The Caledonian Forest is the ancient (old-growth) temperate forest of Scotland. The forest today is a reduced-extent version of the pre-human-settlement forest, existing in . The Scots pines of the Caledonian Forest are directly descended from the first pines to arrive in Scotland following the Late Glacial; arriving about 7000 BC. The forest reached its maximum extent about 5000 BC, after which the Scottish climate became wetter and windier. This changed climate reduced the extent of the forest significantly by 2000 BC. From that date, human actions (including the grazing effects of sheep and deer) reduced it to its current extent.