Fast Fact Library

According to a 2013 study of lawns in the Los Angeles metropolitan area, low-density plantings of trees on irrigated lawns can significantly reduce turfgrass evapotranspiration through partial shading and serve as a...

Litvak, Elizaveta, Neeta S. Bijoor, and Diane E. Pataki. (November 2013). Adding trees to irrigated turfgrass lawns may be a water-saving measure in semi-arid environments. Ecohydrology 7(5): 1314-1330. https://doi.org/10.1002/eco.1458

Data collected from 1990 to 2007 suggests that loss of trees to the emerald ash borer increased human mortality related to cardiovascular and lower-respiratory-tract illness. Across the 15 states in the study area...

Donovan, Geoffrey H., David T. Butry, Yvonne L. Michael, Jeffrey P. Prestemon, Andrew M. Liebhold, Demetrios Gatziolis, and Megan Y. Mao. (2013). The relationship between trees and human health: Evidence from the spread of the Emerald Ash Borer. American Journal of Public Health 44(2), 139-145.

A study of single-family homes in Portland, Oregon found that trees in the public right of way are associated with lower crime rates. The effect of trees on a house's lot was mixed. Lot trees small enough to block...

Donovan, Geoffrey H., and Jeffrey P. Prestemon. (2012). The effect of trees on crime in Portland, Oregon. Environment and Behavior, 44(1), 3-30.

A study of houses in Portland, Oregon found that on average, street trees add 3% to sales price and reduce time-on-market (TOM) by 1.7 days. In addition, the study found that the benefits of street trees spill over...

Donovan, Geoffrey H., and David T. Butry. (2010). Trees in the city: Valuing street trees in Portland, Oregon. Landscape and Urban Planning, 94(2), 77-83.

The average market effect of street trees on all house values in Portland, Oregon yielded a total value of $1.35 billion, potentially increasing annual property tax revenues by $15.3 million.

Donovan, Geoffrey H., and David T. Butry. (2010). Trees in the city: Valuing street trees in Portland, Oregon. Landscape and Urban Planning, 94(2), 77-83.

In a London, Ontario study, aside from living close to school, the presence of street trees and living in a mixed land-use neighborhood were the only other physical environment features that significantly correlated...

Larsen, Kristian, Jason Gilliland, Paul Hess, Patricia Tucker, Jennifer Irwin, and Meizi He. “The Influence of the Physical Environment and Sociodemographic Characteristics on Children’s Mode of Travel to and From School.” American Journal of Public Health 99, no. 3 (2009): 520–26. https://doi.org/10.2105/ajph.2008.135319.

Children living in areas of New York City with more street trees have a lower prevalence of asthma, as indicated by a study of children aged 4-5 years in 42 health service catchment areas. The rate of early...

Lovasi, Gina S., James W. Quinn, Kathryn M. Neckerman, Matthew S. Perzanowski, and Andrew Rundle. (July 2008). Children living in areas with more street trees have lower prevalence of asthma. Journal of Epidemiology and Community Health 62(7): 647-649. http://dx.doi.org/10.1136/jech.2007.071894

Computer modeling estimates that urban trees in the contiguous U.S. remove 711,000 metric tons of carbon, monoxide, nitrogen dioxide, ozone, particulate matter, and sulfur dioxide each year, a service with an annual...

Nowak, David J., Daniel E. Crane, and Jack C. Stevens. (2006). Air pollution removal by urban trees and shrubs in the United States. Urban Forestry & Urban Greening, 4(3), 115-123.

The monetary benefits of urban trees outweigh their maintenance and other associated costs. In a study of five U.S. cities, each dollar invested in urban trees returned between $1.37 and $3.09 in benefits. Benefits...

McPherson, Greg, James R. Simpson, Paula J. Peper, Scott E. Maco, and Qingfu Xiao. (2005). Municipal forest benefits and costs in five U.S. cities. Journal of Forestry 103(8), 411-416.