Sorry I haven't replied ... I honestly missed it somehow!
I like your idea behind this image, though not my style of photography.Might I suggest moving a bit left , so the tree line on the left isn't intersected my the subject tree?
Another idea is possibly hitting the tree with a bit of flash for a different effect, while still exposing the sky nicely as you've done here!(if at all possible with your gear and the exposure time)
CAMERA BIRD NERD #1
BIRD NERD O'CANON
"Any society that would give up a little liberty to gain a little security will deserve neither and lose both" - Benjamin Franklin