The history of Irish forests since the Ice Age.

Abstract

The study of pollen grains recovered from boglands and lake muds helps us to understand the ancient Irish landscape, but provides little information on the ground flora of ancient woodlands. The first tree to invade Ireland after the Ice Age was the birch, followed by hazel, pine and, later, oak and elm. The invasion of warm-loving trees from Europe was restricted by the sea. Forests were steadily cleared during the later Neolithic, Bronze and Iron Ages, except on inaccessible ground. Soil conditions favoured growth of blanket peat on exhausted land rather than woodland regeneration. Evidence suggests that oaks and pine grew on some bogs from about 5,000 to 2,000 years ago. While many forests disappeared thousands of years ago, documentary evidence suggests that extensive oak forests survived around Killarney and the Lower Bann valley up to the seventeenth century. However, this is not supported by pollen evidence and it is likely that these areas were cleared of trees over a period of one thousand years.