Urban Ecosystems and Social Dynamics Program
Urban Ecosystems and Processes
Urban Ecosystems and Social Dynamics
Since 1992 we have provided our customers with reliable scientific evidence that urban forests add real value to communities. Among their many benefits, trees reduce energy costs, intercept air pollutants, store carbon, and reduce stormwater runoff.
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New Tool: Updated, online Tree Carbon Calculator (beta)
A beta release of the public version of the Tree Carbon Calculator, a computer tool to help the public estimate carbon and energy impacts of trees on a single family residential property is available through the ecoSmart Landscapes Portal at www.ecoSmartLandscapes.org. Use Google Chrome, Firefox or IE9 to access. The Carbon and Energy tool is the first in a new suite of tools allowing users to take an integrated approach to planning landscaping at the residential and community level. This release includes all California climate zones. Expect a release for the remainder of the U.S. in 2013. Learn More
Interception and Bioswales
Although urban foresters have embraced tree planting as a stormwater management strategy, relatively little science has quantified its effectiveness. Drs. Qingfu Xiao (UC Davis) and Greg McPherson’s paper “Rainfall interception of three trees in Oakland, California” compared the amount of rainfall intercepted by three tree species, and concentrations of nutrients and metals from samples collected under the trees. In “Performance of engineered soil and trees in a parking lot bioswale”, Drs. Xiao and McPherson compared runoff and pollutant loading from eight parking spaces adjacent to a control and the bioswale treatment in Davis, CA. The bioswale reduced runoff by 89% and total pollutant loading by 95%. In November, McPherson and Peter McDonaugh, a landscape architect, presented “Large Trees for Stormwater Management: Fact or Fiction” to 200 engineers and architects attending the Greenbuild International Conference & Expo at the Moscone Center in San Francisco. For more information please contact Dr. Qingfu Xiao (firstname.lastname@example.org; 530-759-1727).
The Nature Conservancy Municipal Forest Health Threat Assessment in Boston
The Nature Conservancy, in cooperation with the Pacific Southwest Research Station, adapted the Municipal Forest Health Threat Assessment tool created for California as a part of their Healthy Trees, Healthy Boston Initiative. The overall goal of the program is to improve the health of city trees by establishing early pest detection, with help from the public. The development of report cards for Boston, Brookline, Cambridge, Chelsea, and Wellesley using existing inventories serve as the primary evaluation in determining potential non-native invasive threats and asset losses. Visit their website at: http://healthytreeshealthycities.org/cities/boston or like the Massachusetts Nature Conservancey on Facebook. To read the original report card for 29 California cities please visit: http://www.fs.fed.us/psw/publications/mcpherson/psw_2013_mcpherson002.pdf.
Urban Tree Monitoring Protocol
TheThe Urban Tree Growth & Longevity Working Group (UTGL) has developed a draft Urban Tree Monitoring Protocol that Dr. Lara Roman is presenting at the 2013 Partners in Community Forestry Conference (Nov. 7). The protocol is flexible enough to meet diverse needs, but standardized so that data can be easily compared across time periods and project locations to evaluate tree performance. It creates a platform from which researchers can work with practitioners, using science-based findings to improve tree production, site preparation, tree selection, planting techniques and stewardship practices. View the latest at http://www.urbantreegrowth.org/urban-tree-monitoring-protocol.html. If you are interested in helping to apply and revise the protocol, contact Lara Roman (email@example.com).
Science in Practice
Urban Tree Canopy (UTC) Assessments
A new generation of remote sensing and GIS technologies have spurred UTC assessments for urban forest planning and management. This top-down approach was applied in San Jose, CA, where the council proposes to plant 100,000 trees by 2022. The San Jose Urban Forest Inventory and Assessment found that the annual ecosystem services and property values for the current urban forest provide $239.3 million in benefits. The city contains 2.1 million potential tree planting sites and by estimating the benefits of planting 100,000 trees, it was found that the benefits would increase almost 7% to $255.8 million annually. The city is using the report as a baseline for a proposed study of climate change impacts on the urban forest. This knowledge is especially important in the San Francisco Bay area, where increasing temperatures and fluctuations in precipitation might cause salt intrusion from rising sea levels. The FS study has helped the city of San Jose see the big picture and what they need to do to prepare for the changes to come.
Growing and Governing Green Infrastructure
Urban green infrastructure, including urban forests, is an important strategy for providing public goods and increasing resiliency while reducing ecological footprints and social inequity in metropolitan areas. In a recent paper, Drs. Robert Young and Greg McPherson found that visioning, planning and management of six large-scale tree planting initiatives was largely dominated by the public sector, unlike more transdisciplinary strategies in environmental governance. Many of these initiatives have had little success becoming institutionalized. In a previous paper, they described strategies for sustaining such initiatives. Also, Dr. Young described the role of planning in advancing these initiatives, and identified best practices that can inform future efforts to expand tree planting on a metropolitan scale.
Newly Developed Growth Models for Common ash
Paula Peper partnered with Oakville, Southern Ontario, Canada Forestry Services' Claudia Alzate, John McNeil and Jalil Hashemi to develop the first growth models for common ash tree species. The results are now available in the online article Allometric equations for urban ash trees (Fraxinus spp.) in Oakville, Southern Ontario, Canada. Increased knowledge of tree growth will enable more accurate forecasts of ecosystem services, tree maintenance assessments and analyses of alternative management scenarios to determine best management practices for sustainable urban forestry.
What is the value of a tree? What environmental services do they provide and at what cost? Our new Trees Pay Us Back brochures answer these and other questions. Produced in partnership with CAL FIRE Urban and Community Forestry, these brochures present information on trees in the 16 U.S. climate zones where research was conducted for our Community Tree Guide series and i-Tree Streets. From the Southern and Northern California Coast to the Northeast, Coastal Plain, and Central Florida regions, click to view and download the PDF for your region.
New approach to quantify and map urban forest carbon. By incorporating age-related differences among census block groups that influence tree species composition and stand structure, this novel approach improves carbon estimates and increases the resolution at which carbon can be mapped across a region.
Special Issue on Water Scarcity and Urban Forest Management. The articles in this special issue of Arboriculture & Urban Forestry offer "lessons learned" from a serious drought in Australia to inform future policy, research, design and management.
San Jose Mercury News Article Highlights Partnerships. The article highlighted the greening work of PSW partners such as Our City Tree's CEO Rhonda Berry, city arborist Ralph Mize and San Jose's planning director Joe Horwedel. Although built and paved surfaces cover nearly 60 percent of San Jose, these groups remain focused on increasing the number and quality of trees throughout the city. To read the article go to: http://www.mercurynews.com/ci_23089986/nearly-60-percent-urbanized-san-jose-has-been.
All Trees Not Equal. Greg McPherson's blog supports the California Urban Forest Council's Invest From the Ground Up campaign by providing guidelines for selecting and locating trees to maximize climate, energy and environmental benefits.
Greenhouse Gas Inventory of an Ornamental Tree Production System. This article reports the results of a study to determine the greenhouse gas (GHG) emissions from nursery production of ornamental trees for urban forestry.
Comparison of Methods for Estimating Carbon Dioxide Storage by Sacramento's Urban Forest. This chapter by Drs. Elena Aguaron and Greg McPherson in Carbon Sequestration in Urban Ecosystems determines and examines variability among CO2 estimation approaches.
CO2 in Claremont, CA for the Inland Empire Climate Region
Carbon dioxide stored by selected tree species in Claremont, CA at various intervals after planting (1 metric tonne = 2,204.6 lb).
This animation illustrates the differences among tree species as they age in terms of the amount of carbon dioxide (CO2) they store in their above and below ground wood (biomass). Use the arrow below the chart to stop the animation at any of 5 age intervals. For example, stopping at the 35 year interval allows a clear visual comparison showing tulip tree and holly oak each store 5 or more metric tonnes of CO2 between ages 35 and 55, while Callery pear, Turkish pine, and Chinese pistache store less than 1 tonne.
Animation Data: .xlsx, .pdf