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Soil erosion and soil organic carbon (SOC) loss are not always linked linearly because SOC‐rich topsoil is eroded at the initial stages of degradation, while horizons with lower SOC content are eroded later, but often at higher rates. Small, silted‐up farm reservoirs potentially document this change during the period of sediment accumulation. This study tests the specific potential of small farm reservoir sediments from the South African Karoo to reconstruct 20th century SOC and total nitrogen (TN) change in rangeland soils. Five reservoir sediment profiles were sampled and texture, total organic carbon (TOC), TN and 137Cs of the samples were analyzed and compared. The results show that there clearly distinguishable flood couplets have been preserved in the sediment, illustrating their suitability for the chronological reconstruction of soil erosion and SOC. With one exception, the older sediments contain more TOC and TN than the younger ones. The TOC changed mostly in earlier than later stages of deposition, which is indicative of soil degradation early after the construction of the dams in the 1920s and 1930s. These distinct changes illustrate that the small reservoir sediments have the potential to reconstruct the impact of land‐use and associated soil erosion on SOC change in rangelands. Their analysis can therefore contribute to a better understanding of the land‐use associated changes of the global carbon cycle during the 20th century. [ABSTRACT FROM AUTHOR]

Monitoring the changes of ecosystem functioning is pivotal for understanding the global carbon cycle. Despite its size and contribution to the global carbon cycle, Africa is largely understudied in regard to ongoing changes of its ecosystem functioning and their responses to climate change. One of the reasons is the lack of long‐term in situ data. Here, we use eddy covariance to quantify the net ecosystem exchange (NEE) and its components—gross primary production (GPP) and ecosystem respiration (Reco) for years 2010–2022 for a Sahelian semiarid savanna to study trends in the fluxes. Significant negative trends were found for NEE (12.7 ± 2.8 g C m2 year−1), GPP (39.6 ± 7.9 g C m2 year−1), and Reco (32.2 ± 8.9 g C m2 year−1). We found that NEE decreased by 60% over the study period, and this decrease was mainly caused by stronger negative trends in rainy season GPP than in Reco. Additionally, we observed strong increasing trends in vapor pressure deficit, but no trends in rainfall or soil water content. Thus, a proposed explanation for the decrease in carbon sink strength is increasing atmospheric dryness. The warming climate in the Sahel, coupled with increasing evaporative demand, may thus lead to decreased GPP levels across this biome, and lowering its CO2 sequestration. [ABSTRACT FROM AUTHOR]

The Kashmir Himalayas, a region of immense ecological importance, have experienced profound degradation due to land use changes, raising concerns about sustainability. This degradation has significant global implications, including carbon loss, soil quality deterioration, habitat destruction, and loss of biodiversity. This study investigates various key land uses, including economically vital cash crops such as apples and saffron, the socially significant staple food crop rice, as well as forest and pasture systems. The findings reveal that forests and pastures maintain significantly better physical, chemical, microbial, and enzymes activities, and exhibit greater soil nutrient reserves and soil organic carbon (SOC) pools. Specifically, forest soils contain 20.21%, 28.22%, and 34.49% higher total organic carbon (TOC) stocks compared to apple, saffron, and paddy-oilseed soils, respectively. A soil quality index (SQI) was computed using principal component analysis (PCA) based on over 30 soil indicators, including soil nutrients, carbon pools, and various physical, chemical, and biological properties. The SQI ranking is as follows: forest (1) > pasture (0.87) > apple (0.80) > saffron (0.67) > paddyoilseed (0.53). This ranking suggests that the conversion of natural ecosystems to cultivation negatively impacts soil nutrient reserves, microbiome diversity, SOC stocks, and overall soil quality. The land use changes in the Kashmir Himalayas result from a complex interplay of natural forces, demographic shifts, and economic pressures. This research provides valuable insights into comparative soil quality under economically and socially relevant crops based on diverse soil properties. The findings can guide land use planning in Kashmir Himalayas and similar regions beyond geographical boundaries, aiming to preserve the ecologically fragile environment, ensure food security, bolster the economy, and promote long-term sustainability in the face of a changing climate. The significance of this study lies in its relevance to similar regions grappling with land use changes, making its findings pertinent to the global scientific community and holding promise for the development of sustainable practices and policies worldwide. [ABSTRACT FROM AUTHOR]

The Amazon forest contains globally important carbon stocks, but in recent years, atmospheric measurements suggest that it has been releasing more carbon than it has absorbed because of deforestation and forest degradation. Accurately attributing the sources of carbon loss to forest degradation and natural disturbances remains a challenge because of the difficulty of classifying disturbances and simultaneously estimating carbon changes. We used a unique, randomized, repeated, very high-resolution airborne laser scanning survey to provide a direct, detailed, and high-resolution partitioning of aboveground carbon gains and losses in the Brazilian Arc of Deforestation. Our analysis revealed that disturbances directly attributed to human activity impacted 4.2% of the survey area while windthrows and other disturbances affected 2.7% and 14.7%, respectively. Extrapolating the lidar-based statistics to the study area (544,300 km²), we found that 24.1, 24.2, and 14.5 Tg C y-1 were lost through clearing, fires, and logging, respectively. The losses due to large windthrows (21.5 Tg C y-1) and other disturbances (50.3 Tg C y-1) were partially counterbalanced by forest growth (44.1 Tg C y-1). Our high-resolution estimates demonstrated a greater loss of carbon through forest degradation than through deforestation and a net loss of carbon of 90.5 ± 16.6 Tg C y-1 for the study region attributable to both anthropogenic and natural processes. This study highlights the role of forest degradation in the carbon balance for this critical region in the Earth system. [ABSTRACT FROM AUTHOR]

Ecosystem level carbon loss and the resultant loss of CO2 mitigating capacity of rubber (Hevea brasiliensis) plantations of 23 and 30 years in a hilly urbanized terrain dominated by development and construction activities was investigated. The total carbon loss of the rubber ecosystem due to the destruction of a surface area of 10, 25, and 50 hectares of rubber plantation was derived from published data of destructive tree felling based on the biomass and carbon sequestration potential of one hectare of rubber plantation. The popularly cultivated clone RRII 105 since 1980 occupying 85% of the total rubber area in India was chosen for the study. The data was analyzed using ANOVA and Standard Error (SE) Means for the base data and extrapolated to ecosystem-level calculation. Results revealed a total ecosystem carbon loss of 2142, 5355, 10710 tons for 23 years and 3415, 8538, 17075 tons for 30 years under deforested area of 10, 25, and 50 hectares, respectively. The carbon loss (tons) from tree biomass (tons) removal was 570, 1425, 2850, litter fall was 575, 1438, 2875 and sheet rubber was 432, 1080, 2160 for 23 year plantation. In 30 years plantation, carbon loss from tree biomass was 1480, 3700, 740, litter fall was 750, 1875, 3750, and sheet rubber was 621, 1553, 3105 tons. Total soil carbon stock loss (tons) was 565, 1413 and 2825 for both 23 and 30 years, since the soil carbon stock was calculated similarly with one value for both plantation years. Other studied clones such as RRII 414, RRII 429, and RRII 417 recorded 44-50 percent higher carbon loss compared to RRII 105. The highest carbon loss was recorded in the central part and lowest in the area with severe drought. The study clearly depicts the importance of rubber plantations in mitigating climate change due to massive removal of rubber plantations, an important economically and environmentally sustainable agro ecosystem. The study recommends for putting in place appropriate policies and regulations to restrict the removal of economic tree plantations for ecosystem sustainability. [ABSTRACT FROM AUTHOR]

Forestation is a common measure to control erosion-induced soil and carbon (C) loss, but the effect can vary substantially between different types of forest. Here, we measured event-based runoff, soil, dissolved organic carbon (DOC), particulate organic carbon (POC) and total C loss with runoff plots (20 m × 5 m) in a broad-leaved and a coniferous forest in subtropical China and explored their relationships with rainfall amount, average intensity, maximum 5-min intensity and rainfall erosivity. The broad-leaved forest had a denser canopy but sparse understory vegetation while the coniferous forest had a relatively open canopy but dense understory vegetation. The results showed that runoff, soil, DOC, POC and total C losses were all significantly higher in the broad-leaved forest than the coniferous forest despite the potentially higher canopy interception associated with the greater leaf area index of the broad-leaved forest. The mean runoff in the broad-leaved forest was 3.03 ± 0.20 m3 ha−1 event−1 (mean ± standard error) and 12.49 ± 0.18 m3 ha−1 event−1 in the coniferous forest. The mean soil, DOC, POC and total C loss (kg ha−1 event−1) was 1.12 ± 0.16, 0.045 ± 0.003, 0.118 ± 0.016 and 0.163 ± 0.017, respectively, in the broad-leaved forest and 0.66 ± 0.09, 0.020 ± 0.002, 0.060 ± 0.009 and 0.081 ± 0.010, respectively, in the coniferous forest. Runoff and DOC losses were driven by rainfall in two forests, but the key rainfall characteristic driving soil, POC and total C losses was different in the broad-leaved forest from that in the coniferous forest due to their different understory patterns. Soil, POC and total C losses were mostly driven by rainfall amount in the broad-leaved forest but by EI30 in the conifer forest. Our findings highlight that the response of erosion-induced carbon loss to rainfall characteristics differs between different forest types of the same age but contrasting overstory and understory vegetation covers. Moreover, our study underscores the overlooked significance of understory vegetation in regulating these effects. Thus, we call for the inclusion of understory vegetation in the modeling of soil and carbon erosion in forest ecosystems. [ABSTRACT FROM AUTHOR]

Unprecedented seasonal forest fires pose a significant threat to the carbon stocks of diverse ecosystems, particularly in regions like Uttarakhand, west Himalaya. Understanding the impact of varying fire frequencies on different forest types is crucial for effective conservation and management strategies. This study aims to assess the loss of carbon stock in three distinct forest types—Sal, Pine, and Mixed across an elevation gradient in Uttarakhand, facing unprecedented seasonal forest fires. By investigating pre- and post-fire conditions, analyzing biomass dynamics, and mapping fire frequencies, the research aims to provide insights into the complex interplay of fire regimes and forest resilience. The investigation covers vegetation analysis, biomass assessment, and fire frequency mapping. Biomass and carbon stock calculations were carried out using a non-destructive sampling method. Fire frequency maps were generated using Landsat satellite imagery spanning a decade, integrating MODIS hotspot data for classification. The study reveals distinct patterns in biomass changes across Sal, Pine, and Mixed forests in response to varying fire frequencies. Sal forests exhibit resilience to low-intensity fires, while Pine forests show higher sensitivity. Carbon stock contributions of dominant species varied significantly, with Sal and Chir-Pine forests emerging as crucial contributors. High fire frequencies lead to substantial carbon stock reduction in all forest types. The findings emphasize the sensitivity of aboveground biomass to fire frequency, with significant carbon stock loss observed in higher fire frequency classes. The study underscores the importance of nuanced conservation strategies tailored to distinct forest types and species characteristics. This research provides valuable insights for policymakers, forest managers, and conservationists in formulating targeted conservation and management approaches. [ABSTRACT FROM AUTHOR]

Enhanced weathering (EW) has garnered increasing interest as a promising technique for durable carbon dioxide removal, with a range of potential co-benefits including increased soil pH and nutrient availability. However, the potential loss of initially captured CO _2 during river transport remains poorly constrained, undermining the use of this practice as a carbon mitigation strategy. Here, we present results from a first-of-its-kind dynamic river network (DRN) model designed to quantify the impact of EW on river carbonate chemistry in North American watersheds. We map key water quality parameters using machine learning and use a DRN model to simulate changes in carbon degassing during EW. Our model predicts low carbon loss (15%) carbon degassing is also observed, indicating that riverine carbon storage and the impacts of EW on river chemistry must be evaluated in a deployment-specific or regional context.

Harmful algal blooms in eutrophic lakes pose significant challenges to the aquatic environment. Aerobic composting is an effectively method for processing and reusing dewatered algal sludge. The fungal communities are the main driver of composting. However, their relationship with carbon loss and the humification process during algal sludge composting remains unclear. In this study, the succession of fungal communities in algal sludge composting was investigated via internal transcribed spacer (ITS) rRNA amplicon sequencing analysis. Overall, no significant differences were observed with the α-diversity of fungal communities at different stages. The composition of the fungal communities changed significantly before and after compost maturation and became more stable after the compost maturation. Redundancy analysis showed that the fungal communities were significantly correlated with physicochemical properties, including humic acid (HA)/fulvic acid (FA), temperature, pH, humic acid, microcystins, and CO2. The co-occurrence network showed that different fungal community modules had different relationships with physicochemical properties. Structural equation modeling further revealed that different metabolic or transformation processes may be mainly driven by different fungi modules. The microcystin degradation, carbon loss, and humification during composting were mainly mediated by fungal communities which were mainly influenced by temperature. Humification was influenced not only by fungal communities but also by the microcystin levels. These results show that changes in the fungal community composition and interaction and their relationship with physicochemical properties could represent a useful guide for optimizing the composting process. [ABSTRACT FROM AUTHOR]

Drainage is known to reduce carbon sequestration in peatlands, but its effect on the stability of carbon pool and changes in recalcitrant organic carbon fractions remain relatively unknown, especially in temperate montane peatlands. We investigated the effect of drainage on physicochemical properties and organic carbon fractions of six peat cores from drained and near-pristine areas of Baijianghe peatland, NE China, basing on 210Pb and AMS 14C dating. The vegetation biomass and biomass-C sequestration were also measured in both areas. The loss of total soil carbon accumulation due to drainage was 7.5 kg m−2 (− 25%), equivalent to a complete consumption of carbon accumulated for nearly 170 years in the near-pristine area. Vegetation succession after drainage had a little positive effect on ecosystem carbon sequestration, with an increase of 0.26 kg m−2, which compensated for only 3.5% of the peat soil carbon loss. Notably, over 80% of the total carbon loss after drainage was attributed to the loss of the recalcitrant carbon fraction. The study emphasizes the crucial impact of drainage on carbon sequestration in temperate peatlands. Our findings suggest that continuous water table drawdown induced by drainage, together with drought driven by climate warming, will further reduce carbon sequestration in drained peatlands. There is an urgent need to restore hydrology of peatlands in order to mitigate the long-lasting negative effect of drainage. [ABSTRACT FROM AUTHOR]

Unprecedented seasonal forest fires pose a significant threat to the carbon stocks of diverse ecosystems, particularly in regions like Uttarakhand, west Himalaya. Understanding the impact of varying fire frequencies on different forest types is crucial for effective conservation and management strategies. This study aims to assess the loss of carbon stock in three distinct forest types—Sal, Pine, and Mixed across an elevation gradient in Uttarakhand, facing unprecedented seasonal forest fires. By investigating pre- and post-fire conditions, analyzing biomass dynamics, and mapping fire frequencies, the research aims to provide insights into the complex interplay of fire regimes and forest resilience. The investigation covers vegetation analysis, biomass assessment, and fire frequency mapping. Biomass and carbon stock calculations were carried out using a non-destructive sampling method. Fire frequency maps were generated using Landsat satellite imagery spanning a decade, integrating MODIS hotspot data for classification. The study reveals distinct patterns in biomass changes across Sal, Pine, and Mixed forests in response to varying fire frequencies. Sal forests exhibit resilience to low-intensity fires, while Pine forests show higher sensitivity. Carbon stock contributions of dominant species varied significantly, with Sal and Chir-Pine forests emerging as crucial contributors. High fire frequencies lead to substantial carbon stock reduction in all forest types. The findings emphasize the sensitivity of aboveground biomass to fire frequency, with significant carbon stock loss observed in higher fire frequency classes. The study underscores the importance of nuanced conservation strategies tailored to distinct forest types and species characteristics. This research provides valuable insights for policymakers, forest managers, and conservationists in formulating targeted conservation and management approaches.

Soil organic carbon (SOC) plays an essential role in mediating community structure and metabolic activities of belowground biota. Unraveling the evolution of belowground communities and their feedback mechanisms on SOC dynamics helps embed the ecology of soil microbiome into carbon cycling, which serves to improve biodiversity conservation and carbon management strategy under global change. Here, croplands with a SOC gradient were used to understand how belowground metabolisms and SOC decomposition were linked to the diversity, composition, and co‐occurrence networks of belowground communities encompassing archaea, bacteria, fungi, protists, and invertebrates. As SOC decreased, the diversity of prokaryotes and eukaryotes also decreased, but their network complexity showed contrasting patterns: prokaryotes increased due to intensified niche overlap, while that of eukaryotes decreased possibly because of greater dispersal limitation owing to the breakdown of macroaggregates. Despite the decrease in biodiversity and SOC stocks, the belowground metabolic capacity was enhanced as indicated by increased enzyme activity and decreased enzymatic stoichiometric imbalance. This could, in turn, expedite carbon loss through respiration, particularly in the slow‐cycling pool. The enhanced belowground metabolic capacity was dominantly driven by greater multitrophic network complexity and particularly negative (competitive and predator–prey) associations, which fostered the stability of the belowground metacommunity. Interestingly, soil abiotic conditions including pH, aeration, and nutrient stocks, exhibited a less significant role. Overall, this study reveals a greater need for soil C resources across multitrophic levels to maintain metabolic functionality as declining SOC results in biodiversity loss. Our researchers highlight the importance of integrating belowground biological processes into models of SOC turnover, to improve agroecosystem functioning and carbon management in face of intensifying anthropogenic land‐use and climate change. [ABSTRACT FROM AUTHOR]

Soil carbon pools have a significant impact on the global carbon cycle and soil erosion caused by natural or human activities is one of the main drivers of changes in soil carbon sequestration. The present study aimed to estimate the carbon loss associated with soil loss in the watershed using remote sensing and GIS techniques. The study was carried out at the Central MPKV Campus Watershed, Rahuri, located in the rain shadow region of the Maharashtra state, India. The soil loss from the watershed was estimated using USLE model. The soil loss and carbon loss from the watershed were estimated before the implementation of conservation measures and after the implementation of conservation measures. It was found that the average annual soil loss from the watershed before and after conservation measures was 18.68 t/ha/yr and 9.41 t/ha/yr, respectively. Carbon loss was determined by soil loss rate, organic carbon content and the carbon enrichment ratio. The carbon loss from the watershed before and after conservation measures was 348.71 kgC/ha/yr and 205.52 kgC/ha/yr. The findings revealed that soil and carbon erosion was very severe on steep slopes without conservation measures and with limited vegetation cover. It was found that by reducing the carbon loss associated with soil loss, soil conservation measures not only aid in the conservation of natural resources but also serve as a climate change mitigation measure. [ABSTRACT FROM AUTHOR]

Climate warming increases carbon assimilation by plant growth and also accelerates permafrost CO2 emissions; however, the overall ecosystem CO2 balance in permafrost regions and its economic impacts remain largely unknown. Here we synthesize in situ measurements of net ecosystem CO2 exchange to assess current and future carbon budgets across the northern permafrost regions using the random forest model and calculate their economic implications under the Shared Socio‐economic Pathways (SSPs) based on the PAGE‐ICE model. We estimate a contemporary CO2 emission of 1,539 Tg C during the nongrowing season and CO2 uptake of 2,330 Tg C during the growing season, respectively. Air temperature and precipitation exert the most control over the net ecosystem exchange in the nongrowing season, while leaf area index plays a more important role in the growing season. This region will probably shift to a carbon source after 2,057 under SSP5‐8.5, with a net emission of 17 Pg C during 2057–2100. The net economic benefits of CO2 budget will be $4.5, $5.0, and $2.9 trillion under SSP1‐2.6, SSP2‐4.5, and SSP5‐8.5, respectively. Our results imply that a high‐emission pathway will greatly reduce the economic benefit of carbon assimilation in northern permafrost regions. Plain Language Summary: The permafrost regions account for approximately 22% of the land area in the northern hemisphere. The soil organic carbon stored in permafrost is about twice as much as currently contained in the atmosphere. Once permafrost thaws, the soil organic carbon will be utilized by microbes, and large amounts of CO2 will be released, further accelerating climate warming. On the other hand, warming significantly promotes vegetation growth and makes more carbon to be absorbed. The current and future carbon balance in northern permafrost regions remains largely unknown. Here, we calculated the carbon budget based on in situ observations of CO2 flux. Our results provide a deep insight into understanding how much carbon has been assimilated and released in northern permafrost ecosystems. Our findings have important implications for the future role of northern permafrost in regulating the ecosystem carbon cycle and economic benefit. Key Points: Northern permafrost regions are currently carbon sinks of approximately 791 Tg C per yearThe carbon sink will decrease with climate warming and will likely shift to a source in 2057 under a high emission pathwayEconomic benefits of carbon sinks will be greatly reduced under a high emission pathway [ABSTRACT FROM AUTHOR]

Carbon (C)-rich wetland soils are often drained for agriculture due to their capacity to support high net primary productivity. Increased drainage is expected this century to meet the agricultural demands of a growing population. Wetland drainage can result in large soil C losses and the concentration of residual soil minerals such as iron (Fe) and aluminum (Al). In upland soils, reactive Fe and Al minerals can contribute to soil C accumulation through sorption to poorly crystalline minerals and coprecipitation of organo-metal complexes, as well as C loss via anaerobic respiration by Fe-reducing bacteria. The role of these minerals in soil C dynamics is often overlooked in managed wetland soils and may be particularly important in both drained and reflooded systems with elevated mineral concentrations. Reflooding drained soils have been proposed as a means to sequester C for climate change mitigation, yet little is known about how reactive Fe and Al minerals affect C cycling in restored wetlands. We explored the interactions among soil C and reactive Fe and Al minerals in drained and reflooded wetland soils. In reflooded soils, soil C was negatively associated with reactive Fe and reduced Fe(II), a proxy for anaerobic conditions (reactive Fe: R2  = .54-.79; Fe(II): R2  = .59-.89). In drained soils, organo-Al complexes were positively associated with soil C and Fe(II) (Al R2  = .91; Fe(II): R2  = .54-.60). Soil moisture, organo-Al, and reactive Fe explained most of the variation observed in soil C concentrations across all sites (p

Background. Pre-fire fuels, topography, and weather influence wildfire behaviour and firedriven ecosystem carbon loss. However, the pre-fire characteristics that contribute to fire behaviour and effects are often understudied for wildfires because measurements are difficult to obtain. Aims. This study aimed to investigate the relative contribution of pre-fire conditions to fire energy and the role of fire advancement direction in fuel consumption. Methods. Over 15 years, we measured vegetation and fuels in California mixed-conifer forests within days before and after wildfires, with co-located measurements of active fire behaviour. Key results. Pre-fire litter and duff fuels were the most important factors in explaining fire energy and contributed similarly across severity categories. Consumption was greatest for the forest floor (litter and duff; 56.8 Mg ha-1) and 1000-h fuels (36.0 Mg ha-1). Heading fires consumed 13.2 Mg ha-1 more litter (232%) and 24.3 Mg ha-1 more duff (202%) than backing fires. Remotely sensed fire severity was weakly correlated (R2 = 0.14) with fuel consumption. Conclusions. 1000-h fuels, litter, and duff were primary drivers of fire energy, and heading fires consumed more fuel than backing fires. Implications. Knowledge of how consumption and fire energy differ among contrasting types of fire behaviours may inform wildfire management and fuels treatments. [ABSTRACT FROM AUTHOR]

L-leucine is an essential amino acid widely used in food and pharmaceutical industries. However, the relatively low production efficiency limits its large-scale application. In this study, we rationally developed an efficient L-leucine-producing Escherichia coli strain. Initially, the L-leucine synthesis pathway was enhanced by overexpressing feedback-resistant 2-isopropylmalate synthase and acetohydroxy acid synthase both derived from Corynebacterium glutamicum , along with two other native enzymes. Next, the pyruvate and acetyl-CoA pools were enriched by deleting competitive pathways, employing the nonoxidative glycolysis pathway, and dynamically modulating the citrate synthase activity, which significantly promoted the L-leucine production and yield to 40.69 g/L and 0.30 g/g glucose, respectively. Then, the redox flux was improved by substituting the native NADPH-dependent acetohydroxy acid isomeroreductase, branched chain amino acid transaminase, and glutamate dehydrogenase with their NADH-dependent equivalents. Finally, L-leucine efflux was accelerated by precise overexpression of the exporter and deletion of the transporter. Under fed-batch conditions, the final strain LXH-21 produced 63.29 g/L of L-leucine, with a yield and productivity of 0.37 g/g glucose and 2.64 g/(L h), respectively. To our knowledge, this study achieved the highest production efficiency of L-leucine to date. The strategies presented here will be useful for engineering E. coli strains for producing L-leucine and related products on an industrial scale. [Display omitted] • Systems metabolic engineering for L-leucine was applied in Escherichia coli. • High-level and -yield production of L-leucine was achieved. • The nonoxidative glycolysis pathway improved the acetyl-CoA pool and L-leucine yield. • TCA cycle was dynamically modulated to redistribute flux toward L-leucine synthesis. • The redox flux was improved by substituting the NADPH-dependent enzymes. [ABSTRACT FROM AUTHOR]

Soil carbon pools have a significant impact on the global carbon cycle and soil erosion caused by natural or human activities is one of the main drivers of changes in soil carbon sequestration. The present study aimed to estimate the carbon loss associated with soil loss in the watershed using remote sensing and GIS techniques. The study was carried out at the Central MPKV Campus Watershed, Rahuri, located in the rain shadow region of the Maharashtra state, India. The soil loss from the watershed was estimated using USLE model. The soil loss and carbon loss from the watershed were estimated before the implementation of conservation measures and after the implementation of conservation measures. It was found that the average annual soil loss from the watershed before and after conservation measures was 18.68 t/ha/yr and 9.41 t/ha/yr, respectively. Carbon loss was determined by soil loss rate, organic carbon content and the carbon enrichment ratio. The carbon loss from the watershed before and after conservation measures was 348.71 kgC/ha/yr and 205.52 kgC/ha/yr. The findings revealed that soil and carbon erosion was very severe on steep slopes without conservation measures and with limited vegetation cover. It was found that by reducing the carbon loss associated with soil loss, soil conservation measures not only aid in the conservation of natural resources but also serve as a climate change mitigation measure.

Microplastics (MPs) are increasingly being studied because they have become ubiquitous in aquatic and terrestrial environments. However, little is known about the negative effects of co-contamination by polypropylene microplastic (PP MPs) and heavy metal mixtures on terrestrial environment and biota. This study assessed the adverse effects of co-exposure to PP MPs and heavy metal mixture (Cu2+, Cr6+, and Zn2+) on soil quality and the earthworm Eisenia fetida. Soil samples were collected in the Dong Cao catchment, near Hanoi, Vietnam, and analyzed for changes in extracellular enzyme activity and carbon, nitrogen, and phosphorus availability in the soil. We determined the survival rate of earthworms Eisenia fetida that had ingested MPs and two doses of heavy metals (the environmental level — 1 × — and its double — 2 ×). Earthworm ingestion rates were not significantly impacted by the exposure conditions, but the mortality rate for the 2 × exposure conditions was 100%. Metal-associated PP MPs stimulated the activities of β-glucosidase, β-N-acetyl glucosaminidase, and phosphatase enzymes in soil. Principle component analysis showed that these enzymes were positively correlated with Cu2+ and Cr6+ concentrations, but negatively correlated with microbial activity. Zn2+ showed no correlation with soil extracellular enzyme activity or soil microbial activity. Our results showed that co-exposure of earthworms to MPs and heavy metals had no impact on soil nitrogen and phosphorus but caused a decrease in total soil carbon content, with a possible associated risk of increased CO2 emissions. [ABSTRACT FROM AUTHOR]

Grasslands store a third of global terrestrial carbon but are vulnerable to carbon loss due to inappropriate livestock grazing. Grasslands management can be improved with a mechanistic understanding of biogeochemical processes that determine carbon storage, such as plant litter decomposition.Herbicides, such as glyphosate, are used to improve the quantity and quality of the forage. In the Flooding Pampa, the most extensive cattle grazed natural grassland and one of the few remnants' temperate grasslands in South America—glyphosate is applied to promote Lolium multiflorum, a forage grass associated with a fungal endophyte nontoxic for cattle.We studied five mechanistic pathways in which the application of glyphosate can alter litter decomposition. We grouped them into single application pathways, through effects on living plants (1), leaf litter (2) and bare soil (3), and repeated annual application pathways, through legacies on ecosystem properties (4) and through the growth of an annual forage grass with a fungal endophyte (5). Single application pathways were tested in a greenhouse experiment using leaf litter of L. multiflorum and of a native dominant grass. Repeated annual application pathways were tested through a field experiment with 3‐year annual glyphosate application using leaf and root litter of L. multiflorum with and without endophyte association.Glyphosate application on living plants produced leaf litter with 70% higher nitrogen content and 140% higher decomposition constant than naturally senesced litter. In contrast, glyphosate application on naturally senesced leaf litter reduced decomposition constant by 20%. Glyphosate application on the soil did not affect the decomposition of naturally senesced leaf litter but accelerated the decomposition of the glyphosate‐killed plants even more.Legacies of repeated annual application of glyphosate resulted in a notable reduction in plant cover (45%) and potential soil respiration (57%), with a consistent acceleration of leaf (53%) and root (18%) litter decomposition. Furthermore, endophytes in L. multiflorum plants reduced leaf litter decomposition by 22%. On the contrary, endophytes did not alter root litter decomposition.Glyphosate application on living plants and legacies of repeated application on the ecosystem stimulate litter decomposition, which can result in a net carbon loss from grasslands. In other ecosystems, the net result on decomposition would depend on the relative cover of vegetation, above‐ground litter and bare soil. This study highlights that glyphosate application should be considered when evaluating sustainable management to preserve and enhance soil carbon storage in grasslands. Read the free Plain Language Summary for this article on the Journal blog.Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]

Photodegradation is an important mechanism that affects carbon and nutrient cycling; a significant amount of data has been reported previously. The present review includes the effect of a wider spectrum of solar radiation (sun light, UV, and visible light) on plant litter decay in terrestrial ecosystems. Although the positive effect of photodegradation on decomposition is most common, a substantial number of studies reports contrasting results. Litter from 148 plant species, from 41 families, have been used in photodegradation studies, representing functional groups of trees (33%), graminoids (30%), shrubs (23%), forbs (11%), and peat (1%). Although the majority of studies focused on mass loss, a growing number focuses on nutrient release. Positive effects on mass loss are most common across different climate regions and laboratory studies, whereas "positive" influence and "no effect" on nitrogen and lignin release are equally common in temperate and sub-tropical environments. This may potentially be due to other decomposition processes which increase in relevance with increasing moisture and can facilitate microbial activity, leaching, and fractioning by soil fauna. In addition to climate region, initial litter quality influences photodegradation. Field-based and laboratory experiments frequently obtain contrasting results, suggesting that the mechanisms controlling the responses are unclear and might be dependent on several interactions, and/or the differences in experimental approaches (such as UV filters), or coverage by particles. Future research should focus on interactions between different factors, and on conducting experiments that test specific relationships such as the potential interaction between photodegradation, soil moisture, microbial communities, soil fauna, and their effects on litter decomposition (both mass loss and nutrient release). Furthermore, the topic would benefit from international studies applying the same experimental approach, as has successfully been conducted in other fields. [ABSTRACT FROM AUTHOR]

Long‐term atmospheric CO2 concentration records have suggested a reduction in the positive effect of warming on high‐latitude carbon uptake since the 1990s. A variety of mechanisms have been proposed to explain the reduced net carbon sink of northern ecosystems with increased air temperature, including water stress on vegetation and increased respiration over recent decades. However, the lack of consistent long‐term carbon flux and in situ soil moisture data has severely limited our ability to identify the mechanisms responsible for the recent reduced carbon sink strength. In this study, we used a record of nearly 100 site‐years of eddy covariance data from 11 continuous permafrost tundra sites distributed across the circumpolar Arctic to test the temperature (expressed as growing degree days, GDD) responses of gross primary production (GPP), net ecosystem exchange (NEE), and ecosystem respiration (ER) at different periods of the summer (early, peak, and late summer) including dominant tundra vegetation classes (graminoids and mosses, and shrubs). We further tested GPP, NEE, and ER relationships with soil moisture and vapor pressure deficit to identify potential moisture limitations on plant productivity and net carbon exchange. Our results show a decrease in GPP with rising GDD during the peak summer (July) for both vegetation classes, and a significant relationship between the peak summer GPP and soil moisture after statistically controlling for GDD in a partial correlation analysis. These results suggest that tundra ecosystems might not benefit from increased temperature as much as suggested by several terrestrial biosphere models, if decreased soil moisture limits the peak summer plant productivity, reducing the ability of these ecosystems to sequester carbon during the summer. [ABSTRACT FROM AUTHOR]

International trade profoundly impacts global land resource redistribution, creating significant inequalities. However, there is still a considerable gap in studies on land transfer and resulting environmental consequences. This study aims to illuminate inequality patterns by examining the global transfer dynamics of embodied cropland, forestland, and pasture in 2001, 2011, and 2021. The results reveal a notable increase in transfers within developing regions, rising from 21.8 % to 37.1 %. The direction of the largest shifts changed in embodied cropland and forestland. Embodied land outflows from developing regions were mainly related to primary products, while those from developed regions came from manufacturing and services. The carbon losses from trade-induced land use changes indicated that the world experienced an average loss of 37.25 million MgC/yr from carbon sink and 17.60 PgC from carbon storage in 2011. Developing regions not only provided land resources to developed regions but also bore the resulting carbon sink and storage losses. To prevent international trade from worsening regional inequalities and spreading environmental impacts, concerted efforts in improving land-use efficiency and conserving carbon stocks are alternative pathways to foster and promote global sustainability. • Embodied land flows in international trade in developing regions increased rapidly from 2001 to 2021. • The largest flows on embodied cropland and forestland underwent a directional shift. • Developing and developed regions displayed sectoral differences in embodied land flows. • Reallocation of embodied land led to exacerbated carbon losses in developing regions. [ABSTRACT FROM AUTHOR]

Tropical rain forests are global hotspots of biodiversity and key climate change regulators. Despite the decades of conservation efforts, tropical forests are increasingly under continuous threat from human activities. Therefore, understanding the impact of anthropogenic disturbances on biodiversity is necessary for better conservation and management. This study focused on a tropical rainforest located in Kakoi reserve, Assam, in the northeastern Himalayas, aiming to compare tree species composition, diversity, carbon stocks, and regenerating status in two forest sites experiencing disturbance regimes. A total of 55 tree species representing 36 genera and 26 families were recorded in the study area. The tree species richness was slightly higher in moderately disturbed (MD) Dirgha than in the highly disturbed (HD) Kakoi-Rajgarh forest. Tree density and basal area were 582 and 446 individuals ha−1, 38.43, and 32.63 m2 ha−1, respectively, in MD-Dirgha and HD-Kakoi-Rajgarh. Forest stand structure followed a typical reverse J-shaped trend in both sites, with a lesser density of large girth-class (>330 cm girth at breast height) individuals in HD-Kakoi-Rajgarh, reflecting the influence of past onsite disturbances. The analysis of the regeneration strata depicted that seedling and sapling density was 1.8 and 1.4 times lower in HD-Kakoi-Rajgarh compared to MD-Dirgha. Above-ground biomass and total carbon stocks were maximum in MD-Dirgha, followed by HD-Kakoi-Rajgarh. About 63.64% of the recorded tree species, including Critically Endangered Vatica lanceifolia are under IUCN Red List Categories, thus stressing the need for conservation. Our findings suggest that conserving species diversity and carbon reserves in tropical forests would principally depend on minimizing forest loss and degradation.

Biological soil crusts (biocrusts) account for a substantial portion of primary production in dryland ecosystems. They successionally mature to deliver a suite of ecosystem services, such as carbon sequestration, water retention and nutrient cycling, and climate regulation. Biocrust assemblages are extremely well adapted to survive desiccation and to rapidly take advantage of the periodic precipitation events typical of arid ecosystems. Here we focus on the wetting response of incipient cyanobacterial crusts as they mature from "light" to "dark." We sampled a cyanobacterial biocrust chronosequence before (dry) and temporally following a controlled wetting event and used high-throughput 16S rRNA and rRNA gene sequencing to monitor the dynamics of microbial response. Overall, shorter-term changes in phylogenetic beta diversity attributable to periodic wetting were as large as those attributable to biocrust successional stage. Notably, more mature crusts showed significantly higher resistance to precipitation disturbance. A large bloom of a few taxa within the Firmicutes, primarily in the order Bacillales, emerged 18 h after wetting, while filamentous crust-forming cyanobacteria showed variable responses to wet-up across the successional gradient, with populations collapsing in less-developed light crusts but increasing in later-successional-stage dark crusts. Overall, the consistent Bacillales bloom accompanied by the variable collapse of pioneer cyanobacteria of the Oscillatoriales order across the successional gradient suggests that the strong response of few organisms to a hydration pulse with the mortality of the autotroph might have important implications for carbon (C) balance in semiarid ecosystems.IMPORTANCE Desert biological soil crusts are terrestrial topsoil microbial communities common to arid regions that comprise 40% of Earth's terrestrial surface. They successionally develop over years to decades to deliver a suite of ecosystem services of local and global significance. Ecosystem succession toward maturity has been associated with both resistance and resilience to disturbance. Recent work has shown that the impacts of both climate change and physical disturbance on biocrusts increase the potential for successional resetting. A larger proportion of biocrusts are expected to be at an early developmental stage, hence increasing susceptibility to changes in precipitation frequencies. Therefore, it is essential to characterize how biocrusts respond to wetting across early developmental stages. In this study, we document the wetting response of microbial communities from a biocrust chronosequence. Overall, our results suggest that the cumulative effects of altered precipitation frequencies on the stability of biocrusts will depend on biocrust maturity.

Decarburization deteriorates the surface mechanical properties of steel. It refers to the loss of carbon from steel's surface when exposed to an open-air environment in elevated-temperature conditions. Despite the short interaction time and fast thermal cycle of the laser surface-hardening process, decarburization may still occur. This paper investigates if decarburization occurs during the laser surface hardening of AISI 420 martensitic stainless steel. For comparison, surface-hardening results and decarburizations in a conventional air furnace-heated hardening process (water-quenched and air-cooled) of the same steel material were also investigated. Decarburization seems to have occurred in the laser surface hardening of AISI 420SS. However, the decarburization might not be significant, as the hardness of the steel's surface was increased more than three times to 675 HV during the laser surface hardening, and the hardness drop due to decarburization was estimated to be only 3% with the decarburization depth of 40 μm. Simulations using ThermoCalc software to get the carbon concentration profiles along the depth for both laser-hardened and furnace-heated samples were also investigated. [ABSTRACT FROM AUTHOR]

This study aims to calculate the amount of carbon lost and the amount of oxygen that can no longer be produced by the Cogreg Experimental Garden (KPC) due to the harvesting of Nusantara Unggul Teak wood (JUN). Carbon stock loss was measured using the allometric equation method based on the SNI 7724:2011. Calculating the loss of oxygen-producing potential used the comparison method of the atomic weights of carbon and oxygen. The results of this study indicate that the harvesting of JUN at KPC causes a loss of potential carbon storage reserves of 215.384 tons/year or equivalent to IDR7.2 bilions; the loss of oxygen-producing potential is 574,359 tons/year or equivalent to IDR2.66 billions. Meanwhile, the results of harvesting JUN wood can only produce a financial value of IDR1,36 billions. Therefore, the financial value of the KPC's environmental services in the form of carbon storage and oxygen production is much greater than the financial value of harvesting JUN's wood. [ABSTRACT FROM AUTHOR]

A sustainable method for protecting natural resources is the adoption of recommended soil and water conservation (SWC) measures. SWC measures are well recognized for their effective soil protection and water harvesting. Unfortunately, their significance in climate change mitigation has yet to receive global attention. The present study was conducted to highlight the applicability of SWC measures for carbon management in watersheds. In this study, the impact of SWC measures on land cover, soil erosion, carbon loss, and carbon sequestration were investigated using advanced techniques of remote sensing (RS) and geographic information systems (GIS). The study was conducted in the Central Mahatma Phule Krishi Vidyapeeth (MPKV) campus watershed, located in the rainfed region of Maharashtra, India. The watershed is already treated with various scientifically planned SWC measures. Following the implementation of conservation measures in the watershed, average annual soil loss was reduced from 18.68 to 9.41 t ha−1yr−1 and carbon loss was reduced from 348.71 to 205.52 kgC ha−1yr−1. It was found that deep continuous contour trenches (DCCT) constructed on barren, forest, and horticultural land have the soil carbon sequestration rates of 0.237, 0.723, and 0.594 t C ha−1yr−1, respectively, for 0–30 cm depth of soil. Similarly, compartment bunds constructed on agricultural land have a soil carbon sequestration rate of 0.612 t C ha−1yr−1. These findings can be of great importance in the planning and management of climate-resilient watersheds. [ABSTRACT FROM AUTHOR]

The staking (elevating creeping vines above the ground with poles) of yam is practiced to optimize crop yield, but its effect on soil loss due to crop harvesting (SLCH-soil adhering to harvested tubers) and its associated carbon loss has not been investigated globally. A 3-year field experiment was conducted to study the yam (Dioscorea rotundata) staking effect on SLCH and to examine the environmental effect of soil carbon loss. Staking reduced soil loss due to crop harvesting by 55.6% and increased yam yield by 33.3% when compared to un-staking. Soil carbon loss and root hair weight per tuber yield decreased by 47.7 and 58.4%, respectively, under staking compared with un-staking practices. The un-staking with higher moisture (≃42%) exported two times more soil-available nutrients (N, P, K and Ca) than staking. SLCH was also linearly related to root hair weight (R2 = 0.88–0.75; p < 0.05) and moisture content (R2 = 0.79–0.63; p < 0.05). The lower ratio of root hair weight to tuber yield coupled with moderate mound moisture in staking neutralized its higher tuber yield effect on SLCH by reducing soil loss and its carbon loss. Thus, yam staking mitigates soil loss and its carbon loss which can increase the sequestration potential of soil carbon stock. [ABSTRACT FROM AUTHOR]

Aim: Our aim was to quantify the influence of climate and land use on major fires that occurred during the 2020 drought over the Brazilian Pantanal region. Location: Alto Paraguay Basin, central‐western flank of Brazil. Time period: 2003–2020. Methods: We calculated climatic and burned area anomalies and Spearman's correlation between precipitation and sea surface temperature (SST). We assessed water coverage to identify the impact of the 2020 drought. We produced fire recurrence maps, identified the areas that burned for the first time in 2020, and estimated the carbon loss. Lastly, we assessed the burned areas within land‐use classes and land tenure. Results: The anomalies showed that climatic variables in 2020 had an atypical behaviour, being hotter and drier than the historical average. The water surface area in the Pantanal has been decreasing annually from 2003, and in 2020 the reduction was 34% greater than the annual average. Burned areas in 2020 were 200% greater than the long‐term average, and 35% of the burned areas occurred for the first time in this year. We showed that 84% of these new fires occurred within natural vegetation, with 39% of the burned areas occurring in forests, an increase of 514%. Forest fires were responsible for 47% of the carbon loss in 2020. Finally, 70% of the fires in 2020 occurred within rural properties, 5% in indigenous lands and 10% in protected areas. Main conclusions: The unprecedented fires in 2020 were not only a result of atypical climate, but also a consequence of the intensification of fire‐related human activities. Rural properties play a major role in Pantanal fires, requiring law enforcement and a consistent plan for increasing the protection of the conservation areas. We argue that ineffective fire prevention and the lack of suppression strategies were also key in enhancing the magnitude of these fires. [ABSTRACT FROM AUTHOR]

China's diets are undergoing a profound transformation, and carbon storage loss generated by dietary structure change is increasingly serious, accompanied by concerns about sustainable diets and food supply–demand conflicts. This paper designed a dual 'material–environmental' framework based on the dietary structure classification, around which we conducted the heterogeneity analysis of food supply–demand patterns and land carbon loss, and then tracked hotspot diets of trade-generated carbon loss through the multi-regional input–output (MRIO) model. The research found that 31 provinces could be classified into five clusters with obvious spatial agglomeration patterns, most of which still had a high proportion of staches, but also showed an evolutionary trend towards diversified compositions. Driven by dietary structure, the national food supply–demand match under the material accessibility dimension showed barely balanced overall, while in terms of environmental effects, ecosystems lost significant amounts of carbon stocks, with losses of 331 and 950 Tg 1 1 Tg refers to teragram, a weight unit, 1 Tg = 106 t = 1012 g of vegetation carbon and soil organic carbon, respectively, which together accounted for 14 percent of the total carbon stocks in the vegetation and topsoil carbon pools. The clusters to which Henan, Jiangsu, Zhejiang and Guangdong belong were tracked as hot dietary clusters exhibiting hotspots in inter-regional trade, contributing to carbon loss in external provinces through trade linkages. Heilongjiang and Inner Mongolia were at a low level of supply–demand balance but played the role of a carbon storage loser, while Guangdong, Zhejiang, and Jiangsu not only possessed higher balance levels but also pulled more external carbon loss. China's food system should optimise internal cropping structures and monitor external land use conversion. It is equally important to track food consumption side rights and responsibilities. • The "Material-Environmental" framework to diagnose dietary sustainability was designed. • Provinces could be classified into five clusters with obvious spatial agglomeration patterns. • Land use changes driven by dietary transition have resulted in significant carbon losses of 1281 Tg. • Specific clusters were hotspot clusters that pulled carbon loss from external regions during inter-regional trade. • Diet sustainability enhancement based on land use environmental effects deserves attention. [ABSTRACT FROM AUTHOR]

Ultra-high Voltage Direct Current system (UHVDC) can realize long-distance transmission, and its carbon loss reduction is a focus in the power grid field.A multi-objective optimization model for low-carbon, economic, and safe operation on UHVDC is established, where we proposed a Residual Neural Network-Long Short-Term Memory (ResNet-LSTM) deep learning network as the carbon loss implicit objective function. The proposed ResNet-LSTM exhibits superior performance in carbon loss measurement for UHVDC, the experiments show that the Mean Squared Error (MSE) of ResNet-LSTM reaches 0.41%, which surpasses that of ResNet, LSTM, and Convolutional Neural Network- Long Short-Term Memory (CNN-LSTM) by 39.71%, 30.51%, and 21.15% respectively, while also increasing the R-Squared (R2) score by 1.48% on average. An Improved Non-dominated Sorting Genetic Algorithm II (Im-NSGA-II) algorithm is proposed to solve the model based on population initialization and crowding calculation improvements. The experiment results show that the two improvement strategies effectively reduce carbon losses and carbon trading costs. The proposed Im-NSGA-II outperforms the mainstream algorithm Adaptive Grid Evolutionary Multi-Objective Algorithm Based on Decomposition (AGE-MOEA/D), Reference Vector Guided Evolutionary Algorithm (RVEA), Sequentially Multi-Objective Selection based on the Efficient Multi-objective Optimization Algorithm (SMS-EMOA), and Non-dominated Sorting Genetic Algorithm II (NSGA-II), and decreases the other four algorithms on carbon losses and carbon trading costs by 34.73% and 14.74% on average, in the meanwhile, the transformer ratio errors are within the safe range. In the equipment of UHVDC, Direct Current (DC) transmission lines and converter transformers account for the largest proportion, which is the most worthy of attention in the future loss reduction work. After the above treatment, the UHVDC system can better achieve low-carbon economy and safe operation. [ABSTRACT FROM AUTHOR]

[Display omitted] • New infrastructure projects may deforest the threatened NE Brazil Atlantic Forest. • More deforestation will critically impact biodiversity and ecosystem services. • Habitat quality will be worsened, and an enormous amount of stored carbon will be lost. • Landscape connectivity for forest-dependent species will be negatively affected. • Adoption of alternative areas and no more forest clearing is strongly recommended. Projects demanding deforestation to expand urban infrastructure and road networks put pressure on the Atlantic Forest − a hyper-fragmented global conservation hotspot known for its high biodiversity and endemism. To support decision-making, we applied a scientific approach to analyse the immediate and long-term impacts of two major planned projects in the most threatened Atlantic Forest region – the Pernambuco Endemism Center, a crucial area for the survival of many endemic species. A Metropolitan Road Arch and a Training School for Career Sergeants are expected in the Environmental Protection Area Aldeia-Beberibe (31,634 ha) in the next few years. The area has 198 protected forest remnants, including one larger than 10,000 ha. Our analysis shows that the projects' implementation may deforest 189 ha, increase fragment number by 3.5 % and decrease the average patch area by 4 %. The largest fragment will be divided into two. We may lose 335,307 trees and 44,655.59 Mg of carbon. Approximately 112.67 ha of watershed protection will be damaged. Thus, in the medium to long term, habitat quality will worsen, and the probability of connectivity will decrease, restricting forest-dependent species' mobility considerably. To date, alternative areas have been proposed in meetings, working groups, and environmental advisory bodies for the analysed projects. We strongly oppose further deforestation and suggest that science-based approaches must be immediately considered for any project that requires forest suppression in highly fragmented landscapes. This is crucial to mitigate the alarming scenarios of extreme climate and biodiversity loss that we are currently witnessing in Brazil and worldwide. [ABSTRACT FROM AUTHOR]

This study investigated the effects of adding biochar, ferrous sulfate, and their combination during composting of pig manure mixed with straw to reduce the loss of carbon and nitrogen during agricultural waste composting. Four 100 L fermentation tank-scale experimental composting treatments were established: the additive-free control (CK), addition of 5% biochar (BC), addition of 5% ferrous sulfate (SF), and addition of 2.5% BC + 2.5% SF (BS). The transformation of carbon and nitrogen and the change characteristics of bacterial communities during composting of the four treatments were explored. BS significantly reduced NH 3 , N 2 O, CO 2 , and CH 4 emissions by 59.57%, 48.41%, 35.80%, and 32.25% compared with CK, respectively. The BS treatment showed lower carbon and nitrogen losses than the single additive treatment. BS treatment enhanced the diversity and richness of bacterial communities during composting. The redundancy and Pearson correlation analyses revealed that the composition of dominant species between treatments had significant differences in different compost periods (mesophile, thermophilic, and cooling periods). BS treatment significantly increased the abundance ratio of carbon sequestration and nitrogen retention communities, and it enhanced nutrient preservation by microbial metabolism. Therefore, the composite addition of biochar and ferrous sulfate is an effective method to reduce the loss of carbon and nitrogen during agricultural waste composting. [Display omitted] [ABSTRACT FROM AUTHOR]

Carbon emissions will exacerbate the process of global warming, and urbanization can cause carbon loss from terrestrial ecosystems by occupying vegetated lands. Economic and social development are the dominant drivers of urban land expansion in China, and through regional economic links, urbanization can be influenced by external regions. Meanwhile, the external influence on both interior region urbanization and associated carbon pool variation has not yet been analyzed. Based on domestic trade data, land-use images, vegetation carbon densities, and NPP data, and by using the MRIO model and spatial analysis, this study considered the combined influence from external regions and examines urbanization and its influence on vegetation carbon pool (vegetation carbon storage and NPP) from the perspective of tele-coupling. The results show that during 2010–2015, 31,769 km2 of other types of land was transformed into urban land in China, with 54.54%, 12.57%, and 13.13% from cropland, woodland, and grassland, respectively. Urbanization is more densely concentrated in the North China Plain and the Yangtze River Basin. Urbanization caused 6789.72 × 104 t carbon loss, of which 2650.82 × 104 t was from vegetation carbon storage loss and 4138.9 × 104 t from net primary productivity (NPP) reduction. The overall carbon loss spatial distribution indicated a decrease from southeast to northwest. Hebei, Inner Mongolia, and Jiangsu were the top three provinces to be pulled by external provinces for urban land expansion. Conversely, Jiangsu, Henan, Zhejiang, Shandong, and Guangdong were the main pullers for urban expansion in other provinces. Hebei, Hunan, Guizhou, Hainan, Inner Mongolia, Guangxi, Jiangxi, and Hubei presented a high amount of carbon loss pulled by external provinces. Shandong, Shanghai, Shanxi, Guangdong, Henan, Liaoning, Beijing, Heilongjiang, and Zhejiang showed a clear high carbon loss pulled to external provinces. Inequity shows that urbanization in less developed regions was usually more pulled by developed regions and the carbon loss was higher in regions with high biomass coverage. [ABSTRACT FROM AUTHOR]

Tidal flats are widely distributed and provide a variety of ecosystem services. Nevertheless, the consequences of tidal flat loss and implications for services such as carbon (C) sequestration have not been assessed. In unvegetated tidal flat ecosystems, sediment is the most important carbon reservoir, similar to that of vegetated coastal wetlands (i.e., mangroves, salt marshes, and seagrass). We examined the C stocks and C accumulation rate (CAR) reported from 123 locations of tidal flat around the world and compared these results with data from mangroves, salt marshes, and seagrass meadows. The global average CAR of tidal flats is 129.8 g C m-2 yr-1, with the top-meter sediments containing on average 86.3 Mg C ha-1. Globally, tidal flat can bury 6.8 Tg C (24.9 Tg CO2) per year and can store 0.9 Pg C (3.3 Pg CO2) in the top meter sediment. Assuming the same rate of loss tidal flats as in the past three decades and that all disturbed sediment C is remineralized, 4.8 Tg C will be lost from tidal flat sediments every year, equivalent to an emission of 17.6 Tg CO2 to the water column and atmosphere.

Increasing energy need brings people one step closer to energy saving and alternative sources. The search for reliable and sustainable resources also contributes greatly to technological progress. Thanks to advanced technology, energy use becomes more efficient. However, the concept of sustainability emerges in the field of energy as in other sectors. It is expected that electric vehicles, which have started to increase in interest in recent years, will make a positive contribution to issues such as environmental protection and sustainable energy. In addition, production centers for electric vehicles should also be sustainable and sensitive to carbon emissions. In this study, energy and carbon loss assessment was carried out in an electric bus manufacturing factory. With the help of linear regression analysis, the data of the last 3 years were evaluated. Moreover, as a result of internal audits, energy loss points were determined. As a result of this study, sustainability, carbon loss, and energy management issues in an electric vehicle production factory were evaluated and guiding qualities for today's and future technology companies were revealed. [ABSTRACT FROM AUTHOR]

Tropical cyclones can physically alter ecosystems, causing immediate and potentially long‐lasting effects on carbon dynamics. In 2018, Hurricane Michael hit the southeastern United States with category 5 winds at landfall and category 2 winds reaching over 100 miles inland, resulting in extensive damage. Longleaf pine woodlands in the path of the hurricane were damaged, but severity varied based on the storm track. We used a combination of eddy covariance measurements, airborne LiDAR, and forest inventory data to determine whether hurricane affects structure, function, and recovery of two longleaf pine woodlands at the ends of an edaphic gradient. We found that the carbon sink potentials in both sites were diminished following the storm, with reductions in net ecosystem exchange (NEE) primarily due to lower rates of photosynthesis, as respiration only increased marginally. The xeric site carbon losses and physiological reductions were smaller following the disturbance, which led to the recovery of ecosystem physiological activity to prestorm rates before that of the mesic site, as indicated by maximum ecosystem CO2 uptake rates. Two years following the hurricane both stands continued to have reduced NEE, which signaled altered function. We expect both locations to recover their lost carbon stocks in ∼10–35 years; however, long‐term studies are needed to examine how longleaf woodlands respond to compounding disturbances, such as drought, fire, or other wind storms, which vary significantly across the ecosystem's range. Additionally, hurricanes are intensifying due to climate change, potentially amplifying the degree to which they will alter this ecosystem in the future. Plain Language Summary: Hurricane Michael hit the Northern Gulf of Mexico in October 2018, causing damage to ecosystems within its path. The Jones Center at Ichauway experienced damage to longleaf pine woodlands on the reserve. This damage ranged from removal of leaves and needles from the canopy, to snapped limbs and whole tree mortality. We studied the effects the hurricane had on the structure, physiology, and recovery of two longleaf sites, one with high soil water availability (mesic site) and one with lower soil water availability (xeric site). Both stands experienced declines in photosynthesis and increases in respiration, which reduced their carbon sequestration capacity. Two years following the storm, the sites are still recovering. Interestingly the xeric site was less affected by the storm due to the presence of shorter trees with larger root systems and lower tree densities, which are associated with soil water limitations at the site. We predict that it will take the sites ∼10–35 years to recover the carbon loss associated with this hurricane damage. Key Points: Hurricane Michael altered the structure and function of longleaf pine woodlandsEcological memory of water limitations led to less hurricane damage at our xeric siteCarbon recapture at the two sites may take from 10 to 35 years [ABSTRACT FROM AUTHOR]

Peatlands are especially important but fragile tropical landscapes. The importance of peatlands is owing to their ability to 1) sequester a considerable amount of terrestrial carbon, 2) store freshwater, and 3) regulate floods during the rainy season. Nowadays, extensive peatland degradation occurs because of peatland utilization for agriculture purposes, causing severe environmental consequences such as carbon emission, loss of biodiversity, risk of flooding, and peat fire. Meanwhile, local planners and decision makers tend to overlook the long-term strategic function of peatlands for carbon storage and hydrological regulation, preferring peatland utilization for short-term economic benefits. The objective of our study is to quantify the total ecosystem services (except biodiversity) of a tropical peatland landscape in various peat-utilization scenarios to help build awareness among local planners and decision makers on the strategic tradeoff between peatland utilization and restoration. Studies on the total ecosystem services in a tropical peatland landscape involving hydrological regulation are still rare. Based on the net present value calculation, provisioning services, carbon regulation, and hydrological regulation in our study area account for 19, 70, and 11% of the total ecosystem services, respectively. Based on uncertainty analysis, at any combination of the social cost of carbon emission (within a range of USD 52.7–USD 107.4) and discount rate (within a range of 5–10%), the enrichment of peatlands with paludiculture crops (e.g., jelutong) shows superior ecosystem services compared to other peatland-utilization scenarios. Conversely, planting peatlands with monoculture crops, which are associated with peatland drainage, shows a rapid decrease in the total ecosystem services. The fluvial carbon export in our study, which is often neglected in a peatland carbon budget, increases the estimate of the total carbon budget by 8%. Restoring undrained peatlands with paludiculture crops such as jelutong contributes positively to carbon sequestration and potentially reduces carbon emissions by 11%. These quantitative findings can help local planners and decision makers in understanding the tradeoff between the long-term benefits of peatland restoration and the short-term economic benefits of peatland utilization for monoculture crops.

Purpose: Applying carbon-rich materials, such as those resulting from pyrolysis (biochar) or composting (compost), to the agro-ecosystems has been proven to improve soil organic carbon (SOC) storage and reduce CO2 emissions. However, it is not clear how earthworms drive changes in soil C sequestration and mineralization under biochar/compost incorporation. Materials and methods: A 288-day microcosm experiment was conducted to investigate the effects of earthworms on the concentrations of SOC and its fractions, the structural characteristics of SOC and CO2 emissions following three straw incorporation treatments (maize straw, maize straw compost, and maize straw biochar), and no straw addition was used as the control. Each treatment had two variants: one with earthworms (Eisenia nordenskioldi) and one without earthworms. The elemental analysis, 13C NMR spectroscopy, and three-dimensional fluorescence technologies were used to characterize the features of SOC. Results and discussion: Results indicated that the incorporation of straw, compost, and biochar significantly improved the SOC contents compared with the control. Earthworms did not affect the SOC fractions in the control soil but led to the increase in SOC and humic acid (HA) under compost incorporation. The molecular structures of HA showed features pointing to high degrees of humification and aromaticity, as presented by elemental composition, fluorescence intensities, and 13C NMR. The increase of SOC and a slight reduction of CO2 emission in compost-amended soil could be attributed to the accumulation of more stable HA caused by earthworms. In contrast, earthworm presence decreased the aromaticity of HA in biochar-amended soil, and made its structure more hydrophilic, which was not conducive to C sequestration. In addition, the mineralization of microbial C by earthworms also led to an increased CO2 emission from biochar-amended soil. Conclusions: Earthworms weaken the ability of biochar to reduce soil CO2 emissions but improve the C sequestration capacity of compost-amended soil. This study improves our understanding of the contributions of soil macrofauna on the SOM formation and stabilization after incorporation of different maize straw-derived materials. [ABSTRACT FROM AUTHOR]

Annual total precipitation typically fails to predict litter decomposition rates, especially in semi-arid regions, where precipitation frequency (PF) significantly affects decomposition. We hypothesized that low PF would decrease decomposition rates. We performed a litterbag decomposition experiment with litter of three annual species at three depths (aboveground litter, litter at 0–10 and 10–20 cm below the surface). We used the same total amount (280 mm), but three precipitation frequencies (PF1, 10 mm every 5 days; PF2, 20 mm every 10 days; PF3, 40 mm every 20 days) during the growing season. We measured the remaining mass, carbon (C) content, nitrogen (N) content, C:N ratio, and C and N losses of each species at the three positions. Litter decomposition and the C and N dynamics were influenced by species, depth, and PF. Low PF significantly decreased litter decomposition (mass loss rates of 49.7, 49.1, and 41.2% for PF1, PF2, and PF3, respectively). This effect interacted with placement-depth but not with species. This interaction also existed for C and N dynamics except for the N loss rate. The influence of PF on C loss mainly resulted from its effect on mass loss, whereas N loss was not affected by PF. Our results highlight the importance of PF for litter decomposition in a semi-arid region. The relationship between PF and litter decomposition provides a theoretical basis for regional carbon-cycle models and carbon budget predictions. Our results also suggest that non-graminaceous species showed higher potential than grasses for improving soil carbon in semi-arid sandy grasslands due to faster decomposition rates, especially below ground. [ABSTRACT FROM AUTHOR]

The focus of modern agricultural production on reducing greenhouse gas emissions requires attention to newly introduced farming practices, in particular from the standpoint of their influence on CO2 fluxes. Specific features of СО2 emission from soil as a result of short-term summer green manuring of fallow fields (during 35–40 days from sowing to plowing into the soil of Raphanus sativus var. oleifera Metzg) have been studied. This is a non-standard farming practice used in the forest-steppe zone of the Cis-Baikal Region. Changes in the seasonal dynamics of the CO2 emission relative to the traditional black fallow were studied in three-year (2015–2017) field experiments on gray forest silt loamy soil. An increase in the intensity of CO2 emission from the soil surface after the green mass is plowed into the soil was shown for two crop rotations. The total (May–September) CO2 efflux from the soil in the variant with green manure was 1.3–1.6 times higher than that from the traditionally cultivated soil in all years of the experiment. The intensity of mineralization processes on the plots with green manure enhanced by 38–131% in comparison with that in the black fallow. The loss of carbon reached 19–79% of the amount accumulated in the net primary production. The range of fluctuations in the total CO2 efflux from the soil depended on a combination of factors: hydrothermic conditions, the Corg and Ntot content in soil; the C-to-N ratio, the N and water contents in tissues of green manure, and the carbon stock in root and aboveground residues of the precursor. The correlation between the CO2 efflux and the studied factors weakened in the following sequence: qualitative characteristics of the green mass of oil radish > initial soil fertility > carbon pool in residues of the precursor. The results obtained indicate that the application of green manure to the fallow field increases the CO2 emission from gray forest soil during the warm season. [ABSTRACT FROM AUTHOR]