A damning environmental report by the United Nations is warning that one million of the world’s eight million species are at risk of extinction. Amphibians, coral reefs, and many marine mammals could be gone within decades. There are several factors to blame for this sad situation, including climate change, pollution, overfishing, deforestation, and invasive species.
The UN says the numbers of invasive alien species per country have jumped about 70% since 1970. Botanic Gardens Conservation International defines invasive species as non-native and introduced to an ecosystem intentionally or unintentionally.
Native plants grow in any given area naturally and without human intervention. They have unique relationships with other plants, insects, and animals, helping each other to survive.
For example, milkweed plants ensure the survival of monarch butterflies. Females lay their eggs on the plant, caterpillars eat their leaves, and adults eat their nectar.
Invasive species threaten the survival of native plants and other creatures by competing with them for scarce resources. They can also change the landscape and environment, making it challenging for native plants to adapt.
Examples of non-native plants in North America include Buckthorn, vinca vines, and garlic mustard. Animal pests include species such as the emerald ash borer and the lionfish.
Australia is no stranger to invasive species; it has the highest rate of vertebrate mammal extinction in the world. Of the estimated 600,000 species of flora and fauna there, 100 have gone extinct in the last 200 years.
A recent study has been able to pinpoint 207 invasive plants, 57 animals, and three pathogens as the culprits.
Similar situations are playing out around the world, and experts say eliminating these invasive species is paramount.
Removing Invasive Species
An international research team has found that just a few invasive species being introduced to an environment has an immediate and sharp decline in native populations. Early detection is essential, but removing the species at any time can help replenish natural ecosystems.
There are many ways to eliminate alien species from the environment. In Newfoundland, Canada, for example, a government initiative is placing concrete reefs at the bottom of Placentia Bay. The structures look like beehives, and the holes offer refuge to native fish and lobsters growing new shells.
The same project is also focusing on the removal of the green crab, one of the top 100 invasive species in the world. It was first spotted in Canadian waters in 2007 and has since depleted eelgrass, which is a natural habitat for juvenile fish, including Atlantic cod.
In Pittsburgh, goats have been employed to eat unwanted weeds and invasive species in a city park. The herd is taking care of a poison ivy problem in a wooded area in the Perry Hilltop neighborhood.
According to a non-profit called Allegheny GoatScape, goats are a great alternative to herbicides and are also excellent for areas with rough terrain. Who knew?
What You Can Do
We can all help control the spread of invasive species. When shopping for flowers and shrubs at your local nursery, be sure to check that they are native to the area before purchasing them.
If you realize you have an alien plant in your garden or backyard, it’s best to remove them by pulling or digging; be sure to get as much of the root zone as possible to prevent the plant from regrowing. It’s best to use a digging fork, as a shovel can chop the roots and leave some behind.
Controlling invasive species is a big job, but we can all play a small role in making a difference.