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Why is there a "reproductive collapse" of the ecosystem in Greenland

Why is there a

The delayed flowering and nesting of the plants meant that the offspring of some Arctic animals probably did not survive the winter.

Scientists are finding that rising temperatures in the Arctic could be the second biggest threat to wildlife.

Climate variability is also increasing, which means that once-rare extreme events like flash floods and droughts occur more frequently. It is difficult for wildlife to cope with these pulses; Animals have responded to global warming by changing 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.

"A reproductive collapse throughout the ecosystem" and "widespread failure of almost the entire food web" followed recent climatic variation, according to scientists stationed at a Greenland research station.

Northeast Greenland experienced record snowfall in 2018, part of the global trend for northern latitudes to get more rainfall due to climate change. The snow fell more than twice as deep as some recent years. It was so thick that some did not melt until the end of the summer.

"The result was an almost complete reproductive failure of plants and animals of all sizes," says the study.

The researchers found that northeast Greenland normally sees a peak in animal activity and plant growth during July, but almost half of the landscape was still covered in snow. Plants and animals responded by delaying their life cycles; plants flowered later, while shorebirds took longer to nest and lay eggs.

Those descendants arrived so late in the year that it is doubtful they survived the winter. The seeds were unlikely to develop before frost, and the hatchlings did not have time to build forces for southward migration, the researchers said.

Some parts of the ecosystem seemed resistant. The abundance of flowers and insects seemed normal, if delayed, the researchers wrote.

The larger animals suffered more clearly. The researchers found zero Arctic fox cubs and almost no musk calves.

Scientists have been observing northeast Greenland from a dedicated monitoring station for about 20 years. Nothing at that time prepared them for last year.

"We couldn't predict what we found in 2018," the scientists wrote.

As a warning, the researchers noted that Arctic species have adapted to the harsh conditions and high variability; Populations and species have recovered from reproductive collapses before. Even short-lived species like flowers and insects can survive and reproduce for several seasons or years.

At best, the variability could help stabilize the ecosystem. More temperate species are expected to migrate north as temperatures rise, but they generally cannot handle climate variability as well as Arctic species. Thus, an occasional year of extreme conditions could preserve the status quo by keeping potential intruders out, 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.

“A non-breeding year like the one observed in 2018 is not devastating for High Arctic species. The worrying outlook here is that 2018 conditions may offer a glimpse into the future: climate change has already resulted in a variety of species and ecosystem-level responses from Arctic organisms. ”

Video: Greenlands Extreme Melt, 1 Year Later (October 2020).