Problem: Most urban tree problems are a result of soil and site constraints. Unfortunately, urban landscape managers do not have the time, resources, or knowledge to adequately identify urban site and soil problems inhibiting tree growth and health. Soil quality indices have long been used in agriculture and forestry to assess site ad soil conditions without extensive laboratory testing. Urban soils are extremely heterogeneous, so an urban site index would be useful for managers to assess and remediate urban soils for trees. An urban site index would also be invaluable tool for managers to understand their growing conditions in order to maximize tree diversity in the urban forest.
Goals: The goals of this research are to: (1) develop and (2) test a field-based site index to accurately and practically evaluate urban sites for growing trees.
Methods: The USI model produces a score of 0-100 from 15 site and soil parameters. These scores are being tested for their ability to predict tree condition and growth in 400 plots across ten USA cities (Chicago, IL, Milwaukee, WI, Minneapolis, MN, Indianapolis, IN, Toledo, OH, Boston, MA, New York, NY, Baltimore, MD, and Springfield, MA). Fieldwork for this research is occurring over the 2013 and 2014 growing seasons.
Personnel: This project is led by Dr. Bryant Scharenbroch (The Morton Arboretum). Collaborators include: Alan Siewert and Stephanie Miller (Ohio DNR), Dr. Nina Bassuk (Cornell U), Drs. Steve Raciti and Lucy Hutyra (Boston U), Dr. Rick Harper (U Massachusetts-Amherst), Drs. Richard Pouyat and Ian Yesilonis (USDA-FS Northern Region), Dr. Susan Day (Virginia Tech), Dr. Kelby Fite (Bartlett Tree), Dr. Lindsey Purcel (Purdue U), Drs. Les Werner and Rich Hauer (UW–Stevens Point), and Dr. Gary Johnson (U Minnesota).
Funding: This research is funded by the USDA-Forest Service National Urban and Community Forestry Advisory Council, The Tree Research and Education Endowment Fund, and The Morton Arboretum's Center for Tree Science.
Publications
Roman, L., G. McPherson, B.C. Scharenbroch, and J. Bartens. 2013. Identifying common practices and challenges for local urban tree monitoring programs across the United States. Arboriculture and Urban Forestry. 39:292-299.
Scharenbroch, B.C. and M. Catania. 2012. Soil quality attributes as indicators of urban tree performance. Arboriculture and Urban Forestry. 38:214-228.
Scharenbroch, B.C., J.E. Lloyd, and J.L. Johnson-Maynard. 2005. Distinguishing urban soils with physical, chemical and biological properties. Pedobiologia. 49:283-295.
Scharenbroch, B.C. and J.E. Lloyd. 2004. A literature review of nitrogen availability indices for use in urban landscapes. Journal of Arboriculture. 30:214-230.
