关键词: 土壤, 球囊霉素, 丛枝菌根真菌, 环境功能

Abstract: Urbanization leads to the transformation of natural lands and agricultural lands to urban lands. The concentrations of soil organic carbon (SOC) and total nitrogen (TN) in urban green lands vary spatially due to frequent human disturbance. This study, conducted in a typical “central city suburban satellite city” gradient in ChengduWenjiang, aimed to evaluate the impacts of urban development on the spatial distribution of SOC and TN by using the indices of building density, road density, and distance from urban center. The results showed that mean values of SOC and TN concentrations and carbon-nitrogen ratio (C/N) were 15.80 g·kg^-1, 1.24 g·kg^-1 and 13.04, respectively. The concentrations of SOC and TN decreased from central city to suburb, and then increased from suburb to satellite city. Green land types showed no variation in the concentrations of SOC and TN (P>0.05), but the C/N in park green land soil was significantly higher than that in traffic green land (P<0.05). The concentrations of SOC and TN significantly exponentially decreased with the distance from the central city (P<0.05). Concentrations of SOC significantly linearly increased with the increases of building density and road density (P<0.05). Concentrations of TN showed no significant correlation with building density, but significantly linearly increased with the increases of road density (P<0.05). There was no significant correlation between C/N and distance from urban center, building density, and road density. Our findings reveal that urban development may result in accumulation of SOC and TN. The distance from urban center, building density and road density differentially impact the spatial distribution of SOC and TN.

Key words: soil, glomalin, arbuscular mycorrhizal fungi, environmental function