Forest moon

Having seen a couple of animals from the lodge, a pheasant and a red squirrel both from the windows. I took a walk through the forest today in the hope of snapping some wildlife, maybe one of the elusive red squirrels if I was lucky.
Apart from some birds fluttering away out of shot or being partially obscured through branches I didn't really get back with anything but some shots of trees.
Having a difficult choice of interesting forest-y shots to choose and having decided to not post another black and white one after yesterday I went with this one because having recently re-watched the original Star Wars trilogy again it reminded me a little of Endor.
Which made me think of something else, our planet has lots of different environments, desert, forest, snow etc. So why in Sci Fi films / series are planets often presented as one environment all over?