Compositionally, they work quite well. However, as already mentioned, watch the colour balance and don't oversaturate to the point that the landscape no longer looks real. The first two in particular are shifted towards the green/yellow quite a bit. Also, to ensure you maintain detail, it is vital that you have a steady base, ideally a sturdy tripod. I didn't look at all of them closely, but the ones I did are showing quite a bit of camera shake, despite the low resolution web images. The water shot also looks to have had a lot of noise reduction added, which has smeared all the detail to the point of non-existence. Detail is very important in landscape photography and if you want to progress in that field (not easy to say the least with so many doing it), it is important that you follow a good technique.
Don't get me wrong, they are a good start, but if you want to progress, it is important that any deficiencies are pointed out, so that you can iron them out. Composition is the hardest part to master in many ways with landscape photography and you have made a good job there, now you just have to master the technical side.