Welcome to the wonderful world of "Maneuver Damage!"
I was on three REFORGER exercises (AKA REGURGER to many of us) --
1974, 1975, and 1988. We were given classes on what was and was not possible for use in such situations, and using any sort of non- artificial cover was considered a faux pas.
The reason is that unlike the US German forests are managed by forestmeisters who tend to clearing underbrush and damaged or dying trees and scrub. They account for the bits and do not appreciate others using or stealing it -- there have been nasty incidents with service members held at shotgun point unitl a Manuever Damage officer arrives to sort things out.
The very first REFORGER I was on my lieutenant (a typical second looie, not very bright) tore up a beet field getting my platoon into position. The only thing that saved us from paying a stiff fine was the fact that somebody ordered a troop from the 1-4 CAV to give us protection, and the Sheridans tore the field up worse so they got the bill.
Germans were very skilled at milking this system. The record holder was somebody who claimed 80,000 marks for a chicken which was hit by a vehicle. The charge was for all of the eggs that chicken would have laid, the ones that would have been allowed to become chicks and the eggs they would have laid when they grew up to be chickens.
An expensive game, and Lord help you if you damaged a tree!
Cookie Sewell