Soil ecosystem services of an urban park in Mexico as a basis for planning

Abstract

Urban parks in the cities play a crucial role in promoting sustainability and enhancing the quality of life for their residents. In an urban ecosystem, we have to make some trade-offs between the cultural and ecological ecosystem services. The soil ecosystem services depend on specific ecological conditions, therefore information on their potential to provide fundamental services is a basic requirement when constructions are planned in green areas. Mexico City, like other cities in Latin America, has very few green areas that are constantly threatened by sealing. Based on morpho-pedological landscapes (MpL) we quantify the soil carbon sequestration (SOC) and infiltration capacity in Chapultepec park. Among the 12 MpL we found the highest content of SOC in hillslopes with mixed tree vegetation and Phaeozem and the lowest in grass-dominant plain with Technosols and Leptosols. However, the SOC retention decreased by 40-50% because of sealing surfaces. For each MpL, the value of the soil saturated hydraulic conductivity calculated from pedotransfer functions (Ksc) was markedly lower than the Ksm measured with the double ring infiltrometer. In all MpL, both Ksc and Ksm were always higher than the reported maximum rainfall intensity. In the MpLs with more sealing, the runoff reaches more than 40% of the precipitated water. Based on these results, it is recommended to implement different actions such as allowing the leaves on the soils, the de-sealing of obsolete infrastructure, as well as locating the new constructions on Technosols and Leptosols to maintain Chapultepec park as a SOC sink with infiltration potential.