Carbon on the Northwest European Shelf: Contemporary Budget and Future Influences

A carbon budget for the northwest European continental shelf seas (NWES) was synthesized using available estimates for coastal, pelagic and benthic carbon stocks and flows. Key uncertainties were identified and the effect of future impacts on the carbon budget were assessed. The water of the shelf seas contains between 210 and 230 Tmol of carbon and absorbs between 1.3 and 3.3 Tmol from the atmosphere annually. Off-shelf transport and burial in the sediments account for 60–100 and 0–40% of carbon outputs from the NWES, respectively. Both of these fluxes remain poorly constrained by observations and resolving their magnitudes and relative importance is a key research priority. Pelagic and benthic carbon stocks are dominated by inorganic carbon. Shelf sediments contain the largest stock of carbon, with between 520 and 1600 Tmol stored in the top 0.1 m of the sea bed. Coastal habitats such as salt marshes and mud flats contain large amounts of carbon per unit area but their total carbon stocks are small compared to pelagic and benthic stocks due to their smaller spatial extent. The large pelagic stock of carbon will continue to increase due to the rising concentration of atmospheric CO2, with associated pH decrease. Pelagic carbon stocks and flows are also likely to be significantly affected by increasing acidity and temperature, and circulation changes but the net impact is uncertain. Benthic carbon stocks will be affected by increasing temperature and acidity, and decreasing oxygen concentrations, although the net impact of these interrelated changes on carbon stocks is uncertain and a major knowledge gap. The impact of bottom trawling on benthic carbon stocks is unique amongst the impacts we consider in that it is widespread and also directly manageable, although its net effect on the carbon budget is uncertain. Coastal habitats are vulnerable to sea level rise and are strongly impacted by management decisions. Local, national and regional actions have the potential to protect or enhance carbon storage, but ultimately global governance, via controls on emissions, has the greatest potential to influence the long-term fate of carbon stocks in the northwestern European continental shelf

Above ground woody community attributes, biomass and carbon stocks along a rainfall gradient in the savannas of the central lowveld, South Africa

Enumeration of carbon stocks at benchmark sites is a necessary activity in assessing the potential carbon sequestration and possible generation of credits through restoration of intensively impacted sites. However, there is a lack of empirical studies throughout much of the savannas of sub-Saharan Africa, including South Africa. We report an estimation of species specific and site biomass and carbon stocks, and general vegetation structural attributes from three protected areas along a rainfall gradient in the central lowveld, South Africa. Estimates of biomass and carbon stocks were effected through destructive sampling to establish locally derived allometric equations. There was a gradient of increasing woody density, height of the canopy, number of species, density of regenerative stems and a greater proportion of stems in small size classes from the arid locality to the mesic locality, with the semi-arid locality being intermediate. The proportion of spinescent species decreased with increasing rainfall. The mesic locality was significantly more woody than either the arid or semi-arid sites, having double the biomass, four times the density and 40% higher basal area. Above ground carbon pools were also higher; carbon stocks were approximately 9 t/ha for the arid and semi-arid sites and 18 t/ha for the mesic site.

Carbon dynamics in apple orchards in New Zealand and their integration into life cycle assessment : a thesis presented in partial fulfillment of the requirements for the degree of Doctor of Philosophy (Ph.D) in Soil Sciences and Life Cycle Management

Soil carbon sequestration can help mitigate climate change and soil carbon contributes to many of the ecosystem services provided by the soil; thus soil carbon contributes to the sustainability of food production systems. However, changes in soil carbon are difficult and costly to measure due to two constraining characteristics: the spatial variability of the stocks as well as the typically small changes in carbon stocks over time. Consequently, environmental assessment tools such as Life Cycle Assessment (LCA) and carbon footprinting (CF) generally exclude the changes in soil carbon stocks from their analyses. Yet global supermarket chains use the results from these tools to inform consumers about greener products. In New Zealand (NZ), production of horticultural products such as apples is very focussed on export markets. Therefore, if it can be demonstrated that the production of New Zealand apples maintains or increases the carbon stock of the orchard soil and above-ground biomass, this could lead to a reduced net CF and might enhance access to prime retailers’ shelves in major export markets. The main aims of this research were (a) to develop a practical method for measuring a statistically significant and powerful change in the soil-carbon stock of an apple orchard block in New Zealand, and (b) to assess a method to estimate the standing woody biomass carbon stock in apple orchards, in order to provide reliable data for the CF of NZ apples. Since there are no data available, this research sought to quantify the changes in soil-carbon stocks in apple orchards by means of a chrono-sequence. A review of LCA and CF case studies accounting for changes in soil-carbon identified the need to focus on collecting deep, site specific, geo-localised and time-dependent soil-carbon data, as well as communicating its variability and statistical uncertainty for interpretation and transparency of LCA and CF results. Therefore, in a first step to develop a protocol for quantifying the carbon stocks in the soil, a four-year-old apple orchard block was intensively sampled to one meter depth to measure the soil-carbon stock and the spatial patterns. It was found that the soil-carbon stock was influenced by tree planting pattern, and the minimum sampling requirements were determined to detect, from sampling every 20 years, a change of the mean (175.1± 10.8 t C/ha) of 10 % due to the spatial and temporal characteristics of soil carbon. This required sampling nine sites in a systematic grid in the orchard block, with four pooled samples per site evenly distributed between and outside the wheel tracks, at a total cost of NZ$1,590 per sampling campaign. This cost of monitoring seems affordable as it is equivalent to just 0.5premiums could compensate for it, using the carbon market seems unrealistic at present because the price of carbon would need to reach at least NZ$182/tonne. To inform development of a protocol for quantifying the carbon stocks in the woody biomass in a commercial apple orchard block, the relationship between the trunk cross-sectional area (TCA) and the woody dry mass (DM) of the trees was assessed using 10 trees that were destructively harvested. It was found that using this relationship together with a high number of TCAs measured in situ in the orchard block facilitated the rapid and cost effective estimation of the woody biomass carbon stocks at the orchard block scale. At the end of the orchard life, the carbon has been stored out of the atmosphere for the lifetime of the trees and this contributes to reduced climate change. Furthermore, at the end of life the trees may be burned for convenience, chopped for firewood or transformed into biochar and applied to soils. It was found that the biochar scenario provided the largest reduction, and that this benefit was equivalent to 0.7% of the carbon footprint of apples exported to Europe. The choice of a time horizon for the assessment was found to be critical, with comparative results varying up to three fold between the 20 year and the 100 year time horizons. Regarding changes in soil carbon stocks over time, the four-year-old orchard block was part of a 12 year-old chronosequence, also including a one-year, a six-year and a twelve-year old block. The same sampling protocol was carried out in these three other blocks. It was found that all orchard blocks had relatively high soil-carbon stocks. Moreover, there was no significant difference in soil-carbon stocks at the 5% level between the one-year-old, the six-year-old and the twelve-year-old blocks of the chronosequence. Based on the soil-carbon stocks of these three blocks, current management practices seem to be maintaining these carbon stocks over time. Therefore, unless management practices are modified, monitoring may not be required. However, this maintenance of relatively high soil-carbon stocks in orchard systems is beneficial for climate change and the ecosystem services provided by the soil. It should therefore be treated as such in LCA and CF studies although a method is yet to be developed. In addition, despite a high similarity with the other blocks, the four-year-old block showed a higher, significantly different soil-carbon stock, and the levels of variability in soil-carbon stocks were found to be different between all the blocks. This demonstrates the high local specificity of soil-carbon stocks. The six year-old block displayed a coefficient of variation (14%) larger than the other blocks, and so an analysis of sampling requirements was conducted for this block. A change of 10% of the mean could, in theory, be observed by collecting a total of 78 samples, bulked two by two, for carbon content, and using 39 bulk density profiles, all to one meter depth. The associated cost of monitoring is NZ$ 9,420 and is equivalent to 1% of the value of export apples at ship-side in New Zealand. Monitoring soil-carbon stocks would seem therefore affordable, even in the more variable orchard block. Overall, this research has made four main contributions to the science. Firstly, a robust, practical and adaptable protocol for monitoring soil-carbon stocks in apple orchards has been developed. Secondly, a rapid and cost effective method to estimate the carbon stock in standing woody biomass has been verified for use in commercial apple orchard blocks; accounting for this biomass carbon stock may lead to a net reduction of up to 4.6% of the New Zealand based (cradle to NZ port) CF of apples exported to Europe; Thirdly, a chrono-sequence of orchard blocks has suggested that current management practices in apple orchards appear to achieve the maintenance of high soil-carbon stocks over time, and it is suggested that this maintenance should be recognised as beneficial in CF and LCA studies. Finally, soil carbon stocks have been found to be spatially variable within and between similar orchard blocks; therefore LCA and CF studies should use site specific data and communicate the uncertainty of their soil-carbon stock estimates

Cadangan Karbon Tersimpan Pada Tegakan Cemara Laut (Casuarina Equisetifolia L)

This research aimed to estimate the carbon stocks in Casuarina equisetifolia L according to the habitat and to compare the carbon stocks of Casuarina equisetifolia L on two different locations. The method used to calculate carbon stocks is non-destructive method. The result showed that the amount of carbon stocks in Sri Mersing Beach is 18,524 ton/ha while in the Gudang SCM PT.Pertamina Beach is 11,45 ton/ha. The average of carbon stocks in Sri Mersing Beach is 154,36 kg/tree while in the Gudang SCM PT. Pertamina Beach is 69,57 kg/tree . The differences between the amount of carbon stocks in this two research areas are caused by the density of trees and silviculture factor

Are High Carbon Stocks in Agroforests and Forest Associated with High Plant Species Diversity?

Conserving plant diversity and retaining terrestrial carbon stocks are targets for environmental policy and appear to be generally compatible. However, detailed information on the way both respond to agroforestry management is lacking. Rubber and fruit tree agroforestry systems combine planted trees and trees that are tolerated or actively managed that derived from natural vegetation. The research aimed to evaluate plant species diversity, vegetation structure, and C stock in rubber agroforestry system (AF) and secondary forest grown in silty clay and sandy soils in Pulang Pisau Regency, Central Kalimantan province. A number of multistrata agroforestry systems was compared to the secondary (natural) forests (SNF) of the area; these included Fruit-Based Rubber Agroforestry (AFB) of about 100 years of age, Old Rubber Agroforestry (ARO) and Young Rubber Agroforestry (ARY). The highest C stock was found in AFB (415 Mg ha-1), while the average C stocks of other AF and SNF were 217 Mg ha-1. A plant diversity index (H') was only weakly correlated to aboveground C stocks. Including the farmer-managed agroforests in schemes to reduce emissions from deforestation and forest degradation is relevant, as their carbon stocks match or exceed those of remaining forests in the area

Climatic regions as an indicator of forest coarse and fine woody debris carbon stocks in the United States

<p>Abstract</p> <p>Background</p> <p>Coarse and fine woody debris are substantial forest ecosystem carbon stocks; however, there is a lack of understanding how these detrital carbon stocks vary across forested landscapes. Because forest woody detritus production and decay rates may partially depend on climatic conditions, the accumulation of coarse and fine woody debris carbon stocks in forests may be correlated with climate. This study used a nationwide inventory of coarse and fine woody debris in the United States to examine how these carbon stocks vary by climatic regions and variables.</p> <p>Results</p> <p>Mean coarse and fine woody debris forest carbon stocks vary by Köppen's climatic regions across the United States. The highest carbon stocks were found in regions with cool summers while the lowest carbon stocks were found in arid desert/steppes or temperate humid regions. Coarse and fine woody debris carbon stocks were found to be positively correlated with available moisture and negatively correlated with maximum temperature.</p> <p>Conclusion</p> <p>It was concluded with only medium confidence that coarse and fine woody debris carbon stocks may be at risk of becoming net emitter of carbon under a global climate warming scenario as increases in coarse or fine woody debris production (sinks) may be more than offset by increases in forest woody detritus decay rates (emission). Given the preliminary results of this study and the rather tenuous status of coarse and fine woody debris carbon stocks as either a source or sink of CO₂, further research is suggested in the areas of forest detritus decay and production.</p

Long-term effects of fire and harvest on carbon stocks of boreal forests in northeastern China

International audienceAbstractKey messageFire, harvest, and their spatial interactions are likely to affect boreal forest carbon stocks. Repeated disturbances associated with short fire return intervals and harvest rotations resulted in landscapes with a higher proportion of young stands that store less carbon than mature stands.ContextBoreal forests represent about one third of forest area and one third of forest carbon stocks on the Earth. Carbon stocks of boreal forests are sensitive to climate change, natural disturbances, and human activities.AimsThe objectives of this study were to evaluate the effects of fire, harvest, and their spatial interactions on boreal forest carbon stocks of northeastern China.MethodsWe used a coupled forest landscape model (LANDIS PRO) and a forest ecosystem model (LINKAGES) framework to simulate the landscape-level effects of fire, harvest, and their spatial interactions over 150 years.ResultsOur simulation suggested that aboveground carbon and soil organic carbon are significantly reduced by fire and harvest over the whole simulation period. The long-term effects of fire and harvest on carbon stocks were greater than the short-term effects. The combined effects of fire and harvest on carbon stocks are less than the sum of the separate effects of fire and harvest. The response of carbon stocks was impacted by the spatial variability of fire and harvest regimes.ConclusionThese results emphasize that the spatial interactions of fire and harvest play an important role in regulating boreal forest carbon stocks

Elephants and aboveground carbon stocks in a South African protected savanna

Savanna elephants (Loxodonta africana) are known to exert transforming impacts on the vegetation. Due to these impacts, one would expect elephants to have significant effects on aboveground carbon stocks. However, we still know relatively little about the magnitude and direction of the effects of elephants on aboveground carbon stocks. Here, I combined historical data from vegetation surveys and wood density field measurements to estimate the change in aboveground carbon stocks between 1999 and 2017 in relation to different elephant impact levels in Hluhluwe-iMfolozi Park, South Africa. Despite an increasing and relatively high-density elephant population compared to other South African reserves, aboveground carbon stocks did not generally decrease over time, although we found weak evidence for a reduction in aboveground carbon stocks at extreme elephant impact levels. In addition, variation in stem diameter and elephant impact among individuals influenced the wood density of these individual for certain tree species but not for others. This demonstrates the importance of considering drivers of wood density and how their effects vary among tree species when estimating aboveground carbon stocks. Our findings support previous findings and show that elephants might not necessarily conflict with goals focused on conserving aboveground carbon stocks

Analisis Biomasa Dan Cadangan Karbon Pada Berbagai Umur Tegakan Damar (Agathis Dammara (Lamb.) Rich.) Di KPH Banyumas Timur

Increased carbon dioxide in the atmosphere causes global climate change seriously. Forests serve as an important asset that can absorb and store carbon in the form of biomass. One type of potential forest as a carbon sink is forests resin. The amount of carbon stored by standing very dynamic and varies according to the age of its standing. Therefore, studies will be needed to determine the effect of age on biomass and carbon stocks stands resin, determine the relationship between age and standing biomass and carbon stocks resin, and knowing the optimum resin stand age in storing biomass and carbon stocks. This research was conducted at the stands of resin RPH Karang Gandul, KPH Banyumas Timur for four weeks in May 2016. The method used is a survey with a sampling technique using cluster random sampling. Stands resin used in the study were classified into five age groups with 5 replicates. Data were analyzed using ANOVA with an error rate of 5% and continued with LSD for further test results were significant and regression analysis to determine the relationship of age with biomass and carbon stocks stands resin. The results showed that the age effect on biomass and carbon stocks stands resin, the relationship formed between the age of stand with biomass and carbon stocks are quadratic, and age optimum in storing biomass and carbon stocks is 35 years