Investigating extreme habitats

05.10.2021 | Logbook


SLF botanist Christian Rixen recently took part in an expedition around north Greenland to study the world's northernmost plants and the mountain peaks protruding from the ice sheet. He reports how researchers accidentally discovered the world's most northerly island and recounts an unexpected encounter with a polar bear.

Greenland is big – very big in fact. The distance from its northern to its southern tip is the same as from Oslo to Sicily, yet it has fewer than 60,000 inhabitants. Its longest road is only around 51 km long, and no two settlements are connected by road. What's more, north-eastern Greenland is home to the planet's largest but least-visited national park. So the 12 person Swiss-Danish Leister Expedition Around North Greenland 2021 – a plan to circumnavigate the northern half of the island by helicopter and Twin Otter (a light aircraft) – was nothing if not ambitious.

Record holder

One of the goals of the expedition was to investigate extreme habitats, including plants and soil organisms in the far north and on mountain peaks rising from the Greenland ice, known as 'nunataqs'. Studying life at its outermost limits is vital for understanding the changes that are taking place, not least in terms of the climate. So we were curious to find out what the northernmost plant on our planet would be. Interestingly, it turned out to be a saxifrage – in fact, the same species that also holds the altitude record in the Alps, where it lives on the summit of the Dom around 4,500 m above sea level.

Despite its remoteness, the region had been visited by botanists before, which meant that some fascinating conclusions could be drawn about changes in flora. Back in 1934, Danish botanist Paul Gelting mapped plants up to altitudes of over 1,200 m above sea level. From the 1950s onwards, Swiss botanist Fritz Hans Schwarzenbach studied the altitude distribution of plants in various locations across north-eastern Greenland. In 2001, he repeated Gelting's investigations and found that by then many plant species could be found at higher altitudes on mountains, tallying with our research findings in the Swiss Alps.

'The northernmost island'

While I was examining plants on Greenland's northernmost cape, other members of the expedition team set out by helicopter to locate a small island even further north, which had not been seen for several decades. Where the island should have been they found only ice floes. On closer inspection, they spotted what appeared to be  this island some 800 m further north. However, after the expedition it was established beyond any doubt that the previous northernmost island had been wiped out by storms and ice drift, while a new island had formed further to the north. This new island now needs a name. It has been proposed that it be called 'Qeqertaq Avannarleq', Greenlandic for 'the northernmost island '.

Despite being so near to the North Pole, we experienced the effects of climate change first-hand. For instance, some of those on the expedition found that their sleeping bags got too warm during the night. We subsequently learned that the midnight temperature was 19.8 °C, which almost counts as a tropical night! By way of comparison, night-time temperatures in Davos, in the Swiss Alps, have never risen above around 14 °C. During this spell of mild weather, Greenland recorded one of the largest melting events since measurements began. Moreover, soon afterwards the highest point of the Greenland ice sheet (at 3,216 m) experienced rainfall for the first time since records began!

Image 1 of 5
Camp at Citronen Fjord, 772 km from the North Pole. Photo: Christian Rixen, SLF
Image 2 of 5
Although from a distance it looked like just a barren desert, plants were to be found here. Photo: Martin Breum
Image 3 of 5
Looking south from Cape Morris Jesup in north Greenland. In the north there is only ice, a few small islands (also home to saxifrage) and then, around 700 km further on, the North Pole. Photo: Christian Rixen, SLF
Image 4 of 5
Nunataqs are mountain peaks that protrude from the ice. The Alps probably looked similar to them during the last Ice Age. Photo: Christian Rixen, SLF
Image 5 of 5
This polar bear didn't appear to be overly hungry, but still had to be driven away from the camp. Photo: Christian Rixen, SLF

Mixed feelings

Our preparations for the expedition included training in shooting in case of a close encounter with a polar bear. When you travel to Greenland, you do so with decidedly mixed feelings – you do want to see a polar bear, but not at too close quarters! On an island called Ella, it was believed that the chances of coming across one of these animals were very slim. However, on returning from one hike, I promptly saw a cuddly-looking polar bear between us and our camp. The bear, which didn't seem irritable or hungry, slowly approached our camp, where some members of our team were carrying out fieldwork. Using walkie talkies, everyone was quickly informed, and a few warning shots were fired to scare off the bear. This was actually a shame, because initially we managed to observe the creature peacefully in its territory – but even more importantly, neither the team members nor the bear were hurt.

[Translate to Englisch:] Verwandte Blogposts