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Guo Y, Han J, Bao H, Wu Y, Shen L, Xu X, Chen Z, Smith P, Abdalla M. A systematic analysis and review of soil organic carbon stocks in urban greenspaces. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 948:174788. [PMID: 39019284 DOI: 10.1016/j.scitotenv.2024.174788] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2024] [Revised: 07/10/2024] [Accepted: 07/12/2024] [Indexed: 07/19/2024]
Abstract
Urban greenspaces typically refer to urban wetland, urban forest and urban turfgrass. They play a critical role in carbon sequestration by absorbing carbon from the atmosphere; however, their capacity to retain and store carbon in the form of soil organic carbon (SOC) varies significantly. This study provides a systematic analysis and review on the capacity of different urban greenspace types in retaining and storing SOC in 30 cm soil depth on a global scale. Data came from 78 publications on the subject of SOC stocks, covering different countries and climate zones. Overall, urban greenspace types exerted significant influences on the spatial pattern of SOC stocks, with the highest value of 18.86 ± 11.57 kg m-2 (mean ± standard deviation) in urban wetland, followed by urban forest (6.50 ± 3.65 kg m-2), while the lowest mean value of 4.24 ± 3.28 kg m-2 was recorded in urban turfgrass soil. Soil organic carbon stocks in each urban greenspace type were significantly affected by climate zones, management/environmental settings, and selected soil properties (i.e. soil bulk density, pH and clay content). Furthermore, our analysis showed a significantly negative correlation between SOC stocks and human footprint in urban wetland, but a significantly positive relationship in urban forest and urban turfgrass. A positive correlation between SOC stocks and human footprint indicates that increased human activity and development can enhance SOC stocks through effective management and green infrastructure. Conversely, a negative correlation suggests that improper management of human activities can degrade SOC stocks. This highlights the need for sustainable practices to maintain or enhance SOC accumulation in urban greenspaces.
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Affiliation(s)
- Yang Guo
- Research Institute for Urban Planning and Sustainability, Hangzhou City University, Hangzhou 310015, China; School of Public Affairs, Zhejiang University, Hangzhou 310058, China
| | - Jiatong Han
- College of Global Change and Earth System Science, Beijing Normal University, Beijing 100875, China
| | - Haijun Bao
- Research Institute for Urban Planning and Sustainability, Hangzhou City University, Hangzhou 310015, China.
| | - Yuzhe Wu
- School of Public Affairs, Zhejiang University, Hangzhou 310058, China
| | - Liyin Shen
- Research Institute for Urban Planning and Sustainability, Hangzhou City University, Hangzhou 310015, China
| | - Xiangrui Xu
- Research Institute for Urban Planning and Sustainability, Hangzhou City University, Hangzhou 310015, China
| | - Ziwei Chen
- Research Institute for Urban Planning and Sustainability, Hangzhou City University, Hangzhou 310015, China
| | - Pete Smith
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen AB24 3UU, UK
| | - Mohamed Abdalla
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen AB24 3UU, UK
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Li J, Chen C, Ji L, Wen S, Peng J, Yang L, He G. Urbanization-driven forest soil greenhouse gas emissions: Insights from the role of soil bacteria in carbon and nitrogen cycling using a metagenomic approach. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 923:171364. [PMID: 38438026 DOI: 10.1016/j.scitotenv.2024.171364] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2023] [Revised: 02/07/2024] [Accepted: 02/27/2024] [Indexed: 03/06/2024]
Abstract
Increasing population densities and urban sprawl have induced greenhouse gas (GHG) emissions from the soil, and the soil microbiota of urban forests play a critical role in the production and consumption of GHGs, supporting green development. However, the function and potential mechanism of soil bacteria in GHG emissions from forests during urbanization processes need to be better understood. Here, we measured the fluxes of carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) in Cinnamomum camphora forest soils along an urbanization gradient. 16S amplicon and metagenomic sequencing approaches were employed to examine the structure and potential functions of the soil bacterial community involved in carbon (C) and nitrogen (N) cycling. In this study, the CH4 and CO2 emissions from urban forest soils (sites U and G) were significantly greater than those from suburban soils (sites S and M). The N2O emissions in the urban center (site U) were 24.0 % (G), 13.8 % (S), and 13.5 % (M) greater than those at the other three sites. These results were related to the increasing bacterial alpha diversity, interactions, and C and N cycling gene abundances (especially those involved in denitrification) in urban forest soils. Additionally, the soil pH and metal contents (K, Ca, Mg) affected key bacterial populations (such as Methylomirabilota, Acidobacteriota, and Proteobacteria) and indicators (napA, nosZ, nrfA, nifH) involved in reducing N2O emissions. The soil heavy metal contents (Fe, Cr, Pb) were the main contributors to CH4 emissions, possibly by affecting methanogens (Desulfobacterota) and methanotrophic bacteria (Proteobacteria, Actinobacteriota, and Patescibacteria). Our study provides new insights into the benefits of conservation-minded urban planning and close-to-nature urban forest management and construction, which are conducive to mitigating GHG emissions and supporting urban sustainable development by mediating the core bacterial population.
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Affiliation(s)
- Jing Li
- School of Forestry, Central South University of Forestry and Technology, 498 Shaoshan South Road, 410004 Changsha, PR China
| | - Chuxiang Chen
- School of Forestry, Central South University of Forestry and Technology, 498 Shaoshan South Road, 410004 Changsha, PR China
| | - Li Ji
- School of Forestry, Central South University of Forestry and Technology, 498 Shaoshan South Road, 410004 Changsha, PR China.
| | - Shizhi Wen
- School of Forestry, Central South University of Forestry and Technology, 498 Shaoshan South Road, 410004 Changsha, PR China
| | - Jun Peng
- Hunan Geological Experiment and Testing Center, Changsha, 290 Middle Chengnan Road, 410007, PR China
| | - Lili Yang
- School of Forestry, Central South University of Forestry and Technology, 498 Shaoshan South Road, 410004 Changsha, PR China
| | - Gongxiu He
- School of Forestry, Central South University of Forestry and Technology, 498 Shaoshan South Road, 410004 Changsha, PR China.
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Yao Z, Guo H, Wang Y, Zhan Y, Zhang T, Wang R, Zheng X, Butterbach-Bahl K. A global meta-analysis of yield-scaled N 2 O emissions and its mitigation efforts for maize, wheat, and rice. GLOBAL CHANGE BIOLOGY 2024; 30:e17177. [PMID: 38348630 DOI: 10.1111/gcb.17177] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Revised: 01/09/2024] [Accepted: 01/22/2024] [Indexed: 02/15/2024]
Abstract
Maintaining or even increasing crop yields while reducing nitrous oxide (N2 O) emissions is necessary to reconcile food security and climate change, while the metric of yield-scaled N2 O emission (i.e., N2 O emissions per unit of crop yield) is at present poorly understood. Here we conducted a global meta-analysis with more than 6000 observations to explore the variation patterns and controlling factors of yield-scaled N2 O emissions for maize, wheat and rice and associated potential mitigation options. Our results showed that the average yield-scaled N2 O emissions across all available data followed the order wheat (322 g N Mg-1 , with the 95% confidence interval [CI]: 301-346) > maize (211 g N Mg-1 , CI: 198-225) > rice (153 g N Mg-1 , CI: 144-163). Yield-scaled N2 O emissions for individual crops were generally higher in tropical or subtropical zones than in temperate zones, and also showed a trend towards lower intensities from low to high latitudes. This global variation was better explained by climatic and edaphic factors than by N fertilizer management, while their combined effect predicted more than 70% of the variance. Furthermore, our analysis showed a significant decrease in yield-scaled N2 O emissions with increasing N use efficiency or in N2 O emissions for production systems with cereal yields >10 Mg ha-1 (maize), 6.6 Mg ha-1 (wheat) or 6.8 Mg ha-1 (rice), respectively. This highlights that N use efficiency indicators can be used as valuable proxies for reconciling trade-offs between crop production and N2 O mitigation. For all three major staple crops, reducing N fertilization by up to 30%, optimizing the timing and placement of fertilizer application or using enhanced-efficiency N fertilizers significantly reduced yield-scaled N2 O emissions at similar or even higher cereal yields. Our data-driven assessment provides some key guidance for developing effective and targeted mitigation and adaptation strategies for the sustainable intensification of cereal production.
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Affiliation(s)
- Zhisheng Yao
- State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, P.R. China
- College of Earth and Planetary Science, University of Chinese Academy of Sciences, Beijing, P.R. China
| | - Haojie Guo
- State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, P.R. China
- College of Earth and Planetary Science, University of Chinese Academy of Sciences, Beijing, P.R. China
| | - Yan Wang
- State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, P.R. China
| | - Yang Zhan
- State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, P.R. China
- College of Earth and Planetary Science, University of Chinese Academy of Sciences, Beijing, P.R. China
| | - Tianli Zhang
- State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, P.R. China
| | - Rui Wang
- State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, P.R. China
| | - Xunhua Zheng
- State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, P.R. China
- College of Earth and Planetary Science, University of Chinese Academy of Sciences, Beijing, P.R. China
| | - Klaus Butterbach-Bahl
- State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, P.R. China
- Institute for Meteorology and Climate Research, Atmospheric Environmental Research, Karlsruhe Institute of Technology, Garmisch-Partenkirchen, Germany
- Pioneer Center Land-CRAFT, Department of Agroecology, Aarhus University, Aarhus C, Denmark
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Liu W, Sun J, Li S, Zhao R. Impacts of local soil and vehicle NO x emissions on ground-level NO 2 concentrations on a university campus in the city of Shenyang, China. ENVIRONMENTAL MONITORING AND ASSESSMENT 2023; 196:63. [PMID: 38112882 DOI: 10.1007/s10661-023-12098-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Accepted: 11/04/2023] [Indexed: 12/21/2023]
Abstract
Nitrogen dioxide (NO2) is a ubiquitous atmospheric pollutant, and fossil fuel combustion is generally considered its predominant source in and around urban areas. As the total nitrogen deposition is high over here, soil NOx emissions from urban green space might also be an important local source of ground-level NO2. In this study, Willems badge samplers were employed to monitor the spatial and seasonal variations of 2-week mean atmospheric NO2 concentrations at a height of 1.7 m on an urban campus in Northeast China from November 2020 to December 2021. We found considerable small-scale spatial variations of ground-level NO2 concentrations on the campus during the growing season, with local soil NOx emissions as the main driver. According to its linear correlation with green space coverage, the increment in ground-level NO2 concentration was partitioned into two components, with one ascribed to the local soil source (referred to as NO2-Isoil) and the other the local vehicle source (NO2-Ivehicle). NO2-Isoil generally reached a maximum (as high as 25.6 μg/m3) during early spring, while its ratio to the background value generally reached a maximum (could be >1) during late spring and could reach 0.52 to 0.92 during summer. Therefore, soil NOx emissions were an important source of ground-level NO2 on the campus, with the contribution even higher than those of other anthropogenic sources during late spring. Even with light traffic on the campus, NO2-Ivehicle could reach 0.48 times the background value at a site with high frequencies of warm starts.
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Affiliation(s)
- Wei Liu
- College of Environment and Safety Engineering, Shenyang University of Chemical Technology, Shenyang, 110142, Liaoning, China.
| | - Jiahui Sun
- College of Environment and Safety Engineering, Shenyang University of Chemical Technology, Shenyang, 110142, Liaoning, China
| | - Sulian Li
- Research Institute No. 240, China National Nuclear Corporation, Shenyang, 110135, Liaoning, China
| | - Rongbo Zhao
- College of Environment and Safety Engineering, Shenyang University of Chemical Technology, Shenyang, 110142, Liaoning, China
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Chien SC, Krumins JA. Anthropogenic effects on global soil nitrogen pools. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 902:166238. [PMID: 37586519 DOI: 10.1016/j.scitotenv.2023.166238] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Revised: 08/07/2023] [Accepted: 08/09/2023] [Indexed: 08/18/2023]
Abstract
The amount of nitrogen stored in terrestrial soils, its "nitrogen pool", moderates biogeochemical cycling affecting primary productivity, nitrogen pollution and even carbon budgets. The soil nitrogen pools and the transformation of nitrogen forms within them are heavily influenced by environmental factors including anthropogenic activities. However, our understanding of the global distribution of soil nitrogen with respect to anthropogenic activity and human land use remains unclear. We constructed a meta-analysis from a global sampling, in which we compare soil total nitrogen pools and the driving mechanisms affecting each pool across three major classifications of human land use: natural, agricultural, and urban. Although the size of the nitrogen pool can be similar across natural, agricultural and urban soils, the ecological and human associated drivers vary. Specifically, the drivers within agricultural and urban soils as opposed to natural soils are more complex and often decoupled from climatic and soil factors. This suggests that the nitrogen pools of those soils may be co-moderated by other factors not included in our analyses, like human activities. Our analysis supports the notion that agricultural soils act as a nitrogen source while urban soils as a nitrogen sink and informs a modern understanding of the fates and distributions of anthropogenic nitrogen in natural, agricultural, and urban soils.
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Affiliation(s)
- Shih-Chieh Chien
- Doctoral Program in Environmental Science and Management, Montclair State University, Montclair, NJ, 07043, USA.
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Xia N, Du E, Tang Y, Guo H. A distinctive latitudinal trend of nitrogen isotope signature across urban forests in eastern China. GLOBAL CHANGE BIOLOGY 2023; 29:5666-5676. [PMID: 37555694 DOI: 10.1111/gcb.16899] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2023] [Revised: 07/19/2023] [Accepted: 07/20/2023] [Indexed: 08/10/2023]
Abstract
Rapid urbanization has greatly altered nitrogen (N) cycling from regional to global scales. Compared to natural forests, urban forests receive much more external N inputs with distinctive abundances of stable N isotope (δ15 N). However, the large-scale pattern of soil δ15 N and its imprint on plant δ15 N remain less well understood in urban forests. By collecting topsoil (0-20 cm) and leaf samples from urban forest patches in nine large cities across a north-south transect in eastern China, we analyzed the latitudinal trends of topsoil C:N ratio and δ15 N as well as the correlations between tree leaf δ15 N and topsoil δ15 N. We further explored the spatial variation of topsoil δ15 N explained by corresponding climatic, edaphic, vegetation-associated, and anthropogenic drivers. Our results showed a significant increase of topsoil C:N ratio towards higher latitudes, suggesting lower N availability at higher latitudes. Topsoil δ15 N also increased significantly at higher latitudes, being opposite to the latitudinal trend of soil N availability. The latitudinal trend of topsoil δ15 N was mainly explained by mean annual temperature, mean annual precipitation, and atmospheric deposition of both ammonium and nitrate. Consequently, tree leaf δ15 N showed significant positive correlations with topsoil δ15 N across all sampled plant species and functional types. Our findings reveal a distinctive latitudinal trend of δ15 N in urban forests and highlight an important role of anthropogenic N sources in shaping the large-scale pattern of urban forest 15 N signature.
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Affiliation(s)
- Nan Xia
- State Key Laboratory of Earth Surface Processes and Resource Ecology, Faculty of Geographical Science, Beijing Normal University, Beijing, China
- School of Natural Resources, Faculty of Geographical Science, Beijing Normal University, Beijing, China
| | - Enzai Du
- State Key Laboratory of Earth Surface Processes and Resource Ecology, Faculty of Geographical Science, Beijing Normal University, Beijing, China
- School of Natural Resources, Faculty of Geographical Science, Beijing Normal University, Beijing, China
| | - Yang Tang
- State Key Laboratory of Earth Surface Processes and Resource Ecology, Faculty of Geographical Science, Beijing Normal University, Beijing, China
- School of Natural Resources, Faculty of Geographical Science, Beijing Normal University, Beijing, China
| | - Hongbo Guo
- State Key Laboratory of Earth Surface Processes and Resource Ecology, Faculty of Geographical Science, Beijing Normal University, Beijing, China
- School of Natural Resources, Faculty of Geographical Science, Beijing Normal University, Beijing, China
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7
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Shurpali NJ. Urbanization associated changes in biogeochemical cycles. GLOBAL CHANGE BIOLOGY 2023; 29:3237-3239. [PMID: 37021700 DOI: 10.1111/gcb.16698] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Revised: 03/22/2023] [Accepted: 03/23/2023] [Indexed: 05/16/2023]
Affiliation(s)
- Narasinha J Shurpali
- Atmosphere Biosphere Interactions, Grasslands and Sustainable Farming Research Group, Production Systems Unit, Natural Resources Institute Finland (Luke), Halolantie 31 A, 71750, Maaninka, Finland
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