Mean Carbon Content Research Articles

Carbon Content of Amazonian Commercial Tree Boles: Implications for Forest Management

Reliable values for carbon content in trees are essential for quantifying forest carbon stocks and estimating carbon dioxide emissions. This study analyzed the carbon content in the boles of commercial tree species in the Brazilian state of Acre, in the southwestern Amazon. Composite samples were prepared from wood wedges obtained along each individual’s commercial bole (the trunk from the point of cut to the first significant branch). Fifty-seven trees were analyzed, spanning nine families, seventeen genera, and nineteen species in the Amazon forest. The results revealed a variation in carbon content ranging from 49.08% (±3.36) to 51.81% (±0.6), with an overall mean of 50.48% (±0.42). Handroanthus serratifolius, Astronium lecointei, and Dipteryx odorata exhibited the highest carbon contents. The statistical analysis included the calculation of 95% confidence intervals for each species, indicating the precision of the carbon content estimates. ANOVA analysis showed a large effect (η2 = 0.83), indicating that 83% of carbon variability is due to species differences, highlighting the distinct carbon profiles across species. One species (Ceiba pentandra) showed a significant increase in carbon with height along the bole, while the others showed varying but non-significant trends with height. Mean carbon content differed significantly (Tukey’s post hoc test) among the 19 species studied, with the greatest difference between H. serratifolius and Ceiba pentandra. Although differences between species may seem small, in some cases, they can lead to considerable underestimations or overestimations of carbon stocks and emissions when extrapolated to large areas such as the Amazon. The mean carbon content measured in this study (50.48%) exceeds the 0.47 IPCC default value generally used in national reports to the Climate Convention and in various estimates of deforestation emissions and Amazon carbon stocks. This suggests that both emissions and stocks may have been underestimated.

Carbon sequestration potential of Casuarina equisetifolia plantations at harvest age in tropical region of India

Studying the carbon stock of tree plantations is essential for mitigating climate change, as trees act as carbon dioxide sinks by fixing carbon during photosynthesis and storing excess carbon as biomass. With a significant emphasis on the role of carbon in global warming, Afforestation/Reforestation (A/R) activities have the potential to provide a “sink” for carbon from our atmosphere and act as a reservoir. In current study, the sequestered carbon dioxide from atmosphere by Casuarina plantations was calculated and converted into carbon by a particular plantation using the globally accepted formula developed by the IPCC. Simultaneously, the soil organic carbon of the particular Casuarina plantations was also estimated. Finally, the carbon stock of Casuarina equisetifolia plantations were estimated under different management practices. The various management practices like pruning, irrigation and fertilizer application also improves the carbon sink potential of the tree plantations. The mean carbon concentration ranged from 41% (leaf litter) to 46% (wood) in the different components of Casuarina equisetifolia. The plantations recorded a carbon accumulation of 9.12 Mt C ha?¹ year?¹ in biomass components alone at the harvest age of 3 years in the tropical region of Tamil Nadu, India. Proper management practices in tropical regions worldwide have the potential to further enhance carbon stocks in plantations. This data will be ready reckoner for future Clean Development Mechanism (CDM) projects for controlling global warming.

Variability in zoobenthic blue carbon storage across a southern polar gradient

Variability in zoobenthic blue carbon storage across a southern polar gradient

Changes in soil aggregate stability and aggregate-associated carbon under different slope positions in a karst region of Southwest China

Changes in soil aggregate stability and aggregate-associated carbon under different slope positions in a karst region of Southwest China

Empirical Determination of the Carbon Impacts of Urban Forest Management in Hong Kong: Removal of Acacia confusa and Leucaena leucocephala

Urban trees contribute to decarbonisation. However, the removal of trees may release the stored carbon within them. In Hong Kong, Acacia confusa and Leucaena leucocephala are being removed, but with unknown carbon impacts. This industry-academia-government collaborative research aimed to: (1) report the amount of carbon stored inside Acacia confusa and Leucaena leucocephala harvested from slopes; (2) estimate the carbon storage of a tree using dendrometric measurements; and (3) explain the variation in carbon content percentage of urban trees with respect to tree species, part of the tree, and position within the part. 10 Acacia confusa and 10 Leucaena leucocephala were harvested during March–September, 2023. Each tree was weighed for carbon storage estimation. Results showed that Acacia confusa had higher mean wood volume, biomass and carbon storage than Leucaena leucocephala. The mean carbon content of the analysed samples (45.53−52.58%) were mostly significantly different from 50%. But the difference may become insignificant depending on how volatile carbon loss was controlled. Diameter at breast height (mm) was a significant predictor of carbon storage (kg) for both Acacia. confusa (β = 0.9574) and Leucaena leucocephala (β = 0.3909). Significant interaction between tree species and tree part on carbon content percentage was confirmed. This research demonstrated the impacts of past arboricultural decisions on present decarbonisation plans.

Multi-habitat carbon stock assessments to inform nature-based solutions for coastal seascapes in arid regions

Coastal ecosystems are integral to global carbon cycling and are increasingly recognised for their role in mitigating climate change. Within these ecosystems, the dynamics of carbon storage are diverse, varying significantly across different habitats. However, existing management strategies often focus predominantly on vegetated habitats neglecting the contributions of non-vegetated areas. We address this knowledge gap by providing a quantitative spatial assessment of carbon storage across coastal seascapes varying in plant biomass. Our comprehensive multi-habitat inventory of carbon stocks in the United Arab Emirates confirmed that mangroves are the largest carbon-storing habitat per hectare (94.3 t/ha), followed by saltmarshes (63.6 t/ha), microbial mats (51.6 t/ha), mudflats (46.8 t/ha), seagrass (32.5 t/ha), and coastal sabkha (31.0 t/ha).Mean carbon content in the top 50 cm of mangrove soils (53.9 t/ha) was similar to saltmarshes (52.7 t/ha), microbial mats (51.6 t/ha), and mudflats (46.8 t/ha). We highlight the importance of including non-vegetated habitats in carbon accounting and management strategies. Our findings suggest that a more context-specific whole-system approach is essential for guiding effective ecosystem management and designing ecologically meaningful Nature-based Solutions (NbS). Adopting this broader perspective in NbS can ensure more comprehensive conservation and restoration outcomes, which not only protect and enhance blue carbon ecosystems but also contribute to broader ecological and social benefits. This approach is pivotal for advancing our understanding of interconnected coastal ecosystems and their role in climate change mitigation.

Harmonization and variation of deadwood density and carbon concentration in different stages of decay of the most important Central European tree species

Coarse woody debris (CWD) is a major component of the ecosystem carbon (C) balance. The estimation of C storage in CWD is an important element of the German greenhouse gas (GHG) reporting of forests, which is mainly based on the German National Forest Inventory. The deadwood C stock is calculated based on deadwood volume and, according to deadwood density (DD) and carbon concentration (CC) for each decay class (DC). Yet, the data basis of DD and CC per DC for above-ground CWD is still insufficient since there are very few country-specific measurements. Values from literature provide a first approximation for national-level estimates. However, different DC systems often prevent the use of DD and CC of other countries. Therefore, we developed a conversion method for harmonization of these data with the German four-class system. Following this, we conducted a meta-analysis to calculate mean DD and CC values for the main Central European tree species and to assess their variation. Significantly lower DDs were observed with increasing DC, except for beech between DC 3 and 4. Compared to spruce and pine, DD of beech CWD was significantly higher, overall as well as in DC 1 and 2. Species became similar in DD in advanced decay stages. A maximum of 92% of the variation in DD could be explained mainly by DC, CWD type, tree species and their interaction. DD values were mostly higher than current values in GHG reporting. CC increased with increasing DC in spruce and pine and was higher than in beech CWD, where no variation was detected. About 86% of the variation in CC could be explained mainly by DC, tree species and their interactive effect. The default value of 50% employed by the Intergovernmental Panel on Climate Change might under- (spruce, pine) and/or overestimate (spruce, pine, beech) the real CC depending on DC by up to 3.4 (pine) and/or 4.2% (beech). Based on our calculated mean DD and CC values, the accuracy of C stock assessment in deadwood as part of the GHG reporting for Germany can be substantially improved.

Analysis of Land Use Change and Associated Implications on Soil Ecosystem Functions in South Eastern Nigeria

Land use change affects soil functions and its capacity to provide ecosystem services. Though much of the tropics are experiencing accelerated increases in land use change, associated impacts of such changes are poorly understood and studied. This study assessed the extent to which land use changes affect the soil ecosystem functions in a rainforest zone of south eastern Nigeria. Soil samples were collected from 24 sample locations in selected natural forest, cashew and palm plantations. Samples were analyzed in triplicate in the laboratory for geochemical analysis, after which the result was subjected to statistical analysis—ANOVA, correlation and regression. Forest carbon had higher % mean carbon content; though there was no significant difference (F (2, 21) = .246, p = .784) in carbon level across land uses. R value of .301 showed low correlation between % carbon, organic matter and % loss in ignition. Furthermore, R2 value of 9.1% total variation in the dependent variable could only be explained by the independent variables. CEC, Nitrogen, Potassium and Phosphorus content of the land uses did not differ significantly: CEC (F (2, 21) = .844, p (.44); Nitrogen (.243), p (.79), Potassium (.140), p (.87), Phosphorus (.783), p (.47). This showed that there was no significant variation in soil fertility of the land uses, although natural forest had higher concentrations for these variables. Across the land uses, soil texture equally had no significant variations: % sand (F (2, 21) = .320, p (.729) % clay (.430), p (.656), % silt (.043), p (.958). Soil carbon was seen to be more enhanced in natural forest ecosystems than other land uses. Though plantations had reduced capacities to provide ecosystem functions, establishing such in modified landscapes is still advocated as they can coexist with such and yet ensure ecosystem functions.

Occurrence and preservation of primary organic matter in a hybrid unconventional reservoir: Montney Formation, Western Canada Sedimentary Basin

Occurrence and preservation of primary organic matter in a hybrid unconventional reservoir: Montney Formation, Western Canada Sedimentary Basin

'Only One Earth' – Celebrating soil science on World Environment Day 2022

'Only One Earth' – Celebrating soil science on World Environment Day 2022

Analysis of carbon concentration and allometric growth model of carbon content for Larix olgensis

Forest carbon storage accounts for about 45% of terrestrial carbon storage. Accurate assessment of forest carbon storage is of great significance to the scientific management and planning of forests. Based on the data of 77 sampling Larix olgensis trees from Mengjiagang, Shangzhi Maoershan, Xiaojiu Forest Farm and Dongjing, Lin-kou Forestry Bureaus of Jiamusi, Heilongjiang Province from 2015 to 2018, we analyzed the partition of carbon content and variation of carbon concentration for five tree components (i.e., wood, bark, branch, leaf, and root). The mono-element and dual-element additive models of carbon content for each component of L. olgensis were deve-loped. The nonlinear seemly unrelated regression was used to estimate the parameters in the additive models, while the jackknife resampling technique was used to verify and evaluate the developed models. The results showed that the weighted mean carbon concentration of each component differed significantly, branches (49.3%) > bark (48.7%) > foliage (48.5%) > wood (48.2%) > root (47.1%). The aboveground and belowground carbon content accounted for about 80% and 20% of the total carbon content, respectively. The adjusted coefficient of determination (Ra2) of additive models of carbon content was greater than 0.89, the mean absolute error was less than 4.1 kg, and the mean absolute error percentage for most models was less than 30%. Adding tree height in the additive models of carbon content could significantly improve model fitting performance and predicting precision. The additive models of carbon content of total, aboveground, wood and bark were better than that of carbon content of branch, foliage, root and crown.

Mechanisms for the anisotropic enrichment of organic matter in saline lake basin: A case study of the Early Eocene Dongpu Depression, eastern China

Mechanisms for the anisotropic enrichment of organic matter in saline lake basin: A case study of the Early Eocene Dongpu Depression, eastern China

Carbon content and allometric models to estimate aboveground biomass for forest areas under restoration

Maximizing carbon sequestration is crucial to mitigate climate change and indicates that the restoration technique used was effective. To quantify carbon stock over time on areas being restored, suitable allometric equations are needed. These equations are lacking for the Atlantic forest, lacking even more for restoration sites, and rare for restoration areas implemented with the active method, technique often used to restore Atlantic forest areas. Thus, the objective of this study was 3‐fold. First, to provide an equation to estimate aboveground biomass for 5‐year‐old Atlantic forest under restoration implemented with the active method. Second, to determine carbon content for the branch, stem, and foliage pools for those areas. Third, to present biomass, carbon content, and carbon stock benchmarks for 5‐year‐old areas under restoration implemented with the active method. Three sites were sampled with nine plots each, measuring tree height and diameter. One subplot was established in each plot, and all trees within it were harvested and had fresh weight measured and samples were taken to the laboratory to dry weight and carbon content determination. Ten models estimating biomass were fitted and tested. Mean carbon content in foliage, branch, stem, and the weighted average were 44.8, 44.5, 45.8, and 45.3%, respectively. Mean biomass and carbon stock were 20.19 ± 0.146 Mg/ha and 9.73 Mg C/ha. We concluded that the equation that we provide is precise, and very necessary to estimate biomass for young restoration areas at the Atlantic forest.

AUBERT & DUVAL CNS (35NiCr6)

Abstract Aubert and Duval CNS (35NiCr6) is a medium-carbon, nickel-chromium, direct hardening alloy steel. It is a medium hardenability steel in the 0.30 to 0.37 mean carbon content classification. This steel is frequently used for water-quenched parts of moderate section size and for oil-quenched parts of small section size. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on casting. Filing Code: SA-878. Producer or source: Aubert & Duval S.A. (a member of the Eramet Group).

LUCEFIN 50CrMo4 (1.7228)

Abstract Lucefin 50CrMo4 is a medium-carbon, chromium-molybdenum direct hardening alloy steel that is also suitable for flame hardening, induction hardening, and nitriding. This steel is a medium hardenability steel in the 0.45 to 0.50 mean carbon content classification. In general, it is used for medium and large size parts requiring high hardness as well as high strength and good toughness. A minimum of 90% martensite in the as-quenched condition is desirable. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on forming, heat treating, machining, and joining. Filing Code: SA-877. Producer or source: Lucefin S.p.A.

Effect of Thinning Intensity on Litterfall Biomass and Nutrient Deposition in a Naturally Regenerated Pinus Pseudostrobus Lind. Forest in Oaxaca, Mexico

ABSTRACT Litterfall is an important component of forest biomass and nutrient cycling, and can have key impacts on soil fertility through its decomposition. However, theeffect of forest management on litterfall remains unclear. We evaluate the impact of thinning intensity on the biomass and nutrient content (C and N) of litterfall in Pinus pseudostrobus forest in Oaxaca, México, across two thinning intensities in areas with either high or low residual basal area and across seasons. There was significantly higher litter carbon content in the least intensive thinning treatment, but no significant differences in biomass or nitrogen content between treatments. However, there was a significant correlation between residual basal area and litter biomass at the p < .1 level. We found a clear seasonal pattern in litterfall fluxes, with 1.5 times more litter deposition in autumn’s dry season compared to spring. We find that the thinned stand of P. pseudostrobus generated an annual mean litter biomass of 1059.27 ± 346.04 kg ha−1 with mean carbon content of 125.31 ± 46.43 kg ha−1 and mean nitrogen content of 4.76 ± 1.43 kg ha−1. These values present an important contribution for modeling of biomass and nutrient cycling in this ecologically and economically important forest type.

VOESTALPINE AUSTRALIA 4140

Abstract Voestalpine Australia 4140 is medium-carbon, chromium-molybdenum direct hardening alloy steel that is also suitable for flame hardening, induction hardening, and nitriding. This steel is a medium hardenability steel in the 0.40 to 0.42 mean carbon content classification. In general, it is used for medium and large size parts requiring high strength and toughness. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on heat treating, machining, and joining. Filing Code: SA-873. Producer or source: voestalpine High Performance Metals.

CEN 34Cr4 (1.7033), 34CrS4 (1.7037)

Abstract CEN 34Cr4 and 34CrS4 are medium-carbon, 1% chromium, direct hardening alloy steels that are also suitable for flame and induction hardening. These steels are low hardenability steels in the 0.30 to 0.37 mean carbon content classification. They are used for water-quenched parts of moderate section size and for oil-quenched parts of small section size. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on forming, heat treating, and joining. Filing Code: SA-872. Producer or source: European Committee for Standardization.

CEN 46Cr2 (1.7006), 46CrS2 (1.7025)

Abstract CEN 46Cr2 and 46CrS2 are medium-carbon, 0.5% chromium direct hardening alloy steels that are also suitable for flame or induction hardening. These steels are low hardenability steels in the 0.45 to 0.50 mean carbon content classification. In general, they are used for gears and other parts requiring high hardness as well as strength and toughness. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on forming, heat treating, and joining. Filing Code: SA-871. Producer or source: European Committee for Standardization.

New allometric equations for quantifying tree biomass and carbon sequestration in seasonally dry secondary forest in northern Thailand

As tropical deforestation and forest degradation accelerate, carbon-credit trading could provide a financial incentive to preserve and regenerate forests. Since carbon trading relies on the accurate quantification of carbon stocks, allometric equations are urgently needed to derive above-ground dry biomass (AGB) from easily measured variables. Few allometric equations have been published for regenerating secondary forests in Southeast Asia. This study established new allometric equations, to determine AGB and carbon in regenerating secondary forests on shifting cultivation fallows in northern Thailand. To develop the equations, data were collected from 78 trees (136 felled individual stems, including coppices) ranging in size from 1 to 32.9 cm diameter at breast height (D). The dependent variable was AGB. The independent variables were D, tree height (H) and wood density (WD). Wood density varied significantly among species (p < 0.05). Consequently, including WD in the function D2H × WD predicted AGB most accurately, compared with other functions that excluded it. Mean carbon concentration in stems, branches, and leaves was 44.84% ± 1.63 of dry mass, but it varied significantly among tree species (p < 0.05). The new allometric equation revealed that tree ABG was highest in secondary forest, followed by the 7-year-fallow and the 4-year-fallow: 105.3, 38.3 and 10.3 Mg ha−1, respectively, while above-ground carbon was 47.7, 17.4, and 4.6 Mg C ha−1, respectively. Natural regeneration accumulated carbon slower than reported for active restoration, suggesting that managed restoration is preferable to passive regeneration on fallows in northern Thailand. The allometric equations, derived from this study, can be used to accurately determine tree ABG and carbon storage in regenerating secondary forest, with higher precision than has hitherto been possible, thus satisfying the monitoring requirements of REDD+ and other carbon-trading schemes.