Scientists & Staff

Featured Publications & Products

• Greenfield, Eric; Nowak, David J.; Walton, Jeffrey T. 2009. Assessment of 2001 NLCD percent tree and impervious cover estimates. Photogrammetric Engineering and Remote Sensing. 75(11): 1279-1286.
• Walton, Jeffrey T. 2008. Subpixel urban land cover estimation: comparing cubist, random forests, and support vector regression. Photogrammetric Engineering & Remote Sensing. 74(10): 1213-1222.
• Nowak, David J.; Walton, Jeffrey T.; Stevens, Jack C.; Crane, Daniel E.; Hoehn, Robert E. 2008. Effect of plot and sample size on timing and precision of urban forest assessments. Aboriculture & Urban Forestry. 34(6): 386-390.
• Walton, Jeffrey T. 2008. Difficulties with estimating city-wide urban forest cover change from national, remotely-sensed tree canopy maps. Urban Ecosystems. 11:81-90.
• Nowak, David J.; Crane, Daniel E.; Stevens, Jack C.; Hoehn, Robert E.; Walton, Jeffrey T.; Bond, Jerry. 2008. A ground-based method of assessing urban forest structure and ecosystem services. Aboriculture & Urban Forestry. 34(6): 347-358.

Publications & Products

• Nowak, David J.; Walton, Jeffrey T.; Baldwin, James; Bond, Jerry. 2015. Simple street tree sampling. Arboriculture and Urban Forestry. 41(6): 346-354.
• Heisler, Gordon; Walton, Jeffrey; Yesilonis, Ian; Nowak, David; Pouyat, Richard; Grant, Richard; Grimmond, Sue; Hyde, Karla; Bacon, Gregory. 2007. Empirical modeling and mapping of below-canopy air temperatures in Baltimore, MD and vicinity. In: Proceedings of the seventh urban environment symposium; 2007 September 10-13; San Diego, CA. American Meteorological Society. 7 p.
• Nowak, David J.; Hoehn, Robert E., III; Crane, Daniel E.; Stevens, Jack C.; Walton, Jeffrey T. 2007. Assessing urban forest effects and values, San Francisco's urban forest. Resour. Bull. NRS-8. Newtown Square, PA: U.S. Department of Agriculture, Forest Service, Northern Research Station. 22 p.
• Nowak, David J.; Hoehn, Robert E., III; Crane, Daniel E.; Stevens, Jack C.; Walton, Jeffrey T. 2007. Assessing urban forest effects and values, Philladelphia's urban forest. Resour. Bull. NRS-7. Newtown Square, PA: U.S. Department of Agriculture, Forest Service, Northern Research Station. 22 p.
• Nowak, David J.; Hoehn, Robert E., III; Crane, Daniel E.; Stevens, Jack C.; Walton, Jeffrey T. 2007. Assessing urban forest effects and values, New York City's urban forest. Resour. Bull. NRS-9. Newtown Square, PA: U.S. Department of Agriculture, Forest Service, Northern Research Station. 22 p.
• Nowak, David J.; Hoehn, Robert E. III; Crane, Daniel E.; Stevens, Jack C.; Walton, Jeffrey T. 2006. Assessing urban forest effects and values, Minneapolis' urban forest. Resour. Bull. NE-166. Newtown Square, PA: U.S. Department of Agriculture, Forest Service, Northeastern Research Station. 20 p.
• Nowak, David J.; Hoehn, Robert E. III; Crane, Daniel E.; Stevens, Jack C.; Walton, Jeffrey T. 2006. Assessing urban forest effects and values, Washington, D.C.'s urban forest. Assessing urban forest effects and values, Washington, D.C.'s urban forest. Resour. Bull. NRS-1. Newtown Square, PA: U.S. Department of Agriculture, Forest Service, Northern Research Station. 24 p.
• Nowak, David J.; Hoehn, Robert E., III; Crane, Daniel E.; Stevens, Jack C.; Walton, Jeffrey T. 2006. Assessing urban forest effects and values, Casper's urban forest. Resour. Bull. NRS-4. Newtown Square, PA: U.S. Department of Agriculture, Forest Service, Northern Research Station. 20 p.
• Nowak, David J.; Hoehn, Robert; Walton, Jeffrey T.; Crane, Daniel E.; Stevens, Jack C.; Twardus, Daniel; Cumming, Anne; Mielke, Manfred; Smith, Bill. 2006. Urban Forest Health Monitoring in the United States. In: Aguirre-Bravo, C.; Pellicane, Patrick J.; Burns, Denver P.; and Draggan, Sidney, Eds. 2006. Monitoring Science and Technology Symposium: Unifying Knowledge for Sustainability in the Western Hemisphere Proceedings RMRS-P-42CD. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station. p. 181-187
• Nowak, David J.; Twardus, Daniel; Hoehn, Robert; Mielke, Manfred; Walton, Jeffery T.; Crane , Daniel E.; Cumming, Anne; Stevens, Jack C. 2006. Urban Forest Health Monitoring in the United States. In: Proceedings of the sixth annual forest inventory and analysis symposium; 2004 September 21-24; Denver, CO. Gen. Tech. Rep. WO-70. Washington, DC: U.S. Department of Agriculture Forest Service. 126p.
• Nowak, David J.; Smith, Peter D.; Merritt, Michael; Giedraitis, John; Walton, Jeffrey T.; Hoehn, Robert E.; Stevens, Jack C.; Crane, Daniel E.; Estes, Mark; Stetson, Stephen; Burditt, Charles; Hitchcock, David; Holtcamp, Wendee. 2005. Houston's Regional Forest. Texas Forest Service Communication/Urban and Community Forestry 9/05-5000. 24p.
• Nowak, David J.; Walton, Jeffrey T.; Dwyer, John F.; Kaya, Latif G.; Myeong, Soojeong; Myeong, Soojeong. 2005. The Increasing Influence of Urban Environments on US Forest Management. Journal of Forestry. December: 377-382.
• Nowak, David J.; Walton, Jeffrey T.; Walton, Jeffrey T. 2005. Projected Urban Growth (2000 - 2050) and Its Estimated Impact on the US Forest Resource. Journal of Forestry. December: 383-389.
• Heisler, Gordon M.; Grant, Richard H.; Nowak, David J.; Gao, Wei; Crane, Daniel E.; Walton, Jeffery T. 2003. Inclusion of an ultraviolet radiation transfer component in an urban forest effects model for predicting tree influences on potential below-canopy exposure to UVB radiation. In: Slusser, James R.; Herman, Jay R.; Gao, Wei, eds. Proceedings of SPIE, Ultraviolet ground- and space-based measurements, models, and effects III. August 4-6, 2003: San Diego, CA: The International Society for Optical Engineering. 228-235.
• Nowak, David J.; Crane, Daniel E.; Walton, Jeffrey T.; Twardus, Daniel B.; Dwyer, John F. 2002. Understanding and quantifying urban forest structure, functions, and value. In: Kenney, W.A.; McKay, J.; van Wassaneaer, P., eds. Proceedings of the 5th Canadian urban forest conference.; 2002 October 7-9; Markham, Ontario. Region of York, Ontario: Ontario Urban Forest Council: 27-1 - 27-9.