The role of urban function on road soil respiration responses

Soil plays an important role in carbon storage. Accordingly, urban soil carbon and its storage have great impacts on urban carbon balance and future urban sustainable development. In this study, 151 traffic road soils in five urban functional areas were selected. The discrepancies of field soil respiration, soil physiochemical conditions among urban functional areas were calculated. Factor analysis and the Geographic Detector (GeoD) factor model showed that heavy metals had the most important impacts on soil respiration, followed by organic matter and urban function. Using the geographic detector method, individual factors and their interaction effects on soil respiration were tested. The GeoD interaction model demonstrated that no-linear enhanced interaction exhibited between C and ecological function, between N and residential function, S and industrial function. Moreover, no-linear enhanced interaction existed between Ti and ecological function, between Hg, Zn, Ni and residential function. The GeoD risk detector indicated that Soil temperature, N and Hg in different categories had obvious traffic road soil respiration impacts discrepancy. Overall, the results of this study will be useful for further investigation of urban soil treatment to enable healthy urban functional development.