Last month, San Francisco branched out its tree inventory efforts by launching an online map to track tree growth in the city. The Urban Forest Mapping System was designed to help the city's Bureau of Urban Forestry (BUF) inventory existing, future and past trees as well as track maintenance, and calculate costs and benefits of the city's trees. Residents can use the Web site to locate trees, report problems, share photos and stories about local trees and add information about privately owned trees to the city inventory. Friends of the Urban Forest, a local non-profit organization, worked with BUF and the Mayor's Office of City Greening to develop the system using open source software from San Rafael, Calif.-based Autodesk. Visit www.sftreemap.org to view the map.