Board Thread:Spoilers!/@comment-24674051-20141104223506/@comment-25355646-20141123174630

Maybe the apple tree was linked to the curse because that tree seemed to live longer that most apple trees would, so I think the tree was kept alive by magic and because there wasn't a lot of magic in Storybrooke in S1, the magic from the Dark Curse kept the tree healthy and when the curse was weakening, the tree started to die. If you notice in 1x02, Regina picks an apple and looks at it confused. The apples were already looking a little darker than usual. And in 2x02, all the apples were black until Regina inhaled the magical vapors from the spell book.