Descriptive Title:

Percent of land covered by tree canopy

Geographic Unit of Analysis:

Polygon

Percent of land covered by tree canopy (2013)
NeighborhoodPercent
Bayview/Hunter's Point 6.6%
Bernal Heights 12.6%
Castro/Upper Market 14.6%
Chinatown 7.4%
Excelsior 8.8%
Financial District/South Beach 10.4%
Glen Park 25.1%
Golden Gate Park 48.0%
Haight Ashbury 22.1%
Hayes Valley 10.5%
Inner Richmond 12.5%
Inner Sunset 26.0%
Japantown 7.9%
Lakeshore 20.0%
Lincoln Park 39.7%
Lone Mountain/USF 9.9%
Marina 10.4%
McLaren Park 40.1%
Mission 6.8%
Mission Bay 3.2%
Nob Hill 6.3%
Noe Valley 15.8%
North Beach 12.7%
Oceanview/Merced/Ingleside 7.1%
Outer Mission 6.2%
Outer Richmond 9.3%
Pacific Heights 21.6%
Portola 9.7%
Potrero Hill 10.2%
Presidio 33.5%
Presidio Heights 27.0%
Russian Hill 11.5%
San Francisco 13.7%
Seacliff 28.1%
South of Market 3.4%
Sunset/Parkside 13.5%
Tenderloin 3.6%
Treasure Island 18.3%
Twin Peaks 23.0%
Visitacion Valley 8.6%
West of Twin Peaks 17.3%
Western Addition 11.9%

Why Is This An Indicator Of Health and Sustainability?

Trees provide natural cooling through the shading of streets and buildings, reducing exposure to UV radiation and the risk of skin cancer, as well as energy demand and consumption. Trees also capture air pollution, reduce carbon dioxide, increase oxygen, and help capture storm-water runoff, reducing the amount of mercury, oil, and lead going into the Bay. Trees can also serve as buffers to traffic, reducing pedestrian injuries. Several studies show that the presence of forests, trees and other vegetation improves adult recovery from mental fatigue, leading to a reduction in socially unacceptable behavior and crime, as well as increased concentration and fewer behavior problems among children.a,b

Interpretation and Geographic Equity Analysis

 A city’s tree canopy
is measured by the amount of land covered by trees when viewed from above.
San Francisco’s tree canopy (13.7%) 1
 is smaller than Chicago (17%), Los Angeles
(21%), and New York City (24%). This translates to very few trees.
Even worse, the city’s tree canopy is actually shrinking. New tree plantings are
not keeping pace with deaths and removals. As many as 100,000 potential street
tree planting spaces remain empty. Thousands of additional planting spaces exist
in parks and on private property. The city’s trees are also not evenly distributed,

A city’s tree canopy is measured by the amount of land covered by trees when viewed from above. San Francisco’s tree canopy (13.7%) is smaller than Chicago (17%), Los Angeles(21%), and New York City (24%). This translates to very few trees. Even worse, the city’s tree canopy is actually shrinking. New tree plantings arenot keeping pace with deaths and removals. As many as 100,000 potential streettree planting spaces remain empty. Thousands of additional planting spaces existin parks and on private property. The city’s trees are also not evenly distributed, and neighborhoods with more disadvantaged populations generally having less tree canopy. The neighborhoods with the lowest rates of tree canopy coverage include: Mission Bay, South of Market, and Tenderloin which all have less than 5% canopy coverage. In contrast, Seacliff, Presidio Heights, and Inner Sunset all have greater than 25% canopy coverage.

The poor state of San Francisco's urban forest was the inpetus for the 2014 Urban Forest Plan: http://sf-planning.org/urban-forest-plan. The Plan outlines 4 priority recommendations: 1) maximize the benefit of the urban forest through strategic species selection, 2) increase the street tree population with 50,000 new trees by 2035, 3) establish & fund a citywide street tree maintenance program and  4) manage street trees throughout their entire life-cycle by creating an interdependent urban forestry operation.

 A city’s tree canopyis measured by the amount of land covered by trees when viewed from above.San Francisco’s tree canopy (13.7%) 1 is smaller than Chicago (17%), Los Angeles(21%), and New York City (24%). This translates to very few trees.Even worse, the city’s tree canopy is actually shrinking. New tree plantings arenot keeping pace with deaths and removals. As many as 100,000 potential streettree planting spaces remain empty. Thousands of additional planting spaces existin parks and on private property. The city’s trees are also not evenly distributed,

Methods

In preparation for the San Francisco Urban ForestPlan (2013), the Planning Department performed anUrban Tree Canopy (UTC) Analysis using aerial imagery and additional data sets to determine a canopy estimate for the City & County of San Francisco. Detailed explaination of the analysis process can be found in Appendix A of the Urban Forest Plan: http://default.sfplanning.org/plans-and-programs/planning-for-the-city/urban-forest-plan/Urban_Forest_Plan_Final-092314WEB.pdf

Limitations

Because of limited funding for this analysis, low-cost multispectralimagery from the NAIP program was used in conjunction with LiDAR data purchased under current City contracts and licensing with PictometryCorp. There is no guarantee that NAIP will have 2015 imagery available or that the City will have purchased the required LiDAR data needed to perform this analysis exactly the same as described here in the future.

Data Source

Urban Tree Canopy data from the San Francisco Planning Department, 2013

Detailed information regarding census data, geographic units of analysis, their definitions, and their boundaries can be found at the following links:

Interactive boundaries map

http://sfindicatorproject.org/resources/data_map_methods

  1. Kuo FE, Sullivan WC. Environment and crime in the inner city: does vegetation reduce crime? Environment and Behavior. 2001;33(3):343-367.
  2. Taylor AF, Kuo FE, Sullivan WC. Coping With ADD: The Surprising Connection to Green Play Settings. Environment and Behavior. 2001;33(1):54-77.
  3. Maco SE, McPherson EG, Simpson JR, Peper PJ, Xiao Q. City of San Francisco, California Street Tree Resource Analysis. Center for Urban Forest Research, Pacific Southwest Research Station, USDA Forest Service. December 2003.