Why don't you just send an email or mail newsletter instead of sending paper magazines or "snail mails"?
"Save the cheerleader, save the world" "Send an email, save a tree !" is the name of the campaign that Calcium started in order to try and preserve the native New Zealand trees.
If you go to saveatree.co.nz and refer a friend
"...Calcium Communication and its participating partners will make a donation towards the purchase and planting of a native tree in New Zealand."
So, please, check out the website, and refer some friends: you will do a good action to preserve NZ great native tree.
If you want to spread the word, you can also download a badge and put it on your blog's sidebar.