I think for this shot to have any real impact there is too much going on around the focused tree, and I also think you're maybe too zoomed out. Aside from that I think you've got the nice muted tones for it and a good black for the silhouette.

To me this image is very simple and elegant. I can definitely understand why you wanted all that sky in there... It creates a lot of negative space for the little tree to live and I think that adds to the impact of the image.

I would like to see the tree a little bit more to the right... or either dead-center. At this point it's living just off-center and that makes my brain feel a little uneasy.

Other than that, though, I think you've done a great job here. I like the deep, strong blacks and also the tones in the clouds to the left.

Agree with lbstone - great job with blacks, I like the silhouette
It might have more of an impact cropped vertically and off center just a tad.

Nice shot, but too centered, I think. Wonderful light and atmosphere you have captured.

Best,
Jon

I actually like the tree in the middle. My eyes are more attracted to the "waviness" of the ground, and the tree becomes more secondary.