|Greetings form the Critique Club :)
First of all, this is a really great idea, getting a really neat upward perspective on a very photogenic tree.
The white cloud in the upper left corner looks blown out, but it's a white cloud, so there's not really much you could have done except wait till the wind moved it away.
When taking shots of a long (tall) subject that you want in focus, it helps to use the smallest possible aperture to keep the as much as possible in focus, probably f8 unless your camera can go smaller.
In terms of composition, I like the second tree in the photo, but it may have been better to put the top of the main tree following the rule of thirds, not quite as close to the top right corner.
It looks like there is a nail sticking out of the base of the tree, but I'm not sure.
Over all, a very nice shot.