Over the past half century, the planet has seen a dramatic increase in the number of invasive species—be it fungi, insects, plants, reptiles or mammals—that have infiltrated and disrupted native ecosystems. Common wisdom has blamed climate change. Common wisdom might be wrong.
A new study indicates that wealth and population density—the direct derivatives of commerce-driven international travel, which began with the Jet Age of the 1950s—may be the root causes.
“We’re finding that human population and accumulated wealth are important drivers of this problem,” said Susan Shirley, a research assistant at Oregon State University, and co-author of the study, which was published in the Proceedings of the National Academy of Sciences, a professional journal.
The study focused on Europe, an international travel hub.
According to First Science:
Human activities such as trade and transport can trigger alien invasions in a number of ways: while some species (e.g. ornamental plants and some crops) are introduced deliberately, many hitchhike on imported goods and others are imported as pets.
Previous studies have highlighted the role of factors, such as climate, geography and land cover, in biological invasions. However, this study shows that these factors are less important than population density and wealth, and suggests that the impact of these secondary factors may have been overestimated in the past.
"The strong influence of economic factors on the level of invasion by alien species demonstrates that future solutions to the problem of biological invasions will be a considerable challenge," the researchers write.
For solutions, the report suggests "policymakers could seek to ensure that market prices for pets or ornamental plants reflect the risks and costs associated with a potential invasion."