Urbanization and sealing of fertile soils: A case study in Wisconsin 2001–2021

Abstract

Globally, human population growth is coupled with increased urbanization. There is increasing competition for land, along with growing demands for food production and the ecosystem services that soils provide in urban and non-urban areas. Here we analyze the increase in developed land across Wisconsin, USA and within three rapidly developing counties (Brown, Dane, and Waukesha counties) between 2001 and 2021 and quantify what soils have been impacted. In those 20 years, state-wide developed land increased by 85,704 ha (+8 %) while the extent of sealed soils increased by 53,358 ha (+20 %), corresponding to 7 ha day^-1 of soil sealing. Newly developed areas were mostly converted from agriculture (50 % cultivated crops; 29 % hay or pasture). At both state and county scales, development occurred predominantly on Alfisols and Mollisols and disproportionally impacted soils with high agricultural productivity. Future development (2021–2041) in the three counties will affect important farmland (49–68 %) and a high proportion of cultivated crops (28–57 %). Urbanization in Wisconsin largely affects soil security, and the maintenance and improvement of soil resources. This study provides a systematic approach to analyze changes in urban development and its effect on soils distribution and farmland potential.