> It just doesn't seem fair that the tree should die before I did.

Bittersweet (http://newagelink.livejournal.com/122966.html), having emotions like these. I'd try to see it as a good experience, that 1) you have the opportunity to have a tree as a pet, and that 2) you have the capacity to feel for it. There are those that can do neither; on /b/ at 4chan I ran across a thread saying, "Post the picture that made you emotionless," and people posted photographs of mutilated cats and kittens.