Approximately 80 to 90% of urban urban tree problems are derived in the soil. Unfortunately, urban landscape managers do not have the time or resources to adequately address urban soil problems inhibiting tree growth and health. Soil quality indices have long been used in agriculture and forestry to get an idea of the soil conditions without extensive laboratory testing. A soil productivity index developed by Kinry et al. (1983) and Scrivner et al. (1985) has been successfully utilized in both agriculture and forestry for predicting root distribution with soil depth. Scrivner’s index has great value as a starting point for establishing a relative ranking system for urban soils for arboricultural application. The objectives of the proposed research are: 1) to identify a temporal gradient relating to time since residential landscape disturbance in Chicagoland region, 2) to rank the soils on these landscapes using as soil quality index, 3) to quantify tree health on these plots with this index, and 4) to create a new model to predict tree health potential from soil properties that can be easily assessed by arborists in urban residential landscapes. This research is funded in part by a TREE Fund John Z. Duling Grant. PIUS results were presented at the Urban Tree Growth Conference, September 12-13, 2011 at The Morton Arboretum, Lisle, IL.

PIUS - Productivity Index for Urban Soils (2008-2010)

Forest soils with "ideal" tree root distribution, Menfro series (far left) and Ozaukee series (left). Very poor root distribution in this compacted, anaerobic urban soil (middle).Granualar (right) vs. blocky (far right) soil structure found in urban topsoil soil horizons.