USDA Forest Service

Pacific Southwest Research Station


Pacific Southwest Research Station
800 Buchanan Street
West Annex Building
Albany, CA 94710-0011

(510) 559-6300

United States Department of Agriculture Forest Service. USDA logo which links to the department's national site. Forest Service logo which links to the agency's national site.

Programs and Projects

 Picture of Street with Trees
Energy Air Water Fire
Benefits and Costs

Center for Urban Forest Research

Search Our Products & Publications - This is the best tool to find documents produced by the Center for Urban Forest Research

Since 1992 we have provided our customers with reliable scientific evidence that the benefits of urban forests add real value to communities.

Our research confirms that trees in our community forests are assets that pay us back.

  • Conserve energy by shading buildings and paved surfaces
  • Filter airborne pollutants
  • Remove atmospheric carbon dioxide
  • Reduce stormwater runoff
  • Increase the value of our homes
New research

The CUFR Tree Carbon Calculator (CTCC) is now national! The new version of the CTCC works just like the old, but

  • extends use from the 6 California climate regions to 16 US climate zones (same zones used in i-Tree Streets)
  • includes palm species in palm-friendly climate zones
  • emissions factors for 16 regions
  • and energy information for 16 regions (heating and cooling degree days) for energy conservation trees

Users from coast to coast can enter species, tree size (diameter-at-breast height) or tree age and receive information on the amount of biomass and carbon stored in the tree, as well as benefits associated with energy conservation projects. All results are based on tree growth data from each region. To learn more or download this Excel application, visit the U.S. Forest Service's Climate Change Resource Center website.

A help menu and list of frequently asked questions are included online with the CTCC. Additional technical assistance is available via email at

Parking lots, bioswales and structural soils - The results of Dr. Qingfu Xiao's study using engineered soil in a bioswale to mitigate parking lot stormwater runoff are now available. Dr. Xiao's Davis Soil (a mixture of lava rock and local soil) offers several advantages over other engineered soil types. Made of natural materials readily and inexpensively available in California, the porous lava rock traps pollutants, increases stormwater retention, and makes more water available to trees. Read the report here.

Dr. Xiao's earlier report comparing Davis soil with Cornell and Carolina Stalite soils is available here: Qingfu Xiao; Greg McPherson; Aihua Jiang. 2006. Pollutant removal and runoff storage testing of three engineered soils. Prepared for the 4th Biennial CALFED Science Conference 2006, Sacramento, CA.

Urban Forest Project Reporting Protocol - At the beginning of last June, we brought nearly two years of work to an end and delivered our draft of the Urban Forest Project Protocol to the California Climate Action Registry. We're thrilled to announce that our work has borne fruit. After more than 18 months of work, eleven drafts, countless meetings, and extremely helpful feedback from our stakeholder groups, the California Climate Action Registry's Board of Directors approved the Protocol on August 12. You can find the final version here. Let the projects begin!!

For more information on the Urban Forest Protocol and urban trees and global climate change in general, see our Protocol webpage.

Million Trees LA - The Pacific Southwest Research Station is pleased to be able to provide a simple tree selection tool to assist the City of Los Angeles in meeting their goal to plant a million trees. See how to pick a one-in-a-million tree!

To learn more, visit the Million Trees LA website or read our project profile. [PDF 1.9 MB]

The Los Angeles One Million Tree Canopy Cover Analysis is complete! Click here for a low resolution version [PDF 1.7 MB] or click here to download the high resolution version [PDF 4.7 MB].

Urban Forest Research News Briefs

Stay on top of our latest research. Sign up today!

Read current and past issues

December 15, 2010
Benefits of Trees in Urban Ecosystems
Speaker: Paula J. Peper
Conference: Turfgrass and Landscape Institute
Where: Rancho Cucamonga, California
Sponsor: University of California Cooperative Extension and the Southern California Turfgrass Council
Sponsor Email: Contact: Janet Hartin --

December 15, 2010
Managing Trees for Health and Longevity
Speaker: Turfgrass and Landscape Institute
Where: Rancho Cucamonga, California
Sponsor: University of California Cooperative Extension and the Southern California Turfgrass Council
Sponsor Email: Contact: Janet Hartin --

Missed our talks? You can still see the presentations-- View speeches.

Have you seen this before? product thumbnail

Tough budget decisions are being made nationwide, and while the choices may seem tougher than usual, they have been tackled before.

In 1991, the City of Modesto’s tree program was on the chopping block. Peter Cowles, the city’s Operations and Maintenance Director, consulted with Greg McPherson. The result was an extensive study on the services the trees provided as well as the costs they incurred, ultimately demonstrating that for every $1 spent, the forest returned nearly $2 in environmental services and increased property values to the community.

Modesto’s tree budget crisis was also the seed from which the i-Tree Streets software sprouted, a tool enabling all city foresters or managers with an inventory to quantify their forest’s costs and services.

If your urban forestry budget is in need of a strong defense, read our Fact Sheet on ‘How to Prepare for a Budget Cut’. Then put the Forest Service’s i-Tree software to work preparing numbers for your next budget meeting.

Look to these USDA Forest Service resources from CUFR to find out what your tree budget money is buying.

Fall News Brief: Catch up with our latest research quickly by reading our summer News Brief! [pdf] If you'd like to receive future News Briefs, sign up here.

Selecting Reference Cities for i-Tree Streets: Selecting the reference city when using  i-Tree Streets (formerly STRATUM)  is problematic when the subject city is outside the U.S., lays on the border between two climate zones, has a different climate, or tree species composition because of differences in elevation, urban morphology, and environmental quality. A systematic process for selecting the best match is described and illustrated by Greg McPherson in Arboriculture & Urban Forestry (2010. 36(5): 230-240), the scientific journal of the International Society of Arboriculture. Selection criteria are tree species composition, heating and cooling degree days, and annual precipitation. For example, the state of California’s reference cities of Modesto and Claremont proved to be the best match for Lisbon, Portugal.
Download the PDF of Selecting Reference Cities for i-Tree Streets.

ecoSmart Partners CUFR has been seeking partners to develop and disseminate a sustainable sites evaluation tool. That investigation has led to discussions with TreePeople, EcoLayers, UC Davis, and the US EPA Office of Water. These entities share the desire to develop technologies that will guide and support residents, agencies, and other institutions as they retrofit existing landscapes and design new sites for more sustainable performance. We anticipate that the partnership will grow as this project evolves.

Capturing carbon in your community - Did you know that over the course of its life, a tree can store 10,000 lb of carbon dioxide? Or that in hotter climates the greenhouse gas benefits from energy conservation realized by a strategically placed tree can exceed those of carbon storage? Read all about these and other key aspects of the Urban Forest Project Reporting Protocol in the Winter 2008 Western Arborist article by Greg McPherson.

The last Community Tree Guide in the series has been printed. The Central Florida Community Tree Guide, is now available as a hard copy by request or in PDF format. The Central Florida climate zone is included in i-Tree STREETS, allowing communities in Florida to obtain extensive information on the benefits and costs associated with their street tree populations.
The Northern California Coast Community Tree Guide is available as a hard copy by request or as a PDF file: Northern California Coast Community Tree Guide

The Air Resources Board adopted the Urban Forest Project Reporting Protocol to quantify emissions from urban forest projects. Read more about it here.

Our study on locating potential planting sites in Los Angeles using aerial imagery and GIS has just been published in Urban Forestry and Urban Greening. Congratulations Chelsea!

Looking for ways personally to make a difference in the fight against global climate change? Read Kelaine's article in the Spring issue of California Trees for more information on how trees help and what you can do. "Trees have one big advantage compared to all other methods of addressing global warming: they actually remove greenhouse gases from the atmosphere."

Animating trees: Most tree growth animations and, in fact, most trees in any graphics program, are not based on real data. Our new program, developed with scientists at the Institute for Mathematics and Computer Science at Greifswald University in Germany, models tree growth on-the-fly based on measurements from CUFR research and displays the benefits and costs of the trees at the same time. Watch a quick clip of our first tree animation video on or see the latest version below. In the coming weeks, we'll be featuring animations of different species on our website. For information on the research that went into constructing the model, read Visualization of Time-Varying Tree Data [PDF 1 MB] and Inverse Modeling and Animation of Growing Single-Stemmed Trees at Interactive Rates [PDF 180 kB].

Animation of ash tree growth


See what else was new at the Center in our Archive...

Continuing Research

Elm Trials - In the 1930s, Dutch elm disease began ravaging America's urban forests, and by the 1970s almost all of our elm trees were dead. Now scientists across the country are testing newly developed elm varieties in an attempt to bring them back. Visit the National Elm Trial website to learn more and read about the 17 cultivars the Center for Urban Forest Research is testing here at UC Davis in our project profile [PDF 1.9 MB].

Oakland Watershed Restoration and Protection Study - To learn more, read our project profile. [PDF 101 kB]

Sacramento Urban Forest For Clean Air Project - Recently, the EPA has begun to consider new, innovative measures to fight air pollution and trees are being considered as one of the solutions. To read more about the potential role of trees in State Implementation Plans for the Clean Air Act, read our project summary [PDF 1.8 MB]. Read more about the Urban Forests for Clean Air Project in the Sacramento Bee. [PDF 29kB]


STRATUM - an application within the new i-Tree software suite, is an easy to use, computer-based program that helps communities assess the benefits of their street trees.

ecoSmart - a Web-based program designed to evaluate the economic trade-offs between different landscape practices on residential parcels.

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Last Modified: Mar 28, 2013 02:56:38 PM