Increase in ‘invasive’ plants and animal species as a result of human activity could lead to dramatic biodiversity loss worldwide, scientists warn
- Experts collected data from 36 specialists who research biological invasions
- They found that transport, climate change and changing land use are key drivers
- A 20–30% rise non-native species numbers could have major global impacts
An increase in invasive plants and animal species as a result of human activity could lead to dramatic biodiversity loss across the globe, scientists have warned.
Invasions of non-native species — such as the Canada Goose or Japanese knotwood in the UK — have the potential to displace local species and even spread disease.
Canada Geese, for example — first introduced to Britain in the mid-18th Century — are aggressively territorial, damage farmland and pose a threat to local biodiversity.
An international team of experts led from Austria collated data from 36 specialists in biological invasions to identify key causes and likely impacts on future biodiversity.
Human activities like tourism — both intentionally and otherwise — are key drivers for the establishment of plant and animal species in new regions.
The researchers calculated that an increase of 20–30 per cent in numbers of invasive species would trigger a ‘dramatic’ loss of biodiversity across the globe.
An increase in invasive plants and animal species as a result of human activity could lead to dramatic biodiversity loss across the globe, scientists have warned. Pictured, the invasive Canada Goose, which first established populations in Britain in the mid-18th Century
‘At the moment it is not yet possible to generate precise predictions based on computer models as to how the spread and impact of alien species will change in the future,’ said paper author and ecologist Franz Essl of the University of Vienna.
‘Therefore, expert assessments via standardised surveys are an important tool to obtain a better understanding of the causes and consequences of the spread and impact of alien species for the coming decades.’
From their analysis, Dr Essl and colleagues found that a 20–30 per cent increase in the number of newly-introduced invasive species would be sufficient to cause ‘massive’ global biodiversity loss — and that this value would be reached soon.
Humans, the team, explained, are the ‘main driver’ behind the spread of non-native species around the world.
The three main ways in which we are causing the spread of invasive species are our increasing global transport networks, human-driven climate change and the impacts of economic developments such as increasing energy consumption and land use.
However, the researchers also noted that the spread of alien species still had the potential to be slowed down by developing ambitious countermeasures.
Comparing different parts of the globe, the team found that tourism is a major driver of biological invasions in tropical and subtropical regions at present — while climate change will favour invasions in the future, especially in polar and temperate zones.
Dr Essl and colleagues found that a 20–30 per cent increase in the number of newly-introduced invasive species would be sufficient to cause ‘massive’ global biodiversity loss — and that this value would be reached soon. Pictured, predicted uncertainties as to the role that different drivers of invasive species will play in both best- and worst- case scenarios
‘Our study illustrates the option space we currently have to reduce the future impacts of alien species,’ said paper author and conservation biologist Bernd Lenzner, also of the University of Vienna.
‘The results form an important scientific basis for the further development of international agreements such as the Sustainable Development Goals or the Convention on Biological Diversity, he added.
‘This way we will be able to reduce the negative impacts of alien species on global biodiversity and our society.’
‘There has been a rapid escalation in the number of non-native species being transported and introduced by humans around the world,’ said paper author Helen Roy, of the UK Centre for Ecology and Hydrology in Lancaster.
‘The adverse effects of some of these so called invasive non-native species on biodiversity and ecosystems has been extensively documented,’ she added.
‘It is now critical that we work collaboratively to predict future patterns so that we can inform appropriate action going forward — such as improved bio-security to prevent further introductions of the most damaging invasive non-native species.’
The full findings of the study were published in the journal Global Change Biology.
INVASIVE SPECIES ARE THOSE INTRODUCED IN A REGION TO WHICH THEY ARE NOT NATIVE
An invasive species is one – be it animal, plant, microbe, etc – that has been introduced to a region it is not native to.
Typically, human activity is to blame for their transport, be it accidental or intentional.
Hammerhead flatworms have become invasive in many parts of the world. They feast on native earthworms, as shown
Sometimes species hitch a ride around the world with cargo shipments and other means of travel.
And, others escape or are released into the wild after being held as pets. A prime example of this is the Burmese python in the Florida Everglades.
Plants such as Japanese knotweed have seen a similar fate; first propagated for the beauty in Europe and the US, their rapid spread has quickly turned them into a threat to native plant species.
Climate change is also helping to drive non-local species into new areas, as plants begin to thrive in regions they previously may not have, and insects such as the mountain pine beetle take advantage of drought-weakened plants, according to the National Wildlife Federation.