Landscape change patterns in mountains, land use and environmental diversity, Mid-Norway 1960-1993

The Norwegain mountains have had a central role in the subsistence agroecosystems by providing vast biological resources for humans and their livestock since 4000-3500 BP as indicated by paleoecological records. Later with the development of the summer farming system the use of the mountains was intensified. This long-term use of the mountains has shaped a montane cultural landscape by livestock grazing, mowing for hay, fuel collection and a variety of other uses. The result is a significant increase of the grassland areas at the expense of the forest. Those semi-natural grasslands and heathlands with specific biological diversity have until recently dominated the mountains but are today decreasing due to forest invasion - which in turn is a result of changes in human land use. The present paper focuses on changes in landscape pattern and differences in landscape development in two mountain valleys with summer farming activities, in Mid-Norway, over the period 1960s-1990s, and seeks to interpret the changes in relation to differential land use and environmental factors. This study contributes examples from human shaped ecosystems in mountains where the fragmentation of semi-natural habitats is addressed. A set of landscape pattern indices commonly used in landscape ecological studies is also used here, and their ecological relevance in the present context is dealt with. The implications of changed land use for biodiversity conservation in those mountains and the relationships to future sustainable agriculture is also briefly discussed.