Climbers' Corner • Tree Academy
Monday • Tuesday • Wednesday
Life-Cycle Assessment of the Million Trees LA Program
Summary
This presentation describes results from the first life-cycle assessment of a large-scale tree planting initiative. It quantifies the material and energy inputs and outputs associated with planting of nearly 100,000 trees in Los Angeles between 2006 and 2010. A survey of managers of yard, street and park trees provided data to quantify greenhouse gas (GHG) emissions associated with raw material acquisition, transportation and energy use for each life stage: nursery production, site preparation, planting, irrigation, pruning, removal and disposal. Carbon stored by the trees and avoided GHG emissions from tree shade and climate effects on heating and cooling building energy use were simulated for a 40-year life based on a field sample of 86 residential planting sites. Knowledge to be gained from this study includes identifying “leverage points” at each life cycle stage, where actions can be targeted to most effectively reduce GHG burdens and increase benefits. A sensitivity analysis reveals how results are influenced by different variables such as irrigation type and amount, tree species, location, growth, care, longevity, and fate of tree residue. Arborists can use this information to educate customers as to the most cost-effective strategies for reducing their energy and water footprints, and to assess the sustainability of their own practices.
Presenters
Dr. Greg McPherson is a Research Forester with the USDA Forest Service’s Pacific Southwest Research Station located in Davis, CA, Greg grew up under a canopy of American elm trees in the small town of Howell, Michigan. Despite attempts to save the trees, all were lost to Dutch elm disease, and having felt the sting of that loss he became a "green" accountant, developing new methods and tools for quantifying the value of nature’s benefits from city trees. He works with a team of 3 other scientists who measure and model effects of trees on energy use, urban heat islands, air pollutant uptake, carbon sequestration, and rainfall interception. Their research is helping justify investments in urban forest planning and management. In 2000 Greg received the International Society of Arboriculture’s (ISA) L.C. Chadwick Award for Research. Greg chairs the ISA Tree Growth and Longevity Working Group and serves on the Science Policy Advisory Committees of American Forests and the California Urban Forest Council. He attended University of Michigan (BGS), Utah State University (Masters in Landscape Architecture), and SUNY College of Environmental Science and Forestry (Ph.D. Forestry).
Climbers' Corner • Tree Academy
Monday • Tuesday • Wednesday