Also, the idea that the most vulnerable period for trees is in the first few years does not appear to be true.
Example 2005 project : in 2014, when the trees were 8 or so years old, the survival rate decreased in one year from 54% to 43%. A very substantial loss for middle aged trees.
see : http://quintis.com.au/media/1518/tfs-2005_project-accounts_fy14.pdf