KINGSTON, R.I. – June 4, 2024 – The spread of invasive alien species has long been recognized as a global threat to nature and people. In September, the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) for the United Nations issued a global assessment providing clear evidence of the growing threat to people, the economy and nature from invasive alien species.
In a recently published paper in Nature Ecology & Evolution, the authors of last year’s assessment – 88 experts representing 101 organizations from 47 countries – outline the main findings from that report and echo the need for urgency to act now.
Dr. Laura Meyerson, URI professor of invasion science and habitat restoration ecology and editor-in-chief of the journal Biological Invasions, is a contributing lead author on the IPBES assessment and a lead author on the paper – one of two papers Meyerson has recently published in Nature journals.
“Biological invasions are increasing at an alarming rate across the globe, harming human health and well-being, hurting economies across the globe, and contributing to decline and the extinction of native biodiversity,” said Meyerson. “Our research produced overwhelming and unequivocal evidence that the negative impacts of biological invasions far outweigh any benefits and that those who depend most on nature suffer the worst consequences.”
The researchers documented more than 37,000 alien species that had been introduced by people to areas around the world. Of those, more than 3,500 species were considered harmful invasive alien species that negatively affect nature and people’s quality of life.
The number of invasive alien species – major drivers of global biodiversity loss – are expected to continue to rise, the paper says. About 200 new species are expected to be added each year by human activities in regions that have not recorded invasive alien species before. And established species will continue to expand their ranges, spreading into new countries.
Along with that, the paper notes, simple extrapolations from current impacts from invasive alien species are likely to underestimate the level of future impacts, and drivers of biodiversity loss – such as climate change – are acting in concert and those interactions are increasing biological invasions.
“With the number of invasive alien species set to rise, we can provide options to inform immediate and ongoing action,” said lead author Helen Roy, co-chair of the assessment and professor at the University of Exeter. “To achieve this there is a need for collaboration, communication, and cooperation, not only across borders but within countries.”
The paper concludes that urgent, coordinated management actions will be critical in addressing biological invasions, including co-developed efforts among multiple parties, such as government and private sector stakeholders, Indigenous peoples and local communities.
Professor Meyerson noted, “It’s critically important that we all do our part to reverse current trends. The public can make sure that the plants they are buying for their gardens are native species. Pet owners should not release animals, like rabbits or Burmese pythons, that are no longer wanted into the wild. Our state and federal legislators need to work collaboratively with business and tribal nations, as well as internationally, to improve biosecurity to better protect people and nature.”
Biological invitations on Indigenous peoples’ lands
Meyerson is also the senior author on a second major global study that explored the extent of biological invasions on lands owned or managed by Indigenous peoples. The study, led by Hanno Seebens from Justus Liebig University Giessen and the Senckenberg Society for Nature Research, both in Germany, was published in Nature Sustainability in late May.
The spread of animal and plant species into new regions by humans is increasing rapidly worldwide, with thousands of species now present in regions outside their native range. The research team – which included scientists from Austria, Hungary, the U.S., and Australia, as well as Germany – investigated the spread of alien invasive species to lands managed by Indigenous peoples and found significantly fewer alien species in those areas compared with other natural areas.
“This was a really important finding because even after controlling for the remoteness and accessibility of Indigenous peoples’ lands and how land is used, in general, the numbers of invasive species are lower, as is biodiversity loss,” said Meyerson. “While we don’t yet have complete information on why this is so, we do know that there is much to learn from traditional ecological knowledge and that we need to learn from and co-develop knowledge with Indigenous peoples for everyone’s benefit.”
Researchers analyzed millions of available data points from around the globe on the distribution of non-native plant and animal species. On average, there were 30% fewer non-native species on Indigenous peoples’ lands. The study suggests the enormous difference is primarily due to sustainable land use, a higher proportion of forests, and lower accessibility to humans.
Indigenous peoples represent ethnic groups that settled in regions long before the arrival of Europeans – such as Native Americans, the Aborigines of Australia or the Sami in Scandinavia. About 28 percent of the land surface around the globe is inhabited by Indigenous peoples. The majority of these areas are in remote regions of the world and many have enormous importance for conservation of biodiversity such as the Amazon basin and wilderness areas in the Arctic.
“The results show that sustainable land use makes a huge contribution to preventing the spread of alien species,” said Seebens, Ph.D., from the University of Giessen. “Indigenous peoples usually use their lands traditionally and sustainably. Our study makes it clear that protecting the rights of Indigenous peoples is also essential for the protection of biodiversity.”