Managing Rainwater for Urban Sustainability Using Trees and Structural Soils « Rainwater Management « WaterBucket.ca:
Urban Trees Enhance Water Infiltration
A group of researchers from Virginia Tech, Cornell, and University of California at Davis have been investigating innovative ways to maximize the potential of trees to address rainwater/stormwater in a series of studies supported by the U.S. Forest Service’s Urban and Community Forestry Grants Program.
Virginia Tech scientists used two container experiments to establish that urban tree roots have the potential to penetrate compacted subsoils and increase infiltration rates in reservoirs being used to store rainwater/stormwater. In one study, roots of both black oak and red maple trees penetrated clay loam soil compacted to 1.6 g cm-3, increasing infiltration rates by an average of 153%.
Structural soil reservoirs may provide new opportunities for meeting engineering, environmental, and greenspace management needs in urban areas. Further research is needed on the effects of tree roots and detention time on water quality in structural soils. Monitoring continues at four demonstration sites around the United States and updated information is posted as it becomes available.