I have a Christmas tree farm of about 20,000 trees.  May sound like a bunch 
but remember one Mama tree produces 10,000 seeds per year.  Would you that 
would not cut a tree rather kill the extra seeds instead?  It is your choice 
which ones you prefer to kill.  The trees are attacked by fungus, rusts with 
no known cures, molds, bugs etc.  If the tree is allowed to grow to maturity 
one of the above will do it in.  I use Cs trying to help the trees with 
"incurable" rust.
Brickey