IRISH FORESTS A BRIEF HISTORY ANCIENT （爱尔兰古老的森林一个简短的历史）.pdfVIP

IRISH FORESTS –A BRIEF HISTORY ANCIENT FORESTS The last Ice Age ended approximately 15,000 years ago (13,000 BC). It was another 4,000 years before conditions in Ireland were suitable for colonisation by plants and animals. These pioneering plants and animals spread into Ireland mainly from southern and central Europe, probably through the United Kingdom, by way of land bridges (sea levels were lower than at present). The first land plants were mainly herbs and low lying shrubs such as grasses, sedges, various dock species, juniper, dwarf birch and dwarf willow. Many of these species have a restricted distribution in Ireland today and some, such as dwarf birch, no longer occur. As the weather improved, warmth demanding species became established. The birches, accompanied by willows, with hazel following shortly afterwards, were probably the first true trees to arrive in Ireland about 10,500 years ago. Birch does not cast a heavy shade so it is most likely that it was in these woodlands that primroses and anemones first appeared. The birch forests were soon replaced by oak and elm forests, while hazel reverted to a shrub growing under the forest tree canopy. The first humans arrived around 9,000 years ago (7,000 BC). By this time the island was predominantly covered in a blanket of woodland. Oak and Elm were well established, with Scots Pine growing on the lower slopes of some uplands. There were two major woodland types namely, mature deciduous Oak Woods in the lowlands and valleys with an abundance of ferns, mosses and liverworts, and the Pine Forests on poorer soils with ling heather, grasses and bracken occurring in the ground layer. Some birch woodlands would have also ex