I`ve looked at these several times now...what are they painted on? paper? one thing that strikes me is they all have a great deal of weight to them, theres no light coming through the trees, I see patches of colors and I can`t tell where the light source is coming from. If these are on paper, you could scratch off some color in the trees on the second one to allow some light to come through, even if the second one was done from a photo, and there was no light there, trees do have spaces between the branches and amongst the foliage so from my perspective, they are very heavy...and sometimes to lighten an area, one needs to darken the ares next to it, I think if you let more light in on those trees, the areas around would appear darker even if you don`t touch them.
And like I always say, to get better at painting or drawing, ya just gotta do it...work as much as you can, each work is a learning experience, it`s OK to read books `n stuff but experience is the best teacher. Paintpaintpaint every day, it really is the only way to improve. Which is better eh? well, depends, everyone who sees them will have a different opinion, which do you think is better and why?