Dense forests question

[NikToo]

A question on dense forests, as opposed to a dense question about forests, hopefully. I actually live in the south of England, so I pretty much fly over where I live (ten minutes from Tangmere). My question is: around us to the north are the South Downs, which is a hilly ridge, mainly covered in quite thick coniferous forest. However, in COD, it only shows occasional leafy trees. Can dense forests not be recreated as basically a "block" instead of individual trees? I.e. just a big square block with high sides and a textured top. I don't know much about how sims work, but just thought it'd be a way of showing a forest.