Well, I will, in fact, disagree with you hipsterdufus 🙂
I think that the bottom framing, almost a vignetting, by the darker vegitation gives sufficent atmosphere while in the portrait mode version, all it does is leave a cluttered space that activly detracts from the compostion above it.
That said, the square composition looses much more of its effect by the loss of the open sky at the top. The best part of the composition in the original portrait mode version is the balancing of the light and dark areas - the open bright sky giving way to the fog over the water giving way to the dark shaddowed recesses of the vegitation at the bottom of the image.
If I were composing this to print, I would probably loose about half of the bottom dark space while keeping the open space at the top. That would be a better take on the image to my eyes.
Hope this helps,
William