Under the direction of Dr. Bryant Scharenbroch of the Morton Arboretum, the Urban Site Index (USI) model – a field-based assessment protocol used to quantify the suitability of street planting sites – is currently being updated and expanded nationally. This “Revised” Urban Site Index (RUSI) will include a series of other important indicators including climate, urban, space, physical, chemical, and biological indicators. The RUSI will build upon the original USI by including more quantitative data related to tree condition (i.e. diameter (dbh), height, crown volume, age and growth rate) and soil characteristics like texture, moisture, organic matter (OM), electrical conductivity and pH.


Upon being asked to cooperate in this research effort, Ext. Asst. Professor Rick Harper invited Dr. Scharenbroch to add the City of Springfield as a research site, to the existing list of 10 cities located across the country. Including data from localities here in Massachusetts (like Springfield and Boston, which was already a participating site) furthers the applicability of the finalized RUSI model for communities located in the Northeast.  Once the data is analyzed and made available, this model will no doubt prove to be a useful tool in helping to understand urban tree growth response – before the tree planting even takes place!

For further information, contact:

Rick Harper, or 413.545.3747.


To view a presentation on the USI, visit:



To read more about the RUSI, visit:



Dr. Bryant Scharenbroch taking field measurements in Springfield, MA as part of the RUSI Fall 2013 data collection. Springfield, Boston Participate in Revising the Urban Site Index Model