quote newguy: "Does this still need to be hung in a tree, since it's not a bear-proof barrel?"
This isn't a bearproof barrel.
When it comes to bears, the advantage of barrels is that they do a good job of containing the food odors. Lots of people "stash" them somewhere on the ground, away from the heavily-used areas of a campsite, figuring it will make them difficult for bears to find. Many people have used them this way for years without any bear issues.
They also provide protection against rodents, the elements, and general damage (e.g., crushing) which is nice.
Lots of discussion on this site re: barrels if you use the search tool.