Skip to Main Content
Due to a lapse in federal funding, this USDA website will not be actively updated. Once funding has been reestablished, online operations will continue.
Tree and impervious cover change in U.SAuthor(s): David J. Nowak; Eric J. Greenfield
Source: Urban Forestry & Urban Greening. 11(1): 21-30.
Publication Series: Scientific Journal (JRNL)
Station: Northern Research Station
View PDF (313.33 KB)
Related Research Highlights U.S. Urban Tree Cover Declining
DescriptionPaired aerial photographs were interpreted to assess recent changes in tree, impervious and other cover types in 20 U.S. cities as well as urban land within the conterminous United States. National results indicate that tree cover in urban areas of the United States is on the decline at a rate of about 7900 ha/yr or 4.0 million trees per year. Tree cover in 17 of the 20 analyzed cities had statistically significant declines in tree cover, while 16 cities had statistically significant increases in impervious cover. Only one city (Syracuse, NY) had a statistically significant increase in tree cover. City tree cover was reduced, on average, by about 0.27 percent/yr, while impervious surfaces increased at an average rate of about 0.31 percent/yr. As tree cover provides a simple means to assess the magnitude of the overall urban forest resource, monitoring of tree cover changes is important to understand how tree cover and various environmental benefits derived from the trees may be changing. Photo-interpretation of digital aerial images can provide a simple and timely means to assess urban tree cover change to help cities monitor progress in sustaining desired urban tree cover levels.
- Check the Northern Research Station web site to request a printed copy of this publication.
- Our on-line publications are scanned and captured using Adobe Acrobat.
- During the capture process some typographical errors may occur.
- Please contact Sharon Hobrla, firstname.lastname@example.org if you notice any errors which make this publication unusable.
- We recommend that you also print this page and attach it to the printout of the article, to retain the full citation information.
- This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.
CitationNowak, David J.; Greenfield, Eric J. 2012. Tree and impervious cover change in U.S. cities. Urban Forestry & Urban Greening. 11(1): 21-30. DOI: 10.1016/j.ufug.2011.11.005.
Keywordscity trees, ecosystem services, forest monitoring, urban forestry, urban greening, urban trees
- Declining urban and community tree cover in the United States
- Contrasting natural regeneration and tree planting in fourteen North American cities
- Tree and impervious cover in the United States
XML: View XML