Urban soil microbial community and microbial-related carbon storage are severely limited by sealing

Abstract

Purpose Urbanisation causes changes in land use, from natural or rural to urban, leading to the sealing of soil and the replacement of vegetation by buildings, roads and pavements. The sealing process impacts soil properties and services and can lead to negative consequences for microbial attributes and processes in soil. At present, information about the microbial community following soil sealing is limited. As such, we investigated how changes in soil physical and chemical properties caused by sealing affect the soil microbial community and soil ecosystem services. Material and methods Soils were sampled beneath impervious pavements (sealed) and from adjacent pervious greenspace areas (unsealed). Soil properties (total C, total N, C:N ratio and water content) and microbial attributes (microbial biomass C, N-mineralisation and phospholipid fatty acids—PLFA) were measured and correlated. Results and discussion A reduction of total C, total N, and water content were observed in sealed soil, whilst the C:N ratio increased. Sealed soil also presented a reduction in microbial attributes, with low N-mineralisation revealing suppressed microbial activity. PLFA data presented positive correlations with total C, total N and water content, suggesting that the microbial community may be reduced in sealed soil as a response to soil properties. Furthermore, fungal:bacterial and gram-positive:gram-negative bacterial ratios were lower in sealed soil indicating degradation in C sequestration and a consequential effect on C storage. Conclusions Sealing causes notable changes in soil properties leading to subsequent impacts upon the microbial community and the reduction of microbial activity and soil C storage potential.

Plant Growth Modifications Due to Coastal Embankments Affect Soil Bacterial and Archaeal Communities Over the Growing Season in Salt Marshes of Eastern China

“…6). An increased C/N ratio typically suggests that soils are degraded due to the loss of C, which limits microbial growth (Pereira et al 2021). However, in this study, embankments did not change the soil C/N ratio for all vegetation types; thus, they did not modify the microbial community composition by altering the soil C/N ratio (Table 2).…”

Land recycling, food security and Technosols

“…Added to consequences previously stated related to land take, soil sealing upsets environmental balance, because soil ecosystem is isolated from others. Impervious soil not only implies a reduction in capacity to provide ecosystem services, but also supposes provision of negative services (disservices) such as intensification of the urban heat island effect, increase risk of flooding, reduce filtering water that drains into aquifers and evapotranspiration, and adversely affect biodiversity and carbon cycle [3,10,[16][17][18][19] . Consequently, Sobocká et al (2021) [18] concludes that urban centers are the "most environmentally sensitive area" due to high rates of soil sealing (more than 80%) and urban heat island effects, and lack of green areas.…”

“…At this point, we wonder if it is necessary to use topsoil from elsewhere to restore desealed soils, if de-sealed soils can achieve ecosystem services levels prior to sealing, and if so, if de-sealed soils can become biomass producers. Sealed soils experience an alteration of their properties, worse soil structure and organic matter, and moderate to high amount of trace elements, leading to a drastic reduction in microbial community, among others aftermaths [17,18] . In cases where it is completely necessary to add topsoil on de-sealed soils, an option to consider may be incorporation of Technosols made by wastes, to enhance ecosystem services [38] .…”

Comparison of soil organic carbon and nitrogen dynamics between urban impervious surfaces and vegetation

“…Thirdly, the IS may have an effect on the decomposition of SOM (Piotrowska-Długosz & Charzy nski, 2015). IS may lead to a slower turnover of SOM pools due to the hindered energy and gas exchanges between atmosphere and soil, which could eventually facilitate C accumulation (Cheng et al, 2013;Pereira et al, 2021). Nevertheless, soils beneath IS might continue to be utilized as habitats for microorganisms and invertebrates, and therefore microbial degradation and losses of soil C and N can still be ongoing (Hu et al, 2018;Lehmann & Stahr, 2007;Pereira et al, 2021).…”

“…IS may lead to a slower turnover of SOM pools due to the hindered energy and gas exchanges between atmosphere and soil, which could eventually facilitate C accumulation (Cheng et al, 2013;Pereira et al, 2021). Nevertheless, soils beneath IS might continue to be utilized as habitats for microorganisms and invertebrates, and therefore microbial degradation and losses of soil C and N can still be ongoing (Hu et al, 2018;Lehmann & Stahr, 2007;Pereira et al, 2021). The above inconsistency might result from multiple factors, including historical land use, disturbance, climatic factors, and sealing ages of IS (Majidzadeh et al, 2017).…”