Ok thanks the help, does anyone have any more tips, tutorials or anything?

Thanks for the tips but i need to make a full 3D set with trees and all the other stuff.

Hi

For jungle scenery try look at pet shops as they have a great range of products that are cheap and actually look great on dios once given the proper weathering. Also a comapany called Woodland Scenics make a greta range of products for model railways and dios that would be useful as well.

I have attached a few pics of dios I have done using plastic fishtank plants and Woodland Scenics items and if you have questions just give me a yell.

Ron

This might not be helpful but autumn is a good time to start.  Dried leaves can be crushed and mixed with PVA glue to create fantastic ground cover.  The mixture dries hard but looks soft and so you can  stick it to your trees and paint it back to green. 
I was working at a studio last year that had one of the Fantastic Mr Fox Tree House sets in a case in reception (I don't know why, I reckon they nicked it; this was the East End after all) The leaves of the tree seemed to be crushed dried leaves and they were stuck to a fine mesh, kind of like miniature camouflage netting.