Is invasive species management doing more harm than good? (commentary)

Is invasive species management doing more harm than good? (commentary)

  • Conservationists may be thwarting their own efforts, as well as causing harm to wildlife, in their battle against invasive species, a new op-ed argues.
  • In numerous cases, non-native species have been shown to benefit wildlife, while their management – from toxic chemicals to culling – may be causing more harm than good.
  • This article is a commentary. The views expressed are those of the author, not necessarily of Mongabay.

Where I live in the Rocky Mountains, summer is marked by the arrival of the Rocky mountain iris, a favorite for bumble bees and other pollinators, which also make their debut in the brief summer months here. By keeping the land wild and natural, free from threats, retained by nature, I protect and nurture these seasonal interactions. My property may be a bit of an eyesore for the occasional neighbor; the grass isn’t mowed, there are a couple of unsightly snag piles scattered around, and a few dead gnarled trees left standing. All the same, magpies construct their nests in the tall grasses, pollinators frequent the wildflowers that grow in abundance, rabbits call the snags home, and the gnarled trees are favorites for squirrels and owls. Every summer comes with labor; I tend to the land with thoughtful attention, from providing clean water for wildlife to maintaining the invasive alien species (IAS).

Through experimentation and an ever-growing variety of methods, I am finding a balance with the IAS that grow in my region, as does the wildlife. For instance, I harvest common mullein after it loses its blooms so that the bees can take advantage of it as food source, and I can take advantage of its combustible properties (mullein makes for a great fire starter during the winter months in my wood burning stove). While I am a conservationist by trade, this also is conservation for me; I consider myself a steward, a loving caretaker of the Earth. Through this perspective, I see many practices in my field that are destructive for the harmony of nature. I see how we’ve lost our connection to the very same natural world that we are quickly losing through our own actions. Cultivating our relationship with nature and the role that we play within it, will not only heal our planet, but heal societies and ourselves as well. It’s through thoughtful stewardship with nature, even in regards to IAS, that we will begin to understand its delicate balance and how we interact as a part of it.

One of the ways in which conventional conservation may be thwarting its own efforts, as well as causing harm to people, is in the long battle against IAS. For decades the consensus has been that IAS are bad for biodiversity and must be eradicated, but at what cost? IAS management comes in many forms – from chemicals to culling – and its impacts may be causing more harm than good. To illustrate, it’s estimated that in the U.S. millions of acres of public wild lands are sprayed with herbicides and pesticides annually – this equates to hundreds of tons every year – with little known about the combinations of chemicals being used, their effectiveness, their interactions within the environment, and the true financial costs.

Invasive plant managers treat areas of Yosemite National Park with herbicide to curtail growth of Himalayan blackberry. Photo courtesy of the California Invasive Plant Council.

Yet bees, beetles, butterflies, dragonflies, moths and many other economically crucial pollinators (and natural enemies of pests) are threatened by chronic exposure to pollutants, mostly in the form of herbicides and pesticides. Some places have documented a loss in biomass of flying insects by roughly 75% over 30 years, and still vast amounts of chemicals continue to be used as the primary method for invasive weed management. To compound the issue, a recently published study found that 99.8% of a human population in France had quantifiable levels of glyphosate in their urine samples, supporting the idea that people are becoming contaminated through food and water intake.

This describes just one form of IAS management that has negative repercussions. At least one million species are facing extinction in the coming decades (half of these being insects). These extinctions will lead to losses of essential ecosystem services (ES), from reductions in crop pollination and pest management to ramifications in water and air quality, negatively affecting food supply chains, causing significant risks to human wellbeing in ways we have yet to fully understand. This brings a few questions to mind; at what cost is it worth trying to preserve an ecosystem as we have historically known it to be? Are we justified in using immense amounts of chemicals to combat IAS when it’s simultaneously causing the extinction of other species? If we’re anticipating mass extinctions across the globe, should we be eradicating any species and furthering more loss in biodiversity? If IAS bring benefits to local wildlife, should we still be eradicating them?

It’s worth mentioning that most introduced species don’t become invasive. Of the numerous non-native species established globally, only a minority of them are invasive. Yet, according to a recent global assessment report, it’s considered one of the greatest challenges to conservation, costing the U.S. economy in excess of $170 billion per year in management, mitigation, and agriculture losses. Despite these lofty costs and efforts, large-scale attempts of eliminating certain IAS have been unsuccessful, yet these methods are employed repeatedly and liberally, increasing overall cost and adverse impacts because of their convenience or low price, regardless of effectiveness. Research has shown that cost-effective IAS management strategies can be the least effective, while the most effective can be cost prohibitive yet garner numerous other benefits. In fact, they found that commonly used methods like the widespread use of herbicides such as glyphosate, have had little effect in the long-term management of IAS, not only wasting time, effort and tax dollars, but also having adverse side effects.

See related: Mongabay investigation confirms global insect decline, view it here

Monarch butterfly feeding on non-native bull thistle at the Metropolitan Beach Metropark Nature Area, Brighton, MI. Image by Steve Burt via Creative Commons 2.0 license.

Invasive species management is a new science, relatively speaking, and we don’t yet have a comprehensive understanding of its impacts on ecosystems, even less so with the dynamic forces of climate change at play. While early attempts to control IAS were motivated by economic damages in agricultural commodities, many of these practices have proven to have harmful impacts, yet remain common practice.

While conservationists do their best to consider the entire ecosystem before conducting IAS control methods, many of these practices can have unintended consequences that we have yet to discover. In a changing climate with growing extinction rates, we need to consider how each IAS impacts an ecosystem individually before moving towards abatement methods. Consider the island chain of Hawai’i; a collaborative investigation found that non-native birds maintain seed dispersal processes and pollination for native plants. These invasive birds are substituting for the roles of extinct birds and are the sole seed-dispersers of many native plants on Oahu. The abrupt eradication of all non-native birds would strip forests of nearly all birds and render seed dispersal for many native plants obsolete. This is just one example of how each IAS has a unique context that should be considered when determining how control methods impact the entire ecosystem.

As our planet continues to change, our perceptions will also need to change. The preservation of nature in its “historical” state, i.e., the state humanity is accustomed to seeing it in, is no longer an achievable goal. As we continue to see the extinctions of other species that may have once filled certain ecological roles, thoughtful analysis of each IAS scenario with a multifaceted lens for local and cultural values will be crucial in order to consider the functional traits of different IAS to each ecosystem in order to protect important environmental processes and ES, now and into the future.

Perhaps conventional “command and control” methods of IAS management, as well as viewpoints on the separation of people from nature, need to be questioned more frequently as we continue to see greater impacts from climate change and human activities. As we continue to step into the unknown waters, we will have to meet these challenges with new ideas, new perspectives and new practices, some of which may be difficult to shift from old paradigms and ideologies. Addressing global environmental changes will require comprehensive and proactive approaches, as well as conscientious stewardship practices that place greater value on our relationship with nature and incorporate and support diverse knowledge systems.

Janae Malpas earned a Master’s degree in Conservation Leadership from Colorado State University and works to increase conservation stewardship in rural communities through her nonprofit, The Juniper Initiative

Related listening from Mongabay’s podcast: As conservation icons pass away, who will lead the movement to steward the planet’s biodiversity now, and does conservation still need iconic leaders? Host Mike G. speaks with two women with conservation science PhDs who share expansive views on what’s next for leadership in the field, listen here:

See related article:

Release the cats: Training native species to fear invasive predators


This story first appeared on Mongabay

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