This is a really tough exposure situation - the only suggestion would be to possibly change the in-camera white balance to warm this photo a bit. I imagine this tree would look beautiful in early moring or late evening light (not always possible to get for a challenge, I realize!)
unlike many in this challenge, your cropping didn't cut off the tree, so i think it's very good. i wish the tree had a bit more contrast to pull it out from the background, though. i'd like to see some details on how you did this and wonder if a wider angle lens and closer proximity to the tree might have made it stand out more from the background. what did you shoot this with?