> as there are few stands of trees that are not "managed" with regular "harvesting"

Depends on where you are located. Here in upstate New York there are almost unlimited number of potential bee trees. There are several hundred acres of unmanaged forest within easy walking distance of my house. I have aerial photos from the 1930s and the woods are thicker now than then, with the exception of the lot across the street which has been logged twice in 30 years.

On my property three large native magnolias fell last winter. Seems like this tree is always hollow once it gets big enough. Most of the oaks are probably hollow too, but they don't tend to fall (luckily, there are about five within striking distance of my roof). One of them has a large hole at the bottom and I have seen woodchucks going in and out. 

As I have said before, I haven't seen a feral swarm move into any of these trees over the past 30 years.  One of my friends showed me one about a mile from here, though. Speaking of managed, I asked a logger about the value of my woodlot and he said prices are so low, I would be giving the wood away. Plus, loggers aren't interested in small lots anyway.

PLB

             ***********************************************
The BEE-L mailing list is powered by L-Soft's renowned
LISTSERV(R) list management software.  For more information, go to:
http://www.lsoft.com/LISTSERV-powered.html