About the Estimator
The Ontario Residential Tree Benefits Estimator (ORTBE) was developed by LEAF in partnership with Dr. Andrew Millward of Ryerson University’s Urban Forest Research & Ecological Disturbance (UFRED) Group. It was made possible with funding from the Ontario Power Authority’s Conservation Fund which funds new and innovative electricity conservation projects.
The Estimator has the ability to both model future benefits of a newly planted tree as well as estimate the current and accumulated benefits of an existing tree. It is modeled after the Sacramento Municipal Utility District (SMUD) Tree Benefits Estimator using Ontario data and input from the US Forest Service.
Among other benefits, the Estimator models conserved electricity (kWh), instantaneous electricity demand savings (kW) and sequestered/avoided CO2 for residential trees planted in Ontario based upon empirical data including tree species, size, aspect and planting distance from house. The calculations incorporate regionally specific growth curves particular to native and generic tree selections and uses climate normals for Ontario cities to evaluate length of growing season, air temperature and humidity. In estimating the dollar value of electricity savings, current average utility rates specific to Ontario cities are used; the Estimator does not factor in predicted changes to the cost of electricity over time. Lifespan for small stature trees is assumed to be 55 years, 65 years for medium stature, and 75 years for large growing trees. These lifespans are conservative estimates because many urban trees endure stresses that shorten their lifespans.
Tree replacement values are based on recommendations provided by the Council of Tree and Landscape Appraisers.
Development of the Estimator benefited greatly from input given by Misha Sarkovich of SMUD. Assistance in the research and development for Ontario-specific inputs was provided by Michelle Sawka of Ryerson’s UFRED Group. Interface design and programming of the Estimator for online application was provided by Nikesh Bhagat.
Illustrated Tree Benefits