>>7675018The short answer is The Industrial Revolution.
The longer answer is that until coal started to be mined on a massively industrial scale in Britain, and it could be delivered much faster and in greater bulk than a simple horse and cart could ever carry (1 cartload is/was about 1 ton of coal), heavy industry in Britain simply chopped down way more trees (mostly for fuel and construction) than it ever replanted, leaving vast swathes of the British countryside mostly treeless, even to this day.
Plus the quickly expanding towns, industrial areas, and need for farmland, at that time all required increasing amounts of empty land to build on, so even more countryside, including the trees growing there, was simply swallowed up.
Thus the great forests that originally interconnected and once covered most of Britain, which were already shrinking in area anyway, were fairly quickly reduced to comparatively small and isolated patches of forest/woodland separated by open countryside, farmland, and towns & cities.
