Soil Layer Development and Biota in Bioretention

Abstract

As bioretention comes into widespread use, it has become increasingly important to understand the development of bioretention soils over time. A field survey was conducted to investigate the development of bioretention soils and soil ecosystems. Sampling from 10 bioretention cells of various ages provides the first detailed descriptions of bioretention soil profiles. The study reveals much biological activity in bioretention and evidence of pedogenesis even in very young sites. The uppermost soil layers were found to be enriched with organic matter, plant roots, and soil organisms. This survey provides a first glimpse into the biological processes at work in bioretention soils. The research shows that soil organisms are ubiquitous in bioretention cells and suggests that their impact on bioretention performance may be significant.

Keywords

• bioretention
• rain gardens
• stormwater
• low-impact development
• green infrastructure
• pedogenesis
• earthworms
• macroinvertebrates