Biology researchers argue for reconsidering the benefits of invasive species

Over the past half-century, public awareness of non-native species – often referred to as “invasive” – has grown to the point that anyone with a green conscience is aware of them and knows their harmful impacts.

Non-native species are not the boogie man

(Photo: Michael M. Santiago/Getty Images)

The benefits of non-native species are less well known, and Brown University scientist Dov Sax says that needs to change, according to ScienceDaily.

Sax and two co-authors pointed out in a review article published Thursday, Oct. 6 in Trends in Ecology and Evolution that most research on non-native species has focused on their negative implications.

According to them, long-standing biases against non-native species in the scientific literature had clouded the scientific process and hindered public understanding.

The authors of the new paper attempt to shift focus to explore the benefits of non-native species to have a fairer conversation.

According to Sax, a professor of environment and society as well as ecology, evolution and organismal biology, the positive benefits of non-native species are often presented as accidental surprises – the kind of things people can anticipate for occur from time to time, under unusual conditions.

Our new research argues that the beneficial effects of non-native species are neither unexpected nor rare, but rather pervasive, significant and sometimes far-reaching.

The study borrows from a recent framework that examines the benefits of biodiversity to people and nature and applies it to non-native species, demonstrating the diverse, frequent and important ways in which non-native species provide positive value for people. and nature, according to Sax, who is affiliated with the Brown Institute for Environment and Society.

The authors, including Martin Schlaepfer of the University of Geneva and Julian Olden of the University of Washington, acknowledged that some non-native species, such as diseases and agricultural pests, have undeniably high net costs.

They did, however, notice that most domesticated animals, including foods like wheat and tomatoes, textiles like cotton and wool, and pets like dogs and goldfish, provide significant net benefits to human society.

They focused their assessment on species that are not directly controlled by humans – so-called “wild” or “naturalized” species – noting that many of these bring both costs and benefits to both the man than for the environment.

Sax also praised the unexpected benefits of brown trout, another non-native species. Taking the example of New Zealand, he said the majority of non-native species that have invaded the country have negative consequences, so residents are focusing on eradicating them.

New Zealanders value the nutritional benefits of eating brown trout and the recreational benefits of brown trout fishing so much that they have implemented new environmental restrictions to keep the species in their waters, according to Sax.

Read more: Invasive Chinese softshell turtles discovered in the Philippines, biodiversity experts are starting to worry

What qualifies a species as “invasive”?

An invasive species can be any form of living organism – an amphibian (like the cane toad), plant, insect, fish, fungus, bacteria, or even the seeds or eggs of an organism – that does not does not originate in an environment and causes damage, according to National Wildlife Federation.

They have the potential to harm the environment, the economy and even human health. Invasive species are those that grow and reproduce rapidly, spread aggressively and have the potential to cause harm.

An invasive species does not need to be native to another country. Lake trout, for example, are native to the Great Lakes, but are listed as an invasive species in Yellowstone Lake, Wyoming, because they compete for habitat with native cutthroat trout.

Invasive species affect animals in various ways. A new and aggressive species can be introduced into an environment without natural predators or restrictions.

It can reproduce and spread rapidly, invading an area. Native fauna may not have developed defenses against invasion or be unable to compete with a predatorless species.

Invasive species pose direct dangers to native species by preying on them, competing with them for food or other resources, spreading or transporting disease, and preventing native species from reproducing or killing their young.

Invasive species also present indirect dangers. Invasive species can alter the food web of an ecosystem by eliminating or replacing natural food sources.

Invasive species may have little or no nutritional benefit to wildlife.

Invasive species can potentially alter the amount or variety of native species favorable to wildlife.

Aggressive plant species such as kudzu can quickly replace a diverse environment with a monoculture of kudzu.

In addition, some invasive species can alter ecological conditions, such as altering soil chemistry or the intensity of forest fires.

Related article: Using native predators to control invasive species

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