Invasive plants can have devastating effects on local ecologies that are comparable to the effects of global warming.
Despite this, there is currently no reliable estimate of the number of invasive plant species in the world.
A new study led by the University of Massachusetts Amherst and published recently in Ecological Applications is the first to comprehensively identify the various unknowns that must be addressed in order to intelligently manage invasive species around the world.
Invasive plant species are increasing exponentially
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Stopping the spread of invasive species is the most cost-effective way to stop them.
In order for this to happen, managers must first identify which plants are invasive, as per ScienceDaily.
Existing lists of global invasive plants include species that scientists have reported as invasive, but species that have not yet been reported as invasive pose a risk.
The UMass Amherst team, led by Brittany Laginhas, who completed the research as part of her graduate work at UMass, mined a database of 5,893 studies dating back to 1959 to create the most comprehensive picture of the world's invasive species yet.
Despite this, one of the most basic pieces of information is unknown: how many invasive plant species exist in the world-is not entirely clear.
"We're catching roughly two-thirds of the invasives reported in the literature," said Bethany Bradley, senior author of the paper and professor of environmental conservation at UMass Amherst.
Perhaps the most shocking finding is that the number of invasive species appears to be increasing exponentially, with no sign of a plateau.
Despite the fact that the team discovered 3,008 total invasive species reported in the 5,893 papers, their statistical modeling suggests that there should be 4,721 species, altough the identity of the missing 1,713 species remains unknown.
Alhough there could be many reasons why so many invasive species are missing from the literature, it is clear that there has been a systematic and geographically uneven undercount.
While North America has received a lot of attention, Central and South America, as well as Oceania, have received less.
According to Matthew Fertakos, one of the paper's co-authors and a graduate student in organismic and evolutionary biology at UMass Amherst, there are significant differences between studies conducted on different continents.
Scientists have statistical methods that can help us estimate how many species there should be, but actual data is always preferable to estimates.
invasive species cause ecological or economic harm in a new environment
Invasive species can harm both natural resources and human use of those resources in an ecosystem, as per NOAA.
These species can enter a new area through the ballast water of ocean-going ships, intentional and unintentional releases of aquaculture species, aquarium specimens or bait, and other means.
They also have the potential to extirpate native plants and animals, reduce biodiversity, compete with native organisms for limited resources, and alter habitats.
This has the potential to have significant economic consequences as well as fundamental disruptions to the coastal and Great Lakes ecosystems.
Human activities are primarily responsible for the spread of invasive species, which is often unintentional.
People and goods travel quickly around the world, and they frequently bring uninvited species with them.
Aquatic organisms can be carried by ships in their ballast water, while smaller boats can carry them on their propellers.
Insects can enter the wood, shipping palettes, and crates shipped all over the world. Some ornamental plants can spread and become invasive in the wild.
Furthermore, some invasive species are intentionally or unintentionally released pets.
Burmese pythons, for example, are becoming a major issue in the Everglades, as per the National Wildlife Federation
Invasive species harm wildlife in numerous ways. When a new and aggressive species is introduced into an ecosystem, it may lack natural predators and controls.
It can quickly breed and spread, taking over an area.
Native wildlife may not have evolved defenses against the invader, or they may be unable to compete with a predator's species.
Invasive species pose direct threats to native species by preying on them, competing with them for food or other resources, causing or spreading disease, and preventing native species from reproducing or killing their young.
