A study has found that invasive species—non-native organisms that spread rapidly—have their most severe effects on biodiversity in the global south, where fast-growing economies, weak governance, and limited management capacity make ecosystems especially susceptible to biological invasions.
The proliferation of invasive alien species is considered a key factor behind the worldwide decline in biodiversity. Earlier assessments indicate that such species have been involved in around 60 per cent of recorded species extinctions and have caused economic losses amounting to hundreds of billions of dollars.
Researchers, including experts from the University of Fribourg in Switzerland, stated that their findings "challenge the widely held belief that the most severe effects of invasive alien species are mainly concentrated in the Global North."
They further noted that, while the global spread of non-native species is increasingly well documented, the geographic patterns of their environmental impacts are still not well understood.
They noted that most worldwide evaluations depend on indirect measures such as the number of invasive species or the volume of trade, since international trade can bring in non-native species—which have indicated that the most severe impacts occur in the global north.
The researchers added, however, that this pattern may be due to underreporting in the global south rather than actual differences in ecological impact.
The researchers integrated the Global Impacts Dataset of Invasive Alien Species (GIDIAS)—which records over 22,000 documented impacts from more than 3,300 invasive species in 172 countries—with worldwide datasets detailing the distributions of alien species.
The authors calculated the average severity of impacts by country and found it to be higher in the Global South—where research activity is generally lower—even though the Global North has more than twice as many documented cases.
They stated that weak governance and limited management capacity are the primary factors behind the high severity of impacts, and that emerging economies experiencing rapid growth but lacking strong governance are especially at risk.
The team further discovered that among 164 invasive species affecting both the Global North and Global South, the average severity of their impacts was 50 percent higher in the Global South.
According to them, this suggests that local conditions in the Global South, including governance factors, contribute to more severe consequences.
The researchers further noted that overlooking the effects of invasive species in the Global South "shifts focus away from the regions facing the greatest threats."