Natural and cultural heritage management is dependent on knowledge about present species and habitats and presence of cultural heritage sites, respectively. Knowledge about long-term development helps to identify factors explaining both biodiversity and cultural heritage and to predict future changes based on changes in, for example, climate or grazing regimes. In the present interdisciplinary study, vegetation surveys, pollen analysis from a bog and soil profiles within archaeological localities, archaeological test-excavations and historical data have been combined to elucidate cultural landscape development in an upland landscape of Erdalen in Stryn, western Norway. Activity in what is now the summer farm area started in the Bronze Age, followed by clearance and grazing in the Early Iron Age. After a period of reduced activity, most of the valley seems to have been utilised for summer farming in the Late Iron Age and first part of the Medieval Period. A regression period, probably related to the Black Death, is followed by new activity with extensive woodland clearings from the seventeenth century, whereas recent changes have resulted in increased tree cover. The investigations show a close relationship between land-use practices, presence of grassland species and vascular plant species richness. They also show the importance of continued management for existence of semi-natural habitats in the future, and for the visibility of archaeological sites.