Investigating physical soil conditions and tree response to permeable paving

2008 | Justin Morgenroth, New Zealand School of Forestry, University of Canterbury

Permeable pavements are increasingly installed in favor of impermeable alternatives due to their perceived benefits including stormwater management, urban heat island buffering, and ameliorating soil conditions for urban vegetation (Ferguson 2005; Tennis et al. 2004). Though no scientific evidence exists to support the claim that permeable pavements benefit urban trees, it is plausible. By permitting the exchange of air and water between the soil and atmosphere, permeable pavements should improve soil conditions and thus, tree growth and survival. From the perspective of urban tree health, this is a desirable outcome.

Integrating healthy, mature trees into paved urban environments is a challenging task for urban foresters, as impervious pavements are associated with reduced tree growth and survival. It is thought that porous pavements may alleviate this problem due to their permeability to air and water. The authors of the following study tested whether porous pavements affect tree growth relative to impervious pavements by measuring aboveground growth in trees treated with an augmented factorial arrangement of pavement profile designs and pavement types. Fifty oriental plane (Platanus orientalis) seedlings were evenly distributed to control plots or one of four treatments. Treated plots were characterized either by porous or impervious pavement pads measuring 2.3 m × 2.3 m, that were underlain either by fine sandy loam or a gravel base and compacted subgrade, reflecting two pavement profile designs. Results show stem height, diameter, and biomass increased as a result of porous pavements. Greater growth proffered by porous pavements was negated by profile designs including a compacted subgrade and gravel base. Finally, impervious pavements did not negatively influence tree growth, relative to control trees.

Year: 2008

Funding Duration: 3-5 years

Grant Program: Hyland Johns

Grant Title: Investigating Physical Soil Conditions and Tree Response to Permeable Paving

Researcher: Justin Morgenroth

Key words: permeable pavements; soils; root growth

Peer Reviewed Publications from Grant:

• Morgenroth, J., Buchan, G., Scharenbroch, B.C., 2013. Belowground effects of porous pavements-Soil moisture and chemical properties. Ecological Engineering 51, 221-228. View the Publication >
• Morgenroth, J. 2011. Root Growth Response of Platanus orientalis to Porous Pavements. Arboriculture and Urban Forestry 37(2): 45-50. View the Publication >
• Morgenroth, J., and Visser, R. 2011. Above-Ground Growth Response of Platanus orientalis to Porous Pavements. Arboriculture and Urban Forestry 37(1): 1-5. View the Publication >

General Audience/Trade Publications: none

Presentations:

• Morgenroth, J. 2011. Impacts of Porous Pavements on Soil Environment and Street Tree Growth. ISA annual conference, Sydney, Australia. View the Presentation >
• Morgenroth, J. 2009. Effect of Porous Paving on Tree Growth. ISA annual conference, Providence, RI. View the Presentation >
• Morgenroth, J. 2008. Response of urban trees to changes in soil moisture and aeration status as affected by porous paving. In The Landscape below Ground III Conference, Lisle, Illinois.

For more information on this project, contact the researcher via TREE Fund at treefund@treefund.org.