Determination of carbon and microbial biomass amounts in neglected urban pavement crevice soils

Urbanization is causing soil sealing and ecosystem fragmentation, affecting soil health, biodiversity, and carbon storage potential. While green infrastructure is being promoted to address these challenges, small-scale habitats such as urban crevice soils (UCSs), referred to as soils in the gaps between concrete and asphalt surfaces in heavily urbanized areas, remain overlooked. The aim of this study was to determine whether UCSs are advantageous ecological units that sustain microbiological life and perform ecosystem services. This study quantified soil heterotrophic respiration, microbial biomass carbon (MBC) and nitrogen (MBN), soil organic carbon (SOC) and inorganic carbon (SIC), and total nitrogen (TN) in UCSs (with and without plants), nearby roadside soils, and soils from a switchgrass cropland in an urban farm within the Nashville metropolitan area in Tennessee, USA. On average, UCSs exhibited up to 436.2 %, 59.4 %, 217.6 %, and 266.9 % higher SOC, MBC, MBN, and C/N ratio compared to roadside and switchgrass soils, respectively. UCSs with plants have the highest microbial biomass, highlighting the synergistic role of plant presence in enhancing microbial function. These findings challenge the belief that urban soils are universally degraded and biologically inert, and regard UCSs as dispersed, small-scale contributors to urban ecosystem services. UCSs could serve as scalable, low-cost nature-based solutions that support resilient and sustainable cities amid rapid urbanization and environmental stress. Future studies should evaluate the ecological potential of UCSs as microhabitats for microbial biodiversity conservation, carbon storage, and ecosystem service delivery across various cities of different scales.