Communities and neighborhoods vary in their access to green space (parks and open space). This may be because of the amount or area of parks/open space available, or because of the ability to reach the parks (e.g., based on transportation/transit availability).

Evaluate distribution of green space per capita over urban landscapes. Communities and neighborhoods vary in their access to green space (parks and open space). This may be because of the amount of open space/parks available, or because of the ability to reach parks based on transit availability. Equitable distribution of green space is important in urban areas and to disadvantaged communities.

Air pollution can be reduced when natural vegetation is present. Plants can absorb/adsorb pollutants from the air, including very fine particles and gases (e.g., ozone).

Evaluate urban area air quality. Air pollution can be reduced when natural vegetation is present. Plants and trees can absorb harmful pollutants from the air including fine particles and gases. Trees also can reduce the urban heat island effect by reducing urban air temperatures.

Tree canopies in urban settings can provide shade, reducing temperatures considerably. The number of days over 90 oF is one way of measuring potentially harmful heat in urban settings, which will vary with shading by tree canopy.

Evaluate urban areas that have higher percent of days over 90 degrees that can contribute to urban heat islands. Tree canopies in urban settings provide shade and reduce air temperatures considerably. The number of days over 90 degrees is one way of measuring potentially harmful heat in urban settings that can lead to unhealthy air quality and a host of health ailments in sensitive groups.

Urban forests provide relief from heat through shade. The more tree canopy in an urban area, the less air conditioning and therefore fewer days using air conditioning. This is one proxy for the energy savings from urban forests.

Developed surfaces (e.g., roads) are often impervious to water, resulting in excessive runoff from these surfaces to receiving water bodies. Vegetating urban areas (e.g., through green streets programs) can reduce imperviousness.

Evaluate change in urban area impervious cover. Developed surfaces (e.g. roads, houses, sidewalks) are often impervious to water, resulting in excessive storm water runoff from these surfaces to receiving water bodies. Vegetating urban areas through green streets programs, and utilizing permeable hardscape features can reduce imperviousness.

Forests in urban areas provide many ecosystem services and benefits to communities. Trees and forests improve air and water quality by removing pollutants. Urban forests provide limited habitat for wildlife and birds, and therefore wildlife-viewing opportunities for the public.