While impervious surface expands with global urbanization, understanding the quality and quantity changes of soil organic carbon (SOC) under impervious surfaces is essential to assess the impacts of urbanization on the SOC pool and cycling. By comparing soils under impervious surfaces with surface and subsurface soils from adjoining open areas, we present a systematic study on the SOC signature under impervious surfaces. SOC concentration barely changed when comparing soils under impervious surfaces with subsurface soil from the nearby open area; however, the depletion on SOC was 35–62% when it was compared with surface soils. Regardless of comparison with surface or subsurface soils, bulk-level ¹³C NMR spectra and specific molecular biomarkers showed a depletion in carbohydrates and an increase in aromatics in SOC composition. Such an alteration was greater with coverage by concrete slabs than simulated home structures built on crawl spaces and was greater as the coverage duration of residential home structures increased. Long-term coverage of residential home structures suppressed microbial degradation and selectively increased the sequestration of plant suberin- and lignin-derived carbon, which would likely increase the residence time of SOC. This study highlights a possible impact of urbanization on the SOC signature and emphasizes that biogeochemical impacts on SOC vary with the type of impervious surface and coverage time.

中文翻译：

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防渗表面下的土壤有机碳特征

尽管不透水的表面随着全球城市化的发展而扩展，但了解不透水表面下土壤有机碳（SOC）的质量和数量变化对于评估城市化对SOC池和循环的影响至关重要。通过比较不透水表面下的土壤与相邻开放区域的表层和地下土壤，我们对不透水表面下的SOC特征进行了系统的研究。将不透水表面的土壤与附近空旷地区的地下土壤进行比较，SOC浓度几乎没有变化。然而，与表层土壤相比，SOC的消耗为35–62％。不论与表层土壤或地下土壤进行比较，体积级别¹³13 C NMR光谱和特定的分子生物标记物显示碳水化合物的消耗减少，而SOC组成中的芳烃增加。与在爬网空间上建造的模拟房屋结构相比，这种混凝土板覆盖范围的变化更大，并且随着住宅房屋结构覆盖时间的增加而更大。长期覆盖住宅结构可抑制微生物降解，并选择性增加植物木脂蛋白和木质素衍生碳的固存，这可能会延长SOC的停留时间。这项研究强调了城市化对SOC特征的可能影响，并强调了生物地球化学对SOC的影响随不透水表面类型和覆盖时间的变化而变化。