Sweden’s Endangered Pals Mires Monitored With Lasers
Pals mires, one of Sweden’s rarest natural features, may be on the way to eradication without anyone knowing exactly how fast this is occurring or how large the threatened areas are.
Pals mires are permafrost mires where high hummocks of frozen peat form. There is concern that the hummocks will not survive continued warming of the climate. The Norrbotten County Administrative Board is therefore trying to develop an entirely new method of monitoring the pals mires.
“We’re laser scanning a number of pals mires using an airplane at an altitude of 700 meters,” explains Susanne Backe, who works with environmental analyses at the county administrative board. “And what we’re getting is a very detailed, three-dimensional terrain model.”
The pals mire hummocks can be up to seven meters high. They consist of peat and ice, and can form on mires when precipitation and average yearly temperatures are low. The heights of the hummocks can be discerned with laser scanning and changes can be compared between the years. Measurements made from the air cover larger areas than measurements made on the ground according to Susanne Backer.
“If it’s a viable method, we hope we can collaborate with Finland and Norway, and perhaps Russia and other countries as well that have pals mires.”
Many species of birds are attracted to pals mires and the vegetation varies considerably. In Sweden, pals mires are only found in Norrbotten, such as the Tavvavuorna mires north of Kiruna.
After the first of multiple years planned for method development, pals mire hummocks have been observed that have melted and even collapsed. But something quite unexpected has also turned up.
“We’ve found one location where there are actually several new hummocks – hummock embryos if you will,” says Susanne Backe. “And it’s going to be very interesting to monitor them and see what happens. Whether they continue to develop into larger hummocks or if they collapse while still small. And laser scanning will be able to help us with this.”
