Scientists are discovering that the Arctic’s rising temperatures might be the second-biggest threat to wildlife.
Climate variability is increasing, as well, meaning once-rare extreme events like flash floods and droughts happen more often. It’s difficult for wildlife to cope with these pulses; animals have responded to global warming by shifting ranges and behaviors, but these dramatic changes can come too quickly for adaptation.
The impact can be brutal, according to a new study published in PLOS.
“An ecosystem-wide reproductive collapse” and “a pervasive failure across almost the entire food web” followed one recent climate variation, according to scientists stationed at a Greenland research station.
Northeastern Greenland saw unprecedented snowfall in 2018, part of the global trend of northern latitudes getting more precipitation due to climate change. Snow fell more than twice as deep as some recent years. It was so thick that some didn’t melt until the end of summer.
“The result was an almost complete reproductive failure of plants and animals of all sizes,” the study says.
Northeastern Greenland normally sees peak animal activity and plant growth during July, but nearly half the landscape was still covered in snow, researchers found. Plants and animals responded by delaying their life cycles; plants flowered later, while shorebirds took longer to nest and lay eggs.
Those offspring came so late in the year that it’s doubtful they survived winter. The seeds were unlikely to develop before frost, and the hatchlings didn’t have time to build strength for southward migration, the researchers said.
Some parts of the ecosystem seemed resilient. The abundance of flowers and insects seemed normal, if delayed, the researchers wrote.
Larger animals more clearly suffered. The researchers found zero Arctic fox cubs and nearly no muskox calves.
Scientists have been observing northeastern Greenland from a dedicated monitoring station for about 20 years. Nothing in that time prepared them for last year.
“We were unable to predict what we encountered in 2018,” the scientists wrote.
As a caveat, the researchers noted that Arctic species have adapted to harsh conditions and high variability; populations and species have recovered from reproductive collapses before. Even short-lived species like flowers and bugs can survive and reproduce over multiple seasons or years.
In a best-case scenario, variability might help stabilize the ecosystem. More temperate species are expected to migrate north as temperatures rise, but they usually can’t handle climate variability as well as Arctic species. So an occasional year of extreme conditions could preserve the status quo by keeping out would-be intruders, the researchers wrote.
The problem is that climate variability is forecast to worsen. Even hardy Arctic species could struggle with more variability—a “game changer” for population dynamics, the scientists wrote.
“One nonbreeding year like the one observed in 2018 is hardly devastating for High Arctic species. The worrying perspective here is that the 2018 conditions may offer a peep into the future: Climate change has already resulted in a variety of species and ecosystem-level responses of Arctic organisms.”
Reprinted from Climatewire with permission from E&E News. E&E provides daily coverage of essential energy and environmental news atwww.eenews.net.
