particles >20 Am relative to complete dispersion. The most sensitive fraction, with respect to land-use, was SOM in the fraction >20 Am not released after sequential wet sieving and ultrasonic dispersion. In contrast, the proportion of free light (wet sieving, density < 1.8 g cm À 3 ) and occluded light (ultrasonic dispersion with 22 J ml À 1 , < 1.8 g cm À 3 ) particulate organic matter (POM) showed no clear response to land-use. The structural composition of POM indicated its vegetation origin with a selective enrichment of lignin and a loss of O-alkyl C relative to its plant precursors. Decomposition of the occluded light POM was only slightly advanced relative to the free light POM. In mineral fractions < 20 Am, SOM was significantly more transformed than in the coarse fractions, as shown by NMR spectroscopy; however, it revealed no specific land-use pattern. An exception to this was the proportion of O-alkyl C in the clay fraction, which increased with SOC content. Ratios of alkyl to O-alkyl C in mineral fractions < 20 Am differentiated samples gave a better differentiation of samples than the C-to-N ratios. We conclude that neither free nor occluded light POM are appropriate early indicators for changes in land-use at the investigated sites; however, total SOM, its distribution with depth, and SOM allocated in stable aggregates >20 Am were more sensitive. D

The potential non-permanence of sequestered CO 2 emissions is a crucial issue to tackle in order to safely include forestry activities among eligible activities for the Clean Development Mechanism. Rather than looking at accurate ways of... more

The potential non-permanence of sequestered CO 2 emissions is a crucial issue to tackle in order to safely include forestry activities among eligible activities for the Clean Development Mechanism. Rather than looking at accurate ways of securing permanent reductions, some experts studied the possibility of delivering temporary licenses as a way of circumventing the respective drawbacks of previously proposed approaches (e.g. Ton-Year Accounting). This paper focuses on this concept of temporary (or expiring) credits and tries to assess its financial viability using different scenario assumptions while bearing in mind the need to protect the CDM's environmental integrity. Our main finding is that the concept of expiring credits (EC) provides a convincing answer to the issue of non-permanence both from an environmental perspective and from a strictly financial point of view (as it has the property of efficiently dealing with uncertainties and therefore hedges the risk). However, given the specific nature of forestry activities compared with other types of CDM projects, the EC concept should be complemented with additional rules and modalities. D

Problem statement: There is general agreement that human activities such as deforestation and land use change to other land use types have contributed to degraded secondary forests or forestland and increases the emission of greenhouse... more

Problem statement: There is general agreement that human activities such as deforestation and land use change to other land use types have contributed to degraded secondary forests or forestland and increases the emission of greenhouse gases which ultimately led to global climate change. An establishment of forest plantation in particular is regarded as an important approach for sequestering carbon. However, limited information exists on productivity and potential of fast growth exotic and indigenous tree plantations for sequestering CO 2 from the atmosphere through photosynthesis. This study aimed at assessing the productivity and biomass accumulation along with the potential for sequestering CO 2 of planted exotic and indigenous species on degraded forestland. Approach: This study was conducted at Khaya ivorensis and Hopea odorata plantations, which was planted at the Forest Research Institute Malaysia (FRIM) Research Station in Sega mat Johor, Malaysia five years ago. In order, to evaluate the forest productivity and biomass accumulation of both species, we established plots with a size of 40x30 m in three replications in each stand, followed by measuring all trees in the plots in terms of height and Diameter at Breast Height (DBH). To develop allometric equation, five representative trees at each stand were chosen for destructive sampling. Results: The growth performance in terms of mean height, DBH, annual increment of height and diameter and basal area of exotic species (K. ivorensis) was significantly higher than that of the indigenous species (H. odorata). We used the diameter alone as independent variable to estimate stem volume and biomass production of both species. The stem volume of K. ivorensis stand was 43.13 m 3 ha −1 and was significantly higher than H. odorata stands (33.66 m 3 ha −1). The results also showed that the K. ivorensis and H. odorata stands have the potential to absorb CO 2 from the atmosphere which was stored in aboveground biomass with value 15.90 Mg C ha −1 and 13.62 Mg C ha-1 , respectively. In addition, the carbon content in root biomass of H. odorata stand was higher than that in K. ivorensis stand with value 7.67 Mg C ha −1 and 4.58 Mg C ha −1 , respectively. Conclusion/Recommendation: The exotic (K. ivorensis) and indigenous (H. odorata) species which was planted on degraded forestland exhibited different growth rate, biomass production and ability to absorb CO 2 from the atmosphere in each part of the tree. In general, forest productivity and ability to absorb CO 2 from the atmosphere of exotics species (K. ivorensis) was higher than that indigenous species (H. odorata). These findings suggest that forest plantation productivity has been affected by species characteristics and suitability of species to site condition. Thus, to sustain high productivity with suitable species selection for carbon sequestration, these factors should be considered for future forest establishment.

Organic agriculture has experienced remarkable growth in recent decades as societal interest in environmental protection and healthy eating has increased. Research has shown that relative to conventional agriculture, organic farming is... more

Organic agriculture has experienced remarkable growth in recent decades as societal interest in environmental protection and healthy eating has increased. Research has shown that relative to conventional agriculture, organic farming is more efficient in its use of non-renewable energy, maintains or improves soil quality, and has less of a detrimental effect on water quality and biodiversity. Studies have had more mixed findings, however, when examining the impact of organic farming on greenhouse gas (GHG) emissions and climate change. Life cycle assessments (LCAs) in particular have indicated that organic farming can often result in higher GHG emissions per unit product as a result of lower yields. The organic movement has the opportunity to embrace the science of LCA and use this information in developing tools for site-specific assessments that can point toward strategies for improvements. Responding effectively to the climate change crisis should be at the core of the organic movement's values. Additionally, while societal-level behavioral and policy changes will be required to reduce waste and shift diets to achieve essential reductions in GHG emissions throughout food systems, organic farming should be open to seriously considering emerging technologies and methods to improve its performance and reduce GHG emissions at the production stage.

Past research with high temperature molten carbonate electrochemical cells has shown that carbon dioxide can be separated from flue gas streams produced by pulverized coal combustion for power generation. However, the presence of trace... more

Past research with high temperature molten carbonate electrochemical cells has shown that carbon dioxide can be separated from flue gas streams produced by pulverized coal combustion for power generation. However, the presence of trace contaminants, i.e., sulfur dioxide and nitric oxides, will impact the electrolyte within the cell. If a lower temperature cell could be devised that would utilize the benefits of commercially-available, upstream desulfurization and denitrification in the power plant, then this CO2 separation technique can approach more viability in the carbon sequestration area. Recent work has led to the assembly and successful operation of a low temperature electrochemical cell. In the proof-of-concept testing with this cell, an anion exchange membrane was sandwiched between gas-diffusion electrodes consisting of nickel-based anode electrocatalysts on carbon paper. When a potential was applied across the cell and a mixture of oxygen and carbon dioxide was flowed over the wetted electrolyte on the cathode side, a stream of CO2 to O2 was produced on the anode side, suggesting that carbonate/bicarbonate ions are the CO2 carrier in the membrane. Since a mixture of CO2 and O2 is produced, the possibility exists to use this stream in oxy-firing of additional fuel.From this research, a novel concept for efficiently producing a carbon dioxide rich effluent from combustion of a fossil fuel was proposed. Carbon dioxide and oxygen are captured from the flue gas of a fossil-fuel combustor by one or more electrochemical cells or cell stacks. The separated stream is then transferred to an oxy-fired combustor which uses the gas stream for ancillary combustion, ultimately resulting in an effluent rich in carbon dioxide. A portion of the resulting flow produced by the oxy-fired combustor may be continuously recycled back into the oxy-fired combustor for temperature control and an optimal carbon dioxide rich effluent.

Correlations are presented to compute the mutual solubilities of CO2 and chloride brines at temperatures 12–300°C, pressures 1–600 bar (0.1–60 MPa), and salinities 0–6 m NaCl. The formulation is computationally efficient and primarily... more

Correlations are presented to compute the mutual solubilities of CO2 and chloride brines at temperatures 12–300°C, pressures 1–600 bar (0.1–60 MPa), and salinities 0–6 m NaCl. The formulation is computationally efficient and primarily intended for numerical simulations of CO2-water flow in carbon sequestration and geothermal studies. The phase-partitioning model relies on experimental data from literature for phase partitioning between CO2 and NaCl brines, and extends the previously published correlations to higher temperatures. The model relies on activity coefficients for the H2O-rich (aqueous) phase and fugacity coefficients for the CO2-rich phase. Activity coefficients are treated using a Margules expression for CO2 in pure water, and a Pitzer expression for salting-out effects. Fugacity coefficients are computed using a modified Redlich–Kwong equation of state and mixing rules that incorporate asymmetric binary interaction parameters. Parameters for the calculation of activity and fugacity coefficients were fitted to published solubility data over the P–T range of interest. In doing so, mutual solubilities and gas-phase volumetric data are typically reproduced within the scatter of the available data. An example of multiphase flow simulation implementing the mutual solubility model is presented for the case of a hypothetical, enhanced geothermal system where CO2 is used as the heat extraction fluid. In this simulation, dry supercritical CO2 at 20°C is injected into a 200°C hot-water reservoir. Results show that the injected CO2 displaces the formation water relatively quickly, but that the produced CO2 contains significant water for long periods of time. The amount of water in the CO2 could have implications for reactivity with reservoir rocks and engineered materials.

Over a 3-years period, the CO 2 , N 2 O and CH 4 fluxes exchanged with the atmosphere were studied in an upland semi-natural grassland site which was divided at the start of the experiment in two large paddocks continuously grazed by... more

Over a 3-years period, the CO 2 , N 2 O and CH 4 fluxes exchanged with the atmosphere were studied in an upland semi-natural grassland site which was divided at the start of the experiment in two large paddocks continuously grazed by cattle. The soil at the site is an Andosol with high organic matter content. The intensively managed paddock was supplied with mineral N fertilizer and was grazed at a target sward height of 6 cm. The extensively managed paddock received no N fertilization and was stocked at half the stocking density of the intensive paddock. The net ecosystem exchange of CO 2 was continuously measured in each paddock using the eddy covariance technique. Nitrous oxide emissions were measured fortnightly in both paddocks using static chambers. Methane emissions by the grazing cattle were measured four times per year in each paddock using the SF 6 tracer method. Averaged across the 3 years, the two paddocks were net sinks of atmospheric CO 2 (97 and 75 g CO 2 -C m À2 year À1 in the intensive and extensive treatments, respectively). Taking into account the LW gain of the cattle and the C loss through methane emissions, the net C storage was estimated at 87 and 69 g C m À2 year À1 in the intensive and extensive treatments, respectively. Emissions of nitrous oxide and methane reduced by 89 and 55% the atmospheric sink activity of the intensive and extensive treatments, respectively. The average greenhouse gas (GHG) balance across the 3 years was À10 and À31 g CO 2 -C equivalents in the intensive and extensive treatments, respectively. However, the net biome productivity (NBP) and GHG sink activities increased over time in the intensive grazing treatment, whereas they declined after 1 year in the extensive treatment, possibly as a result of a reduced nitrogen status of the vegetation. It is concluded that the suppression of fertilizer N supply combined with a strong reduction in grazing pressure may not be able to increase in the short term the GHG sink per unit land area of managed grasslands. #

Proposed European policy in the agricultural sector will place higher emphasis on soil organic carbon (SOC), both as an indicator of soil quality and as a means to offset CO 2 emissions through soil carbon (C) sequestration. Despite... more

Proposed European policy in the agricultural sector will place higher emphasis on soil organic carbon (SOC), both as an indicator of soil quality and as a means to offset CO 2 emissions through soil carbon (C) sequestration. Despite detailed national SOC data sets in several European Union (EU) Member States, a consistent C stock estimation at EU scale remains problematic. Data are often not directly comparable, different methods have been used to obtain values (e.g. sampling, laboratory analysis) and access may be restricted. Therefore, any evolution of EU policies on C accounting and sequestration may be constrained by a lack of an accurate SOC estimation and the availability of tools to carry out scenario analysis, especially for agricultural soils. In this context, a comprehensive model platform was established at a pan-European scale (EU + Serbia, Bosnia and Herzegovina, Croatia, Montenegro, Albania, Former Yugoslav Republic of Macedonia and Norway) using the agro-ecosystem SOC model CENTURY. Almost 164 000 combinations of soil-climate-land use were computed, including the main arable crops, orchards and pasture. The model was implemented with the main management practices (e.g. irrigation, mineral and organic fertilization, tillage) derived from official statistics. The model results were tested against inventories from the European Environment and Observation Network (EIONET) and approximately 20 000 soil samples from the 2009 LUCAS survey, a monitoring project aiming at producing the first coherent, comprehensive and harmonized top-soil data set of the EU based on harmonized sampling and analytical methods. The CENTURY model estimation of the current 0-30 cm SOC stock of agricultural soils was 17.63 Gt; the model uncertainty estimation was below 36% in half of the NUTS2 regions considered. The model predicted an overall increase of this pool according to different climate-emission scenarios up to 2100, with C loss in the south and east of the area (involving 30% of the whole simulated agricultural land) compensated by a gain in central and northern regions. Generally, higher soil respiration was offset by higher C input as a consequence of increased CO 2 atmospheric concentration and favourable crop growing conditions, especially in northern Europe. Considering the importance of SOC in future EU policies, this platform of simulation appears to be a very promising tool to orient future policymaking decisions.

We estimated the standing biomass and carbon sequestration potential of tropical deciduous forests of Nallamalais, a centre of plant diversity located in the state of Andhra Pradesh, India. A total of 30 randomly stratified sample sites... more

We estimated the standing biomass and carbon sequestration potential of tropical deciduous forests of Nallamalais, a centre of plant diversity located in the state of Andhra Pradesh, India. A total of 30 randomly stratified sample sites comprising 12 ha area were inventoried following a non-destructive method. The total standing biomass and carbon stocks of the study area are estimated as 56.047 Mt and 26.34 Mt respectively. Among all life forms, trees are the main contributors of standing biomass and carbon stocks in the study area accounting for 96.72% of the above-ground live biomass. The carbon stock accounted for Nallamalais is equivalent to 97.568 Mt of sequestered atmospheric carbon dioxide. With respect to total carbon stock of Indian forests worked out in different studies, Nallamalais share 0.26% to 0.90% of the total carbon stocks of India.

Sacred groves are small or large patches of forest and are rich in biodiversity, store carbon (C) in biomass and soil, besides providing important ecosystem services. However, the information on tree species diversity, biomass, and C... more

Sacred groves are small or large patches of forest and are rich in biodiversity, store carbon (C) in biomass and soil, besides providing important ecosystem services. However, the information on tree species diversity, biomass, and C storage in sacred groves of Central India, Madhya Pradesh is elusive and fragmented. In the present study, 41 sacred groves were inventoried for tree species diversity, biomass, and C storage in vegetation and soil. A total of 103 tree species from 81 genera belonging to 37 families were recorded. Shannon's diversity, Dominance, Fisher's alpha, and species evenness indices for trees varied: 0.77-2.53, 0.07-0.64, 1.58-20.37, and 0.28-0.90 respectively. Tree density ranged 75-675 no. of stems ha −1 with a mean of 271 no. of stems ha −1 , while basal area ranged 6.8-47 m 2 ha −1 with a mean value of 27 m 2 ha −1. Tree biomass ranged 34.9-409.8 Mg ha −1 with a mean value of 194.01 Mg ha −1 , while, tree C ranged between 17.5 and 204.9 Mg C ha −1 wit...

Sustainable use of solid residues and carbon dioxide, the two largest and most important waste products from thermal processes, is an urgent issue both for the industry involved and society as a whole, considering the financial and... more

Sustainable use of solid residues and carbon dioxide, the two largest and most important waste products from thermal processes, is an urgent issue both for the industry involved and society as a whole, considering the financial and environmental repercussions of their production. This Knowledge Platform focuses on three types of waste-to-product valorisation: production of a carbon sink, construction materials, or sorbents. Thermal processes are widely applied in metals and cement production, waste incineration, etc. They produce major amounts of solid waste materials, such as slag and fly ash, and generate a vast amount of carbon dioxide. Mineral carbon sequestration in alkaline waste materials is a feasible solution because of high reactivity, on-site production, waste stabilization and low cost. Turning waste into construction materials is another route for transforming low-cost input materials into potentially high-value products. The production of a sorbent for wastewater and flue gas treatment is another promising industrial option for in-house treatment of waste streams. A successful approach requires a broad consortium with relevant expertise for the scientific investigation, but which at the same time can be easily tailored to a particular valorisation option that emerges. The Platform aims at this dual objective by bringing together all parties and by focusing on the challenging aim of valorising thermal process wastes into high-value products by intensified processes and with clear prospects on the economic and legislative feasibility, ecological benefits and societal relevance.

Regrowing forests on cleared land is a key strategy to achieve both biodiversity conservation and climate change mitigation globally. Maximizing these co-benefits, however, remains theoretically and technically challenging because of the... more

Regrowing forests on cleared land is a key strategy to achieve both biodiversity conservation and climate change mitigation globally. Maximizing these co-benefits, however, remains theoretically and technically challenging because of the complex relationship between carbon sequestration and biodiversity in forests, the strong influence of climate variability and landscape position on forest development, the large number of restoration strategies possible, and long time-frames needed to declare success. Through the synthesis of three decades of knowledge on forest dynamics and plant functional traits combined with decision science, we demonstrate that we cannot always maximize carbon sequestration by simply increasing the functional trait diversity of trees planted. The relationships between plant functional diversity, carbon sequestration rates above ground and in the soil are dependent on climate and landscape positions. We show how to manage 'identities' and 'complementarities' between plant functional traits to achieve systematically maximal cobenefits in various climate and landscape contexts. We provide examples of optimal planting and thinning rules that satisfy this ecological strategy and guide the restoration of forests that are rich in both carbon and plant functional diversity. Our framework provides the first mechanistic approach for generating decisionmakingrules that can be used to manage forests for multiple objectives, and supports joined carbon credit and biodiversity conservation initiatives, such as Reducing Emissions from Deforestation and forest Degradation REDD+. The decision framework can also be linked to species distribution models and socio-economic models to find restoration solutions that maximize simultaneously biodiversity, carbon stocks, and other ecosystem services across landscapes. Our study provides the foundation for developing and testing cost-effective and adaptable forest management rules to achieve biodiversity, carbon sequestration, and other socio-economic co-benefits under global change.

... of C sequestration and timber production (eg, [22] , [Kurz et al., 2002] , [Backéus et al., 2005] and [Gusev and Nasonova, 2007] ), simulation of effects of management and climate on C sequestration by forests (eg, [Kurz and Apps,... more

... of C sequestration and timber production (eg, [22] , [Kurz et al., 2002] , [Backéus et al., 2005] and [Gusev and Nasonova, 2007] ), simulation of effects of management and climate on C sequestration by forests (eg, [Kurz and Apps, 1995] , [Liski et al., 2001] , [Harmon and Marks ...

A critical issue for geologic carbon sequestration is the ability to detect CO 2 in the vadose zone. Here we present a new process-based approach to identify CO 2 that has leaked from deep geologic storage reservoirs into the shallow... more

A critical issue for geologic carbon sequestration is the ability to detect CO 2 in the vadose zone. Here we present a new process-based approach to identify CO 2 that has leaked from deep geologic storage reservoirs into the shallow subsurface. Whereas current CO 2 concentration-based methods require years of background measurements to quantify variability of natural vadose zone CO 2 , this new approach examines chemical relationships between vadose zone N 2 , O 2 , CO 2 , and CH 4 to promptly distinguish a leakage signal from natural vadose zone CO 2. The method uses sequential inspection of the following gas concentration relationships: 1) O 2 versus CO 2 to distinguish in-situ vadose zone background processes (biologic respiration, methane oxidation, and CO 2 dissolution) from exogenous deep leakage input, 2) CO 2 versus N 2 to further distinguish dissolution of CO 2 from exogenous deep leakage input, and 3) CO 2 versus N 2 /O 2 to assess the degree of respiration, CH 4 oxidation and atmospheric mixing/dilution occurring in the system. The approach was developed at a natural CO 2-rich control site and successfully applied at an engineered site where deep gases migrated into the vadose zone. The ability to identify gas leakage into the vadose zone without the need for background measurements could decrease uncertainty in leakage detection and expedite implementation of future geologic CO 2 storage projects.

The matrix volume of coal swells when CO 2 /CH 4 adsorb on the coal structure. In coalbed gas reservoirs, matrix swelling could cause the fracture aperture width to decrease, causing a considerable reduction in permeability. On a unit... more

The matrix volume of coal swells when CO 2 /CH 4 adsorb on the coal structure. In coalbed gas reservoirs, matrix swelling could cause the fracture aperture width to decrease, causing a considerable reduction in permeability. On a unit concentration basis, CO 2 causes greater degree of coal matrix swelling compared to CH 4 . Much of this difference is attributable to the differing sorption capacity that coal has towards carbon dioxide and methane. This condition in a coal reservoir would lead to differential swelling. Differential swelling will have consequences in terms of porosity/permeability loss, with serious implication for the performance and implementation of carbon sequestration projects.

Approximately half of the tropical biome is in some stage of recovery from past human disturbance, most of which is in secondary forests growing on abandoned agricultural lands and pastures. Reforestation of these abandoned lands, both... more

Approximately half of the tropical biome is in some stage of recovery from past human disturbance, most of which is in secondary forests growing on abandoned agricultural lands and pastures. Reforestation of these abandoned lands, both natural and managed, has been proposed as a means to help offset increasing carbon emissions to the atmosphere. In this paper we discuss the potential of these forests to serve as sinks for atmospheric carbon dioxide in aboveground biomass and soils. A review of literature data shows that aboveground biomass increases at a rate of 6.2 Mg ha Ϫ 1 yr Ϫ 1 during the first 20 years of succession, and at a rate of 2.9 Mg ha Ϫ 1 yr Ϫ 1 over the first 80 years of regrowth. During the first 20 years of regrowth, forests in wet life zones have the fastest rate of aboveground carbon accumulation with reforestation, followed by dry and moist forests. Soil carbon accumulated at a rate of 0.41 Mg ha Ϫ 1 yr Ϫ 1 over a 100-year period, and at faster rates during the first 20 years (1.30 Mg carbon ha Ϫ 1 yr Ϫ 1 ). Past land use affects the rate of both above-and belowground carbon sequestration. Forests growing on abandoned agricultural land accumulate biomass faster than other past land uses, while soil carbon accumulates faster on sites that were cleared but not developed, and on pasture sites. Our results indicate that tropical reforestation has the potential to serve as a carbon offset mechanism both above-and belowground for at least 40 to 80 years, and possibly much longer. More research is needed to determine the potential for longer-term carbon sequestration for mitigation of atmospheric CO 2 emissions.

Wetlands provide numerous ecosystem services including sequestration of atmospheric carbon–dioxide (CO2) which play an important role in mitigation of green house gases (GHGs). Present study aimed to assess soil / sediment carbon (C)... more

Wetlands provide numerous ecosystem services including sequestration of atmospheric carbon–dioxide (CO2) which play an important role in mitigation of green house gases (GHGs). Present study aimed to assess soil / sediment carbon (C) stock of different wetlands under different physiographic regions of West Bengal. West Bengal has a number of wetlands situated in different biogeographic regions like lower Gangetic plains, central Himalaya, Chotanagpur plateau and coasts. A total of 19
wetlands were selected for present study and were categorized into six wetland types viz., floodplain wetlands (FP), wetlands from forested hill region (FH), Himalayan region (HM), Chotanagpur plateau and adjacent area (CP), coastal wetlands (CO) and wastewater–fed fishponds of East Calcutta Wetlands (ECW) ecosystems. Soil /sediment organic carbon (SOC) content of both bank soil and bottom sediments of the wetlands varied widely among study sites. Highest amount of bank SOC were recorded from HM wetlands (50.54 ± 6.65 t ha–1) whereas bottom SOC values from FP wetlands (36.81±17.80 t ha–1). Different allochthonous inputs like sewage water, runoff from catchment area; wetland macrophytes; sediment texture; physicochemical properties of water influence C sequestration potential of wetlands. Findings of present study can be compared with 22.35% of total wetland area of the state and it can be assumed that these types of wetlands can sequester 6.63 M t carbon in soils and sediments.