In just seven years, as much as one-third of the mountain-birch forest in the North Calotte region was severely defoliated by two moth species. Researchers now have a better understanding of what happened.
Herders are struggling to find thousands of reindeer that have run away in search of food. "We are driving for hours and hours to locate our reindeers and to herd them back, but it has been very difficult in these wintry conditions. So, we are also using helicopters and this is very unusual - and very expensive too."