New Insights Into the Factors Affecting Urban Soil Development.

We conducted a study to assess the relationships between anthropogenic factors and urban soil properties in Tampa, Florida. Specifically, we explored the effects of (1) urbanization as measured by land use, land cover, population density, and years since development and (2) socioeconomics as measured by household income and property values, on key soil physical and chemical properties. Results indicate that Tampa’s soils were affected –to varying degrees–by these factors, with property value and land cover having the most significant effects.  Urban soil chemical properties, in general, were more variable than physical properties.  Soil phosphorus (P) and sodium (Na) contents were highest in residential land uses and soil calcium (Ca) was highest in commercial land uses. Soils in urban forests had lower bulk densities, were more acidic, and had lower nutrient and heavy metal contents than soils in other land covers. Soil P and Na were lowest in recently urbanized sites.  Significant relationships were found between socioeconomic factors and several soil chemical properties. Soil Ca and Mg contents, for example, were significantly greater in lower income areas and pH, P, Ca and Na were lowest in the lowest property value class (<$60,000 USD). Our findings provide insight into the complexity of subtropical, coastal urban soils and the multiple scale drivers affecting urban soil quality and ecosystem services. They also highlight the inadequacies of the traditional US soil survey approach for urban soil classification.