" For the Cambrian Mountains were once densely forested. The story of what happened to them and – at differing rates – to the uplands of much of Europe is told by a fine-grained pollen core taken from another range of Welsh hills, the Clwydians, some forty miles to the north.3 A pollen core is a tube of soil extracted from a place where sediments have been laid down steadily for a long period, ideally a lake or a bog in which layers of peat have accumulated. Each layer traps the pollen that rains unseen onto the earth, as well as the carbon particles which allow archaeologists to date it. "

― George Monbiot , Feral: Rewilding the Land, the Sea and Human Life