
Caption: Researchers have developed an extensive database cataloging what trees are suitable in different urban settings.
Planting trees in urban spaces just got a lot easier.
A new database has been unveiled, which is aimed at helping urban foresters find the perfect spruce, elm and oak.
The U.S. Forest Service’s Pacific Southwest Research Station recently published a technical manual and an extensive database cataloging urban trees with their projected growth tailored to specific geographic regions, a tool that could be utilized by urban planners across the country.
“Knowing a tree’s maximum size can avoid future conflicts between roots and sidewalks or branches and power lines,” said Greg McPherson, research forester for the Forest Service and lead author of the technical report and database, in a statement.
The database is a culmination of research on urban tree growth data between 1998 and 2012 from 17 cities in 13 states, including Arizona, California, Colorado, Florida, Hawaii, Idaho, Indiana, Minnesota, New Mexico, New York, North Carolina, Oregon and South Carolina.
“There are very few studies, if any in the world, that can compare to this in terms of scope with regard to the number of trees studied, the species analyzed, the geographic range and ages and so forth,” McPherson said.
Over the 14 years, the scientists recorded data from a consistent set of measurements on over 14,000 trees to develop an extensive list of growth equations for 171 distinct species of trees.
The database includes the raw data, growth equations, coefficients, application information for each species’ volume and dry-weight biomass equations for urban and rural forest trees and an expanded list of biomass density factors for common urban tree species.
The research team has also taken advantage of advances in statistical modeling, which has given the projected growth dimensions an enhanced level of accuracy by incorporating 365 sets of tree growth equations to project growth.
“Although tree growth is the result of complex processes, growth equations capture changes in tree size with age in a surprisingly simple and accurate way,” said Natalie van Doorn, a research urban ecologist with the Forest Service and co-author on the study, in a statement.
Each of the 365 sets of allometric equations consists of eight equations for each of the approximately 20 most abundant species in each of the 16 climate regions.
For example, information can be found about the red maple in Central Florida, apple trees in the Midwest and the blue spruce in the north.
One of the benefits for city foresters in using the database is they can assist in projecting the costs for pruning and removing trees, which tend to increase with tree size. It can also provide knowledge of maximum tree size, which helps inform tree selection to avoid conflicts between tree roots and nearby sidewalks or between crowns and utility lines.
The Urban Tree Database and Allometric Equations can be viewed here.