Scientists say rising arctic temperatures are allowing forests to cover unique and treeless Siberian tundra. They predict the tundra may all but disappear.
The Siberian tundra is a unique habitat where trees are uncommon, but forests are slowly creeping north due to climate changeImage: Maxim Shemetov/REUTERS
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Researchers based at the Alfred Wegener Institute in Germany have used computer modeling to predict "dramatic losses" of the Siberian tundra by the middle of the millennium due to temperature rises in the Arctic.
In a paper published in eLife, the researchers say that even with an ambitious climate mitigation strategy only about 30% of the Siberian tundra will survive by the year 2500.
The Siberian tundra is a unique ecosystem, or biome. Tundras are typically cold and windy and have so little rain that trees do not grow there. But they are home to many special plants and animals.
Tundra can be found in the Arctic, close to the north pole, but also at the top of mountains and in some parts of Antarctica. Arctic tundras have permafrost, meaning that the ground, although not necessarily the surface, is always below zero degrees Celsius (32 degrees Fahrenheit).
Researchers from the Alfred Wegener Institute (AWI) in Potsdam are documenting how forest trees are covering Siberian tundraImage: Ulrike Herzschuh/AWI
Unique life in the tundra
The specific environmental and climate conditions of the tundra give life to a unique and beautiful, although not very diverse, range of flora and fauna.
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Imagine a freezing soil covered with shrubs, moss and small, flowerless green plants — and hardly any animals around. If you are lucky, you might see an arctic fox. If you are less lucky, you might encounter a polar bear.
To the untrained eye, tundras are barren. But the scientists say this barren land is being overrun by a wall of forest trees that is now marching into the area.
The forest begins where the tundra ends. And it is expanding towards the north as temperatures rise, pushing a boundary called the "treeline ecotone."
Vegetation in the tundra is uniquely suited to its landscape — here, in May 2022, researchers took photos of vegetation in Keperveyem, SiberiaImage: Julius Schröder/Alfred-Wegener-Institut
The forest is expanding north
For their study, the scientists used a model called LAVESI to predict the growth of the Siberian larch forest.
The LAVESI model assesses the number of seeds produced in the area, how they are distributed on the ground and how many will turn into adult trees.
"We can very realistically depict the advancing treeline in a warming climate," said Stefan Kruse, a lead author of the study.
The team says that under the most likely climate change scenario, they expect the tundra to reduce to almost 6% of its current size by the middle of the millennium.
But strong mitigation strategies, like the ones required by current international agreements, may help us preserve a bit more than 30% of the tundra.
Kruse and co-author Ulrike Herzschuh say in their paper that if we manage to protect 30% of the tundra and create large reserves and protected areas, it could allow for tundra species to survive and later recolonize.
Edited by: Zulfikar Abbany
Scientists watch Arctic polar bears to track climate change
Russian scientists are on a research expedition to assess the effects of climate change on Arctic wildlife. A particular focus is on polar bears, who are among the animals most vulnerable to global warming.
Image: Gavriil Grigorov/Tass/picture alliance
Sleepy research participant
This polar bear is participating in the research — although not quite voluntarily. Scientists had to anesthetize the animal first. A Russian study is currently in its main stage to measure the effects of climate change on Arctic wildlife. Polar bears are a focal point of the project.
Image: Gavriil Grigorov/Tass/picture alliance
In close contact
The project aims to keep an eye on the health and behavior of the polar bears, and find out more about how they are reacting to the changes in their habitat — changes largely linked to the climate.
Image: Gavriil Grigorov/Tass/picture alliance
The poster child of climate change
The Arctic is warming at twice the rate of the rest of the planet. This has gravely afflicted the area's wildlife. Despite being the land’s largest predators, polar bears are one of the most vulnerable species to climate change.
Image: Gavriil Grigorov/Tass/picture alliance
No ice, no hunt
Polar bears rely on the sea ice around the Arctic Ocean to hunt for seals and fish. As sea ice shrinks, the apex carnivore is forced to swim for long distances or roam the shore to find food. Paleontologists say that polar bears have maintained their diet for centuries, even during the last period of Arctic warming that occured 1000 years ago.
Image: picture-alliance/Arco Images/H. Schouten
Going after eggs
The bear's diet maintains the balance between seals and fish poplulation, but this is changing. A recent study at the Canadian University of Windsor revealed that the hungry predator has increasingly resorted to foraging for seabird eggs. This, in turn, can eventually trigger a chain of damages to the environment that starts with endangering the seabird species.
Image: picture-alliance/dpa/Greenpeace
Exploring the polar bears' favorite hunting habitat
To better understand the impact of climate change on polar bears and how to mitigate its damages, scientists joined the UMKA2021 expedition. It takes place in Russia's Franz Josef Land, an archipelago of almost 200 islands joined together via sea ice, the polar bears' hunting grounds.
Image: Gavriil Grigorov/Tass/picture alliance
Measuring vital signs
After capturing the bears, scientists measure and record factors such as their weight, reserve body fat and blood pressure. This helps them find out more about their diet and energy consumption.
Image: Gavriil Grigorov/Tass/picture alliance
GPS messages
The bears are then released with GPS tags on their ears that send regular messages to the researchers containing information about their health. Scientists receive the messages in form of emails everyday, The tags also make it possible to track the bears with helicopters and drones.
Image: Gavriil Grigorov/Tass/picture alliance
Gone by 2100?
The scientists believe that closely tracking the polar bears could help prevent their extinction. The bear's number is rapidly decreasing and several studies project that they could vanish by the end of the century unless more is done to slow climate change.
Image: picture-alliance/blickwinkel/McPHOTO
No texts from the bears
Every time a polar bear dies, its GPS tag stops sending messages. The scientists will no longer receive news from the animal. Only one bear off the mailing list it may be, but for the planet's biodiversity, the decline in the population of this Arctic predator is much more alarming.
