{"title":"Isotope signature and ecoenzymatic stoichiometry as key indicators of urban soil functionality","authors":"Francesca Vannucchi, Andrea Scartazza, Cristina Macci, Francesca Bretzel, Serena Doni, Irene Rosellini, Eliana Tassi, Roberto Pini, Grazia Masciandaro, Eleonora Peruzzi","doi":"10.1007/s11368-024-03892-w","DOIUrl":null,"url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Purpose</h3><p>This study aimed to assess the feasibility of the ecoenzymatic stoichiometry and isotope signature approaches as indicators of urban soil functionality, related to carbon and nutrient cycles.</p><h3 data-test=\"abstract-sub-heading\">Methods</h3><p>In Pisa and Livorno (Italy), study sites with three degrees of urbanization (natural, peri-urban and central urban sites) were selected, where holm oak (<i>Quercus ilex</i> L.) was the most common evergreen species. The urban and peri-urban sites differed in terms of NO<sub>2</sub> emissions. At each site, topsoil and plant litter were sampled, pH, EC, TOC, and TN were measured in soil and δ<sup>13</sup>C and δ<sup>15</sup>N in soil and plant litter. The β-glucosidase, acid phosphatase and N-acetyl-β-D-glucosaminidase enzyme activities were also determined in soil and the ratios were calculated.</p><h3 data-test=\"abstract-sub-heading\">Results</h3><p>The δ<sup>15</sup>N in plant litter increased from peri-urban to urban sites, along with the NO<sub>2</sub> emissions, emerging as a sensitive indicator of atmospheric N deposition. The δ<sup>15</sup>N and δ<sup>13</sup>C increased in soil, indicating more rapid N cycles and organic matter degradation in peri-urban and urban areas than in natural areas. The ecoenzymatic stoichiometry revealed C and P microbial limitations for all the sites studied. However, the microbial needs of C and P increased and decreased, respectively, along the urbanization gradient. Isotope abundance and microbial nutrient limitations were found to correlate with soil properties. Specifically, soil δ<sup>15</sup>N was closely correlated with microbial C limitations.</p><h3 data-test=\"abstract-sub-heading\">Conclusion</h3><p>The isotope signature and enzymatic stoichiometry used as indicators revealed that the soil characteristics affected the soil carbon and nutrient cycles as well as microbial energy and nutrient needs.</p>","PeriodicalId":17139,"journal":{"name":"Journal of Soils and Sediments","volume":"25 1","pages":""},"PeriodicalIF":2.8000,"publicationDate":"2024-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Soils and Sediments","FirstCategoryId":"97","ListUrlMain":"https://doi.org/10.1007/s11368-024-03892-w","RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"ENVIRONMENTAL SCIENCES","Score":null,"Total":0}
引用次数: 0
Abstract
Purpose
This study aimed to assess the feasibility of the ecoenzymatic stoichiometry and isotope signature approaches as indicators of urban soil functionality, related to carbon and nutrient cycles.
Methods
In Pisa and Livorno (Italy), study sites with three degrees of urbanization (natural, peri-urban and central urban sites) were selected, where holm oak (Quercus ilex L.) was the most common evergreen species. The urban and peri-urban sites differed in terms of NO2 emissions. At each site, topsoil and plant litter were sampled, pH, EC, TOC, and TN were measured in soil and δ13C and δ15N in soil and plant litter. The β-glucosidase, acid phosphatase and N-acetyl-β-D-glucosaminidase enzyme activities were also determined in soil and the ratios were calculated.
Results
The δ15N in plant litter increased from peri-urban to urban sites, along with the NO2 emissions, emerging as a sensitive indicator of atmospheric N deposition. The δ15N and δ13C increased in soil, indicating more rapid N cycles and organic matter degradation in peri-urban and urban areas than in natural areas. The ecoenzymatic stoichiometry revealed C and P microbial limitations for all the sites studied. However, the microbial needs of C and P increased and decreased, respectively, along the urbanization gradient. Isotope abundance and microbial nutrient limitations were found to correlate with soil properties. Specifically, soil δ15N was closely correlated with microbial C limitations.
Conclusion
The isotope signature and enzymatic stoichiometry used as indicators revealed that the soil characteristics affected the soil carbon and nutrient cycles as well as microbial energy and nutrient needs.
期刊介绍:
The Journal of Soils and Sediments (JSS) is devoted to soils and sediments; it deals with contaminated, intact and disturbed soils and sediments. JSS explores both the common aspects and the differences between these two environmental compartments. Inter-linkages at the catchment scale and with the Earth’s system (inter-compartment) are an important topic in JSS. The range of research coverage includes the effects of disturbances and contamination; research, strategies and technologies for prediction, prevention, and protection; identification and characterization; treatment, remediation and reuse; risk assessment and management; creation and implementation of quality standards; international regulation and legislation.