PROVIDENCE, R.I. [Brown University] — Awareness of non-native — often called “invasive” — species has vastly increased over the past half-century, to the point where anyone with a green conscience has heard of them and their negative impacts.
Less recognized are the benefits of non-native species — and according to Brown University biologist Dov Sax, that needs to change.
In a review article published on Thursday, Oct. 6, in Trends in Ecology and Evolution, Sax and two co-authors pointed out that most research on non-native species focuses on their negative consequences. They argued that long-standing biases against non-native species within the scientific literature have clouded the scientific process and hindered public understanding. In the article, the authors try to shift the focus to consider the benefits of non-native species for a more balanced discussion.
“Positive impacts of non-native species are often explained as serendipitous surprises — the sort of thing that people might expect to happen every once in a while, in special circumstances,” said Sax, a professor of environment and society, and of ecology, evolution and organismal biology. “Our new paper argues that the positive impacts of non-native species are neither unexpected nor rare, but instead common, important and often of large magnitude.”
Sax — who is affiliated with the Institute at Brown for Environment and Society — said the study borrows from a recent framework that examines the benefits of biodiversity for people and nature and applies it to non-native species, showing the diverse, frequent and important ways that non-native species provide positive value for people and nature.
“We want to provide a framework for the way that scientists can think about non-native species constructively going forward and explicitly document their benefits,” Sax said. “It’s only then that we’ll be able to accurately and fully compare and contrast them in order to perform the kind of cost-benefit analyses that can be truly helpful in making policy decisions.”
The authors, who include Martin Schlaepfer from the University of Geneva and Julian Olden from the University of Washington, recognized that some non-native species, such as introduced pathogens and agricultural pests, involve indisputably large net costs. But they noted that most domesticated species, including food like wheat and tomatoes, fibers such as cotton and wool, and pets including dogs and goldfish, provide large net benefits to human societies. They focused their review on species that are not directly managed by people — so-called “wild” or “naturalized” species, noting that many of these simultaneously provide both costs and benefits for people and nature.