A Board of Supervisors committee approved legislation Monday that would give city officials wider powers to protect large trees in San Francisco, including those on private property.

[...]

After landmark status is granted for a tree, it could not be removed without a public hearing and approval from the Department of Public Works. Cutting down a landmark tree without permission could bring a fine as high as $1,000 and a requirement to pay for replacement of the tree.

Link.

But over in Oakland:

Take a stroll around the lake and you'll find red-tagged trees everywhere you look. Some of them are coming down because they are dead or dying; others are so old and heavy they've become a safety risk; still others have to go to make way for widened and improved paths and jogways. But others seem to have been condemned for entirely arbitrary reasons. And we're not mollified by the city's plan to plant more trees than it cuts down: We know the difference between a tree that's stood for sixty or more years and a sapling that will need to be held up by wooden poles for its first five years.

Link.