Jason HarrisEcologyIntroductionToday, the woods remaining in the Killarney Valley, totalling 1,400 hectares, are the closest approximation to the ancient forests which long ago covered this country.
on the Carboniferous Limestone of the lowlands, swamp forest or carr dominated by Alder is present on the low lying lake edges. On the limestone reefs on the Muckross Penninsula, just west of Muckross house, a Yew woodland exists;the only significant stand of Yew in the country. The most extensive forest areas, however, are the Oak woodlands.
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These are found on the lower slopes of the Old Red Sandstone mountains of Killarney National Park and rarely go above the 200 metre contour so that the upland landscape is vitually treeless.Because of the underlying limestone and the cover of glacial deposits, the soils of the killarney lowlands are more fertile and provide a richer agricultural resource. Over the last three centuries, therefore, these lowlands have been intensively managed for agriculture by the two great estates of the Killarney Valley; the Muckross Estate and the Kenmare Estate. Just over two hundred years ago, the agricultural journalist, Arthur Young, visited the Muckross Estate and stayed with the owner, Thomas Herbert. In his journal, Young describes the various agricultural improvements that Mr. Herbert had put into effect.
He tells how Mr. Herbert had reclaimed 140 acres which had been covered with great rocks, stones, furze and brambles. The brown sandstones to which Young refers, were erratic boulders of Old Red Sandstone, which had been carried along by glacial action, whereas the limestone which could not be broken up by fire was outcrops of the Carboniferous limestone reef.Along the Dinis loop walk is a small lake called Doo Lough and it is fringed by Oak woodland, the dominant vegetation type on Old Red Sandstone. The swamp by Doo Lough is made up of lake mud and peat nearly 7 meters deep. By radiocarbon dating, it is possible to determine the age of the peat at any particular layer. Therefore we can tell what the vegetation was like at particular times in the past.
Those studies tell us that the deepest layers of peat were laid down 12,000 years ago. At that time the vegetation was typical of a very cold climate, such as we would find in the Arctic today. These studies also tell us that the woodlands of Killarney in their present form became established only 1,800 years ago.Further on from Doo Lough is another neck of land called Camillan Point. You can see that the major tree species is the sessile Oak with an understorey of Holly.
Rhododendron ponticum, an introduced species, threatens the long term survival of the Oak woods. It competes directly with Holly as the understorey species but with its heavy canopy it completely shades out the ground layer species, and prevents the regeneration of Oaks. Bird species that reside in the oak woods include blue tit, common chaffinch, goldcrest, European robin, and wren. Mammals include badger, fox, pine marten, red deer, sika deer, and red squirrel. Insects include many species of the parasitic gall wasp and the purple hairstreak butterfly, whose caterpillar is entirely dependent upon oak trees.Materials and Methods