Impacts and prediction of land use change on ecosystem carbon sequestration in Zhejiang Province, China.

It is crucial to clarify the impact of land use change on ecosystem carbon sequestration service for exploring natural-based carbon neutral solutions. We used InVEST and FLUS models to analyze land use change and its impacts on ecosystem carbon sequestration service in Zhejiang Province from 2000 to 2021, and predict ecosystem carbon sequestration service potential and its economic value of land use pattern in 2035 and 2050 under three scenarios of natural development, ecological protection, and cultivated land protection. The results showed that the area of cultivated land, forest, grassland, and water was continuously reducing and the area of construction land was continuously increasing from 2000 to 2021 in Zhejiang Province. The total amount of ecosystem carbon sequestration service decreased by 29.9658 million t, and the net income of carbon sequestrqtion service was -170.7184 million dollars. The distribution of ecosystem carbon sequestration services showed a spatial pattern of high in the southwest and low in the northeast. In the future, the total amount of ecosystem carbon sequestration services in Zhejiang Province would be the highest under the ecological protection scenario, followed by the cultivated land protection scenario, and the lowest under the natural development scenario. From 2021 to 2035 and 2050, ecosystem carbon sequestration services in Zhejiang Province would increase by 3.2326 million and 4.73 million t respectively under the ecological protection scenario, generating carbon sequestration service benefits of 77.0786 million and 111.8391 million dollars, respectively. Under the cultivated land protection scenario, it would be reduced by 10.1318 million and 16.1611 million t, and the net loss of carbon sequestration service value would be 241.3849 million and 381.9109 million dollars, respectively. Under the natural development scenario, it would be reduced by 11.6490 million and 16.1651 million t, resulting in a net loss of carbon sequestration service value of 277.5393 million and 382.0063 million dollars, respectively. In the context of actively addressing climate change and striving to achieve the goal of carbon neutrality, Zhejiang Province should focus on protecting ecological land such as woodlands, grasslands, and water, expand the scale of ecological land, optimize the spatial structure of ecological land, and continuously enhance carbon sequestration and sink enhancement functions of ecological land.

Relationship between net primary productivity and stand age in typical plantation forests in China.

Plantation forests play an important role in carbon sink in terrestrial ecosystems. Based on tree rings of five main plantation tree species (Robinia pseudoacacia, Quercus variabilis, Cunninghamia lanceolata, Pinus sylvestris var. mongolica, and Pinus tabuliformis) at 25 sites in China, we calculated the average annual NPP of standard trees in each study area by the biomass equations and extended to the stand scale. The relationships between NPP and stand age were fitted by the InTEC and Law models. The results showed that NPP of R. pseu-doacacia, C. lanceolata, and P. tabuliformis plantations increased to a peak and then leveling off with stand age, while that of Q. variabilis and P. sylvestris var. mongolica plantations reached a peak and then showed a decreasing trend. The inflection points of NPP-stand age curve for different planatations was 11 years for P. sylvestris var. mongolica, 14 years for C. lanceolata, 16 years for P. tabuliformis, and 20 years for R. pseudoacacia. The NPP peak was 6.65, 7.58, 4.70 and 2.59 t·hm-2·a-1, respectively. Both the InTEC and Law NPP-stand age models had high fitting accuracy at a large scale, with the lowest R2 of 0.95 and RMSE of 0.55 t·hm-2·a-1 for the P. sylvestris var. mongolica InTEC model and the highest R2 of 0.99 and RMSE of 0.26 t·hm-2·a-1 for the C. lanceolata InTEC model. The construction of NPP-stand age relationship for major plantations in China provided mechanistic support for the estimation of carbon sinks in plantations at long time scales and provided a reference for the diversification of afforestation tree species selection.

UAV hyperspectral combined with LiDAR to estimate chlorophyll content at the stand and individual tree scales.

Chlorophyll is an important indicator of vegetation health status, accurate estimation of which is important for evaluating forest carbon sink. In this study, we estimated the chlorophyll content of coniferous forests, broad-leaved forests and mixed forest stands at stand and individual tree level by unmanned air vehicle (UAV) hyperspectral data combined with light detection and ranging (LiDAR) point clouds, which improved the non-destructive estimation accuracy of forest chlorophyll. We further comprehensively analyzed the spatial distribution of chlorophyll content at different scales. A total of 36 spectral characteristic variables related to chlorophyll content were screened by correlation analysis based on the fusion of UAV hyperspectral data and LiDAR point clouds combining with the empirical data from ground plots. We constructed multiple models for chlorophyll estimation by using statistical model, including multiple stepwise regression, BP neural network, BP neural network optimized by firefly algorithm, random forest and hybrid data-driven PROSPECT mechanism model. The optimal model was selected to estimate the chlorophyll content. The horizontal and vertical distribution of chlorophyll content at the stand level and individual tree level were analyzed. The results showed that the random forest model was superior to the models constructed by multiple stepwise regression, BP neural network and BP neural network optimized by firefly algorithm for chlorophyll estimation with R2 and RMSE of 0.59-0.64 and 3.79-5.83 µg·cm-2, respectively. The accuracy of the mechanism model was the highest, with R2 and RMSE of 0.97 and 3.40 µg·cm-2. The chlorophyll contents differed across stand types, with that in broad-leaved forest (25.25-31.60 µg·cm-2) being higher than mixed forest (13.52-23.93 µg·cm-2) and coniferous forest (6.40-13.71 µg·cm-2). There were significant differences in chlorophyll contents the in vertical direction among different stands. For individual tree of different species, the chlorophyll content inside the canopy was lower than that outside the canopy in the horizontal direction. In the vertical direction, there was no difference in chlorophyll content among different layers of Pinus sylvestris var. mongolica canopy. However, significant differences were observed among the upper, middle, and lower layers of Juglans mandshurica canopy. Using the fusion of hyperspectral image and LiDAR point cloud data, the mechanism model driven by hybrid data could effectively improve the accuracy and stability of chlorophyll content estimation at different scales.

Relationship between carbon stock and the structure of coniferous and broad-leaved mixed forest in Tianmu Mountains, China.

Taking the coniferous and broad-leaved mixed forest of Tianmu Mountain National Nature Reserve in Zhejiang Province as research object, we divided the tree species into three pairs, including evergreen and deci-duous species, broad-leaved and coniferous species, dominant and non-dominant species, to compare the difference of the individual tree carbon stock of each pair and analyze the diameter distribution pattern and tree height distribution pattern of carbon stocks. The relationship between spatial structure and individual tree carbon stock was analyzed by using spatial structure indicators including V_Hegyi competition index, complete mingling and aggregation index, to reveal the relationship between the structure of coniferous and broad-leaved forests and carbon stocks, and provide a theoretical basis for management of forest carbon sequestration. The results showed that the average individual carbon stock for evergreen and deciduous species, broad-leaved and coniferous species, dominant and non-dominant species were 57.7 and 87.4 kg, 54.6 and 74.7 kg, 67.4 and 48.1 kg, respectively. The individual tree carbon stock of evergreen species was significantly lower than that of deciduous species, the individual tree carbon stock of broad-leaved species was significantly lower than that of coniferous species, and the individual tree carbon stock of dominant tree species was significantly higher than that of non-dominant tree species. The diameter distribution and height distribution of carbon stock of each species group obeyed normal distribution. The V_Hegyi competition index was significantly negatively correlated with individual tree carbon stock, and it was consistent with the power function distribution. Both complete mingling and aggregation index were linearly and positively correlated with individual tree carbon stock. The direction of influence of different spatial structures on the individual tree carbon stock was consistent. The structure of coniferous and broad-leaved mixed forest had a significant impact on individual tree carbon stock. In the management of forest carbon sequestration and sink enhancement, it is necessary to regulate the unreasonable forest structure and promote its succession to the climax community in order to improve forest carbon stock.

Exploring the potential of roof greening for low-carbon landscapes.

As one type of urban artificial ecosystems, roof greening exhibits carbon source/sink characteristics during their life cycle. The carbon cycle mechanism is complex. The lack of exhaustive carbon performance quantification methods and assessment indicators hinders the promotion and implementation of green roof urban decarboni-zation. Focusing on the quantification of roof greening low-carbon landscape potential, we analyzed the internal carbon cycle mechanism of green roof systems and explored four carbon reduction and sink pathways (P1-P4): biogenic carbon sink, embodied carbon, operational carbon, and bioenergy supply. Based on the dual performance indicators of normalized value of carbon emissions and carbon payback time, we summarized the normalized value measurement method of each pathway. The potential and characteristics of each pathway were quantified by extracting data from the literature. The results showed that the quantified potential values for P1 to P4 were 9.54, -2.26, 2.96 and 0.35 kg CO2·m-2·a-1, respectively, and that the potential values for each pathway were strongly influenced by plant types, climate, and other factors. The imperfect base database and the heterogeneity of assessment scenarios impacted the accuracy of the measurements. The integrated low carbon landscape potential of extensive green roofs was discussed in sub-scenarios, with the 40-year-life cycle integrated carbon reduction ranging from 92.24 to 433.42 kg CO2·m-2 and the carbon payback period ranging from 5 to 14 years. Finally, we summarized the problems in the assessment to facilitate future updates and improvements.

Intentional creation of carbon-rich dark earth soils in the Amazon.

Fertile soil known as Amazonian dark earth is central to the debate over the size and ecological impact of ancient human populations in the Amazon. Dark earth is typically associated with human occupation, but it is uncertain whether it was created intentionally. Dark earth may also be a substantial carbon sink, but its spatial extent and carbon inventory are unknown. We demonstrate spatial and compositional similarities between ancient and modern dark earth and document modern Indigenous practices that enrich soil, which we use to propose a model for the formation of ancient dark earth. This comparison suggests that ancient Amazonians managed soil to improve fertility and increase crop productivity. These practices also sequestered and stored carbon in the soil for centuries, and we show that some ancient sites contain as much carbon as the above-ground rainforest biomass. Our results demonstrate the intentional creation of dark earth and highlight the value of Indigenous knowledge for sustainable rainforest management.

Microbial growth under drought is confined to distinct taxa and modified by potential future climate conditions.

Climate change increases the frequency and intensity of drought events, affecting soil functions including carbon sequestration and nutrient cycling, which are driven by growing microorganisms. Yet we know little about microbial responses to drought due to methodological limitations. Here, we estimate microbial growth rates in montane grassland soils exposed to ambient conditions, drought, and potential future climate conditions (i.e., soils exposed to 6 years of elevated temperatures and elevated CO2 levels). For this purpose, we combined 18O-water vapor equilibration with quantitative stable isotope probing (termed 'vapor-qSIP') to measure taxon-specific microbial growth in dry soils. In our experiments, drought caused >90% of bacterial and archaeal taxa to stop dividing and reduced the growth rates of persisting ones. Under drought, growing taxa accounted for only 4% of the total community as compared to 35% in the controls. Drought-tolerant communities were dominated by specialized members of the Actinobacteriota, particularly the genus Streptomyces. Six years of pre-exposure to future climate conditions (3 °C warming and + 300 ppm atmospheric CO2) alleviated drought effects on microbial growth, through more drought-tolerant taxa across major phyla, accounting for 9% of the total community. Our results provide insights into the response of active microbes to drought today and in a future climate, and highlight the importance of studying drought in combination with future climate conditions to capture interactive effects and improve predictions of future soil-climate feedbacks.

Exploring the impacts of ecosystem services on human well-being in Qinghai Province under the framework of the sustainable development goals.

Ecosystem services (ESs) play vital roles in meeting the needs of human well-being and supporting sustainable development. However, there is limited research on how the types, amounts, interactions, and changes of the ESs collectively impact human well-being under the context of sustainable development goals (SDGs) of the United Nations. This study selected Qinghai Province of China as the study area and intended to make such an attempt to fill this gap in terms of the following aspects: (1) analyzing the spatial patterns and changing trends of ten ESs (food supply, water supply, carbon sink, soil retention, sand fixation, hydrological regulation, flood mitigation，cultural service，net primary productivity, and habitat quality) in Qinghai Province from 2000 to 2018; (2)constructing a multi-level index system of human well-being under the framework of the SDGs, and setting the criteria to assess the level of local human well-being; and (3) building a structural equation model to explore the direct and indirect impacts of the types, amounts, interactions and changes of the ESs on actual human well-being and the gaps between actual and targeted human well-being. The findings revealed that: (1) most of the ecosystem services fluctuated with significant downward or upward trends during 2000-2018, except for four ESs (i.e., carbon sink, soil retention, flood mitigation, and habitat quality); (2) only a few indicators of local residents' well-being such as meat production, milk production, the numbers of medical technical personnel in hospitals and health centers, and the numbers of scientific and technical personnel met the SDG criteria in most time, while other indicators remained at low levels and there were large gaps between them and the SDG criteria; (3) actual human well-being and the gaps between actual and targeted human well-being were affected by the types, amounts, interactions and changes of the ESs with different degrees directly or indirectly. The approaches and results in this study are instructive for other regions of the world to make certain the roles of ESs in promoting human well-being and substantiating the SDGs.

Integration of biochar with nitrogen in acidic soil: A strategy to sequester carbon and improve the yield of stevia via altering soil properties and nutrient recycling.

The health of agroecosystems is subsiding unremittingly, and the over-use of chemical fertilizers is one of the key reasons. It is hypothesized that integrating biochar, a carbon (C)-rich product, would be an effective approach to reducing the uses of synthetic fertilizers and securing crop productivity through improving soil properties and nutrient cycling. The bamboo biochar at different quantities (4-12 Mg ha-1) and combinations with chemical fertilizers were tested in stevia (Stevia rebaudiana) farming in silty clay acidic soil. The integration of biochar at 8 Mg ha-1 with 100% nitrogen (N), phosphorus (P), and potassium (K) produced statistically (p ≤ 0.05) higher leaf area index, dry leaf yield, and steviol glycosides yield by about 18.0-33.0, 25.8-44.9, and 20.5-59.4%, respectively, compared with the 100% NPK via improving soil physicochemical properties. Soil bulk density was reduced by 5-8% with biochar at ≥ 8 Mg ha-1, indicating the soil porosity was increased by altering the soil macrostructure. The soil pH was significantly (p ≤ 0.05) augmented with the addition of biochar alone or in the combination of N because of the alkaline nature of the used biochar (pH = 9.65). Furthermore, integrating biochar at 8 Mg ha-1 with 100% NPK increased 22.7% soil organic C compared with the sole 100% NPK. The priming effect of applied N activates soil microorganisms to mineralize the stable C. Our results satisfy the hypothesis that adding bamboo biochar would be a novel strategy for sustaining productivity by altering soil physicochemical properties.

Carbon Sequestration Potential of Biomass Production along Highways in China.

In response to climate change, China is making great efforts to increase the green area for carbon sequestration. Road verges, as marginal land with favorable conditions for plant growth and ease of transportation, can be used for biomass production, but the biomass production and carbon sequestration potential have not been assessed. Here, we mapped the biomass production potential of road verges in China by combining a biomass model and Geographic Information System and then evaluated the effect of road runoff and CO2 fertilization on the production according to the runoff coefficient and vehicle emission inventory. Nationwide, road verges can produce 15.86 Mt C yr-1 of biomass. Road runoff contributes to a biomass production of 1.26 Mt C yr-1 through increasing soil water availability, which mainly occurs in arid regions. The CO2 fertilization effect by vehicle emission is considerable in Eastern and Southern China, contributing to a production of 0.09 Mt C yr-1. Life cycle assessment shows that major road verges in China have a carbon sequestration potential of 6.87 Mt C yr-1 currently. Our results revealed that road verges can make a significant contribution to carbon neutrality under proper management.

Environmental Consequences of Intensive Aquaculture Practices at Moyna Purba Medinipur West Bengal India with Special Reference to Carbon Footprint and Carbon Sequestration.

Moyna of Purba Medinipur district is widely known as an aquaculture hub of West Bengal, India. Though very good production is achievable from this fish culture system, management practices are inappropriate, which could create the sustainability problem of this culture system. The present study was thus undertaken for the estimation of plankton population, water quality, carbon footprint and carbon sequestration of this intensive aquaculture practices. Information on spawn to fry, fry to fingerlings and grow-out culture were collected through the structured questionnaire from the fish farmers. The plankton density, primary productivity, carbon footprint and carbon sequestration were analyzed using standard procedures. The phytoplankton, zooplankton and primary productivity were maximum at the stocking period and minimum during the middle of culture period. The lowest feed conversion ratio (FCR) was noticed with the minimum amount of feed applied in the pond. The CO2-e emission ranged from 0.56 to 4.89 kg CO2-e/kg fish (av. 2.13) for the production levels of 5.0 to 10.7 t/ha/yr. The pond water developed salinity and ammonium-N increased from 0.01 to 0.50 mg/l. The ponds with high feed loading (28 to 32 t/ha/yr) had the highest average sediment accumulation rate (11.0 ± 3.0 cm/yr) and carbon sequestration (704 ± 30 g C/m2/yr).

Effects of herbivore on seagrass, epiphyte and sediment carbon sequestration in tropical seagrass bed.

Herbivores strongly affect the ecological structure and functioning in seagrass bed ecosystems, but may exhibit density-dependent effects on primary producers and carbon sequestration. This study examined the effects of herbivorous snail (Cerithidea rhizophorarum) density on snail intraspecific competition and diet, dominant seagrass (Thalassia hemprichii) and epiphyte growth metrics, and sediment organic carbon (SOC). The growth rates of the herbivorous snail under low density (421 ind m-2) and mid density (842 ind m-2) were almost two times of those at extremely high density (1684 ind m-2), indicating strong intraspecific competition at high density. Herbivorous snails markedly reduced the epiphyte biomass on seagrass leaves. Additionally, the seagrass contribution to herbivorous snail as food source under high density was about 1.5 times of that under low density, while the epiphyte contribution under low density was 3 times of that under high density. A moderate density of herbivorous snails enhanced leaf length, carbon, nitrogen, total phenol and flavonoid contents of seagrasses, as well as surface SOC content and activities of polyphenol oxidase and ß-glucosidase. However, high density of herbivorous snails decreased leaf glucose, fructose, detritus carbon, and total phenols contents of seagrasses, as well as surface SOC content and activities of polyphenol oxidase and ß-glucosidase. Therefore, the effects of herbivorous snail on seagrass, epiphyte and SOC were density-dependent, and moderate density of herbivorous snail could be beneficial for seagrasses to increase productivity. This provided theoretical guidance for enhancing carbon sink in seagrass bed and its better conservation.

Potential soil organic carbon sequestration vis-a-vis methane emission in lowland rice agroecosystem.

Mitigating the atmospheric greenhouse effect while enhancing the inherent soil quality and productive capacity is possible through soil carbon (C) sequestration, which has a significant potential to counteract the adverse effects of agroecosystem level C emission through natural and anthropogenic means. Although rice is the most important food in India, feeding more than 60% of the country's population, it is commonly blamed for significant methane (CH4) emissions that accelerate climate change. Higher initial soil organic matter concentrations would create more CH4 under the flooded soil conditions, as reducible soil C is a prerequisite for CH4 generation. In India, rice is generally cultivated in lowlands under continuous flooding. Less extensive organic matter breakdown in lowland rice agroecosystems often significantly impacts the dynamics of soil active and passive C pools. Change from conventional to conservation agriculture might trap a significant quantity of SOC. The study aims to investigate the potential of rice-based soils to sequester C and reduce the accelerated greenhouse effects through modified farming practices, such as crop residue retention, crop rotation, organic farming, varietal selection, conservation agriculture, integrated nutrient management, and water management. Overall, lowland rice agroecosystems can sequester significant amounts of SOC, but this potential must be balanced against the potential for CH4 emissions. Management practices that reduce CH4 emissions while increasing soil C sequestration should be promoted and adopted to maximize the sustainability of rice agroecosystems. This review is important for understanding the effectiveness of the balance between SOC sequestration and CH4 emissions in lowland rice agroecosystems for adopting sustainable agricultural practices in the context of climate change.

Carbon stock in biomass pool of fragmented mangrove habitats of Kochi, Southern India.

Even though, the blue carbon ecosystems are gaining keen research interest around the globe, the carbon stock of South-West coast of India was poorly reported, and this study is a pioneer attempt and will be an important document for filling the gaps in uncertainties in global carbon stock assessment and also will increase knowledge on biomass variability among mangrove species and mangrove habitats. The study also highlighted the vital role of biomass carbon pool for long-term soil carbon burial. We estimated the above and below-ground biomass carbon stock of 13 mangrove species using two common allometric equations and species-specific equations and reported a very high mean total living biomass carbon stock of Kochi mangroves at 237.19 ± 113.82 Mg C ha-1, 295.78 ± 143.14 Mg C ha-1, and 272.42 ± 132.78 Mg C ha-1 according to Chave's, Komiyama equation and species-specific equation respectively corresponding to carbon dioxide equivalent (CO2e) of approximately 4,37,774.51 Mg CO2e. The biomass stock was significantly differed between the stations (p = 0.000) and also within species (p = 0.020). Among the mangrove species, Avicennia officinalis contributed highest and Bruguiera sexangula contributed least. Variation was observed for biomass stock of mangroves with large trunk diameter while comparing different allometric equations and therefore projected the need for the development of site- and species-specific equations for solving the uncertainty in global mangrove carbon stock. The study observed that dominant mangrove vegetation type, salinity and also the geomorphology of mangrove habitat had strong influence on variability in biomass stock within a small regional area. The study also suggests that understanding the structure and biomass carbon storage of each regional mangrove habitats can be wisely used in mangrove restoration and conservation programmes and in turn for nature-based solutions for climate change mitigation efforts.

Sharp decline in future productivity of tropical reforestation above 29°C mean annual temperature.

Tropical reforestation is among the most powerful tools for carbon sequestration. Yet, climate change impacts on productivity are often not accounted for when estimating its mitigation potential. Using the process-based forest growth model 3-PGmix, we analyzed future productivity of tropical reforestation in Central America. Around 29°C mean annual temperature, productivity sharply and consistently declined (-11% per 1°C of warming) across all tropical lowland climate zones and five tree species spanning a wide range of ecological characteristics. Under a high-emission scenario (SSP3-7.0), productivity of dry tropical reforestation nearly halved and tropical moist and rain forest sites showed moderate losses around 10% by the end of the century. Under SSP2-4.5, tropical moist and rain forest sites were resilient and tropical dry forest sites showed moderate losses (-17%). Increased vapor pressure deficit, caused by increasing temperatures, was the main driver of growth decline. Thus, to continue following high-emission pathways could reduce the effectiveness of reforestation as climate action tool.

The challenge of selecting an appropriate soil organic carbon simulation model: A comprehensive global review and validation assessment.

Promotion of soil organic carbon (SOC) sequestration as a potential solution to support climate change mitigation as well as more sustainable farming systems is rising steeply. As a result, voluntary carbon markets are rapidly expanding in which farmers get paid per tons of carbon dioxide sequestered. This market relies on protocols using simulation models to certify that increases in SOC stocks do indeed occur and generate tradable carbon credits. This puts tremendous pressure on SOC simulation models, which are now expected to provide the foundation for a reliable global carbon credit generation system. There exist an incredibly large number SOC simulation models which vary considerably in their applicability and sensitivity. This confronts practitioners and certificate providers with the critical challenge of selecting the models that are appropriate to the specific conditions in which they will be applied. Model validation and the context of said validation define the boundaries of applicability of the model, and are critical therefore to model selection. To date, however, guidelines for model selection are lacking. In this review, we present a comprehensive review of existing SOC models and a classification of their validation contexts. We found that most models are not validated (71%), and out of those validated, validation contexts are overall limited. Validation studies so far largely focus on the global north. Therefore, countries of the global south, the least emitting countries that are already facing the most drastic consequences of climate change, are the most poorly supported. In addition, we found a general lack of clear reporting, numerous flaws in model performance evaluation, and a poor overall coverage of land use types across countries and pedoclimatic conditions. We conclude that, to date, SOC simulation does not represent an adequate tool for globally ensuring effectiveness of SOC sequestration effort and ensuring reliable carbon crediting.

Bioenergy crop production and carbon sequestration potential under changing climate and land use: A case study in the upper River Taw catchment in southwest England.

Reductions in CO2 emissions are essential to support the UK in achieving its net zero policy objective by around mid-century. Both changing climate and land use change (LUC) offer an opportunity to deploy suitable bioenergy crops strategically to enhance energy production and C sequestration to help deliver net zero through capturing atmospheric CO2. Against this background, we applied process-based models to evaluate the extent of net primary productivity (NPP) losses/gains associated with perennial bioenergy crops and to assess their C sequestration potential under changing climate in the upper River Taw observatory catchment in southwest England. In so doing, we also determined whether LUC from permanent grassland to perennial bioenergy crops, considered in this study, can increase the production and C sequestration potential in the study area. The results show that a warming climate positively impacts the production of all crops considered (permanent grassland, Miscanthus and two cultivars of short rotation coppice (SRC) willow). Overall, Miscanthus provides higher aboveground biomass for energy compared to willow and grassland whereas the broadleaf willow cultivar 'Endurance' is best suited, among all crops considered, for C sequestration in this environment, and more so in the changing climate. In warmer lowlands, LUC from permanent grassland to Miscanthus and in cooler uplands from permanent grassland to 'Endurance', enhances NPP. Colder areas are predicted to benefit more from changing climate in terms of above and belowground biomass for both Miscanthus and willow. The study shows that the above LUC can help augment non-fossil energy production and increase C sequestration potential if C losses from land conversion do not exceed the benefits from LUC. In the wake of a changing climate, aboveground biomass for bioenergy and belowground biomass to enhance carbon sequestration can be managed by the careful selection of bioenergy crops and targeted deployment within certain climatic zones.

Estimation of biogas generation rate and carbon sequestration potential from two landfill sites in southern India.

Anaerobic digestion of organic solid waste is one of the mechanisms for sustainable development since it permits both the energy-efficient disposal of solid waste and the use of biogas. As a result, this study provides an assessment of the potential energy and emissions saved by using biogas energy generated from the biodegradation of solid waste. For present study two major cities are selected in south India namely Madurai, Tamil Nadu and Hyderabad, Telangana. The LandGEM 3.03 model is used to estimate the concentration of total landfill gases. The landfill in Madurai produced 2.162 × 106 cu. m per year of methane emissions in the year 2013. The production of biogas has increased over time would continue to increase until 2045, when a production rate of 6.32 × 107 cu. m per year was recorded as the largest concentration of biogas ever generated. For the Hyderabad landfill, methane concentrations during the year 2013 was recorded to be 2.5 × 107 cu. m per year and reached a peak in 2046 with a concentration of 3.7 × 108 cu. m per year, was found to have a potential to generate 2.1 × 106 kWh per year. For the Madurai dump site, the energy potential increases gradually and reaches a peak during the year 2047 with a value of 4.54 × 107 kWh per year. Whereas for Hyderabad dump site was found to have an energy equivalent of 2.1 × 108 kWh per year during 2024 and reaches a peak during 2046 with an energy equivalent of 5.1 × 108 kWh per year.