Canopy cover: the area occupied by the crowns of trees when viewed from above.
Carbon sequestration: the process through which trees absorb carbon dioxide (CO2) and remove it from the atmosphere. [sub-script all chemicals]
Carbon storage: carbon currently held within tree tissue (roots, stems, and branches). As trees grow, more carbon is absorbed and stored in their accumulated tissue. As trees die and decay, including use as firewood or mulch, this stored carbon is released back into the atmosphere.
Combined sewers:a sewer system that carries both raw sewage and stormwater runoff. Normally, its entire flow goes to a waste treatment plant, but during heavy rains high volumes of water may cause overflows of untreated stormwater and sewage into streams and rivers. Surface runoff may also carry toxic chemicals from streets or industrial areas into the sewer system.
CSO (Combined Sewer Overflow): discharge of a mixture of stormwater runoff and sewage when the capacity of a sewer system is exceeded during heavy rainstorms.
DFS (Delaware Forest Service): agency within the Delaware Department of Agriculture. Provides services to help citizens manage and improve their forest resources in the areas of conservation, protection and education.
DNREC (Delaware Department of Natural Resources & Environmental Control): state agency that works to protect and manage vital natural resources, protect public health and safety, provide quality outdoor recreation, and educate citizens of the First State about the wise use, conservation, and enhancement of Delaware’s environment.
EPA (Environmental Protection Agency): federal agency that conducts environmental science, research, education, and assessment efforts to protect human health and the environment.
Gray infrastructure: structures such as buildings, roads, utilities and parking lots. Gray infrastructure is impervious, forcing water to run off, which must be managed and cleaned before entering rivers.
Green infrastructure: areas covered with trees, shrubs and grass. Green infrastructure is porous, allowing rain to soak into soil, which recharges ground water and naturally filters pollutants before entering rivers.
Greenhouse gas: compounds such as carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), and ozone (O3) in the Earth’s atmosphere that trap energy from the sun.
Impervious cover: the amount of land in an area that cannot absorb rainwater due to paving and roofs.
i-Tree: a software suite from the U.S.Forest Service that provides urban and community forestry analysis and benefits assessment tools. i-Tree is in the public domain and available free through the i-Tree website. The Forest Service, Davey Tree Expert Company, National Arbor Day Foundation, Society of Municipal Arborists, and International Society of Arboriculture provide technical support and training for the software.
Non-sanitary flow: Water, primarily from rain and carried by the combined sewers, that is not from residential or industrial sources.
NCCMC (New Castle County Metro Corridor): designated data area of the UFORE study representing the major metropolitan areas from Wilmington to Newark bound by Interstate 95, Route 2 (Kirkwood Highway) and Route 41.
STRATUM (Street Tree Management Tool for Urban forest Managers): part of the i-Tree collection of software tools. Developed by researchers at the Center for Urban Forest Research, this computer application uses tree inventory data to quantify the structure, function, value and management needs of any street tree resource.
TFW (Trees for Wilmington): a working group of the Wilmington Beautification Commission focused on improving the City’s urban forest and promoting more sustainable management techniques. This coalition is composed of a variety of stakeholders, including city residents, policy-makers, government agency representatives, and municipal employees.
Tree Stewards: volunteers coordinated through the Delaware Center for Horticulture to preserve and restore Wilmington’s urban forest. Stewards apply for tree-planting grants for their neighborhoods, attend community plantings, assist with tree maintenance, and act as advocates for the urban forest.
UFORE (Urban Forest Effects): computer model that calculates structure, environmental effects, and values of urban forests. It was developed in the late 1990s by researchers at the U.S. Forest Service.
Urban Forest: the sum of all trees and associated vegetation in and around dense human settlements.
Urban heat island/heat island effect: phenomenon causing cities to be 6 – 8°F hotter than surrounding rural areas throughout the year. Asphalt and concrete in roads, buildings, and other structures absorb solar heat, causing surface temperatures and overall ambient temperatures to rise.
Volatile Organic Compounds (VOCs): molecules containing carbon and varying proportions of other elements such as hydrogen, oxygen, fluorine, and chlorine. These "precursors" that react in sunlight and heat to form ground-level ozone.
WBC (Wilmington Beautification Commission): chartered by official City Council legislation in 2004. Led by the Delaware Center for Horticulture, WBC membership includes representatives from City Council, government agencies, civic associations, and a host of other environmental groups. In addition to a growing number of city parks improvements, WBC launched “Think Green for a Change,” a promotional campaign encouraging residents and businesses to make more environmentally friendly lifestyle and development choices.