Unnatural environment - Have campaigners for the return of Scotland's forests got it wrong?
点击量： 时间：2017-04-12 03:01:10
By Rob Edwards THE popular theory that human activity destroyed the native woods of the Scottish Highlands is a myth, claims a leading ecologist. He warns that conservationists who are trying to recreate the ancient Caledonian pine forest by planting native trees risk destroying natural moorlands and peat bogs. James Fenton, the ecological adviser to the National Trust for Scotland, argues that much of the Highlands has been “virtually treeless” for the past 4000 years. Deforestation was caused not by human activity, he says, but by natural climate change. Between 4000 and 7000 years ago, Scotland’s summers became cooler, its winters wetter and its soils more acidic. Fenton says that these changes, which took place before farming had a significant impact, encouraged the growth of peat bogs and discouraged the regeneration of native trees, which do not grow well in waterlogged ground. Fenton bases his argument mainly on evidence from peat bogs. For example, tree remains are mostly confined to the lowest levels of bogs, suggesting that they have not been able to recolonise the land for the past 5000 years. Regeneration may also have been inhibited by populations of grazing deer. Other evidence comes from pollen samples taken from two sites on the island of Skye. The government is backing plans by forestry and conservation organisations to restore Scotland’s native pine and birch woods. The Millennium Forest for Scotland Trust is using over £11 million from the National Lottery to encourage the planting and regeneration of 8000 hectares of native forest. Fenton calls such schemes grandiose and misguided. The commercial plantations of alien conifers that have scarred the Scottish landscape for decades might simply be replaced by blanket plantations of native woodlands, he says. “What concerns me is the unthinking application of the philosophy that all trees are good.” In the latest issue of Scottish Forestry, a journal published by the Royal Scottish Forestry Society, Fenton dismisses the assumption of most conservationists that the Highlands is a degraded environment. The open moors and peat bogs that characterise the landscape could be more natural than forests, he says. In addition, Scotland’s mosses and liverworts are rarer and afforded better international protection than its native pine trees. Fenton is supported by scientists such as Adam Watson,