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Aliens in the Arctic
Scientists have developed a new method to map and monitor alien species in the polar regions.
In a recent study a team of researchers have mapped invasive plants in Svalbard, and the results leave no doubt; invasive plants grow where humans have been.
The research team found 36 invasive plant species, and they only grew in areas with human activity. These plants grew in tourist attractions near the settlements, and where there had previously been farming.
"Many of the seeds traveled with hay and straw for livestock decades ago, others with imported soil. Seeds and insects that stick to visitors backpacks, hiking equipment, under shoes and in velcro are a growing problem", says Jesamine Bartlett, researcher at the Norwegian Institute for Nature Research (NINA).
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A few decades ago, during the golden age of mining, there were farmers in Svalbard who imported hay and feed for the animals. Over the years, both mining and agriculture are practiced to a less degree. But the alien plants that came with the imports remain, like here at Pyramiden. Photo: Kristine Bakke Westergaard /NINA.
A threat to biodiversity
Alien plants are one of the major threats to global biodiversity. Increased human activity, combined with a warmer climate, increases the probability of introduction and establishment of alien plant species.
In ecosystems with few species, such as the Arctic, alien plants could compete with the local flora. Many of the plants from the mainland will not survive the Arctic winters. But considering that global warming is happening twice as fast in the Arctic, the probability of alien plants taking root here is constantly increasing. A survey to map the status of alien plants is therefore urgent.
"This is the most comprehensive survey to date of alien vascular plants on Svalbard. We also propose an overall approach to mapping and monitoring that can be included in a regular evaluation of threat levels and measures useful for several Arctic areas", says Virve Ravolainen at The Norwegian Polar Institute.
Mapping and monitoring
The researchers have systematically mapped both bird cliffs and settlements for alien plants.
"With this study we have a valuable reference point for monitoring the presence of alien species in Svalbard. By using the same methodology, it will be possible to repeat the field survey at regular intervals, and thus reveal any new species and the development of alien species that have already been introduced", Kristine Bakke Westergaard, researcher at NINA explains.
Yarrow does not belong on Svalbard. Yellow rocketcress is another alien species that, literally, has taken root in Barentsburg. It is hardy, it can compete with other plants, and spreads easily. Photo: Kristine Bakke Westergaard / NINA.
Both settlements and bird cliffs were thoroughly combed for alien plants. No aliens were found here at Alkhornet. Photo: Ingrid Paulsen / Norsk Polarinstitutt.
It may take decades before the results of introduced species are detectable, and it is hard to say whether alien plants will have a crucial effect on the ecosystem. However, the researchers don’t want to take any chances.
"Right now we have a window of opportunity to eradicate introduced species before they spread beyond control", says Bakke Westergaard.
Some species have already been considered to be such a large threat that the environmental authorities have put measures in place. The Governor in Barentsburg has successfully removed wild chervil over several years.
The slope below the old barn in Barentsburg is still full of alien plant species, but the researchers were happy to confirm that the measures to remove wild chervil have been a success.
Photo: Kristine Bakke Westergaard /NINA
Drones could prove to be a valuable method for mapping larger areas. High-resolution drone images may uncover unnaturally green areas that require further investigation.
Photo: Kristine Bakke Westergaard.
The lack of alien species in bird colonies surprised the researchers. The soil found in these bird cliffs is rich in nutrients, and the conditions are well suited for alien plants to take hold. Many of the bird cliffs are also popular landing areas for cruise tourists.
However, the study showed no signs of alien species in these areas. If alien species are discovered here later, the researchers know that they were introduced after this survey.
Photo: Kristine Bakke Westergaard / NINA.
Kristine Bakke Westergaard examins yellow rocketcress, an alien species in Barentsburg.
Visiting Svalbard? You can contribute!
Currently there are no measures that prevent alien species from entering polar regions, so visitors themselves must take responsibility to avoid becoming part of the problem. In the " Stop Arctic Aliens " and " Polar Alien Hunters " campaigns, researchers, the tourism industry and the administration have joined forces to inform people about what they should do before traveling to the Arctic and Antarctic.
If you are visiting the polar regions, make sure you don’t bring any stowaways with you. Brush, vacuum and wash your bags, clothes, shoes and equipment before leaving home.
Spread the word - and not the seeds!
Background
Researchers from the Norwegian Institute for Nature Research (NINA), the Norwegian Polar Institute, the Norwegian University of Science and Technology and ETH Zürich have recently carried out the most comprehensive survey of alien vascular plants in Svalbard to date, providing a status within settlements, surveying high risk habitats such as those with high visitor numbers and nutrient enrichment from bird colonies and presenting a systematic monitoring method that can be implemented in future work on alien plant species in Arctic environments.
The work is based on compilations of previous plant data, on data from assignments given to the Norwegian Polar Institute in allocation letters and from the Governor of Svalbard, as well as Norwegian work in the Arctic Council's biodiversity groups on behalf of the Norwegian Environment Agency, and expands the findings with larger mapping and put in place in the form of a monitoring plan submitted to the Ministry of Climate and Environment.
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More on polar alien species:
Arctic Aliens: A rising threat (Fram Forum)
Podcast: Aliens in the arctic
Stop Arctic aliens