The color is somewhat flat in all of them.
The first and third are clearly 'hey, cool, I should get a shot of that' photographs. These rarely work out well. Too much junk around the cool thing, you haven't isolated any coolness and, ultimately, the cool thing just isn't that cool. These are the kinds of things where you go 'wow, cool' in real life, gaze at it for 5 seconds, and then never look at it again. The photograph isn't going to fare much better.
The second one is a little trite, we see this sort of thing a lot, but that's largely because it's a good idea. The shapes of the tree and the reflection give us more interesting stuff to look at. It's still a cool thing, but it's a cool thing that we're willing to look at, and maybe even backtrack on the trail to see again. At least we're looking forward to another look at it on the way back. I'm not wild about the way the ridgeline on the right vanishes into the tree -- the repeated line there is good, but a little separation would have been nice. Let us see the ridge, and the branch, repeating the line but in parallel.
The fourth one is just another 'hey cool' thing that wouldn't be worth more than a few seconds, except that you did a good job isolating it for us. There's not a bunch of distracting junk around, so we can enjoy the shapes and maybe, for some of us, it becomes something a little more than a 5-second 'hey, cool' thing.
