James Fenton, ecological advisor to the Natural Trust of Scotland, says it is incorrect to say that human activity has destroyed the native woods of the Scottish Highlands. He adds that conservationists who are trying to recreate the ancient Caledonian pine forest by planting native trees risk destroying natural moorlands and peat bogs. Fenton points out that much of the Scottish Highlands has been treeless for the last 4,000 years and deforestation has resulted from natural climate change, not by human activity. The climatic changes, which started before farming had a major impact, encouraged the growth of peat bogs and discouraged the regeneration of native trees ( New Scientist , Vol 157, No 2126).