Thanks for the comments: please remember that this was just testing out the trees.
I didn't use soft shadows and the tree detail was at medium. If I use a realistic sun diameter I doubt that soft shadows would make a noticeable difference as the distances over which the shadows are cast is small.
It was the slightly un-natural tree distribution, reminiscent of managed landscape planting found in public city parks. For this reason I wanted regularly tended close cropped grass, I don't think I have seen a good example of this yet; the closest I have seen has been made using very tall tiny fake stones, which is what I have used here.
I do like the idea of a picnic but this would requite figures and I have not seen any Free downloads that I think are good enough. Also would they not be strange picnicking in such deep shade?
I did have a thought about maybe finding a clearing and seeing what I could do with Ogre's fountain.