This article is from the Disney's Haunted Mansion FAQ, by Don Bertino bertino@netcom.com with numerous contributions by others.
No.
According to blueprints that are in the Haunted Mansion Office, the trees
as you go down into the graveyard are listed as "Mechanical Trees", but
there is nothing mechanical about them.
These trees were recently gone over with a flashlight and a fine toothed
comb. 8(;-) There was NO mechanisms inside, only steel framework covered
with heavy foil, then painted.
 
Continue to: