ABSTRACT The utilization of woody biomass plays a key role in the path towards a sustainable future for many stakeholders. To assess the climate impact of wood energy and products, it is essential to assess the impact of biogenic carbon, which has become a topic of increasing interest. The goal of this study is to build on existing approaches for the assessment of biogenic CO 2 and provide a new framework termed the Green Carbon Cycle (GCC) Approach. This new framework brings together key methods for biogenic carbon assessment into one consistent framework for practitioners of LCA to follow. The GCC Approach includes the whole life cycle of biogenic carbon from the removal from the atmosphere by forest growth, harvesting and use of wood products and fuelwood until the end of life by natural decay or combustion. It covers five steps: (1) Analysis of the biomass source and affected GCC flows, (2) formulation of use‐ and counterfactual scenario, (3) simulation or calculation of emission profiles, (4) application of dynamic LCA to calculate emission factors, and (5) implementation of emission factors in LCA. Beyond presenting this framework, its implementation compared to existing methods and generic emission factors for wood is shown. To calculate forestry based biogenic emission factors the carbon dynamics of five representative forest stands typical for Germany were simulated with different harvest intensities compared to a non‐harvest scenario. Forest residues were analyzed in contrast to a non‐use natural decay scenario. From the differences to the baseline scenarios global warming potential (GWP) bio 20 and GWP bio 100 factors were calculated. The generic emission factors show a strong impact of harvest intensity and species mix in a forest stand. With high harvest intensities leading to consistently higher emission factors and in most cases resulting in climate‐positive factors for coniferous wood and climate negative ones for deciduous species.
ABSTRACT Sustainable production of lignocellulosic biomass on marginal lands requires strategies that enhance yield while minimizing nutrient losses and supporting circular resource use. In this study, a two‐year (2023–2024) greenhouse meso‐scale experiment was conducted using Miscanthus × giganteus cultivated on nutrient‐poor soil amended with wood‐ or straw‐derived biochar (450°C) and fertilized with either mineral fertilizer (NPK) or spent coffee grounds (Cof). Biomass production and allocation, nutrient mobility in leachates, elemental composition of plant biomass and resulting phyto‐ashes, root anatomy, and plant physiological status were evaluated. Total biomass ranged from 250 to 491 g d.w. m −2 in the first growing season and reached 1495 g d.w. m −2 after two growing seasons. Biomass allocation was dominated by belowground fractions (58%–89% of total biomass), particularly in Cof‐amended plots. The highest biomass production was observed in the plot amended with straw biochar and Cof, indicating potential complementarity between biochar amendment and organic fertilization under marginal soil conditions. Some biochar‐amended plots (wood biochar + Cof) showed lower and more stable event‐based nitrogen loads in leachates, consistent with reduced nitrogen mobility. Cof‐amended plots exhibited higher chlorophyll‐related indices, while the highest TKN concentration, 9726 mg kg −1 d.w., was recorded after the second growing season, indicating differences in nitrogen availability and allocation among amendment scenarios. Root anatomical organization also varied among plots. Endpoint Fv/fm values ranged from 0.72 to 0.77 and were below the range commonly reported for non‐stressed plants, while Fm/Fo and Y(II) indicated that PSII photochemical activity was maintained. Here, we demonstrate that biochar combined with organic residues (Cof) modifies biomass partitioning and nutrient dynamics in Miscanthus × giganteus cultivated on marginal soil. In addition, the resulting phyto‐ashes were characterized by elevated K and P concentrations and low levels of potentially toxic elements, supporting their potential relevance for circular nutrient management.
ABSTRACT The catalytic hydrogenolysis of glucose to produce 1,2‐propylene glycol (1,2‐PG) has opened promising avenues for sustainable chemical production. However, traditional Ru‐based catalysts suffer from issues such as high metal loading, poor dispersion, and a tendency to agglomerate under harsh conditions, leading to rapid deactivation. This work reports a highly dispersed, low‐loading Ru catalyst supported on a magnesium–aluminum ferrite (MAFO) spinel to address these limitations. Strong covalent metal–support interactions (CMSI) between Ru species and the MAFO support not only achieve efficient stabilization of Ru nanoparticles but also promote their redispersion. Under optimized reaction conditions (518 K, 5 MPa H 2 , and 1 h), the Ru/MAFO catalyst achieves 100% glucose conversion and 59.3% selectivity to 1,2‐PG. Notably, the catalyst maintains outstanding activity and stability after six consecutive reaction cycles. This study provides an efficient and robust catalytic strategy for 1,2‐PG production from glucose, offering significant insights for designing high‐performance and stable catalysts for biomass valorization.
ABSTRACT Afforestation of former agricultural land is increasingly prioritized as a natural climate solution, yet tree establishment is inhibited by herbaceous competition, browsing pressure, limited seed dispersal, and planting costs. Short‐rotation willow (Salix spp.) crops could provide renewable biomass for multiple rotations and subsequently transition to forest by facilitating hardwood establishment through rapid canopy closure, suppression of competing vegetation, and improvement of site conditions. This potential, hardwood regeneration within nine willow fields in New York State was assessed using two sequential studies. In study 1, a rapid point‐quarter survey quantified seedling density, height, and spatial gradients relative to seed sources. In a follow‐up study, fixed‐area plots were established across these gradients to quantify seedling densities and evaluate stand, soil, and seed‐source proximity attributes. Hardwood regeneration was dominated by wind‐disseminated species, primarily Fraxinus and Acer spp., with mean densities reaching 30,000 seedlings ha−1 in some locations. Regeneration was spatially structured, declining with increasing distance from seed sources; densities typically fell below 2500 seedlings ha−1 beyond 40–75 m from forest edges. The point‐quarter method underestimated fixed‐plot densities but reliably distinguished areas of high and low regeneration. Logistic regression indicated that regeneration exceeding thresholds associated with successful forest establishment (1500 and 2500 seedlings ha−1) was positively related to proximity to seed sources and higher willow survival, whereas other soil and stand properties were not associated with seedling density. These findings suggest that short‐rotation willow systems could function as a hardwood nurse crop and integrate biomass production with afforestation.
ABSTRACT Miscanthus × giganteus (M×g) is a high‐yielding perennial C4 bioenergy crop, but genetic improvement by breeding is constrained by triploid sterility and clonal propagation. Improving genetic transformation methods for M×g would provide opportunities for advantageous trait introgression. Use of an easy to phenotype reporter gene is a promising strategy to improve transformation processes and efficiency. This study presents an efficient novel method for biolistic transformation of inflorescence‐derived callus in M×g and demonstrates its efficacy using RUBY, a betalain‐based noninvasive reporter that is visible throughout the transformation process. RUBY expression (Zea mays codon optimized) was visible from callus stage through plantlet development into maturity. RUBY expressing independently transformed plants were confirmed by hygromycin phosphotransferase ELISA and by genomic PCR demonstrating that the RUBY phenotype is sufficient for screening transformants. The Zea mays codon optimized hygromycin selection marker was driven by previously established promoters for Miscanthus, ZmUBI and 2×35S, while the RUBY gene expression was controlled by a known Zea mays C4 promoter, Brachypodium UBI10, newly employed in Miscanthus. The construct containing the 2×35S promoter for hygromycin had a 15.1% transformation efficiency while the ZmUBI promoter had a 20.5% transformation efficiency. This study provides a novel, highly efficient protocol for successful biolistic transformation of M×g for stable expression. This study also demonstrates that RUBY expression can be used as a convenient and powerful monitor of transformation in ongoing and future work to engineer M×g into an improved bioproduct feedstock.
ABSTRACT Understanding how climate change may alter species distributions is important for conservation planning and the sustainable expansion of bioenergy crops. Macaúba palms (Acrocomia aculeata, A. totai, and A. intumescens) are promising nonedible oilseed resources in Brazil, yet their future environmental suitability remains poorly quantified. Here, we developed a standardized ensemble modeling framework integrating biologically informed calibration areas, spatial block cross‐validation, and multistage covariate selection to evaluate climate‐driven shifts in the potential distribution of the three species. A key methodological feature was the generation of bioclimatic layers aligned with temporally explicit 20‐year historical windows matching occurrence records, reducing temporal mismatch between climate and biodiversity data. Models were built using climatic, edaphic, and elevation predictors, and future projections incorporated six CMIP6 global climate models under SSP2‐4.5, SSP3‐7.0, and SSP5‐8.5 for mid‐ and late‐century scenarios. All species achieved high predictive performance but differed markedly in their environmental responses and projected dynamics. Sensitivity analyses based on repeated random reductions of occurrence records showed limited variation in model performance metrics, indicating that ensemble projections were relatively insensitive to moderate occurrence‐data uncertainty. Acrocomia aculeata exhibited broad climatic and edaphic tolerance, resulting in relative stability and moderate redistribution among suitability classes. Acrocomia totai showed consistent gains in climatically suitable areas under future scenarios, suggesting potential expansion of environmentally compatible conditions. In contrast, Acrocomia intumescens, characterized by narrower environmental requirements, emerged as the most vulnerable species, with consistent losses in high and very high suitability areas, particularly under late‐century high‐emission scenarios. Together, these findings reveal contrasting climate change responses within Acrocomia, ranging from relative resilience to marked vulnerability, with direct implications for conservation, agricultural zoning, and climate adaptation strategies. Results also support A. aculeata as one of the most promising species for sustainable bioenergy production in Brazil.
ABSTRACT Bioenergy systems in the United States offer a dual opportunity to supply renewable feedstocks while enhancing ecosystem services such as hydrologic regulation, erosion control, and soil carbon (C) storage. National assessments highlight the potential to grow perennial energy crops to improve soil function and ecosystem resilience. Realizing this potential requires understanding the ecological mechanisms that govern how C is added, transformed, and stabilized in soils. Plant traits determine the quantity, depth, and chemistry of organic inputs, while microbial processes—including carbon use efficiency, necromass formation, and trophic interactions—mediate their transformation and partitioning among soil carbon pools. These biological pathways are shaped by soil physical and chemical properties, including aggregation, texture, and mineralogy, and by environmental drivers such as temperature, moisture, and disturbance, leading to context‐dependent outcomes across landscapes. Management practices that diversify feedstocks, minimize disturbance, and maintain soil cover can promote both biomass production and C retention, while microbial amendments and rhizosphere engineering offer emerging, but often context‐dependent, tools to optimize plant–microbe interactions. Trade‐offs between biomass yield and soil carbon storage may arise when systems favor rapid aboveground productivity at the expense of belowground inputs and microbial processing, underscoring the importance of trait combinations that support both functions. Advances in monitoring, reporting, and verification—spanning precision agriculture, remote sensing, and biosensing—are improving predictive capacity through microbial‐explicit process models and model–experiment (ModEx) frameworks. By connecting soil, plant, and microbial processes with advances in modeling and biosensing, this review outlines research priorities focused on trait‐based parameterization and ModEx integration. These priorities will support the design of bioenergy systems that are both reliable and resilient, enhancing renewable energy production and ecosystem sustainability.
ABSTRACT Low nitrogen‐use efficiency (NUE) and excessive application of nitrogen fertilizers pose serious threats to sustainable agriculture, causing severe soil fertility depletion, environmental degradation, and economic losses. Biochar‐based nitrogen fertilizers (BBNFs) offer a promising strategy to enhance NUE through controlled nutrient release and improved soil quality. However, the effect of BBNFs on lady's finger (Abelmoschus esculentus L.) production is still limited. Therefore, this study was conducted to evaluate the effects of BBNFs on the growth, yield, and nutritional quality of lady's finger. Seven treatments were employed, including conventional urea, biochar‐mixed urea (BMU), and biochar‐coated urea (BCU). Results demonstrated that BCU (T7) significantly (p ≤ 0.05) outperformed all other treatments, producing the highest number of leaves, leaf area, plant height, photosynthetic rate, biomass accumulation, and pod yield (13.62 t ha−1), representing a 65.9% increase over conventional urea. BCU also achieved the greatest agronomic nitrogen‐use efficiency (24.27 g g−1), harvest index (55.41%), and cost‐income ratio (2.63). Nutritional quality traits, including TSS, ascorbic acid, total flavonoids, protein, etc., were also significantly enhanced under BCU. The findings highlight the potential of BCU as a sustainable fertilizer management strategy that improves yield, fruit quality, and economic returns in lady's finger, while providing actionable approaches to enhance NUE and mitigate environmental degradation.
ABSTRACT Understanding how agroecosystems respond to environmental variability is fundamental to predicting productivity and sustainability under a changing climate. We analyzed 55 site‐years of high‐frequency eddy covariance observations from five agroecosystems—two perennial grasses (miscanthus and switchgrass), two annual rotation systems (maize–soybean and sorghum–soybean), and a restored native prairie—to examine ecosystem‐scale carbon, water, and energy fluxes. Using an interpretable machine‐learning framework with regression tree ensembles, Shapley Additive Explanations, and Accumulated Local Effects, we quantified how environmental and temporal factors regulate gross primary productivity (GPP), evapotranspiration (ET), water‐use efficiency, and the Bowen ratio. Perennials exhibited stronger physiological buffering and maintained fluxes across a broader range of temperature and moisture conditions, reflecting deeper rooting and persistent canopy cover. Annuals, in contrast, showed greater short‐term variability and stronger coupling to atmospheric demand, with GPP and ET declining rapidly under low humidity or soil moisture. Differences in temperature sensitivity of Bowen ratio further revealed that perennials sustained proportionally greater sensible heat flux under cool conditions, whereas annuals exhibited constrained energy exchange when evaporative demand was low. Together, these results demonstrate that crop life cycle and canopy structure are fundamental determinants of ecosystem‐scale carbon–water–energy coupling. By integrating long‐term flux observations with interpretable machine learning, this study identifies the environmental drivers that shape agroecosystem function and highlights how conversion from annual to perennial feedstocks can enhance climatic resilience and alter land–atmosphere energy feedbacks. These findings provide a data‐driven basis for improving crop and Earth‐system models and for guiding bioenergy landscape design under future climate scenarios.
ABSTRACT Excessive nitrogen (N) inputs in warm and wet sugarcane cropping systems lead to substantial ammonia (NH3) volatilization, nitrous oxide (N2O) emission, nitrate (NO3−) leaching, and dissolved inorganic N (DIN) runoff, posing risks to air quality, aquatic ecosystems, and climate forcing. A global, integrative understanding of the drivers of these loss pathways and the effectiveness of management practices is required to balance sugarcane productivity with reductions in environmental N pollution across diverse sugarcane regions. Here we synthesized data from global sugarcane experiments to derive region‐specific emission factors (EFs) for multiple N loss pathways and to identify key biophysical and management controls on N losses, crop yield, and their trade‐offs. Brazil showed the highest NH3 volatilization EF (7.4%); Australia the highest N2O emission EF (2.6%); and Brazil the highest NO3− leaching EF (8.9%), highlighting strong regional contrasts in N loss dynamics. Across regions, N application rate and cane trash retention were major regulators of NH3 volatilization, with surface trash retention overriding soil pH and clay effects. N2O emissions increased with high N inputs and carbon availability, but were negatively associated with water inputs, suggesting enhanced complete denitrification under wetter conditions. High N and water inputs increased DIN runoff. Increasing N input enhanced sugarcane yield but also amplified all major N loss pathways. Cane trash retention increased yield but raised NH3 and N2O losses, whereas adding carbon‐rich sugar mill by‐products reduced NH3 but increased N2O emissions. Urease and nitrification inhibitors effectively reduced NH3 and N2O losses, respectively, while controlled‐release fertilizers showed inconsistent impacts. Scenario‐based modelling demonstrates trade‐offs between N loss reduction and productivity, with urease and nitrification inhibitors substantially reducing N losses without compromising yield, outperforming strategies based solely on N rate reduction or cane trash removal. These findings together inform sustainable N management strategies that mitigate environmental impacts while maintaining sugarcane productivity.
Fatty acid esters were produced by phototransesterification of canola oil using TiO2 as a photocatalyst and employing either UVA or sunlight as radiation sources. Conversions of approximately 73% (+/- 1.41) and 19% to fatty acid methyl esters (FAME) were achieved with methanol (1 TGL [triglyceride] mol:55 MeOH mol, 20% TiO2 w catalyst/w TGL, 65 degrees C, 4 h). In contrast, ethanol resulted in a lower conversion rate of 38%. Conventional thermal methods employing acid and alkali catalysts were employed to compare their corresponding FAME contents to those generated through photocatalysis. The kinetic curves were established for temperature ranges of 25 degrees C-65 degrees C. This study evaluated six kinetic mathematical models, among which the second forward/fourth backward model exhibited the greatest accuracy (R 2 of 0.996). This indicates that a homogeneous system model can be applied to a heterogeneous process, given that the mass transfer to the active sites of the solid catalyst is not the rate-limiting factor. The thermodynamic data (Delta G 328.15K = 29.98 kJ/mol, Delta G 338.15K = -6.88 kJ/mol, Delta H = 83.00 kJ/mol and Delta S = 0.27 kJ/mol K) suggest that this endothermic reaction requires temperatures of approximately 65 degrees C to reach substantial conversion rates. These findings support the development of sustainable, low-waste biodiesel production pathways aligned with global decarbonisation goals.
ABSTRACT Maize is a major biofuel feedstock, accounting for 64% of the global share of ethanol production. Recent improvements in life cycle analyses (LCAs) have accounted for temporal changes in the improved efficiency of farming practices, with reductions in the carbon intensity (CI) of maize grain production over time. There has been little progress on understanding the spatial variation of the CI of maize grain production. The average life cycle CI of US maize production at the farm gate converts to a contribution of 251 g CO2e/kg of maize produced, used in policy calculations related to biofuel production. The objective of this work was to understand the spatial variation in CI scores using Illinois, USA as a case study to conduct life cycle analysis for modeling county‐level CI score. The average CI score of maize produced in Illinois has a range of 9%–12% lower than the national average CI when averaged across the state using county‐level yield and fertilizer application data. Maize grown within 56 km of ethanol facilities in Illinois has scores 14%–17% lower than the national average, when adjusted for ethanol output. This is mainly due to the high yields in Illinois and more efficient use of fertilizer across counties delivering to ethanol plants. There was spatial variation in the impact of cover crop seeding and conservation tillage across a transect of counties. Further refinement of life cycle models will provide more accurate assessments of the carbon intensity of maize production at smaller spatial scales than national averages.
ABSTRACT Perennial energy crops (PECs) are increasingly being recommended for cultivation on marginal lands to support the bioeconomy and promote soil restoration, owing to their low input requirements and large potential for soil organic carbon sequestration. However, the effects of the cultivation of PECs on the trade‐offs or synergies among soil functions, and consequently on ecosystem multifunctionality (EMF), remain unclear, hindering large‐scale adoption. We conducted our measurements in a long‐term field experiment that was established a decade ago, where Miscanthus and switchgrass were cultivated alongside a native C3 grass mixture (Cyperus rotundus L. and Setaria viridis L.) as reference to assess the effects of PECs on soil multifunctionality. We assessed 10 ecosystem functions grouped into provisioning, supporting, and regulating services. The results demonstrate that Miscanthus and switchgrass cultivation elevated the overall EMF by an average of 5.29‐fold over the C3 native grass control, with supporting, regulating, and provisioning services increasing by 2.08, 7.27, and 43.98‐fold, respectively. Specifically, the two PECs improved all 10 measured soil functions, with the exception of abiotic stress regulation under switchgrass cultivation. Miscanthus outperformed switchgrass by 41.54% in supporting services and 81.09% in provisioning services, resulting in higher EMF. Moreover, strong positive relationships were observed among the three service categories, indicating that the cultivation of PECs improves EMF consistently without significant trade‐offs. These findings suggest that cultivating PECs on marginal land can simultaneously provide sustainable biomass feedstock and enhance soil health, supporting the feasibility for larger‐scale deployment.
ABSTRACT This study investigates the effects of biochar and sediment amendments, particularly Mn‐modified biochar (Mn‐BC), on soil nutrient dynamics, microbial activity, and nitrogen (N) mineralization. Sediments were collected from a fishpond in San Jiang, Hainan Province, and biochar was produced from bamboo and modified with manganese (Mn) to enhance its properties. A 90‐day incubation experiment was conducted with six treatments: control (T1), sediment alone (T2), soil with 10% sediment (T3), soil with 3% biochar (T4), sediment with 3% biochar (T5), and soil with 10% sediment and 3% biochar (T6). Results showed that biochar and sediment amendments significantly increased soil pH, organic carbon content (SOC), and microbial biomass carbon (SMBC) and nitrogen (SMBN) with T6 exhibiting the highest increases in pH (9.51) and SOC (7.82 g kg−1), compared to the control (5.51 pH and 5.58 g kg−1 SOC). SMBC and SMBN were also significantly higher in T6, with increases of 37.32% and 76.11%, respectively. Additionally, N‐acquiring enzyme activities, particularly N‐acetylglucosaminidase (NAG) and leucine aminopeptidase (LAP), were enhanced in the biochar‐sediment treated soils, with T6 showing a remarkable increase compared to the control. N mineralization was significantly improved by the amendments, with T6 showing a 60.84% increase in total mineralized nitrogen. The N mineralization potential (No) in T6 was 61.87 mg kg−1, compared to 39.20 mg kg−1 in the control, and the mineralization rate constant (k) was highest in T6 (0.22 d−1). These results highlight the potential of Mn‐modified biochar and sediment as sustainable soil amendments that improve soil fertility, microbial activity, nitrogen cycling, and overall soil health in agricultural systems.
Urban green roofs are increasingly deployed for stormwater and microclimate regulation, yet their contribution to non-CO2 greenhouse-gas exchange remains poorly understood, particularly for vegetation. We quantified foliar methane (CH4) and nitrous oxide (N2O) fluxes in a factorial field experiment involving two vegetation types and biochar amendments at the University of Toronto (Toronto, Canada). Daytime foliar fluxes of CH4, CO2, and H2O were measured with dynamic leaf chambers coupled to off-axis integrated cavity output spectroscopy, and foliar N2O with optical feedback cavity-enhanced absorption spectroscopy, across four seasonal campaigns (fall 2023 to fall 2024). Across plant types and seasons, biochar (20 t ha(-1); 5.4% v/v) increased foliar CH4 uptake approximately threefold relative to controls (-0.492 +/- 0.046 vs. -0.167 +/- 0.022 nmol.m(-2).s(-1); p < 0.001) and reduced foliar N2O emissions (1.11 +/- 0.043 vs. 1.50 +/- 0.039 pmol.m(-2).s(-1); p < 0.001), while foliar CO2 flux was unaffected (p = 0.29). Native vegetation exhibited stronger CH4 uptake than stonecrop under both control and biochar treatments and higher CO2 uptake and H2O flux overall. Soil-foliar coupling differed by gas: foliar N2O was strongly associated with soil N2O flux (R-2 = 0.252-0.427; p < 0.001), whereas foliar CH4 relationships with leaf H2O and soil CH4 fluxes were weaker and vegetation dependent. A single nocturnal campaign in stonecrop showed no CO2 uptake and minimal transpiration, with no treatment effects on nighttime CH4 or N2O fluxes. City-scale extrapolation suggests that biochar use could increase net foliar non-CO2 climate mitigation by similar to 270% relative to control conditions, driven by both enhanced CH4 uptake and reduced N2O emissions.
ABSTRACT In this study, the biogas potential of source‐separated cow urine (CU) was evaluated through anaerobic co‐digestion with waste paper (WP) under mesophilic conditions (37°C ± 1°C) in batch mode. Anaerobic digestion performance was assessed in terms of biogas‐biomethane yields, total (TS) and volatile solids (VS) removal, pH, volatile fatty acids (VFA), soluble chemical oxygen demand (sCOD), and carbon‐to‐nitrogen (C/N) ratios and compared with WP mono‐digestion. Five different blends were prepared in duplicate with an inoculum‐to‐substrate ratio of 1:1. The proportions were: 100% WP (CU0 control), 90% WP + 10% CU (CU10), 80% WP + 20% CU (CU20), 70% WP + 30% CU (CU30), and 50% WP + 50% CU (CU50) operated over a 66‐day hydraulic retention time. The CU50 bioreactor showed the highest efficiency, achieving 86% TS and 87% VS removal, and yielding 92.5% and 150% higher biogas and biomethane yields, respectively, compared with the control. The pH values and VFA concentrations of the bioreactors ranged from 5.395 to 7.83 and 1615.46 to 7280.02 mg L−1, respectively. Effluent sCOD values in CU30, CU20, CU10, and CU0 increased by 80.05, 111.07, 154.41, and 293.94 mg sCOD g−1 VS, respectively, relative to influent values, whereas CU50 achieved 47.2 mg sCOD g−1 VS removal. Comparison of C/N ratios showed a 14.35% decrease in the control, whereas CU50 achieved an optimal C/N ratio of 25.1312, facilitating biogas production. Co‐digesting source‐separated cow urine with waste office paper effectively enhanced biogas production.
ABSTRACT Switching from high‐emitting fossil fuel to lower‐emitting biomass fuels is one approach to help to lower greenhouse gas (GHG) emissions. Most remote communities in Canada are primely positioned to take advantage of fuel switching for space heating as they are closer to sustainable biomass resources than urban areas. Furthermore, bioheat in remote communities can improve both environmental and socio‐economic outcomes by allowing communities to gain energy independence and security when using local renewable resources. This study examines the GHG emissions reduction potential of substituting fossil fuels with woody residues to produce heat in remote communities in northeastern Ontario, Canada. We examined both hydronic and electric heat using forest harvest and sawmill residues as biomass fuel types. We found the largest emission reductions in the electric bioheat scenarios, with the scenario using forest harvest residues that would have otherwise been burned showing the greatest emissions reduction potential (−256.32 gCO2eq·MJheat−1 by 2124). Biomass fuel type rankings for all scenarios, regardless of heating system or fossil fuel substitution, are: forest harvest residues from burn slash piles > forest harvest residues from decay slash piles > sawmill residues. All scenarios were carbon neutral in the first year of bioheat production and remained so for the 100‐year study period. While our study showed the environmental benefit of fuel switching, social, economic, and operational risks of a project such as this should not be overlooked.
ABSTRACT Methane accounts for more than 20% of current anthropogenic warming. While fossil methane emissions can likely be reduced substantially, biogenic methane from agriculture and waste will remain difficult to fully abate. Achieving climate neutrality therefore requires counterbalancing the warming effect of residual emissions. The rapid atmospheric decay of methane suggests that temporary carbon sinks can serve this purpose, yet current accounting approaches do not consistently quantify their time‐dependent cooling effect. Here we develop a time‐explicit method that enables offsetting the 100‐year warming impact of a methane emission pulse with an equally sized cooling effect delivered by carbon dioxide removal over 20 years. Based on a CO2 atmospheric impulse–response function (IRF), we define the total climate effect (TCE) as time‐integrated warming and cooling of greenhouse gas emissions and dynamic carbon sinks expressed in CO2‐equivalent units. The developed method yields the amount of CO2 removal and storage duration over a chosen time horizon to counterbalance methane‐induced warming. For example, over a 20‐year horizon, complete offsetting of 1 t CH4 of biogenic origin requires 94.6 t CO2e stored in a constant C‐sink. The method allows differentiation between temporary and geologically persistent carbon dioxide removal by explicitly accounting for storage duration and time horizon. By providing a physically grounded basis for valuing temporary carbon storage—a question actively debated in the EU Carbon Removals and Carbon Farming Regulation and Article 6.4 of the Paris Agreement—the approach supports near‐term climate mitigation and may bridge the decades required for scaling permanent CDR solutions by creating financial incentives for temporary carbon sink technologies.
Camelina (Camelina sativa (L.) Crantz) is an underutilized oilseed crop proposed as low-input feedstock for biofuel production, such as sustainable aviation fuel, under Mediterranean climate. However, its productivity is lower than that of more commonly used biofuel crops. Among agronomic techniques, sulfur fertilization is an underrated practice that can positively affect crop seed yield. This study evaluated the agronomic and environmental performance of camelina under different sulfur fertilization strategies, using industrial gypsum as a recycled S source. Field trials were conducted in central Italy over two consecutive growing seasons (2023-2024), evaluating five N-S combinations on spring-sown camelina. Agronomic performance, seed quality, and Life Cycle Assessment (LCA) of camelina subjected to different fertilization strategies were evaluated. The combined application of 60 kg N ha-1 with 40 kg S ha-1 significantly increased seed (+39%) and straw (+33%) yields compared to N-only fertilization. Sulfur improved the agronomic efficiency of nitrogen fertilization by 78%, without negatively affecting seed quality (glucosinolates, oil and protein content). LCA revealed that the use of sulfur fertilizers reduced camelina's environmental impact compared to the typical fertilization strategy. This is mainly due to the reduction in land required to produce 1 Mg of seeds and to the process associated with land management (primarily tillage and N fertilizers). However, modeling choices such as the inclusion of indirect land use change can significantly affect the output assessment. Overall, moderate S fertilization optimized both productivity and environmental impact, supporting camelina's role as a promising alternative to be introduced in Mediterranean traditional cropping systems.
Phytoremediation of saline-alkali soils has emerged as a key strategy to boost agricultural output and mitigate food security challenges. Identifying plants for biomass production and soil recovery is vital for marginal land sustainability, and perennial switchgrass (Panicum virgatum L.) is preferred for its broad adaptability, stress tolerance, high yield and good quality. In this study, we evaluated switchgrass biomass allocation and its effects on soil physicochemical properties and soil microbial community structure in severely saline-alkali coastal soil over a three-year period. The results showed that after 3 years of cultivation, switchgrass above- and below-ground biomass increased from 1.86 to 12.64 t ha-1 and 0.08 to 7.17 t ha-1, respectively. These plant responses were tightly coupled with rapid soil improvement, including a 2.54-fold increase in large water-stable aggregates (0.25-2 mm), a 95.7% reduction in water-soluble Na+, a 4.69% reduction in soil pH and a 21.32-fold reduction in electrical conductivity. Soil fertility was concurrently enhanced, as indicated by increased soil organic matter content and cation exchange capacity. Microbial community analyses revealed pronounced domain-specific response strategies. Bacterial communities maintained a stable core structure while undergoing functional reorganization toward enhanced organic matter decomposition and nutrient cycling. In contrast, archaeal and fungi communities exhibited stronger niche-driven turnover, including a shift from methanogenesis toward potential nitrification in archaea and increased abundance of arbuscular mycorrhizal and saprotrophic fungi. These microbial responses were strongly regulated by shifts in key soil environmental factors, including reduced salinity and pH (electrical conductivity and total water-soluble salts) and increased soil organic matter and cation exchange capacity. Overall, switchgrass cultivation triggered a coupled plant-soil-microbe feedback that sustained biomass production and accelerated the recovery of saline-alkali soils, highlighting its potential for bioenergy production and ecological restoration in coastal saline-alkali regions.
