Lasers mapping threatened Swedish Arctic habitats

Pals mires, one of Sweden's rarest natural bogland features, may be on the way to extinction.

Pals mires are permafrost mires made up of low hills of frozen peat. Researchers are concerned that they are being wiped out by climate change, and Norrbotten County, in the far north is working on a new method to monitor them.

"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."

Pals mire hummocks - or hillocks - can be up to seven meters high. They contain peat and ice, and can form on boggy land 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 that also 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 county, such as the Tavvavuorna mires north of Kiruna, 200 kilometres north of the Arctic Circle.

Some pals mire hummocks which have been observed for a number of years, have recently melted and even collapsed. But something quite unexpected has also turned up from the latest research.

"We've found one location where there are actually several new hummocks (hillocks) – 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."

Reporter: Sara Sällström, SR Norbotten

This article is part of a series of reports from the Eye on the Arctic, a cooperation project between Sámi Radio, Radio Sweden, SR Vetenskaps Radio, and overseas radio stations including Radio Canada International and Alaska Public Radio Network.