Surrounding Growing Environment (E). Second-, third-, and fourth-tier variables relating to (E), 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); SOM (soil organic matter); CEC (cation exchange capacity).
| Number | Second-tier variable | Third-a and fourth-tierb variable(s) | Description and possible values | Other UF frameworks |
|---|---|---|---|---|
| E1 | Near-tree considerations | Features of the growing environment nearest to the tree or trees. | ||
| E1-1 | Interference with aboveground infrastructure’ | Whether the tree is touching or otherwise interfering with buildings, fences, signs, lighting, aboveground utility wires, or other aboveground infrastructure. | SES1 | |
| E1-2 | Interference with at/belowground infrastructurea | Whether the tree roots are interfering with building foundations; sidewalks, curbs, roads, or other paved surfaces; water/sewer lines, underground utility wires, etc. | SES1 | |
| E1-3 | Ground cover under the canopy and/or at the base of the treea | Impervious/pervious surface; kind of ground cover present (turf grass, perennials, planted annuals, soil, weeds, concrete, mulched ground, etc.). | SES1 | |
| E2 | Planting area characteristics | Features related to the space in which the trees is located. | MORT | |
| E2-1 | Type of planting areaa | Boulevard/tree lawn, tree pit, median, road shoulder, park, front or back yard, etc. | SES1 | |
| E2-2 | Planting area dimension(s)a | Width, length, depth; total available rooting volume. | SES1 | |
| E2-3 | Planting substratea | Kind of medium into which the tree has been planted: soil, structural soil, gravel, etc. | ||
| E2-X | Other planting area characteristicsa | Elevation relative to nearby roads or other paved or impervious surfaces (above or below grade); presence/intactness of a curb; previous land use/brownfield status, etc.; impact of exposure to pollutants, water infiltration, etc. | SES1 | |
| E3 | Proximity to other features in the urban environment | Other trees or vegetation, roads, sidewalks, buildings, bodies of water, other above or belowground infrastructure, etc.b | Influences competition for light and space, exposure to heat and pollutants, etc. | SES1 |
| E4 | Urban form | Physical characteristics of surrounding growing environment; can be defined locally (e.g., within a particular distance of a tree or forest of interest) or for an entire system or part of a system (e.g., a census tract or neighborhood/community area). | LEG, MORT | |
| E4-1 | Impervious surfacesa | Percentage of land area in pavement, buildings, other nonpermeable surfaces. | SES1 | |
| E4-2 | Zoning and/or land use type—currenta | Macrolevel land use categorization (residential vs. commercial vs. industrial use; single vs. mixed use); microlevel land use (residential-estate, residential-high density, etc.), or specific land use (hospital, residential apartment building with 6+ units, office building, school, playground, vacant lot, etc.). | PAT | |
| E4-3 | Age of buildings/neighborhooda | Date of construction of a particular building, the average building in a neighborhood, or date of the founding of a neighborhood. | ||
| E4-4 | Lot size and designa | Total lot dimensions; design might include building type and height, setback from street, etc. | ||
| E4-5 | Constructiona | Extent, intensity, recency of construction of any kind (roads, curbs/sidewalks, buildings, other infrastructure repair) in the vicinity. | MORT | |
| E4-X | Other important characteristics of urban forma | The width/type/busyness of nearby roads/sidewalks, etc. | ||
| E5 | Ecological and environmental characteristics of nearby urban environment | Overall site suitability, site connectivity, site size (# acres, # trees planted), watershed catchment area, open greenspace or canopy cover in vicinity, local microclimate, etc.b | A huge variety of nearby ecological parameters might be relevant; which should be considered depends on the system and the urban forest outcomes of interest, where system boundaries are drawn, and how much variability there is across the system within the boundaries. | SUS, SES1, VULN, MOS, MORT, NBS, PAT |
| E6 | Soil/substrate conditions | Substantially impact tree outcomes and can vary widely across the urban forest. | PAT, NBS | |
| E6-1 | Soil volumea | In cubic feet or meters, how much soil growing volume is available to the tree’s root system. | VULN | |
| E6-2 | Soil physical propertiesa | Temperature, evaporation, infiltration/retention/drainage rates, splashing, soil density, soil porosity, compaction (Note 20). | ||
| E6-3 | Soil chemical propertiesa | SOM content, CEC, pH/acidification, plant nutrient availability, micronutrient chelation, toxic material binding potential, salinization (Note 20). | VULN | |
| E6-4 | Soil biological propertiesa | Carbon resource, energy supply, microflora activity/biomass, mineralization capacity, bio-aggregation, soil fauna, bio-pores (Note 20). | ||