Total Carbon Research Articles

Research on the Construction and Application of Rural Digital Design Ecosystem under the “Dual Carbon” Goal—Take the Carbon Sequestration Benefits of Street Trees in Nanjing’s Bulao Village as an Example

By constructing a rural digital design ecosystem, this paper develops ecological villages through design empowerment, enhances the carbon sequestration benefits of plants in rural areas, and strengthens rural vitality. Combined with the carbon sequestration benefits of street trees in Bulao Village in Nanjing, the feasibility of the digital design ecosystem in rural planning was verified, and the ways and methods of rural environmental renewal were explored. Through the existing literature, the possibility of constructing a digital design ecosystem was deduced, the theoretical framework was derived, field research was carried out in the village of Bulao, the carbon sequestration benefit of street trees was quantified by the i-Tree model, and a structure chart of street trees, including breast diameter, tree height, type, etc., was formed. There were 35 species of street trees in Bulao Village, belonging to 33 genera in 22 families, including 19 species of trees, a total of 312 trees, and 16 species of shrubs. The street trees’ total carbon sink benefit was equivalent to RMB 30,327.47, a single street tree’s average carbon sequestration benefit was RMB 96.86, and the average CO2 absorption was 164.64 kg. The average CO2 absorption and single benefit of elm trees were the highest, reaching 465.48 kg·plant−1 and 186.81 RMB·plant−1, respectively. The CO2 absorption (185.13 kg) and the average benefit per plant (RMB 109.48) of the camphor tree were lower than those of the elm. However, because their number far exceeded that of elms, their total carbon sequestration benefit contribution was the highest, reaching RMB 25,837.28, accounting for 85.19% of the total benefit. In addition, the contribution rates of elm and willow’s total annual carbon sequestration benefits were also relatively high, reaching RMB 747.24 and RMB 710.04, respectively, accounting for 2.46% and 2.34% of the total benefits. This paper uses the digital design ecosystem’s theoretical framework to quantify street trees’ carbon sequestration benefits through field research. It optimizes and improves the plant allocation of parking lots in Bulao Village from the ecology and carbon sink perspectives. Practice shows that inheriting the connotation values of rural culture, improving the quality of the rural environment, and increasing residents’ and tourists’ sense of belonging and identity to the countryside are conducive to jointly promoting sustainable rural development against the background of “dual carbon”. Combining art design with quantitative scientific methods of ecological environment indicators provides a reference for future rural development.

Quantifying carbon pool in ex-mining lake-converted constructed wetlands of Paya Indah Wetlands, Selangor, Malaysia.

Ex-mining lake-converted constructed wetlands play a significant role in the carbon cycle, offering a great potential to sequester carbon and mitigate climate change and global warming. Investigating the quantity of carbon storage capacity of ex-mining lake-converted constructed wetlands provides information and justification for restoration and conservation efforts. The present study aims to quantify the carbon pool of the ex-mining lake-converted constructed wetlands and characterise the physicochemical properties of the soil and sediment. Pearson's correlation and a one-way ANOVA were performed to compare the different sampling stations at Paya Indah Wetland, Selangor, Malaysia. An analysis of 23years of ex-mining lake-converted constructed wetlands of Paya Indah Wetlands, Selangor, Malaysia, revealed that the estimated total carbon pool in soil and sediment accumulated to 1553.11 Mg C ha-1 (equivalent to 5700 Mg CO2 ha-1), which translates to an annual carbon sink capacity of around 67.5 Mg C ha-1 year-1. The characterisation showed that the texture of all soil samples was dominated by silt, whereas sediments exhibited texture heterogeneity. Although the pH of the soil and sediment was both acidic, the bulk density was still optimal for plant growth and did not affect root growth. FT-IR and WDXRF results supported that besides the accumulation and degradation of organic substances, which increase the soil and sediment carbon content, mineral carbonation is a mechanism by which soil and sediment can store carbon. Therefore, this study indicates that the ex-mining lake-converted constructed wetlands of Paya Indah Wetlands, Selangor, Malaysia have a significant carbon storage potential.

Joint green dynamic order batching and picker routing problem using PSO with global worst experience

With the increasing importance of various countries’ initiatives on reducing carbon emissions (e.g., carbon border adjustment mechanism, CBAM), intelligent order picking systems have assisted electronic retailers in realizing a green supply chain. Previous studies on picker routing operations focused on adopting offline static customer order information to carry out operational decisions. However, in practice, the customer order information is updated dynamically; and high-efficiency warehouse layouts have been increasingly concerned. Therefore, this study creates a mixed-integer programming model for minimizing both the total carbon footprint and the total penalty cost for delayed orders in the joint order batching and picker routing problem with dynamic arriving orders and shipping time constraints in a high-efficiency fishbone warehouse layout. To solve this complex problem, a particle swarm optimization algorithm that integrates the swarm’s previous global and local worst experiences and a migration mechanism is further proposed to increase solution quality and computing efficiency. In addition, a three-dimensional space for the warehouse floorplan and shipping time constraints is designed to divide orders into batches to address the constraints. Theoretical analysis of this algorithm is conducted, and experimental analysis shows that this algorithm finds superior solutions than current practical strategies, to offer a valuable reference for carbon emission reduction in greening warehousing.

Carbon footprint of Nepalese healthcare system: A study of Dhulikhel Hospital

Background Though direct greenhouse gas emissions cannot be observed in health care sectors, there can exist indirect emissions contributing to global climate change. This study addresses the concept of the carbon footprint and its significance in understanding the environmental impact of human activities, with a specific emphasis on the healthcare sector through gate-to-gate (GtoG) life cycle assessment. Transportation, energy consumption, and solid waste generated by hospitals are the primary sources of carbon emissions. Methods Different standards, guidelines and parameters were used to estimate emissions from both the primary and secondary data. All steps and sub-steps involved in GtoG were accessed and analyzed within the standard ISO 14040:44 guideline. An extensive review of existing literature was carried out for the evaluation and verification of secondary data. Results The total carbon footprint of generators, electricity consumption, transportation activities, LPG cylinders, PV systems was found to be 58,780 kg-CO2-eq/yr, 519,794 kg-CO2-eq/yr, 272,375 kg-CO2-eq/yr, 44,494 kg-CO2-eq/yr, 35,283 kg-CO2-eq/yr respectively and the emissions from non-biodegradable solid waste was found to be 489,835 kg-CO2/yr. Local air pollutants such as PM10, CO, SO2, NOX, and VOCs generated by generators and transportation were also estimated. The CH4 emissions from liquid waste were 1177.344 kg CH4/BOD yr, and those from biodegradables were 3821.6954 kg CH4/yr. Conclusions Healthcare professionals and policymakers can take action to reduce the sector's carbon footprint by implementing best practices and encouraging sustainable behavior. This study can be taken as foundation for further exploration of indirect emissions from healthcare sectors not only in Nepal but also in south Asian scenario.

Calculated Maximal Volume Ventilation (cMVV) as a Marker of Early Respiratory Failure in Amyotrophic Lateral Sclerosis (ALS).

Respiratory failure assessment is among the most debatable research topics in amyotrophic lateral sclerosis (ALS) clinical research due to the wide heterogeneity of its presentation. Among the different pulmonary function tests (PFTs), maximal voluntary ventilation (MVV) has shown potential utility as a diagnostic and monitoring marker, able to capture early respiratory modification in neuromuscular disorders. In the present study, we explored calculated MVV (cMVV) as a prognostic biomarker in a center-based, retrospective ALS population belonging to the Piemonte and Valle d'Aosta registry for ALS (PARALS). A Spearman's correlation analysis with clinical data and PFTs showed a good correlation of cMVV with forced vital capacity (FVC) and a moderate correlation with some other features such as bulbar involvement, ALSFRS-R total score, blood oxygen (pO2), carbonate (HCO3-), and base excess (BE), measured with arterial blood gas analysis. Both the Cox proportional hazard models for survival and the time to non-invasive ventilation (NIV) measurement highlighted that cMVV at diagnosis (considering cMVV(40) ≥ 80) is able to stratify patients across different risk levels for death/tracheostomy and NIV indication, especially considering patients with FVC% ≥ 80. In conclusion, cMVV is a useful marker of early respiratory failure in ALS, and is easily derivable from standard PFTs, especially in asymptomatic ALS patients with normal FVC measures.

Soil warming affects sap flow and stomatal gas exchange through altering functional traits in a subtropical forest

Climate warming influences the structure and function of ecosystems. However, the mechanisms of plant water use and gas exchange responses to climate warming have been less studied, especially from the perspective of different functional traits. We conducted a field experiment to investigate how soil warming (+2 °C) affects sap flow and stomatal gas exchange through plant functional traits and nutrient characteristics in a subtropical forest. We measured stomatal gas exchange of trees (Acacia auriculiformis and Schima superba) and shrubs (Castanea henryi and Psychotria asiatica), and monitored long-term sap flow of both tree species. Besides, plant leaf nutrient contents, functional traits, and soil nutrients were also studied. It is demonstrated that soil warming significantly increased maximum sap flow density (Js_max, 35.1 %) and whole-tree transpiration (EL, 46.0 %) of A. auriculiformis, but decreased those of S. superba (15.6 % and 14.9 %, respectively). Warming increased the photosynthetic rate of P. asiatica (18.0 %) and water use efficiency of S. superba (47.2 %). Leaf nutrients and stomatal anatomical characteristics of shrubs were less affected by soil warming. Soil warming increased (+42.7 %) leaf K content of A. auriculiformis in dry season. Decomposition of soil total carbon, total nitrogen, and available nitrogen was accelerated under soil warming, and soil exchangeable Ca2+ and Mg2+ were decreased. Trees changed stomatal and anatomic traits to adapt to soil warming, while shrubs altered leaf water content and specific leaf area under soil warming. Warming had a greater effect on sap flow of trees, as well as on their leaf gas exchange (total effect: −0.27) than on that of shrubs (total effect: 0.06). In summary, our results suggest that the combination of functional and nutrient traits can help to better understand plant water use and gas exchange responses under climate warming.

Unraveling carbon stock dynamics and their determinants in China's Loess Plateau over the past 40 years

Synergies and trade-offs among land use and land covers (LULCs) pose considerable uncertainties in achieving the dual carbon goals for China's Loess Plateau (CLP). In this context, we unraveled the carbon stock dynamics induced by land use and land cover change (LUCC) in the CLP over the past 40 years using the satellite-derived annual LULC maps and the InVEST model. Then, mixed measures were employed to quantify the global and local responses of the carbon stock dynamics to both natural and anthropogenic factors. We found that approximately a total of 5.58 × 109 Mg of carbon was stored in the CLP's ecosystems in 2019. Chronologically, the total carbon stock showed a slight decrease in the CLP from 1980 to 2019 due to the extensive LUCCs linked to socioeconomic activities. Specifically, the total carbon density loss rate accelerated in urban–rural-wild continuum (RUWC) types with higher human activity intensity, such as villages and urban, while it decelerated in woodlands, and croplands, where the human activity intensity is lower. Moreover, the total carbon density gain rate in wildlands was accelerating. Finally, we revealed that the carbon stock dynamics in the CLP over the past 40 years were primarily influenced by socioeconomic variables and have responded diversely to the drivers in space.

Carbon stock estimation of Sonneratia alba in mangrove restoration area in Pasar Rawa, Langkat North Sumatera

Mangrove forests must be protected because they are an important ecosystem for climate mitigation. Mangrove forests are one of the “blue carbon” ecosystems capable of absorbing significantly more carbon than terrestrial forests. Mangrove restoration is being carried out in various regions as part of an effort to rehabilitate damaged ecosystems, one of which being Pasar Rawa Village in Langkat Regency. Sonneratia alba is a native plant that is employed in restoration activities. The purpose of this study is to investigate carbon stock in the S. alba monoculture restoration area in Pasar Rawa Village, Langkat Regency, North Sumatra Province. Purposive sampling was employed in this study, with plots distributed evenly around the research area. Carbon stock estimation is performed non-destructively by estimating carbon estimates based on diameter at breast height (DBH) and total height of trees. According to the research findings, the total carbon stored in the Sonneratia alba restoration area is quite low, at 60.89 ton.ha−1. S. alba produced 192.13 ton.ha−1 of absorbed carbon with CO2 absorption of 19212.84 g/m2 and so was classified as low.

The carbon footprint of American Academy of Orthopaedic Surgeons and Pediatric Orthopaedic Society of North America national meetings

BackgroundThe health care sector contributes substantially to carbon emissions. Estimating the carbon emissions of an event can help determine its climate impact. This study calculates the carbon footprints of the 2019 American Academy of Orthopaedic Surgeons (AAOS) Annual Meeting and the 2019 Pediatric Orthopaedic Society of North America (POSNA) Annual Meeting. MethodsData regarding attendance volume, geographic origin of attendees and vendors, hotel room nights, event space, and duration of meetings were obtained from AAOS and POSNA. Data were entered into an online calculator designed to measure the carbon footprint of large events (www.terrapass.com). ResultsThe AAOS 2019 annual meeting was attended by 29 448 people, requiring 66 000 hotel room nights and 2 308 800 ft2 of convention center space for 5 days. We estimated 7179 short, 8374 medium, and 13 421 long-haul round-trip flights. The POSNA 2019 annual meeting was attended by 1103 people, requiring 1932 hotel room nights and 52 100 ft2 of convention center space for 4 days. We estimated 501 short, 280 medium, and 280 long-haul round-trip flights. The AAOS 2019 meeting emitted 26 075 metric tonnes of carbon dioxide equivalents (CO2e), while the POSNA 2019 meeting emitted 544 metric tonnes. Eighty-one percent of the carbon emissions from AAOS and 80% from POSNA came from flight travel alone. Carbon neutralization of in-person AAOS and POSNA annual meetings would require carbon-offset purchases of approximately $273 700 and $5700, respectively. ConclusionsAnnual orthopaedic meetings contribute to climate change through their large carbon footprint. Leaders in the field of orthopaedics should consider strategies to mitigate the impact of such meetings, examples of which include transitioning to hybrid formats when appropriate and by purchasing carbon offsets for essential in-person participation. Key Concepts1)Calculating the carbon footprint of an event estimates its total carbon dioxide emissions to help determine how to reduce its climate impact.2)The AAOS 2019 meeting emitted 26 075 metric tonnes (MT) of carbon dioxide equivalents (CO2e), while the POSNA 2019 meeting emitted 544MT, with ∼80% coming from air travel alone.3)Carbon neutralization of in-person AAOS and POSNA annual meetings would require carbon-offset purchases of approximately $273 700 and $5700, respectively. Level of EvidenceIV

Assessment of Particulate Matter, Heavy Metals, and Carbon Deposition Capacities of Urban Tree Species in Tehran, Iran

Air pollution is a pressing environmental concern in urban areas, with particulate matter (PM) posing serious health and environmental threats. Urban greening has emerged as a potential solution to capture and retain PM. This study assesses the PM deposition capacity of five common tree species: Morus alba (M. alba), Ailanthus altissima (A. altissima), Platanus orientalis (P. orientalis), Robinia pseudoacacia (R. pseudoacacia), and Ulmus minor (U. minor) in two highly polluted sites in Tehran, Iran. Additionally, this study investigates the accumulation of heavy metals (Ni, Fe, Cd, and Pb), Organic Carbon (OC), Elemental Carbon (EC), and Total Carbon (TC) on the leaves of these tree species. The results demonstrate species-specific differences in PM deposition capacity, with U. minor and M. alba showing high PM retention. A. altissima exhibits strong capability in adsorbing PM 0.1–2.5, while U. minor demonstrates greater retention of PM > 2.5. Moreover, the deposition of heavy metals varies among species, with R. pseudoacacia and A. altissima capturing higher levels. This study highlights the significance of appropriate tree utilization in urban environments against air pollution in order to make the air healthier in major cities. Awareness of the different tree species capacities leads urban planners and policymakers to make intelligent decisions about urban greening initiatives to improve air quality and overall well-being.

Airborne Suspended Particulate Matter and the Prevalence of Allergic Conjunctivitis in Japan.

Background This study aimed to examine the association of suspended particulate matter (SPM) with outpatient attendance for allergic conjunctivitis. Methodology The information on air pollution, encompassing total hydrocarbons, non-methane hydrocarbons, methane, carbon monoxide, nitrogen oxide, nitric oxide, oxidants, and SPM alongside data concerning daily weather conditions such as temperature, wind speed, and humidity, was gathered. Subsequently, the weekly mean values for outpatient visits, air pollution, and weather parameters were computed. Results The number of outpatient visits for allergic conjunctivitis was significantly associated with SPM levels (r = 0.70, p = 0.0037), oxidant levels (r = 0.70, p = 0.0038), wind speed (r = 0.48, p = 0.0472), and humidity (r = 0.77, p = 0.0009) from January to March, as well as SPM levels (r = 0.53, p = 0.0309) and carbon monoxide (r = 0.56, p = 0.0230) from April to June. Multivariate analysis showed that SPM (odds ratio = 1.37, p = 0.0161) and wind velocity (odds ratio = 1.52, p = 0.0038) were significant predictors of the number of outpatient visits from January to December. Conclusions SPM levels were the only independent predictor of outpatient visits for allergic conjunctivitis, suggesting that SPM contributes to the pathophysiology of this condition.

Reducing Livestock Greenhouse Gass Emissions by Forage Cultivation at Selobanteng, Situbondo, East Java, Indonesia

Cattle is the strategic commodities in Selobanteng Village, Situbondo, East Java. Based on population monograph data, total cattle population in Selobanteng was recorded around 23.35% of total cattle population in Banyuglugur District, Situbondo Regency. The efforts to reduce greenhouse gas emissions on livestock is through the planting of forage cultivation, which has a measured area and scheduled harvest time. In this way, the age of the forage plants will continue to regenerate so that they can periodically increase carbon absorption. This problem is answered by implementation of forage cultivating. This research was observed at Selobanteng, Banyuglugur sub-district, Situbondo district, East Java. Cattle population was recorded in April-June 2022. The ability of carbon absorption from the forage cultivation area was converted from February to September 2022. Greenhouse gas emissions from cattle, biomass and carbon from forage estimation refers to the Intergovernmental Panel on Climate Change - Agriculture, Forestry and Other Land Use. Total cattle population at Selobanteng was 1,230 cows which was equivalent to 674.6 animal units. Total greenhouse gas emissions based on livestock population is 81.52 Gg CO2-e/year. The forages planted in this program were calliandra, lamtoro, gmelina, corn, banana, rice, and elephant grass. The absorption value of total carbon emissions from forage were 137.68 Gg CO2-e/year. Surplus value of carbon absorption were 56.16 Gg CO2-e/year. Planting forage provides positive benefits for the environment to increase carbon absorption.

Nutrient content of vegetation and soil of four conifer species growing under different site and competing vegetation management conditions

In this study we examined the long-term effects of competing vegetation control on the total nutrient content of different ecosystem components of 19-year-old Douglas-fir (DF), western hemlock (WH), western redcedar (WRC), and grand fir (GF) stands growing in Oregon’s central Coast Range (CR) and of DF and WRC growing in Oregon’s Cascade mountain foothills (CF). Nutrient content responses were evaluated under two contrasting vegetation control treatments, including the Control (no herbicide application post-planting), and VM (5 consecutive years of herbicide application post-planting). Both treatments involved a pre-planting herbicide application. The ecosystem components were divided into overstory (planted crop trees), midstory, understory, forest floor, fine roots, and mineral soil. All samples were analyzed for content (mass per unit ground area) of total carbon, nitrogen, phosphorus, potassium, calcium, magnesium, sulfur, boron, copper, iron, manganese, sodium, and zinc. VM effects on total plant derived nutrient masses were more prominent than differences in concentrations. Ca was the only nutrient for which all species showed higher plant derived masses in the VM condition. Plant derived tissue content of C, Cu, P, and B all tended to be higher in VM plots, with the exception of WRC plots at the CR site. This case was an outlier due to the fact that Control plots developed significantly more biomass as a result of high midstory biomass, whereas the VM plots developed relatively little midstory and crop tree biomass. There were few differences in soil nutrients content between species and treatments, and those that were significant were unable to be explained by differences in uptake by plant species. Notably, total soil N of WRC at the CR site was significantly lower for VM plots. This may indicate the potential for VM applied to a slow growing species, such as WRC, to reduce ecosystem retention of N. With the exception of C and N, total soil nutrient reserves were orders of magnitude greater than total plant derived masses. This indicated that there is low probability of an adverse effect of VM on soil nutrient stores.

Straw Soil Conditioner Modulates Key Soil Microbes and Nutrient Dynamics across Different Maize Developmental Stages.

Soil amendments may enhance crop yield and quality by increasing soil nutrient levels and improving nutrient absorption efficiency, potentially through beneficial microbial interactions. In this work, the effects of amending soil with straw-based carbon substrate (SCS), a novel biochar material, on soil nutrients, soil microbial communities, and maize yield were compared with those of soil amendment with conventional straw. The diversity and abundance of soil bacterial and fungal communities were significantly influenced by both the maize growth period and the treatment used. Regression analysis of microbial community variation indicated that Rhizobiales, Saccharimonadales, and Eurotiales were the bacterial and fungal taxa that exhibited a positive response to SCS amendment during the growth stages of maize. Members of these taxa break down organic matter to release nutrients that promote plant growth and yield. In the seedling and vegetative stages of maize growth, the abundance of Rhizobiales is positively correlated with the total nitrogen (TN) content in the soil. During the tasseling and physiological maturity stages of corn, the abundance of Saccharimonadales and Eurotiales is positively correlated with the content of total carbon (TC), total phosphorus (TP), and available phosphorus (AP) in the soil. The results suggest that specific beneficial microorganisms are recruited at different stages of maize growth to supply the nutrients required at each stage. This targeted recruitment strategy optimizes the availability of nutrients to plants and ultimately leads to higher yields. The identification of these key beneficial microorganisms may provide a theoretical basis for the targeted improvement of crop yield and soil quality. This study demonstrates that SCS amendment enhances soil nutrient content and crop yield compared with conventional straw incorporation and sheds light on the response of soil microorganisms to SCS amendment, providing valuable insights for the future implementation of this material.

Performance of industrially implemented turbulent contact absorbers – A comparative study

The current study aims to assess the performance and industrial feasibility of using three-phase fluidized bed absorption columns for post-combustion carbon dioxide (CO2) capture. The analysis is based on a mathematical model of a scaled-up fluidized bed absorption column that has been validated using pilot plant experimental data. The focus is on evaluating the energy efficiency of the fluidized bed column in comparison to packed bed technologies, which are currently widely used. The results of the analysis are evaluated in terms of three performance indicators (i.e., absorption efficiency, carbon capture rate, and energy performance index) and compared to packed bed columns. Simulation results indicate that the best column configuration is represented by a three-stage absorber and that the system performs optimally when particle diameter and density decrease with each section. Consequently, this leads to an increase in the total fluidized bed height and carbon capture rate by up to 25%. The energy performance index is maintained below 3.6, indicating an energy-efficient operation of the system. As such, the findings of this study suggest that the use of gas-solid-liquid three-phase fluidized bed absorption columns for post-combustion CO2 capture is a promising technology for the implementation of CCUS and for achieving of climate neutrality targets.

Understanding the Relations between Soil Biochemical Properties and N2O Emissions in a Long-Term Integrated Crop–Livestock System

Edaphoclimatic conditions influence nitrous oxide (N2O) emissions from agricultural systems where soil biochemical properties play a key role. This study addressed cumulative N2O emissions and their relations with soil biochemical properties in a long-term experiment (26 years) with integrated crop–livestock farming systems fertilized with two P and K rates. The farming systems consisted of continuous crops fertilized with half of the recommended P and K rates (CCF1), continuous crops at the recommended P and K rates (CCF2), an integrated crop–livestock system with half of the recommended P and K rates (ICLF1), and an integrated crop–livestock at the recommended P and K rates (ICLF2). The ICLF2 may have promoted the greatest entry of carbon into the soil and positively influenced the soil’s biochemical properties. Total carbon (TC) was highest in ICLF2 in both growing seasons. The particulate and mineral-associated fractions in 2016 and 2017, respectively, and the microbial biomass fraction in the two growing seasons were also very high. Acid phosphatase and arylsulfatase in ICLF1 and ICLF2 were highest in 2016. The soil properties correlated with cumulative N2O emissions were TC, total nitrogen (TN), particulate nitrogen (PN), available nitrogen (AN), mineral-associated organic carbon (MAC), and microbial biomass carbon (MBC). The results indicated that ICLF2 induces an accumulation of more stable organic matter (OM) fractions that are unavailable to the microbiota in the short term and result in lower N2O emissions.

Micro-biological degradation and transformation of dissolved organic matter following continuous cropping of tobacco.

In recent years, the problems associated with continuous cropping (CC) that cause soil degradation have become increasingly serious. As a key soil quality property, dissolved organic matter (DOM) affects the circulation of carbon and nutrients and the composition of bacterial communities in soil. However, research on the changes in the molecular composition of DOM after CC is limited. In this study, the soil chemical properties, DOM chemical diversity, bacterial community structure, and their interactions are explored in the soil samples from different CC years (CC1Y, CC3Y, CC5Y, and CC7Y) of tobacco. With increasing CC year of tobacco, most of the soil chemical properties, such as total carbon, total nitrogen and organic matter, decreased significantly, while dissolved organic carbon first decreased and then increased. Likewise, the trends of DOM composition differed with changing duration of CC, such as the tannin compounds decreased from 18.13 to 13.95%, aliphatic/proteins increased from 2.73 to 8.85%. After 7 years of CC, the soil preferentially produced compounds with either high H/C ratios (H/C > 1.5), including carbohydrates, lipids, and aliphatic/proteins, or low O/C ratios (O/C < 0.1), such as unsaturated hydrocarbons. Furthermore, core microorganisms, including Nocardioides, wb1-P19, Aquabacterium, Methylobacter, and Thiobacillus, were identified. Network analysis further indicated that in response to CC, Methylobacter and Thiobacillus were correlated with the microbial degradation and transformation of DOM. These findings will improve our understanding of the interactions between microbial community and DOM in continuous cropping soil.

City-level building operation and end-use carbon emissions dataset from China for 2015–2020

sThe building sector, which accounts for over 20% of China’s total energy-related carbon emissions, has great potential to reduce emissions and is critical to achieving China’s emissions peak and carbon neutrality targets. However, the lack of data on operational carbon emissions and end-use carbon emissions in the building sector at the city level has become a major barrier to the development of building energy conservation policies and carbon peaking action plans. This study uses a combination of “top-down” and “bottom-up” methods to account for the operational carbon emissions of buildings in 321 cities in China from 2015 to 2020. The energy consumption in buildings is further broken down into six end uses: central heating, distributed heating, cooking and water heating (C&W), lighting, cooling, appliances and others (A&O). The dataset can serve as a reference to support city-level policies on peak building emissions and is of great value for the improvement of the carbon emissions statistical accounting system.

Impact of Urbanization on the Sustainable Production of Regional Specialty Food: Evidence from China’s Potato Production

The rapid urbanization process has gradually deepened its role in the sustainable development of agriculture, especially in the sustainable supply of food in poor areas, and has attracted more attention from international academic circles. However, the impact mechanism of different dimensions of urbanization on food sustainability in poor areas has not yet been fully unpacked. Therefore, this study focuses on potatoes as a specialty food mainly grown in poor areas of China, explores the impact mechanism of urbanization on the carbon emission intensity of potato production (CEIPP) with the spatial Durbin model, and compares with the carbon emission intensity of staple grain (CEISG) results. The main conclusions are as follows: the urbanization of main potato-producing areas developed rapidly from 2002 to 2020, which is in line with the decrease in CEIPP. The decrease in CEIPP has a significant impact on slowing down the growth of total carbon emissions and has greater potential for reduction, especially in Central and Western China, which has a large poverty-stricken population. Compared with traditional staple grain, urbanization has become a key factor influencing CEIPP. The results indicate that different dimensions of urbanization have varying degrees of impact on the sustainable production of regional specialty foods in China. The improvement of comprehensive urbanization, population urbanization, and economic urbanization reduces CEIPP, while land urbanization increases CEIPP. Therefore, to reduce CEIPP and promote its sustainable development, it is necessary to improve population urbanization and economic urbanization, properly avoid the disorderly expansion of land urbanization, and improve the quality and level of comprehensive urbanization.

Evaluation of Fine Root Morphology and Rhizosphere Environmental Characteristics of the Dioecious Idesia polycarpa Maxim

To explore the differences in the fine root characteristics and rhizosphere environment of male and female Idesia polycarpa Maxim at different stages, 7-year-old male and female I. polycarpa were used as plant materials. The fine root characteristics were measured with a root scanner, and rhizosphere soil was collected at the flowering stage (May), fruit accumulation stage (July), and fruit maturity stage (October). In addition, this study analyzed the soil nutrient characteristics of these conditions at different stages. At the same time, Illumine high-throughput sequencing technology and gas chromatography–tandem mass spectrometry (GC–MS) technology were used to analyze the rhizosphere microbes and metabolites of male and female plants at different stages. The results showed that the total root length, surface area, total volume, root tip number, and total average diameter of the fine root of female plants were larger than those of male plants, and the difference reached its maximum in the fruit material accumulation stage. Total carbon (TC) and total nitrogen (TN) content in the rhizosphere soil of male and female plants significantly differed over multiple stages, while available soil nitrogen and potassium content significantly differed during fruit ripening. The rhizosphere microbial composition of male and female plants was similar, and the dominant bacteria in the rhizosphere soil of each stage were Proteobacteria, Acidobacteria, Ascomycota, and Mortierellomycota. The relative abundance of Bacillus, Arthrobacter, Volutella, and Neocosmospora in rhizosphere soil at different stages differed between male and female plants. Combined with the OPLS-DA model and database retrieval, 29 significantly different metabolites, most of which were carbohydrates, were detected in the rhizosphere soil of male and female plants. Moreover, there were more significant metabolites in the rhizosphere soil at the flowering stage than in the fruit ripening stage. Through RDA analysis, available potassium (AK), Pedomicrobium, Chaetomium, and Glucose 1 had the greatest influence on fine root traits of I. polycarpa. The results indicated that the fine root traits were negatively correlated with AK and rhizosphere metabolites. Moreover, positive correlations were found with rhizosphere microorganism traits. The above results laid a foundation for the field management of I. polycarpa and the screening and application of rhizosphere growth-promoting bacteria resources.