Biomass, carbon stock and sequestration potential of Oxytenanthera abyssinica forests in Lower Beles River Basin, Northwestern Ethiopia

Carbon Sequestration in Soils of Latin America

The many opportunities for mitigating atmospheric carbon emissions in developing countries include reforesting degraded lands, implementing sustainable agricultural practices on existing lands and slowing tropical deforestation. This analysis shows that over the next 10 years, 48 major tropical and subtropical developing countries have the potential to reduce the atmospheric carbon burden by about 2.3 billion tonnes of carbon. Given a central price of $10 per tonne of carbon and a discount rate of 3%, this mitigation would generate a net present value of about $16.8 billion collectively for these countries. Achieving these potentials would require a significant global effort, covering more than 50 million hectares of land, to implement carbon-friendly practices in agriculture, forest and previously forested lands. These estimates of host-country income potentials do not consider that outside financial investment may or may not be available. Our calculations take no account of the additional benefits of carbon sequestration in forest soils undergoing reforestation, increased use of biomass and reduced use of fossil-fuel inputs and reduced agricultural emissions. In all events, realizing these incomes would necessitate substantially greater policy support and investment in sustainable land uses than is currently the case.

Tree biomass and carbon stock assessment of subtropical and temperate forests in the Central Himalaya, India

Carbon stock and sequestration potential of Ibodi monkey forest in Atakumosa, Osun state, Nigeria

BackgroundThe spruce forests are dominant communities in northwest China, and play a key role in national carbon budgets. However, the patterns of carbon stock distribution and accumulation potential across stand ages are poorly documented.MethodsWe investigated the carbon stocks in biomass and soil in the natural spruce forests in the region by surveys on 39 plots. Biomass of tree components were estimated using allometric equations previously established based on tree height and diameter at breast height, while biomass in understory (shrub and herb) and forest floor were determined by total harvesting method. Fine root biomass was estimated by soil coring technique. Carbon stocks in various biomass components and soil (0–100 cm) were estimated by analyzing the carbon content of each component.ResultsThe results showed that carbon stock in these forest ecosystems can be as high as 510.1 t ha−1, with an average of 449.4 t ha−1. Carbon stock ranged from 28.1 to 93.9 t ha−1 and from 0.6 to 8.7 t ha−1 with stand ages in trees and deadwoods, respectively. The proportion of shrubs, herbs, fine roots, litter and deadwoods ranged from 0.1% to 1% of the total ecosystem carbon, and was age-independent. Fine roots and deadwood which contribute to about 2% of the biomass carbon should be attached considerable weight in the investigation of natural forests. Soil carbon stock did not show a changing trend with stand age, ranging from 254.2 to 420.0 t ha−1 with an average of 358.7 t ha−1. The average value of carbon sequestration potential for these forests was estimated as 29.4 t ha−1, with the lower aged ones being the dominant contributor. The maximum carbon sequestration rate was 2.47 t ha−1 year−1 appearing in the growth stage of 37–56 years.ConclusionThe carbon stock in biomass was the major contributor to the increment of carbon stock in ecosystems. Stand age is not a good predictor of soil carbon stocks and accurate evaluation of the soil carbon dynamics thus requires long-term monitoring in situ. The results not only revealed carbon stock status and dynamics in these natural forests but were helpful to understand the role of Natural Forest Protection project in forest carbon sequestration as well.

Carbon stocks and sequestration potential of community forests in Bhutan

Abstract. Bao TQ, Ha NT, Nguyet BTM, Hoan VM, Viet LH, Hung DV. 2021. Aboveground biomass and carbon stock of Rhizophora apiculata forest in Ca Mau, Vietnam. Biodiversitas 23: 403-414. Despite the small proportion of mangrove forests globally, they contribute significantly in carbon storage. Yet, biomass and carbon stock in mangrove forests might vary depending on various factors including the dominant species that occurred. This study was conducted to determine the biomass and carbon stock of a mangrove forest dominated by Rhizophora apiculata Blume in Ca Mau, Vietnam. Data were collected from 56 representative sample plots (50m x 50m), and 46 sample trees with different age classes and diameter sizes were cut down to measure the fresh biomass. The dry biomass and carbon content were analyzed in the laboratory. The average aboveground biomass and carbon stock of the individual tree and the R. apiculata forest at different diameter sizes had a significant difference and were mostly found in the stem (74.5%-79.5%). The conversion factor from fresh biomass to dry biomass was 0.56; the conversion factor from dry biomass to carbon was 0.46. The total biomass of the individual trees had a close relationship with two variables diameter at breast height (DBH) and height (Hvn) in the form of the logarithmic function: ln(Wtk) = -1,86412 - 1,95419*ln(Hvn) + 2,26798*ln(DBH*Hvn). The total biomass and carbon stock of the entire forest stand increased in accordance with the diameter size and age classes. The R. apiculata stand had a density of 1,040-15,800 trees/ha and a timber volume of 27.2 to 365.6 m3/ha. The average biomass of the R. apiculata stand was 191.1 tons/ha with a range from 49.6 to 357.4 tons/ha. The carbon stock in forest biomass ranged from 23.8 to 188.7 tons C/ha, with an average of 117.4 tons C/ha. The forest’s CO2 absorption ranged from 60.0 to 691.7 tons CO2/ha, with an average of 415.9 tons/ha. The carbon stocks of trees of age class I to age class VI were 41.6 tons C/ha, 79.4 tons C/ha, 101.4 tons C/ha, 132.9 tons C/ha, 154.0 tons C/ha, and 167.4 tons C/ha, respectively.

Estimating the carbon sequestration potential of Moso bamboo (Phyllostachys pubescens) forests and optimizing management strategies play pivotal roles in enhancing quality and promoting sustainable development. However, there is a lack of methods to simulate changes in carbon sequestration capacity in Moso bamboo forests and to screen and optimize the best management measures based on long-term time series data from fixed-sample fine surveys. Therefore, this study utilized continuous survey data and climate data from fixed sample plots in Zhejiang Province spanning from 2004 to 2019. By comparing four different algorithms, namely random forest, support vector machine, XGBoost, and BP neural network, to construct aboveground carbon stock models for Moso bamboo forests. The ultimate goal was to identify the optimal algorithmic model. Additionally, the key driving parameters for future carbon stocks were considered and future aboveground carbon stocks were predicted in Moso bamboo forests. Then formulated an optimal management strategy based on these predictions. The results indicated that the carbon stock model constructed using the XGBoost algorithm, with an R2 of 0.9895 and root mean square error of 0.1059, achieved the best performance and was considered the optimal algorithmic model. The most influential driving parameters for vegetation carbon stocks in Moso bamboo forests were found to be mean age, mean diameter at breast height, and mean culm density. Under optimal management measures, which involve no harvesting of 1–3 du bamboo, 30% harvesting of 4 du bamboo, and 80% harvesting of bamboo aged 5 du and above. Our predictions show that aboveground carbon stocks in Moso bamboo forests in Zhejiang Province will peak at 36.25 ± 8.47 Tg C in 2046 and remain stable from 2046 to 2060. Conversely, degradation is detrimental to the long-term maintenance of carbon sequestration capacity in Moso bamboo forests, resulting in a peak aboveground carbon stock of 29.50 ± 7.49 Tg C in 2033, followed by a continuous decline. This study underscores the significant influence of estimating carbon sequestration potential and optimizing management decisions on enhancing and sustaining the carbon sequestration capacity of Moso bamboo forests.

Forests play a crucial role in climate change mitigation by acting as a carbon sink. Understanding the influence of soil properties on carbon stocks in forests is essential for developing effective forest management strategies. The aim of the study was to assess the impact of soil texture on carbon stocks in the biomass of deciduous and coniferous tree stands of a forest-steppe ecotone. Soil samples were collected from 55 soil pits, and forest inventory data were obtained from eight permanent sample plots. The results showed that the distribution of mechanical particles in soils, particularly the stocks of silt and clay, significantly influenced the accumulation of carbon in tree stands. The stock of silt and clay was shown to increase with an increase in the diversity of tree species in forests and carbon stocks in forest stands. While soil organic carbon stocks did not exhibit a clear relationship with tree stand carbon stocks, a strong positive correlation (r = 0.802, p < 0.05) was found between the stocks of fine particles in the 2 m root-inhabited soil layer and the carbon stocks in tree biomass. The study provides a classification of forest types based on soil texture, which can facilitate differentiated forest management strategies for enhancing the carbon sequestration potential of forest ecosystems in the forest-steppe zone.

Assessment of carbon sequestration potential of tropical tree species for urban forestry in India

Forests can play an important role in climate change mitigation. However, limited information is available worldwide regarding forest carbon and biomass stocks. Financial mechanisms such as ‘reducing emissions from deforestation and forest degradation and the role of conservation of forest carbon, sustainable management of forests and enhancement of forest carbon stocks’ (REDD+) also emphasize the quantification of forest biomass and carbon. This study aimed to estimate the forest biomass in two forests of Margalla Hills National Park (MHNP): Sub-tropical Chir Pine Forest (SCPF) and Sub-tropical Broadleaved Evergreen Forest (SBEF). For this, circular sampling plots of a 20 m radius were used for the collection of the variables, “diameter at breast height (DBH) and height”. Statistical analysis was done for exploring regression relationships between the variables. We found a mean Aboveground Carbon (AGC) of 73.36 ± 32.55 Mg C ha−1 in SCPF and a mean AGC of 16.88 ± 25.81 Mg C ha−1 in SBEF. The mean Aboveground Biomass (AGB) for SCPF was recorded as 146.73 ± 65.11 Mg ha−1, while for SBEF it was 33.77 ± 51.63 Mg ha−1. It was therefore concluded that the SCPF had higher mean AGB and mean AGC than the SBEF. Similar differences were also noticed in the structural characteristics of the two forests. These could be valuable information while designing sustainable management plans and afforestation programmes for the future and also for accessing nature-based funding such as REDD+.

Forests play a vital role in the global carbon balance and combating global climate change by sequestering and retaining carbon from the atmosphere in their biomass and soil. Thus, this study aims to estimate the carbon stocks in the biomass and soil along with various environmental factors in the Geramo forest in southern Ethiopia. Ninety-six plots (20 × 20 m2) were laid at a distance of 250 m along 16 line transects that were laid 300 m apart. Five 1 × 1 m2 subplots (4 at the corner and 1 at the center) were laid inside each main plot for LHG and soil data collection. The results revealed that the estimated total carbon stocks and mean carbon stock densities of the study forest were 57994 Mg h−1and 604 ± 344 Mg h−1, respectively, with a mean CO2 equivalent of 2217 ± 1262 Mg h−1. This result indicates the remarkable role of the Geramo forest in carbon stock and sequestration potential compared with other remnant forests in Ethiopia. Thus, the Geramo forest plays a crucial role in climate change mitigation through carbon sequestration, and hence, this forest can generate carbon credits as financial benefits to the nearby population in the future. The results also revealed that anthropogenic disturbances were negatively associated with the carbon stocks of the forest. Therefore, sustainable forest conservation activities are needed to conserve forest resources, protect the forest from growing anthropogenic disturbances, and sustain its current global climate change mitigation and adaptation benefits.

Forest degradation and deforestation are some of the major global concerns as they can reduce the forest carbon stock and sequestration capacity. However, the carbon stock and sequestration potential in a mixed dipterocarp tropical forest remains unclear due to a lack of information. This study was carried out on the carbon stock and estimated its economic value to justify its conservation. Six plots were established in the Endau Rompin National Park, Johor and subplots measuring 50 × 20 m were established in each plot. All trees greater than 15 cm DBH (diameter at breast height) were identified and the parameters measured included tree height and diameter. The aboveground carbon (AGC) content was about 222 Mg(C) ha-1, belowground carbon (BGC) was 53 Mg (C) ha-1 and it was 6 Mg (C) ha-1 for other components. In total, the carbon stock amounted to 281 Mg (C) ha-1. On the other hand, the total CO2 sequestrated in the mixed dipterocarp forest amounted to 1,040 t CO2 ha-1. The carbon value was estimated at RM32,240 t CO2 ha-1 or $7,280 t CO2 ha-1. Therefore, the study found that the dipterocarp forest should be preserved to mitigate greenhouse gas emissions.

The study was carried out to quantify the carbon stock and sequestration potential of the multifunctional agroforestry (MFA) system established for small and marginal farmers in Tamil Nadu, India. The MFA consists of 316 multi-utility trees and shrubs across four quadrats and border trees on a 0.75 acre land. The results showed significant variation in the above-ground and below-ground carbon stock among the different tree and shrub species. Neolamarckia cadamba recorded the highest above and below-ground stock of 70.65 kg tree-1 and 18.37 kg tree-1, respectively. The total carbon sequestered by the vegetation was 3.82 tons (3823.94 kg), with the highest contribution from Quadrat II (1591.85 kg) and the lowest from border trees (132.30 kg). The soil organic carbon (SOC) stock decreased with increasing depth, with the maximum stock observed in the 0–20 cm layer. The total change in SOC stock from the MFA during the study period was 12.99 mg ha-1, with a carbon sequestration rate of 0.18 mg ha-1 yr-1. The total carbon revenue from the vegetation and soil was estimated at US$ 311.4 (US$ 140.3 from vegetation and US$ 171.1 from soil). The findings highlight the significant potential of MFA systems in carbon sequestration and mitigation of climate change, particularly for small and marginal farmers in developing countries.

Tropical forests play a key role in climate change mitigation by sequestering and storing carbon from the atmosphere. In Ethiopia, there are inadequate data in the form of carbon accumulation records or databank to assess the carbon sequestration potential of different forests. This study intended to estimate the living biomass and carbon stocks of woody plants in Chilimo-Gaji Forest. Totally, 10 circular plots with 20 m radius each having 1,256 m2, estimated the biomass of 17 tree species using the nondestructive allometric equation. The total woody biomass of the study area estimated to be 1013.3 t ha-1, of which, about 83.3 % (844.4 t ha-1) was aboveground, and 16.7% (168.9 t ha-1) was below ground biomass. The total carbon stocks and total carbon sequestration potential of the study area was about 506.7 t C ha-1 and 1859.45 t ha-1, respectively. The result indicates that the Chilimo-Gaji Forest has huge potential for carbon stock compared to research conducted on other remnant forests in Ethiopia. This is mainly due to the improvement in the forest stocks as a result of participatory forest management practices in the area. Generally, Chilimo-Gaji Forest is playing a vital role in carbon sequestration, thereby contributing to climate change mitigation. Therefore, in the future, the forest can generate carbon credits as financial benefits to the indigenous population, which could help to strengthen the conservation efforts of forest resources in the study area.