Ingvild Austad

Land-cover and structural changes in a western Norwegian cultural landscape since 1865, based on an old cadastral map and a field survey

Many studies of land-cover and structural changes in cultural landscapes have used historical maps as a source for information about past land-cover. All transformations of historical maps onto modern coordinate systems are however burdened with difficulties when it comes to accuracy. We show that a detailed land survey of the present landscape may enable transformation of an old cadastral map directly onto the present terrain with very high accuracy. The detailed resulting map enabled us to locate remnants of semi-natural grasslands and man-made structures with continuity from 1865 and to test hypotheses about relationships between landscape changes and landscape characteristics. The main land-cover change 1865–2002 was decrease of arable fields, and addition of three new land-cover classes: horticultural, orchard and abandoned areas. Of the 330 man-made structures present in 1865, only 58 remained in 2002, while 63 new structures had been built after 1865. We found that semi-natural grasslands with continuity since 1865 were situated on ground with significantly lower production capacity than mean 1865 production capacity. The man-made structures with continuity since 1865 were also associated with areas with significantly lower production capacity than the 1865 mean, situated in significantly steeper terrain but not further from the hamlet. Our study illustrates the potential of digitised and accurately transformed historical cadastral maps combined with detailed field surveys for analysis of land-cover and structural changes in the cultural landscape.

Road Verges: Potential Refuges for Declining Grassland Species Despite Remnant Vegetation Dynamics

Whether road verge vegetation can be manipulated to resemble traditionally managed grassland has been much debated. This short-term study compared management effects on road verge and pasture vegetation in western Norway. We quantified vegetation change and explored whether it occurred along underlying environmental gradients. We found management-related variation in species richness and vegetation physiognomy, but high resistance in species composition prevented directional changes in vegetation dynamics. Initial differences between the habitats indicated historical management effects on traditionally managed pastures and road verges. Given proper management, road verges may have a nature conservation potential. Moreover, their linear structure may enable fine-scale mosaic management that allows the coexistence of a wide range of grassland species.

Historical Cadastral Maps as a Tool for Valuation of Today’s Landscape Elements

Physical and biological traces of human activity in the landscape such as various stone structures, buildings, irrigation channels, semi-natural vegetation types and land use patterns can give us information about the past and particular historical periods. However, it can often be difficult to fix the exact age of such traces, and to evaluate their continuity, because fragments dating from different parts of a long history may be recovered alongside each other in today’s landscape. Historical cadastral maps may be very useful tool for evaluating such landscape elements. They can be used to distinguish between older and younger man made structures, and may thus tell us, which structures survived land consolidation, which structures were built later on, and which have been lost. Knowledge of the types and locations of previously existing structures may also help us to understand other traces in today’s landscape. An understanding of the history of the landscape gives us information on areas with a long continuity of land use and management. Historical materials and historical maps have therefore been used in a number of ecological and geographical studies (Foster 1992; Kienast 1993; Skanes 1996; Ihse & Blom 2000; Cousins 2001). In Sweden, Riddersporre (1995) described the old agricultural landscape from before the 17th century and Borgegard (1994) demonstrated how historical maps could be used in the reconstruction of an old agricultural landscape.