The Intergovernmental Platform on Biodiversity and Ecosystem Services (IPBES) has recently publicized an “Assessment Report on Invasive Alien Species and their Control.” The report divulges the worrying escalation of invasive alien species worldwide. It further elaborates on their harmful effect on biodiversity globally.
Key Findings of IPBES Report on Invasive Alien Species
The report discloses the existence of approximately 37,000 alien species across different regions and biomes worldwide, brought over by human activities. More than 3,500 are identified as invasive alien species, posing significant threats to local ecosystems. About 6% of alien plants, 22% of alien invertebrates, 14% of alien vertebrates, and 11% of alien microbes are known to be invasive.
The water hyacinth tops the list as the most widespread invasive alien species on land. Lantana, a flowering shrub, and the black rat occupy the second and third spots on the global invasion scale. Invasive alien species have played a critical role in 60% of documented global plant and animal extinctions. They are now perceived as one of the five primary catalysts of biodiversity loss.
Regional distribution data reveals that the Americas experience 34% of the impacts of biological invasions, followed by Europe and Central Asia at 31%, Asia and the Pacific at 25%, and Africa at around 7%. Most negative impacts occur predominantly on land, particularly in forests, woodlands, and cultivated areas.
Understanding Invasive Alien Species
Invasive alien species are organisms introduced to regions outside of their native range, which establish self-sustaining populations. These species often outcompete native species, disrupting the balance in ecosystems and leading to various negative impacts.
Increasing Prevalence of Invasive Species
Increased globalization in trade and travel has unintentionally moved species across borders. Cargo ships, airplanes, and vehicles can accidentally carry invasive species in various ways, facilitating their unwanted spread. Changes in temperature and precipitation patterns due to climate change also foster environments conducive to the colonization and proliferation of invasive species. Instances of humans deliberately introducing non-native species for purposes like gardening and pest control have also led to invasions.
The Damaging Effects of Invasive Alien Species
Invasive alien species pose a range of threats to both ecosystems and economies. They can outcompete native species for resources, leading to a decline or extinction of native species. Some invasive species may become predators of native species, causing declines in prey populations. Economically, the global cost of invasive alien species has quadrupled every decade since 1970, exceeding USD 423 billion annually in 2019. Lastly, invasive species can greatly reduce food supply and spread diseases impacting human health.
International Policies Addressing Invasive Species
Several international agreements and programs have recognized and begun addressing the issue of invasive species. The Kunming-Montreal Global Biodiversity Framework (2022) commits governments to reducing the rate of introduction and establishment of invasive alien species by at least 50% by 2030. The Convention on Biological Diversity (CBD – 1992), Convention on the Conservation of Migratory Species (CMS – 1979), and the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES – 1975) all include measures to control or eliminate invasive alien species and consider their impact.