Thank you... now that you mention it, the treefarm-boundarys are flawed. The are to close to the tress, and not high enough.
As I tried to chop down a very hihg tree, I could not reach all of the wood and left a note on a sign...
(cunlock of course)

I may be a good idea to widen the treefarms Worldguard-zone

Beregolas

PS.:
I hope you don't mind if I write in english
I fear my german is not as good as your english seems to be.