As I think it would be easy to create all the textures and do the UV layout etc. for the first setting, I wanted to model the second and third setting. Below are screenshots of my progress of modelling the second setting. Like the first setting, it isn't in the animation for too long, as it is only in the animation for around 6 seconds.
I haven't made it look too detailed as of yet, as I want to decide what more can be added to it at the time of creating the UVs. Overall, it looks very similar to the first setting, which is obviously a good thing as it should look like the same forest.
With regards to adding more to the scene, I think different variations of tree and an uneven floor would make sense.