Beavers are reshaping the arctic tundra. Here’s why scientists are concerned | Smart News
Beavers have the ability to completely transform landscapes. They eat away at trees, build dams and flood new areas to create ponds, earning them the title of “ecosystem engineers”. But a northward migration of these sawtooth builders worries scientists, reports Hannah Osborne for News week.
New Beaver Report Part of National Oceanic and Atmospheric Administration (NOAA) Annual Report Arctic Bulletin. Comparing decades-old aerial images of an area in western Alaska with more recent images, the researchers found that the number of ponds created by beavers had doubled in the past 20 years. They found over 12,000 ponds; in this same district in 1955, there was not a single one, reports Alexandra Larkin for SCS.
“We didn’t know what we were going to find and ended up being quite surprised,” Ken Tape, an environmentalist at the University of Alaska, Fairbanks, told Oliver Milman for the Guardian.
“There are areas of Alaska that had no evidence of beavers 50 years ago and are now apparently saturated with them,” he says. “It’s only a matter of time before they head further north. Considering this is probably happening in the rest of the Arctic in Canada and Russia, that gives you an idea of the magnitude of this change. “
Beavers can create shallow puddles when building dams. This has increased the total amount of surface water in the area, raising concerns as these ponds are hotter than the surrounding ice, causing the permafrost to thaw – the permanently frozen ground. Permafrost is a critical carbon sink, and its thawing releases carbon dioxide and methane that have been stored for years, News week reports.
The researchers saw a dramatic increase in surface water in the area, and they attributed about 66% of the increase to the presence of beavers, reports CBS.
“These ponds absorb heat better, they change the hydrology of the area and the permafrost reacts to that,” Tape told the Guardian. “It accelerates the effects of climate change. When you realize that what happened in western Alaska is likely to happen in northern Alaska, it makes you think.”
There is also additional concern about how the reshaped landscape and waterways will affect Indigenous communities in Alaska. Beaver dams could affect aquatic food webs and fish populations, as well as make boat access more difficult. Further research is currently underway to analyze how beavers will affect the ecosystem and indigenous livelihoods, says Helen Wheeler, an ecologist at Anglia Ruskin University in England, in a declaration.
It is still not clear why the beavers are growing north in the first place. It could be that the effects of global warming, such as more vegetation, have made the area more habitable for beavers, Guardian reports.
It could also be a burgeoning beaver population spreading north to predator-free areas, or a combination of the two.
“[It] isn’t entirely clear, but we do know that beavers have a significant impact on the ecosystems they colonize, ”Wheeler said.