A group called TreesNY thinks so, and has come up with a simple and inventive piece of street furniture that protects street trees and provides.... A group called TreesNY thinks so, and has come up with a simple and inventive piece of street furniture that protects street trees and provides bicycle parking at the same time!

To quote:

Trees New York conceived a new kind of street furniture. The solution encompasses a way to support nonpolluting cyclists and protect trees: a bike rack that doubles as a tree guard. We sponsored an international student competition in a search for the best possible designs. Available to you are our two winners--the Adonis and the X-Type. Our models will safeguard trees, encourage bikers' clean transportation, and increase the attractiveness of your neighborhood.

See their brochure for more info, or to order one. (Note: file is a PDF.)

Lots of interesting street-tree-related news and activities for New Yorkers here, so check it out.