The effects of sealing on urban soil carbon and nutrients

Abstract

Abstract. Urban soils are of increasing interest for their potential to provide ecosystem services such as carbon storage and nutrient cycling. Despite this, there is limited knowledge on how soil sealing with impervious surfaces, a common disturbance in urban environments, affects these important ecosystem services. In this paper, we investigate the effect of soil sealing on soil properties, soil carbon and soil nutrient stocks. We undertook a comparative survey of sealed and unsealed greenspace soils across the UK city of Manchester. Our results reveal that the context of urban soil and the anthropogenic artefacts added to soil have a great influence on soil properties and functions. In general, sealing reduced soil carbon and nutrient stocks compared to greenspace soil, however, where there were anthropogenic additions of organic and mineral artefacts this led to increases in soil carbon and nitrate content. Anthropogenic additions led to carbon stocks equivalent to or larger than those in greenspaces, potentially of a stable nature with long residence times. This suggests that in areas with an industrial past, anthropogenic additions can lead to a legacy carbon store in urban soil and make important contributions to urban soil carbon budgets. These findings shed light on the heterogeneity of urban sealed soil and the influence of anthropogenic artefacts on soil functions. Our research highlights the need to gain further understanding into urban soil processes, in both sealed and unsealed soils, and the influence and legacy of anthropogenic additions on soil functions and important ecosystem services.

Urban Land Conversion Reduces Soil Organic Carbon Density Under Impervious Surfaces

“…for the labile pool, is significantly suppressed in ISA (Majidzadeh et al., 2018; Raciti et al., 2012; Wei, Wu, Zhou, et al., 2014). It is also suspected that soil sealing reduces the soil O 2 concentration and thus inhibits soil respiration, but more evidence is needed (O'Riordan et al., 2021).…”

“…Only 13 city‐level observational studies on SOC ISA (Table 1) were conducted using different methodologies and usually focus only on the topsoil. These studies were unable to attain an overall picture of the distribution pattern of SOC ISA and its related environmental factors at a large scale (Bae & Ryu, 2020; O'Riordan et al., 2021; Raciti, Hutyra, & Finzi, 2012). This knowledge gap has hampered our efforts to assess the SOC budget and to evaluate urbanization impact on carbon dynamics, since SOC is the largest carbon pool in urban ecosystems and ISAs occupy 60% of the global urban area (Kuang, 2019; Seto et al., 2012).…”

Soil ecosystem services of an urban park in Mexico as a basis for planning

“…The main impacts of sealing effects include loss of vegetation and alteration of the local microclimate through an increase in atmospheric temperature (Gábor et al, 2009;Scalenghe and Ajmone, 2009) that can generate a "heat island" (Fokaides et al, 2016). Sealing decreases carbon and nutrient content (O'Riordan et al, 2021) and increases surface runoff (Ungaro et al, 2014). Sealed soils can also be contaminated by heavy metals and organic contaminants (Kayhanian et al, 2007).…”