The net effect of these urban effects on the physical, chemical, and biological properties of soils is an alteration of the fundamental nature of the belowground component of urban ecosystems, which ultimately shifts ecosystem functions and processes related to biogeochemical cycling . Kaye et al. (2006) suggest that cities have a fundamentally different biogeochemistry than “natural” systems because human actions alter control points, inputs, and outputs in urban ecosystems. As such, comparisons with “natural” and nonurban systems may have little utility in defining baseline conditions or evaluating success of restoration within urban settings