Creating a wildlife snag from a live tree

We are converting our backyard from invasive blackberries & a few scattered trees to a food forest.   I need to remove a couple of 20 year old douglas firs.  One of them has a metal t-post partially embedded in the trunk (oops) so cutting it down would be tricky. 

I was reading this page about creating wildlife snags from live trees, and decided to give it a shot.  Yesterday I climbed the tree and girdled it about 1/3 down from the top.  I also removed about 2/3 of the branches.  The idea is to let the tree die slowly, hopefully rotting from the inside out (vs. outside in), which provides better conditions for wildlife (cavity-nesting birds, etc.).  Above the girdle the tree will die quickly, and the top will break off, leaving an open wound for fungus to rot the tree from the inside.

I am wondering if anyone else here has tried that?  Especially on a douglas fir?  What tools did you use?  I used an axe, but if I were to do very many trees I think a draw knife would be easier.  The handle of the axe really got in the way, tangling with the branches.  Also there is not enough room to swing the axe, so I basically held the blade in my hands and pushed it up/down to peel the bark in a band about 10" wide.  However the axe did work really well for removing branches.  In many cases all it took was one good chop.

I'll try to post pictures as the tree slowly dies.

I would love to hear from anyone else who has tried this.

I had kind of given up on this project because the tree didn't seem to be fazed by my girdling. But on Saturday we had a pretty good wind storm, and the tree broke off right where I had girdled it - hooray! I'll post some photos soon.

How far is this tree from the house ?

I've girdled a few broad leafed maples. They have multiple trunks, and I thinned them. In order to get rot going and to provide nesting sites, a few plunge cuts were made. Woodpeckers worked those cuts into a variety of holes. I use a chainsaw.

Dale Hodgins wrote:How far is this tree from the house ?

I've girdled a few broad leafed maples. They have multiple trunks, and I thinned them. In order to get rot going and to provide nesting sites, a few plunge cuts were made. Woodpeckers worked those cuts into a variety of holes. I use a chainsaw.

It is about 200 feet from the nearest house. It smashed a few blackberries and a bit of a small tree but it should recover.

Some photos:





This t-post is one of the reasons we are getting rid of this tree. I placed it next to the tree when I planted it so that I could find it in the thick blackberries. But I left it too long

Six months ago I girdled two more trees (cottonwood & another doug fir). The cottonwood broke off Friday night, and fortunately didn't damage anything. There was about 35 feet above the girdling so it was quite a chunk of wood that came down.

The fir is closer to important things so yesterday I secured it with some heavy wire rope to hopefully catch the top before it hits the ground. I'll try to get some pictures and post them.

Woodweb had a thread up a few years ago, about things found in trees when someone went to cut up the wood.  One was a waterpump out of a car I believe.  I believe the thread also talked about munitions found in trees, which adds more complexity.

I think today, if I had to cut a tree or log or ... that was known to contain metal, I would have a look at waterjet cutting, where some abrasive was being used as well.  And some kind of shielding so that if the water stream was diverted/reflected by an object, that it not do any damage.