Characteristics of Trees in the Urban Forest (T). Second-, third-, and fourth-tier variables relating to (T), one of the five core first-tier factors in the UFSES framework. Abbreviations in the “Other UF frameworks” column correspond to shorthand citation keys for frameworks described in Table 2. Notes for Table 3 through Table 9 appear in Appendix D. UFSES (urban forest social-ecological system); UF (urban forest); DBH (diameter at breast height).
| Number | Second-tier variable | Third-a and fourth-tierb variable(s) | Description and possible values | Other UF frameworks |
|---|---|---|---|---|
| T1 | Tree taxonomy | Family, genus, species, cultivar; native/nonnative/invasive; seed sourceb | Taxonomy influences tree form, size-at-maturity, average growth rate, drought/flood tolerance, nutrient requirements, pest vulnerabilities, climate change vulnerability, etc. (Note 18). | SUS, SES1, CC, VULN, MORT |
| T1-1 | Tree traitsa | Tree traits are nested within T1. Tree taxonomy as traits are directly connected to the species/cultivar of a tree. | ||
| T1-1a | Tree typeb | Deciduous, coniferous, evergreen, fruit trees, palms, etc. | ||
| T1-1b | Stature/expected size-at-maturityb | Large, medium, small, ornamental, etc. | ||
| T1-1c | Tree form/growth habitb | Excurrent, decurrent, columnar, etc. | ||
| T1-1d | Drought or flood toleranceb | How well a tree is expected to be able to withstand periods of low or no rainfall/water or excessive moisture during periods of flooding; connected to tree species and cultivar. | ||
| T2 | At-planting parameters | Planting packaging type/size, nursery of origin, size/age of tree at time of planting, planting season, etc.b | Legacy effects of nursery growing conditions impact tree outcomes during the establishment phase, 3 to 5 years post-transplanting, especially; less relevant for larger, mature trees, unless the tree is planted improperly or the planting packaging is left on (Notes 18, 19). | SES1, MORT |
| T3 | Current tree size | DBH, caliper, total height of tree, width of crown, proportion of tree in live crown, etc.b | Impacts the provision of benefits, likelihood of survival, risk assessment, etc. (Note 18). | SES1, VULN, MORT |
| T4 | Canopy condition | Crown dieback, crown exposure to light, leaf density, leaf condition such as presence and degree of chlorosis, canopy pest presence, etc.b | Canopy condition affects tree health/vigor and the level of urban forest benefits (Note 18). | SES1, VULN, MORT |
| T5 | Trunk condition | Presence of a root flare, damage to lower trunk, trunk pest presence, etc.b | Trunk condition affects tree health/vigor and overall condition; extensive damage to the trunk can be a contributing factor to tree mortality (Note 18). | SES1, MORT |
| T6 | Overall tree condition | Evidence of other damage to tree, overall good-fair-poor or numeric condition rating, hazard rating, etc.b | Overall assessment of condition affects tree health/vigor, vulnerability to pests and diseases, etc. (Note 18). | SES1, MORT |
| T7 | Tree age | Date of planting, years (or days) since planting, number of growth rings, estimated ageb | Calculated or estimated age from size or from known planting date or from number of growth rings (Note 18). | SES1, MORT |