Scientists at the UK Centre for Ecology & Hydrology (UKCEH) are playing a key role in major assessments on global threats to biodiversity that will inform governments’ action to protect nature.

Professor Helen Roy is a co-chair of a new international report for IPBES, published on 4 September 2023, which has provided the most indepth assessment so far of the multiple risks posed by invasive alien species to nature and people.

It was carried out by 86 international experts from 49 countries, from all regions of the world. They assessed the current status and trends of these invasive plants, animals and other organisms, how they spread, as well as their impacts on biodiversity, food and water security, economies and human health. 

Meanwhile, as the data visualisation expert for the assessment, UKCEH computational ecologist Dr Tom August worked with many of the authors to translate key findings into figures and tables.

Often described as the ‘IPCC for Biodiversity’, IPBES (the Intergovernmental Science-Policy Platform on Biodiversity) is tasked with providing the best-available evidence to decision-makers, for people and nature. It published its Invasive Alien Species Assessment Report after discussion and approval by members at the IPBES-10 Plenary event in Bonn, Germany.

IPBES has cited invasive alien species as one of the five major direct drivers of biodiversity loss globally, alongside land and sea-use change, direct exploitation of organisms, climate change and pollution. Most non-native species spread to other regions through human activity, either intentional or accidental. For example, they are concealed in plants or attached to boats. Some are invasive, threatening other species by predation, competition for food, water or habitat, or transmission of disease.

Professor Roy, an ecologist at UKCEH, explains: “Invasive alien species are a major threat to biodiversity and can cause irreversible damage to nature, including local and global species extinctions, and also threaten human wellbeing. 

“The accelerating global economy, intensified and expanded land- and sea-use change, as well as demographic changes are likely to lead to increases in invasive alien species worldwide. Even without the introduction of new alien species, already established alien species will continue to expand their ranges and spread to new countries and regions. Climate change will make the situation even worse.” 

The key findings of the report include:
•    More than 37,000 alien species have been introduced by many human activities worldwide, of which around 3,500 are harmful
•    These invasive species play a key role in 60% of global extinctions of plant and animal extinctions 
•    They pose a challenge to people in all regions of the world, particularly indigenous peoples and local communities which have greater direct dependence on nature
•    The global annual cost to economies has quadrupled every decade since the 1970s, to at least US 423 billion dollars, though the actual figure is likely to be much higher
•    83% of countries do not have national legislation to tackle Invasive alien species and 45% of countries do not invest in the management of biological invasions.

The authors say preparedness and prevention are the most effective methods in tackling the problem but add eradication, management and control to deal with biological invasions are often possible.

In addition to approving the report, the IPBES-10 Plenary event also heard of progress on the IPBES Nexus Assessment, which is investigating the links between biodiversity, water, food, health and climate change. Professor Paula Harrison, Principal Natural Capital Scientist at UKCEH, is co-chair of this assessment, which will be discussed at the IPBES-11 Plenary.

Further information

A press release on the Invasive Alien Species Assessment and a Summary for Policymakers are available on the IPBES website.

The assessment has been in development for more than four years, led by Professor Roy and her fellow co-chairs, Professor Aníbal Pauchard from Chile and Professor Peter Stoett from Canada. 

It draws on more than 13,000 documents that capture the diversity of existing knowledge on invasive alien species, including scientific articles, governmental reports, and indigenous and local knowledge.