“There is essentially no chance for native species to keep up with climate change without human help.”
(Bethany Bradley, professor of Environmental Conservation at UMass Amherst)
An international team of scientists recently found that non-native species are expanding their ranges many orders of magnitude faster than native ones, largely due to unintentional human help. Even seemingly sedentary exotic plants are moving at three times the speed of their native counterparts in a race where, given the rapid pace of climate change and its effect on habitat, speed matters. To survive, plants and animals need to shift their range 2 miles per year just to keep up with rising temperatures and associated climate changes, a rate that native species cannot handle without human help. . Led by scientists at the University of Massachusetts Amherst, the team includes researchers from New Jersey, Michigan, Colorado and Hawaii in the US, as well as Seville and Zaragoza in Spain and was published in Annual Reviews of Ecology, Evolution and Systematics.
“We know The number of invasive plant species is increasing exponentially around the world.,” says Bethany Bradley, professor of environmental conservation at UMass Amherst and lead author of the paper. “We also know that plant nurseries are exacerbating the climate-driven spread of invasive species. and so? Confronting invaders is one of the best ways to prepare for climate change.. “What we wanted to know is how fast native and non-native species are moving right now, and how far they might go.”
To find out how fast species are moving, Bradley and his colleagues exhaustively examined a large number of previously published papers and publicly available data sets on how far and how fast native and non-native species have been moving, representing different taxa and diverse ecosystems. . An important subset of this quest was to collect data showing how humans are helping to accelerate the spread of non-native species, either accidentally, such as when a particular species is found in a shipping container traveling between continents, or intentionally, When a gardener buys an invasive ornamental plant from a nursery and brings it back to his home.
The conclusion reached by Bradley and his colleagues is that terrestrial species, including plants, must move at more than 3.25 kilometers per year if they want to stay ahead of climate change, while marine species must move at 2.75 kilometers by year. . Unfortunately, native species only manage to move an average of 1.74 kilometers per year.
Non-native species, however, are spreading on their own at about 35 kilometers per year. When the human role in the spread of non-native species is taken into account, the rate jumps to an astronomical 1,883 kilometers per year, 1,000 times faster than the rate at which native species spread.
“Essentially,” Bradley says, “there is no chance for native species to keep up with climate change without human help.”
For the second part of their research, Bradley and his colleagues wanted to understand to what extent both native and non-native species could spread in a warming world, since not all ecosystems are suitable habitats.
While the team had to synthesize and analyze fewer case studies, their research indicates that non-native species are likely to find more territory to their liking than native species. “However,” says Bradley, “while this means that non-native species could have more territory to gain from climate change, it also means they have more territory to lose as some range margins become increasingly unsuitable.” “.
What does this mean for the future then?
“It's very clear that people are very good at translocating species, and this is one of the biggest advantages that non-native species have,” Bradley says. “We need to seriously consider and start implementing assisted migration” (the practice of deliberately helping native species move to more suitable locations) “if we want our native plants and animals to have a chance.”
More: Study finds plant nurseries are exacerbating climate-driven spread of 80% of invasive species
Recent research from the University of Massachusetts Amherst is the first to accurately map horticulture's role in the spread of invasive species, projecting warming ranges below 2 degrees Celsius.
Source: “Non-native plants and animals expanding 100 times faster than native species, according to new research led by UMass Amherst,” UMass Amherst news release June 18, 2024.
Above and corresponding image of the connected home page: UMass Amherst
