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 green space 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 green space 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 green spaces; this was likely a result of charcoal additions, leading to carbon stores 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 a further understanding of urban soil processes, in both sealed and unsealed soils, and of the influence and legacy of anthropogenic additions for soil functions and important ecosystem services.

中文翻译：

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封堵对城市土壤碳养分的影响

城市土壤因其提供碳储存和养分循环等生态系统服务的潜力而受到越来越多的关注。尽管如此，关于不透水表面的土壤密封（城市环境中的常见干扰）如何影响这些重要的生态系统服务的知识有限。在本文中，我们研究了土壤封闭对土壤性质、土壤碳和土壤养分储量的影响。我们对英国曼彻斯特市的密封和未密封绿地土壤进行了比较调查。我们的研究结果表明，城市土壤环境和添加到土壤中的人为人工制品对土壤性质和功能有很大影响。一般来说，与绿地土壤相比，密封减少了土壤碳和养分；然而，在人为添加有机和矿物制品的地方，这导致土壤碳和硝酸盐含量增加。人为添加导致碳储量等于或大于绿色空间中的碳储量；这可能是添加木炭的结果，导致碳储存的停留时间长。这表明在具有工业历史的地区，人为添加可以导致城市土壤中遗留的碳储存，并对城市土壤碳预算做出重要贡献。这些发现揭示了城市封闭土壤的异质性以及人为人工制品对土壤功能的影响。我们的研究强调需要进一步了解密封和未密封土壤中的城市土壤过程，以及人为添加对土壤功能和重要生态系统服务的影响和遗产。