"Mini jungle": Alaska’s tundra grows taller and greener as temperatures rise

Alaska’s Arctic tundra is becoming greener and taller as rising temperatures reshape plant life, creating a chain of effects across the region’s fragile ecosystems.

On Alaska’s North Slope, where there are no tall trees, dwarf birch and rhododendrons can grow to around 25 centimetres, Euronews reports.

Scientists say the region’s harsh conditions have historically kept plants small, with frozen permafrost limiting root growth and cold and wind exposing taller vegetation to damage.

But the climate is changing. The area is now about 2.7C warmer than it was 40 years ago, largely because of the burning of coal, oil and gas.

“Plants that are already there are growing taller,” said plant ecologist Anne Bjorkman of the University of Gothenburg, adding that they are likely to grow even taller in the future.

Taller shrubs are also moving into areas where they previously could not survive, a process known as shrubification. Darker vegetation protruding above the snow absorbs more solar energy than the white snow cover, which reflects heat, potentially accelerating Arctic warming.

“It's certainly a major fingerprint of change that we can see,” said University of Colorado plant ecologist Sarah Elmendorf.

The expansion of shrubs may have further consequences. They can trap more snow, warming the ground beneath and allowing microbes to release more methane during winter. At the same time, increased vegetation could absorb more carbon dioxide, partly offsetting those effects.

Changes in vegetation are also affecting waterways. Expanding stands of willows are providing more shade to streams and altering conditions for fish, insects and birds. Researchers are studying whether Arctic ecosystems can adapt to these changes, including through genetic evolution.

Scientists at Alaska’s Toolik Field Station are also examining how Arctic plants interact with one another. Rather than simply competing for limited sunlight, nutrients, water and pollinators, some species may cooperate to survive in the harsh environment.

One focus of the research is the Arctic lousewort, a parasitic plant that takes nutrients from the roots of neighbouring plants. Researchers are investigating whether its purple flowers attract scarce bumblebees and increase pollination for nearby plants.

“Tiny changes in a tiny jungle make a big difference,” said Jake Francis, a professor at Florida Atlantic University.

Researchers are testing the theory by manually pollinating plants around the lousewort to determine whether they receive more pollination than plants further away.

Amid rapid Arctic warming, scientists say the changes offer a reminder that even small shifts in the region’s vegetation can have wider consequences for its ecosystems.

“It would be wonderful if humans were the same way,” Francis said.

By Aghakazim Guliyev