Native trees play vital role in maintaining biodiversity
WE continue with the theme of trees this week to celebrate the upcoming National Tree Week, promoted by the Tree Council of Ireland and sponsored by the ESB.
The Tree Council of Ireland has given us 200 native saplings to distribute to community groups and schools throughout Kerry. If you wish to avail of their generosity, please e-mail mocoilea@kerrycoco.ie and we will arrange a suitable pick up point.
Ireland lost most of its flora and fauna during the Ice Age as plants and animals retreated south in the path of the advancing glaciers. When this cold period was eventually over some 10,000 years ago the land was recolonised by species that crossed via land bridges that existed between Ireland, Britain and the Continent. Some species, however, did not arrive in time as the land bridges disappeared under the rising seas from the glacial melt waters. As a result, some common tree species that are native to the continent are not represented in the native Irish flora such as beech and Norway spruce. Beech succeeded in crossing to the south of England but did not arrive naturally in Ireland.
Most of our native trees are broadleaves – such as oak, ash, birch (pictured right) etc while conifers are represented by only three species– Scots pine, yew and juniper – the latter being only a shrub. Conifers form only a very minor part of the native species resource and consequently reference to native species usually means native broadleaves.
Currently, native species form only a small percentage of our forests due to their low productivity in relation to introduced species. Native broadleaves are more difficult to grow and require sheltered, fertile sites and a high degree of silvicultural skill if productive stands of quality timber are to be achieved. Better quality of land is, however, becoming available for afforestation in farm forests and along with attractive grants and premiums, native broadleaf species are being planted in higher numbers than any time since the start of the afforestation programme which began in the 1920s. Scots pine is also being planted but mostly as a nurse species in mixture with broadleaves.
Native species are being planted not only for timber production but also to encourage and enhance biodiversity in our forests. Native trees have a long association with many indigenous animals and plant species and provide rich and diverse habitats that are not seen in stands of introduced species, particularly conifers.
Old forests and stands of native species are important islands of native biodiversity and it is from these areas that native plants and animals spread to new habitats. Their conservation and enhancement is therefore an important objective in forest management which today is also concerned with the environmental sustainability of the forest resource.