EFFECTS OF INFRASTRUCTURE ON MIGRATION AND RANGE USE OF WILD REINDEER

Abstract

We studied reindeer (Rangifer tarandus tarandus) distribution in relation to possible travel barriers (roads and power lines) in south-central Norway, 1997–2000, using lichen biomass as an indicator of reindeer use. We recorded lichen cover on both sides of potential barriers within comparable habitat in 42 sites for 3 different reindeer herds. We used cover–biomass regressions to assess the relationship between lichen cover and biomass. In 2 of the regions, lichen biomass was 5.3 times and 2.8 times higher in areas isolated by 2 parallel power lines and an adjacent winter-closed road compared to biomass on the other side of the potential barrier. In a third region, lichen biomass did not vary significantly between areas on either side of a single winter-closed road. Lichen biomass data suggested that wild reindeer used both sides of a closed road in winter, whereas 2 parallel power lines and a winter-closed road in combination reduced reindeer migration and resulted in very different grazing pressures on either side of the power lines, even 30 years after the power lines were constructed. Construction of power lines, and particularly parallel power lines, should thus be avoided in wild reindeer habitat. Fragmentation of wild reindeer ranges in Norway results in a substantial reduction in available ranges and traditional migration routes between important seasonal ranges, with a likely overall reduction in carrying capacity.