Source: Michelle Robertson, “First major SF tree census: 20,000 more trees in city than previously thought,” SFGate; Kelaine Ravdin, “SF street tree species, by the numbers,” Urban Forest Map
San Francisco, CA (March 21, 2017) – San Francisco is home to nearly 125,000 street trees and a staggering 628 species and cultivars. That’s the news following a year long citywide tree inventory. San Francisco’s tree population is even more diverse than its citizenry.
Officials with the SF Urban Forest Map painstakingly recorded every street tree in San Francisco during the year long inventory. Trees in public parks and on private property were excluded from the count.
Gina Simi, communications manager at the SF Planning Department, noted that “efforts are currently in place to secure additional funding” for future inventories of trees at schools and in the city’s open spaces. The map was last updated in 2010, using data primarily from the Department of Public Works.
Combining data from the Friends of the Urban Forest, the City of San Francisco, businesses, and citizen scientists, this year’s update reported 20,000 more trees than the previous iteration.
A typical city hosts 80-100 different tree species, according to a statement on the Urban Forest Map’s website. San Francisco’s diversity of species aids the plants in warding off pests and diseases, and the data helps forest managers plan future tree plantings.
London plane trees proved to be the most abundant species by far, with over 8,000 covering the city. The planes surround Civic Center Plaza, while the famed English sycamores act as a natural red carpet ushering visitors to San Francisco City Hall.
Beyond their decorative purposes, serving to break up the deluge of grey concrete buildings and foggy skies, the trees serve an essential municipal purpose. The Urban Forest Map estimates that the city saves $240,296 annually from the abundance of trees, as they filter stormwater and carbon dioxide, improve air quality, and conserve energy.