LAND: How to prevent invasion of alien species onto urban hills and coastal heathland ecosystems: Sustaining biodiversity in cultural lands

The coastal heath ecosystem is classified as greatly endangered under the EU Habitats Directive. This is because of land-use changes resulting in a dramatic decrease in the utilisation of outfields for grazing. The threatened heathlands are invaded not on ly by native scrub and trees, but also by large alien coniferous species. The UN Millennium Ecosystem Assessment (MEA 2005) states that alien species will represent a major threat to biodiversity and ecosystem services. Norway is responsible for the manag ement of northern heaths of Europe, but we do not have an official plan to prevent these ecosystems becoming dominated by alien trees. A similar process is found on urban hills where alien conifers are spreading from old plantations (>100yrs). There are t hree main drivers that change the heathland ecosystems: in addition to reduced grazing, nitrogen deposition and rainfall are increasing, especially in the winter. This may drive the ecosystem towards a closed forest, i.e. secondary succession. It is like ly that the alien conifers will become dominant in this succession and will alter the ecosystem and its function. The main intruder is Sitka spruce that invades from plantations. It may shade out local flora and reduce the biodiversity because of its size (3-4 times local trees). Mountain pines (Pinus mugo complex) are invading coastal ecosystems and mountains. We will assist the environmental authorities to quantify the effects of alien trees on the biodiversity of native species and ecosystem functionin g, and find possible measures for limiting the spread. This will be done in collaboration with the Environmental Department of the county governor, a PhD-student and a team of researchers, i.e. international specialists on invasive conifers, experts on he athlands and the species groups involved. This will facilitate the implementation of the Convention on Biological Diversity (1993), EU Habitats Directive (92/43/EEC), and the strategic plan to manage alien species.