Dynamics of land transformation and carbon stock loss from nickel laterite open-pit mining in Indonesia

Effects of land use and cover change on terrestrial carbon stocks in urbanized areas: a study from Changzhou, China

Variation in ecosystem services across an urbanization gradient: A study of terrestrial carbon stocks from Changzhou, China

Impacts of land use/cover change on terrestrial carbon stocks in Uganda

Carbon stock assessment studies at the watershed level remain limited due to the absence of standardized methodologies, leading to inconsistent and incomparable estimates across ecosystems. The present study evaluated carbon stock distribution across major land cover types in the Vitalapura sub-watershed of Kadur Taluk, Chikmagaluru District, using high-resolution QuickBird satellite imagery (0.61 m) combined with ground-truthing. The identified land cover categories included agricultural land (21.82 %), coconut plantation (16.67 %) and forest (0.45 %). Statistical analysis revealed significant variations in biomass and carbon pools among these land covers. Forests recorded the highest above ground biomass (104.29 Mg ha-1), below ground biomass (28.16 Mg ha-1) and total carbon stock (208.29 Mg C ha-1), while agricultural lands showed the lowest values. Soil organic carbon (SOC) was also greatest in forests (146.04 Mg ha-1) and least in agricultural land (77.88 Mg ha-1). Although forests had the highest per-hectare carbon stock, their limited spatial extent restricted their contribution to only 2 % of the total carbon stock. By contrast, coconut plantations and agricultural land, owing to their wider distribution, contributed 56 and 42 % of the total carbon stock, respectively. These findings demonstrate the critical role of land cover in regulating carbon sequestration potential. The study highlights the significance of coconut plantations as a major carbon pool in the sub-watershed and the comparatively reduced contribution of forests due to their limited area. Overall, the results emphasise the need for sustainable land use planning and management strategies that enhance carbon storage, conserve existing forest patches and optimise agricultural and plantation systems for improved carbon sequestration in the region.

Urbanization is a vital factor inducing the loss of terrestrial carbon stocks， and evaluating the impacts of urbanization on terrestrial carbon stocks under shared socioeconomic pathways can provide decision-making references for achieving the dual carbon goals and selecting low-carbon urban development models. In this study， terrestrial carbon stock loss resulting from urbanization and the spatiotemporal evolution of urbanization in Guangdong Province during 2020 to 2050 were systematically assessed under the shared socioeconomic pathways scenario framework. The results show that most of the newly added urban area occurs in western Guangdong and the Pearl River Delta， including Zhanjiang， Maoming， Guangzhou and Foshan. Urbanization stabilizes in 2047 or 2048 under all SSP scenarios except SSP1， under which urbanization ceases to expand by 2039. Secondly， the loss of terrestrial carbon stocks （measured by C） resulting from urban expansion in Guangdong ranges from approximately 2.60 to 4.43 Tg under the five typical SSPs scenarios. Among all the SSPs scenarios， the slowest urbanization rate and minimum loss of terrestrial carbon stocks occurs under SSP1， while the largest newly added urban area and the maximum loss of terrestrial carbon stocks occurs under SSP5. Thirdly， cropland is the primary land cover type encroached upon by urban expansion under all of the SSP scenarios， accounting for approximately 85% of the total newly added urban built-up area. Water body， shrubland， forest， and others account for about 9%， 4%， 1%， and less than 1%， respectively， of the other land cover types transformed to newly added urban area. Correspondingly， the loss of carbon stocked in cropland contributes about 90% of the total carbon stock loss induced by urbanization. Shrubland and forest share the remaining 10% carbon stock loss. Finally， soil carbon stock， which accounts for more than 98% of the total carbon loss， is the main source of the total carbon stock loss resulting from urbanization.

Carbon sequestration in terrestrial ecosystems is gaining a global attention, including Nepal, to address the issues of climate change. Since, the quantification of carbon stock under different land use systems with focus on both biomass and soil profile is lacking, objective of this paper is to quantify carbon stock in biomass and in soil profile under different land use regimes, namely community forest, leasehold forest and agricultural land of Chitwan district. The carbon stock in biomass was calculated using the standard allometric equations, and Dry Combustion Method was used to determine the Soil Organic Carbon (SOC). The carbon content in above ground tree biomass (AGTB) was found to be higher (81.25 t/ha) in community forest than in leasehold forest (80.09 t/ha). The carbon stock in above ground sapling biomass (AGSB) was calculated only for the community forest, and was found to be 3. 67 t/ha. Similarly, the density of leaf litter, herbs and grasses (LHG) was also found to be higher (9. 25 t/ha) in the community forest in comparison to leasehold forest (6.45 t/ha). Further, the root carbon stock density was also higher (16.25 t/ha) in the community forest than in the leasehold forest (16.02 t/ha). However, the SOC density was highest in the agricultural land (73.42t/ha) followed by the community forest (66.38 t/ha)and the leasehold forest (52. 62 t/ha). Overall, the carbon stock was highest in the community forest (176.8 t/ha) then in leasehold forest (155.18 t/ha) followed by the agricultural land (73.42 t/ha). Hence, this study shows that well managed community forest can contribute significantly in offsetting global carbon emission.

Converting mangroves to other land cover types can induce large emissions of carbon dioxide, depending on the type of land use and land cover (LULC) change. However, mangroves may also recover their ecosystem carbon stocks rapidly following restoration, potentially offsetting carbon stock losses. While studies have quantified these tradeoffs at global scales using coarse metrics, fewer studies have quantified them at national scales at higher resolution. Here, we used high‐resolution data sets of LULC for mangroves in Thailand to quantify district‐level gross and net changes in mangrove carbon stocks from ~1960 to 2014. We found emissions based on gross gain and loss statistics (7.18 ± 0.24 million Mg C) to be greater than those associated with emissions based on net area change statistics (1.65 ± 0.26 million Mg C) by a factor of four. The difference in estimates arises from slower rates of carbon stock recovery following reforestation relative to carbon stock loss following LULC change. Overall, we found the greatest gains in mangrove carbon stocks to be from mangrove expansion in areas of accreting sediments, which were strongly correlated with district‐level extent of undisturbed mangroves. Our results show that net loss statistics may greatly underestimate emissions associated with LULC change in mangroves. Additionally, our findings suggest that gains in mangrove carbon stocks associated with natural establishment at the periphery of standing mangroves may offset substantial carbon stock losses at national scales.

BackgroundDeveloping countries participating in the mitigation mechanism of reducing emissions from deforestation and forest degradation (REDD+), are required to establish a forest reference emission level (FREL), if they wish to seek financial support to reduce carbon emissions from deforestation and forest degradation. However, establishment of FREL relies heavily on the accurate estimates of carbon stock as one of the input variable for computation of the emission factors (EFs). The product of an EF and activity data, such as the area of deforestation, results in the total emissions needed for establishment of FREL. This study presents the carbon stock estimates for different land cover classes based on an analysis of Tanzania’s national forest inventory data generated through the National Forest Resources Monitoring and Assessment (NAFORMA).ResultsCarbon stocks were estimated in three carbon pools, namely aboveground, belowground, and deadwood for each of the three land cover classes (i.e. Forest, non-forest, and wetland). The weighted average carbon stock was 33.35 t C ha−1 for forest land, 4.28 t ha−1 for wetland and 5.81 t ha−1 for non-forest land. The uncertainty values were 0.9% for forest land, 11.3% for wetland and 1.8% for non-forest land. Average carbon stocks for land cover sub-classes, which make up the above mentioned major land cover classes, are also presented in our study.ConclusionsThe values presented in this paper correspond to IPCC tier 3 and can be used for carbon estimation at the national scale for the respective major primary vegetation type for various purposes including REDD+. However, if local based estimates values are needed, the use of auxiliary data to enhance the precision of the area of interest is recommended.

West African savannas are experiencing rapid land cover change that threatens biodiversity and affects ecosystem productivity through the loss of habitat and biomass, and carbon emissions into the atmosphere exacerbating climate change effects. Therefore, reducing carbon emissions from deforestation and forest degradation in these areas is critical in the efforts to combat climate change. For such restorative actions to be successful, they must be grounded on a clear knowledge of the extent to which climate change affects carbon storage in soil and biomass according to different land uses. The current study was undertaken in semi-arid savannas in Dano, southwestern Burkina Faso, with the threefold objective of: (i) identifying the main land use and land cover categories (LULCc) in a watershed; (ii) assessing the carbon stocks (biomass and soil) in the selected LULCc; and (iii) predicting the effects of climate change on the spatial distribution of the carbon stock. Dendrometric data (Diameter at Breast Height (DBH) and height) of woody species and soil samples were measured and collected, respectively, in 43 plots, each measuring 50 × 20 m. Tree biomass carbon stocks were calculated using allometric equations while soil organic carbon (SOC) stocks were measured at two depths (0–20 and 20–50 cm). To assess the impact of climate change on carbon stocks, geographical location records of carbon stocks, remote sensing spectral bands, topographic data, and bioclimatic variables were used. For projections of future climatic conditions, predictions from two climate models (MPI-ESM-MR and HadGEM2-ES) of CMIP5 were used under Representative Concentration Pathway (RCP) 8.5 and modeling was performed using random forest regression. Results showed that the most dominant LULCc are cropland (37.2%) and tree savannas (35.51%). Carbon stocks in woody biomass were higher in woodland (10.2 ± 6.4 Mg·ha−1) and gallery forests (7.75 ± 4.05 Mg·ha−1), while the lowest values were recorded in shrub savannas (0.9 ± 1.2 Mg·ha−1) and tree savannas (1.6 ± 0.6 Mg·ha−1). The highest SOC stock was recorded in gallery forests (30.2 ± 15.6 Mg·ha−1) and the lowest in the cropland (14.9 ± 5.7 Mg·ha−1). Based on modeling results, it appears clearly that climate change might have an impact on carbon stock at horizon 2070 by decreasing the storage capacity of various land units which are currently suitable. The decrease was more important under HadGEM2-ES (90.0%) and less under MPI-ESM-MR (89.4%). These findings call for smart and sustainable land use management practices in the study area to unlock the potential of these landscapes to sequestering carbon.

This study analyses the decrease in soil organic carbon (SOC) stocks due to changes in land use following the earthquake in Düzce, Turkey, 1999. The primary objective of the study is to determine the changes in land use within Düzce and to provide a multi-dimensional approach to the spatial and quantitative distributions of SOC losses. Corine Land Use- Land Cover (LULC) within the study is used to determine the change in land use. The loss of LULC and carbon stocks were identified by means of LULC with transfer matrix method and GIS-based analysis. The study of land-use change caused by urbanisation and agricultural activity shows that the limited green spaces around the urban core created by degrading natural areas do not compensate for the loss of SOC. SOC stocks decline after the land use changes from agricultural regions to artificial areas (− 5%), Natural- Semi-natural (N-SN) regions to artificial areas (− 15%), N-SN areas to agricultural areas (− 20.9%) and agricultural areas to water bodies (− 9%), and SOC stocks increase after land use changes from artificial areas to N-SN areas (+ 29.6%), artificial areas to agricultural areas (+ 8%), agricultural areas to N-SN areas (+ 25%). However, in some agricultural areas, SOC stocks are similar to semi-natural and natural areas. For instance, in sparsely vegetated areas, SOC stocks from fruit and berry plantations may be poor. Although it is generally assumed that SOC loss can occur on land transformed from natural areas, this rule of thumb may be revised in some particular circumstances. Therefore, local ecological restoration decisions should not be based on land cover generalisations.

Developing countries must submit forest reference emission levels (FRELs) to the UNFCCC to receive incentives for REDD+ activities (e.g. reducing emissions from deforestation/forest degradation, sustainable management of forests, forest carbon stock conservation/enhancement). These FRELs are generated based on historical CO2 emissions in the land use, land use change, and forestry sector, and are derived using remote sensing (RS) data and in-situ forest carbon measurements. Since the quality of the historical emissions estimates is affected by the quality and quantity of the RS data used, in this study we calculated five metrics (i-v below) to assess the quality and quantity of the data that has been used thus far. Countries could focus on improving on one or more of these metrics for the submission of future FRELs. Some of our main findings were: (i) the median percentage of each country mapped was 100%, (ii) the median historical timeframe for which RS data was used was 11.5 years, (iii) the median interval of forest map updates was 4.5 years, (iv) the median spatial resolution of the RS data was 30m, and (v) the median number of REDD+ activities that RS data was used for operational monitoring of was 1 (typically deforestation). Many new sources of RS data have become available in recent years, so complementary or alternative RS data sets for generating future FRELs can potentially be identified based on our findings; e.g. alternative RS data sets could be considered if they have similar or higher quality/quantity than the currently-used data sets.

Since China’s reform and opening-up period, the southern Jiangsu urban agglomeration has been one of the fastest urbanizing regions in the country. This rapid urbanization has led to dramatic changes in land use cover that have been the primary drivers of carbon stock changes in the terrestrial ecosystem. In this study, we utilize the Integrated Valuation of Ecosystem Services and Trade-offs (InVEST) model and a patch-generating land use simulation (PLUS) model to analyze the land use changes and carbon stocks in the southern Jiangsu urban agglomeration over the past 30 years. We then simulate the carbon stock changes in the study area in the year 2050 under natural growth, cultivated land conservation, and ecological conservation scenarios. The results showed that 1) over the past 30 years, the urban area has increased by 2.98 times, reaching 7,408.42 km2 by 2020. In contrast, the area of cultivated and forested land has continued to decrease with rapid urbanization. 2) Between 1990 and 2020, the carbon stock of the urban agglomeration in southern Jiangsu decreased by 5.34%. The changes in the spatial distribution of carbon stocks are consistent with the changes in land use. 3) By 2050, the carbon stock loss was the largest under the natural growth scenario at 10.49 mt, while the carbon stock loss was the smallest under the cultivated land protection scenario at 0.97 mt. Under the ecological protection scenario, the carbon stock loss was 9.9 mt. The results indicate that the adoption of cultivated land and ecological protection measures can effectively control the reduction of carbon stock in rapidly urbanizing areas. 4) The conversion of cultivated land and forest land to urban land was the primary reason for the carbon stock reduction in the study area, which was primarily located in the urban outward expansion area. This study provides a reference- and data-based support for the management, decision-making, and planning in rapidly urbanizing areas.

Geospatial assessment of long-term changes in carbon stocks and fluxes in forests of India (1930–2013)

Woody species diversity and carbon stock potentials in homegarden agroforestry and other land use systems, northern Ethiopia

Abstract. Eddy S, Setiawan AA, Taufik M, Oktavia M, Utomo B, Milantara N. 2023. Loss of carbon stock as an impact of anthropogenic activities in a protected mangrove forest. Biodiversitas 24: 6493-6501. The significant anthropogenic activities within the mangrove forest, known as the Air Telang Protected Forest (ATPF) in the Banyuasin District, South Sumatra, Indonesia, have led to an alarming degradation, leaving only its primary mangrove forests, currently constituting approximately 26% of the total forest area. This study aims to analyze changes in land cover, quantify carbon reserve loss due to CO2 emissions, and assess carbon sequestration in the ATPF over two periods: 1999-2010 and 2010-2023. Remote sensing data for 1999, 2010, and 2023 were utilized from Landsat imagery, employing ENVI and ArcGIS for land cover classification. Carbon density, CO2 emissions, and carbon sequestration were analysed using the Land Use Planning for Multiple Environmental Services (LUMENS) software. The research findings reveal an increase in the primary forest area in the first period (by almost a quarter); however, more than half of this area was lost in the second period. The secondary forest area consistently decreased over the two periods, while the open area experienced significant growth. Carbon stocks in 2010 exceeded those in 1999 due to an increase in the primary forest area, but by 2023, carbon stocks decreased significantly due to extensive land clearing. The second period witnessed the largest emissions, exceeding those of the previous period by five times. Carbon sequestration in the first period surpassed that in the second period by more than three times, with the most significant sequestration resulting from the growth of secondary mangrove forests into primary mangrove forests. The study highlights the necessity of restoration and conservation of mangrove forest areas in ATPF for sustenance of its natural function as a protected forest.