Are soils in urban ecosystems compacted? A citywide analysis

Area of Science:

• Environmental Science
• Soil Science
• Urban Ecology

Background:

• Soil compaction is a significant global issue impacting terrestrial ecosystem services, particularly in agricultural lands.
• While agricultural soil compaction is well-researched, its extent in urban ecosystems remains largely unstudied.
• Urban areas are expanding rapidly, and their soil functionality is often presumed to be compromised due to compaction.

Purpose of the Study:

• To quantify and compare soil compaction levels across different urban greenspace types and agricultural soils.
• To assess the physical condition of urban soils in relation to ecosystem service provision.

Main Methods:

• Bulk density (BD) measurements were conducted citywide to a depth of 14 cm.
• Soil compaction was compared between various urban greenspace classes (under trees, shrubs, herbaceous vegetation) and agricultural soils.

Main Results:

• Urban soils exhibited a wider range of BD values compared to agricultural soils.
• On average, urban soils showed significantly lower compaction, with 12% lower mean BD to 7 cm depth than agricultural soils.
• Soil compaction was lowest in urban areas with trees and shrubs and highest under herbaceous vegetation like lawns, with values comparable to semi-natural habitats.

Conclusions:

• Urban soils, contrary to common assumptions, are often in better physical condition than agricultural soils.
• Urban greenspaces, particularly those with woody vegetation, can support ecosystem services due to better soil physical properties.
• Further research into urban soil health is vital for sustainable urban development and ecosystem service management.