USDA Forest Service

Pacific Southwest Research Station

Pacific Southwest
Research Station

800 Buchanan Street
Albany, CA 94710-0011
(510) 883-8830
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Publications and Products

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General Technical Report

Title: Urban Tree Database and Allometric Equations

Authors: E. Gregory McPherson, Natalie S. van Doorn, and Paula J. Peper

Date: 2016

Source: Gen. Tech. Rep. PSW-GTR-253. Albany, CA: U.S. Department of Agriculture, Forest Service, Pacific Southwest Research Station

Station ID: GTR-PSW-253

Description: Information on urban tree growth underpins models used to calculate the effects of trees on the environment and human well-being. Maximum tree size and other growth data are used by urban forest managers, landscape architects, and planners to select trees most suitable to the amount of growing space, thereby reducing costly future conflicts between trees and infrastructure. Growth data are used to examine relationships between growth and influencing factors such as site conditions and stewardship practices. Despite the importance of tree growth data to the science and practice of urban forestry, our knowledge in this area is scant. Over a period of 14 years, scientists with the U.S. Forest Service Pacific Southwest Research Station recorded data from a consistent set of measurements on over 14,000 trees in 17 U.S. cities. Key information collected for each tree species includes bole and crown size, location, and age. From this Urban Tree Database, 365 sets of tree growth equations were developed for the 171 distinct species. Appendices contain field data collection protocols, foliar biomass data that are fundamental to calculating leaf area, tree biomass equations for carbon storage estimates, and a user guide that illustrates application of the equations to calculate carbon stored over many years for tree species that were measured in multiple cities. An online database at includes the raw data, growth equations, coefficients, and 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.

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  • McPherson, E. Gregory; van Doorn, Natalie S.; Peper, Paula J. 2016. Urban Tree Database and Allometric Equations. Gen. Tech. Rep. PSW-GTR-253. Albany, CA: U.S. Department of Agriculture, Forest Service, Pacific Southwest Research Station. 86 p.