bare soil land cover: Areas mapped as bare soil typically include vacant lots, construction areas, and baseball fields. canopy: Branches and foliage which make up a tree’s crown.
canopy cover or community tree canopy: The area of land surface that is covered by tree canopy as seen from an aerial perspective.
community tree canopy assessment: A study performed of land cover classes to gain an understanding of tree canopy coverage, particularly as it relates to the amount of current tree canopy and potential tree canopy. This assessment is typically performed using aerial photographs, GIS data, or Lidar.
existing tree canopy: The amount of tree canopy present within the community boundary.
geographic information systems (GIS): A technology that is used to view and analyze data from a geographic perspective. The technology is a component of an organization's overall information system framework. GIS connects location to information (such as people to addresses, buildings to parcels, or streets within a network).
greenspace: A land use planning and conservation term used to describe protected areas of undeveloped landscapes.
impervious land cover: Area that does not allow rainfall to infiltrate the soil and typically includes buildings, parking lots, and roads.
i-Tree Canopy: The i-Tree Canopy tool allows users to easily photo-interpret Google aerial images of their area to produce statistical estimates of tree and other cover types, along with calculations of their estimates. This tool serves as a simple, quick, and inexpensive means for cities and forest managers to accurately estimate their tree and other cover types.
i-Tree Tools: State-of-the-art, peer-reviewed software suite from the USDA Forest Service that provides urban forestry analysis and benefits assessment tools. The i-Tree Tools help communities of all sizes to strengthen their urban forest management and advocacy efforts by quantifying the structure of community trees and the environmental services that trees provide. Tree benefits were calculated using the i-Tree Vue model and TR-55 hydrologic equations. i-Tree Vue estimates carbon storage and sequestration and air pollutant removal. TR-55 hydrologic equations model stormwater runoff.
land cover: Physical features on the earth mapped from satellite or aerial imagery such as bare soils, canopy, impervious, pervious, or water.
nitrogen dioxide (NO2): Nitrogen dioxide is a compound typically created during the combustion processes and is a major contributor to smog formation and acid deposition.
open water land cover: The land cover areas mapped as water typically include lakes, oceans, rivers, and streams.
other vegetation: Pervious cover or a vegetated area (grass, shrubs, etc.) that allows rainfall to infiltrate the soil; typically includes parks, golf courses, and residential areas.
ozone (O3): A strong-smelling, pale blue, reactive toxic chemical gas with molecules of three oxygen atoms. It is a product of the photochemical process involving the sun’s energy. Ozone exists in the upper layer of the atmosphere as well as at the Earth’s surface. Ozone at the Earth’s surface can cause numerous adverse human health effects. It is a major component of smog.
particulate matter (PM10): A major class of air pollutants consisting of tiny solid or liquid particles of soot, dust, smoke, fumes, and mists.
pervious land cover: A vegetative area that allows rainfall to infiltrate the soil and typically includes parks, golf courses, and residential areas.
possible UTC—impervious: The amount of land within the city boundary covered by impervious surface that is theoretically available for the establishment of tree canopy. This excludes all buildings and all pavement within the public right-of-way (ROW).
possible UTC: The amount of land that is theoretically available for the establishment of tree canopy within the city boundary. This includes the combination of Possible UTC - Vegetation and Possible UTC - Impervious.
possible UTC—vegetation: The amount of land within the city boundary covered by non-tree vegetation that is theoretically available for the establishment of tree canopy.
riparian: Of or relating to or located on the banks of a river or stream.
right-of-way (ROW): A strip of land generally owned by a public entity over which facilities, such as highways, railroads, or power lines, are built.
street tree: A street tree is defined as a tree within the right-of-way.
species: Fundamental category of taxonomic classification, ranking below a genus or subgenus and consisting of related organisms capable of interbreeding.
sulfur dioxide (SO2): A strong-smelling, colorless gas that is formed by the combustion of fossil fuels. Sulfur oxides contribute to the problem of acid rain.
tree: A tree is defined as a perennial woody plant that may grow more than 20 feet tall. Characteristically, it has one main stem, although many species may grow as multi-stemmed forms.
tree benefit: An economic, environmental, or social improvement that benefits the community and results mostly from the presence of a tree. The benefit carries real or intrinsic value.
urban forest: All of the trees within a municipality or a community. This can include the trees along streets or rights-of-way, parks and greenspaces, and forests.
vegetative swale: Constructed open-channel drainageways used to convey stormwater runoff. Vegetated swales are often used as an alternative to, or an enhancement of, traditional storm sewer pipes.