Article Figures & Data
Tables
Variable Description Plot IDz Unique identifier Plot addressy Date and crew Photo number Used to help identify plot Measurement unitsz Units for all measurement in the plot; metric (m/cm) or English (ft/in) Reference objectsy At least two objects that will assist in locating plot center for future plot remeasurements Distance to reference objecty Distance from plot center to each reference object (ft or m) Direction to objecty Direction from plot center to each reference object (degrees) Tree measurement point (TMP)y If plot center falls on a building or other surface (such as a highway) where plot center cannot be accessed, the plot is not moved; all distances and directions to trees are measured and recorded from a recorded fixed point (e.g., building corner) referred to as the TMP Percent measuredz Proportion of the plot that is actually measured as portions of plot may be denied access Land usez As determined by crew in the field from a standard list of land uses Percent inz Proportion of the plot in each land use to nearest 1% Tree coverz Percent of plot area covered by tree canopies estimated to nearest 5% Shrub coverz Percent of plot area covered by shrub canopies estimated to nearest 5% Plantable space Percent of plot area that is plantable for trees (i.e., plantable soils space not filled with tree canopies) and tree planting would not be restricted as a result of land use (footpath, baseball field, and so on); to nearest 5% Variable Description Species code Species code from standard list currently containing over 10,000 tree and shrub species Average height of mass Where mass is a group of shrubs species or genera of similar height (ft or m) Percent area Percent of total shrub cover on plot occupied by shrub mass Percent shrub mass missing Percent of shrub mass volume (height × ground area) that is not occupied by leaves; estimated to nearest 5% UFORE = Urban Forest Effects.
- Table 3.
Tree variables collected for UFORE analysis with associated reason for data collection
Variable Description Tree ID Unique tree number Distance (ft/m) and direction (degrees) from plot center or TMPz Used to identify and locate trees for future measurements; TMP is tree measurement point (Table 1) Species codey (A, C, E, S, V) Species code from standard list currently containing over 10,000 tree and shrub species Number of dbhs recordedy For multistemmed trees Dbhy (C, S) Diameter at breast height (in/cm) for all recorded stems Dbh measurement height Recorded if dbh is not measured at 1.37 m (4.5 ft) Total heighty (A, C, E, S, V) Height to top of tree (ft/m) Height to crown basey (A, S, V) Height to base of live crown (ft/m) Crown widthy (A, S, V) Recorded by two measurements: N-S (north–south) and E-W (east–west) widths (ft/m) Percent canopy missingy (A, S, V) The percent of the crown volume that is not occupied by leaves; two perpendicular measures of missing leaf mass are made and the average result is recorded; recorded to nearest 5% Diebacky (C,E, S) Percent crown dieback to nearest 5% Percent impervious beneath canopy (H) Percent of land area beneath entire tree canopy’s drip line that is impervious Percent shrub cover beneath canopy (H) Percent of land area beneath canopy drip line that is occupied by shrubs Crown light exposurey (C, S) Number of sides of the tree receiving sunlight from above; used to estimate competition and growth rates Distance (ft/m) and direction (degrees) to space-conditioned residential buildingsy (E) Measured for trees at least 6.1 m (20 ft) tall and within 18.3 m (60 ft) of structures three stories or less in height Street tree Y/N; used to estimate proportion of population that is street trees Tree status Indicates if tree is new or removed from last measurement period - Table 4.
Estimates of total number of trees and standard error (SE), tree density, percent tree cover, leaf area index (LAI), and most common tree species from 14 cities analyzed using the UFORE model.z
City Number of trees Tree density (no./ha) Tree cover (%) LAIy Most common tree species Year Sample typex No. of plots Total SE Atlanta, GAw 9,415,000 749,000 275.8 36.7 2.2 Liquidambar styraciflua 1997 SR 205 Baltimore, MDv 2,571,000 494,000 122.9 21.0 1.3 Fagus grandifolia 2004 SR 200 Boston, MAw 1,183,000 109,000 82.9 22.3 1.0 Acer platanoides 1996 SR 217 Casper, WYu 123,000 16,000 22.5 8.9 0.3 Populus sargentii 2006 RG 234 Freehold, NJt 48,000 6,000 94.6 34.4 1.6 Acer platanoides 1998 SR 144 Jersey City, NJt 136,000 22,000 35.5 11.5 0.4 Ailanthus altissima 1998 SR 220 Minneapolis, MNs 979,000 165,000 64.7 26.4 1.0 Fraxinus pennsylvanica 2004 RG 110 Moorestown, NJt 583,000 53,000 153.4 28.0 1.7 Acer rubrum 2000 SR 206 New York, NYw 5,212,000 719,000 65.2 20.9 0.9 Ailanthus altissima 1996 SR 206 Philadelphia, PAw 2,113,000 211,000 61.9 15.7 0.8 Prunus serotina 1996 SR 210 San Francisco, CAu 668,000 98,000 55.7 11.9 0.4 Eucalyptus globulus 2004 RG 194 Syracuse, NYv 876,000 119,000 134.7 23.1 1.2 Acer saccharum 2001 SR 197 Washington, DCr 1,928,000 224,000 121.1 28.6 1.0 Fagus grandifolia 2004 RG 201 Woodbridge, NJt 986,000 97,000 164.3 29.5 1.6 Liquidambar styraciflua 2000 SR 215 ↵zDivide tree density (no./ha) by 2.471 to convert to no./ac.
↵yTotal tree leaf area divided by total city area.
↵xSR = stratified random; RG = randomized grid.
↵wData collected by ACRT, Inc.
↵vData collected by U.S. Forest Service.
↵uData collected by city personnel.
↵tData collected by New Jersey Department of Environmental Protection.
↵sData collected by Davey Resource Group.
↵rData collected by Casey Trees Endowment Fund and National Park Service.
