Bomb stores were usually out in the open, some may have used woodland but most I have seen were completely open and Turweston may also have been open and the undergrowth has grown up in the last 60 odd years.
RAF Keevil is in the open.
RAF Blakehill Farm is in the open.
RAF Acaster Malbis is now in woodland as the area has been turned into a nature reserve.
The RAF as far as I know did not camouflage their bomb stores after a certain date (date not known by me) as I did find some camouflage fittings at RAF Keevil (although they could have been American?), but the Americans did and I have seen several photos of US stores camouflaged.
I have just been looking at an earlier post and Peter has a link to a bomb store on Pathe News and that has a camouflage net,http://www.britishpathe.com/record.php?id=23323