Living in Canberra it's easy to spend time at the Australian War Memorial, where there is a superb collection of photographs (B&W and Colour) available for perusal on WWI.
One of the things most striking is the landscape (and I'm talking aerial photo's here). It's brown, muddy, pitted, pockmarked, dismal and thoroughly torn up. And this is up to 15 miles on either side of the line!
Which pretty well covers the arena for aerial combat. Yet in both RB3D and the screenshots from Aspect the land depicted is lush, green and nicely tilled with neat paddocks and fields showing.
It really does need to get down and dirty to create a more realistic atmosphere. Some greenery by all means, but the exception rather than the rule.