There is absolutely no defense against Tiger -- especially trees.
For one, his ability to recover from the trees is second to none. In fact, at times he might hit better shots from the trees than he does from the fairway. When he is in the trees he must focus even more intensley than normal -- and we all know what that means.
For two, the man is so incredibly talented and intelligent that just because the trees are giving him momentary difficulty doesn't mean that he won't adjust his game to take the trees out of play. He isn't senslessly bombing the ball, he is doing it because it gives him the best chance to make birdies. Unless you force him to hit 4 irons off every tee by lining 15 yd fairways with dense trees on either side, Tiger will hit 3-wood/5-wood when needed and be sure to MISS IN THE SAFEST LOCATION with his driver. He's going low no matter what you do.
Maybe, just maybe, the best defense against Tiger is shag-carpet greens. Imagine if he showed up at Agusta and the greens were running, say, 7 on the stimp. It would throw him completely off his game. For a second, at least.