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How Do Introduced Species Affect Ecosystems and the Economy?

Ellen Cameron
Readability
8.77

How does this align with my curriculum?

When a species ends up outside of its natural zone, the consequences on other species, ecosystems and human industries can be severe. Climate change and human activities can introduce species into new zones.

Did you know that aliens are among us? Alien species, that is. Scientists use the term native species to describe plants, insects and animals that originated in an area naturally, without human action. Native species live in specific areas because they need certain environmental conditions, resources and interactions with other species.

For example, we don’t expect to see elephants in the wild in Canada. But why? For one thing, elephants do not like to live in the cold conditions that occur during winters in Canada. Elephants are also very big and eat up to 150 kilograms of food a day! While Canada has lots of tasty food for Canadian animals, it doesn’t contain the food that elephants need. Elephants also play an important role in their native ecosystems. They clear out vegetation on plains and create new land for new plants to grow. Would an elephant be happy in Canada playing in the snow, far from its favourite foods? Probably not!

But what happens when a species ends up in an ecosystem? Aliens!

Alien organisms are organisms living outside of their natural range. They can be introduced into the new area through humans (introduced species) or by a change in the environment.

Let’s look at the relationship between humans and introduced species. How can human activities result in species introductions, and how can these introduced species affect human activities?

Can humans bring in alien species?

Humans can introduce alien organisms both on purpose and by accident. For example, some people may plant decorative plants in their gardens. This is an example of alien species that humans introduce intentionally. Meanwhile, some animals catch a free ride on various forms of transportation, such as boats. These are examples of alien species that humans introduce accidentally.

Zebra mussels on a boat propeller
Zebra mussels on a boat propeller (Source: JeffCaughey via iStockphoto).

Did you know? 

Scientists believe zebra mussels arrived in Canada as stowaways on commercial ships! 

Climate Change and Introduced Species 

Species are also driven to extend outside their natural range because of climate change. Human activities (such as driving cars) are contributing to climate change, and temperatures are rising at a faster rate. Changes in temperatures can push creatures out of their original habitats, and they can also allow creatures to thrive in areas where they could not before.

For example, the mountain pine beetle originally lived only in western North America. But due to climate change, winters are milder and summers are warmer. The mountain pine beetle has now extended north in British Columbia and is extending eastward through the Boreal forest in Alberta. This beetle is also able to fly, so it’s able to reach new regions very easily.

Mountain pine beetle
Mountain pine beetle (Source: milehightraveler via iStockphoto).

Did you know? 

Northern leopard frogs are being threatened in British Columbia by American bullfrogs, which are native to Central and Eastern Canada.  As you can see, invasive species don’t necessarily have to come from another country! 

How do invasive species affect humans? 

When alien species threaten the native species around them we call them invasive. This can  happen when they act as predators, parasites or competitors for resources. Alien species don’t always directly affect humans. However, they can disrupt and damage ecosystems. This can also cause problems for human health and the economy.

For instance, the mountain pine beetle is native to BC but is moving east. It poses a threat to forest communities. Trees are damaged when female pine beetles make holes to lay their eggs inside the tree. When the eggs hatch, the larvae spend time feeding underneath the tree bark. Eventually, this leads to the death of the tree.

Damage to tree bark caused by mountain pine beetles
Damage to tree bark caused by mountain pine beetles (Source: wwing via iStockphoto).

During the 1990s and early 2000s, mountain pine beetles damaged over 18 million hectares of forests in roughly ten years. That’s roughly 18 million football fields!

Did you know? 

In early 2019, parts of North America experienced a polar vortex. Many humans complained about colder than usual temperatures. However, the polar vortex may have killed off many invasive insects who weren’t adapted to survive in the extreme cold!

How to stop ecosystem invaders

The Canadian government has developed ways to help protect Canadian ecosystems from current and new invasive alien species. For example, technicians and border agents now inspect containers on ships and planes to make sure no alien species are hiding.

When alien species do get in, it’s important to detect them early on and remove them before they severely damage an ecosystem. For example, to help prevent the spread of the mountain pine beetle, forest management staff are burning trees that are infested with this species.

Did you know? 

Every now and then, an invasive species can be helpful. The samurai wasp in British Columbia kills the embryos of another invasive insect, the stink bug. 

Since native species often are not equipped to survive against alien species, it’s up to us humans to help protect our ecosystems from invaders! Check your boots after going hiking. Clean your dog after a walk. Buy local plants. Don’t move small animals in the wild from place to place. These are steps you can take to make sure you prevent the spread of aliens!

Starting Points

Connecting and Relating

  • Have you ever found any invasive species in your own neighbourhood or your garden? If so, what was it?
  • Have you ever unknowingly planted a plant that was an invasive species? How did you find out it was invasive?
  • Do you think it is possible to prevent the problem of invasive species? How? 

Connecting and Relating

  • Have you ever found any invasive species in your own neighbourhood or your garden? If so, what was it?
  • Have you ever unknowingly planted a plant that was an invasive species? How did you find out it was invasive?
  • Do you think it is possible to prevent the problem of invasive species? How? 

Relating Science and Technology to Society and the Environment

  • How do you think mountain pine beetles impact Canada’s resource availability?
  • How do you think mountain pine beetles impact the industries that depend on forests?
  • What can governments do to help prevent the spread of invasive species?
  • In what ways can species move from place to place to become alien or alien invasive species? What is the biggest cause of invasive species?   

Relating Science and Technology to Society and the Environment

  • How do you think mountain pine beetles impact Canada’s resource availability?
  • How do you think mountain pine beetles impact the industries that depend on forests?
  • What can governments do to help prevent the spread of invasive species?
  • In what ways can species move from place to place to become alien or alien invasive species? What is the biggest cause of invasive species?   

Exploring Concepts

  • Define the terms predators, parasites and competitors.
  • What role can climate change play in the spread of alien species? Research examples of species that are at risk of becoming alien species due to climate change.
  • Conduct research on an invasive species or an alien species that is affecting your local environment.  

Exploring Concepts

  • Define the terms predators, parasites and competitors.
  • What role can climate change play in the spread of alien species? Research examples of species that are at risk of becoming alien species due to climate change.
  • Conduct research on an invasive species or an alien species that is affecting your local environment.  

Nature of Science/Nature of Technology

  • Who needs to be involved in the prevention, identification, monitoring, and eradication of invasive species?
  • How is the issue of alien invasive species similar or different from the issue of climate change? 

Nature of Science/Nature of Technology

  • Who needs to be involved in the prevention, identification, monitoring, and eradication of invasive species?
  • How is the issue of alien invasive species similar or different from the issue of climate change? 

Media Literacy

  • What invasive species have you learned about through the media? Do you think the media has a role to play in keeping the public informed about invasive species?
  • Have you seen any movies that address the topic of climate change and its impacts? If so, do any of these films show the impact of alien invasive species? 

Media Literacy

  • What invasive species have you learned about through the media? Do you think the media has a role to play in keeping the public informed about invasive species?
  • Have you seen any movies that address the topic of climate change and its impacts? If so, do any of these films show the impact of alien invasive species? 

Teaching Suggestions

  • Teachers could use this article to support the topic of invasive species and ecosystem dynamics. The article defines and differentiates the concepts of alien organisms, introduced species and native species.
  • Prior to reading the article, have students complete an Admit Slip learning strategy. After reading, have students complete the definitions they learned through these resources. Ready-to-use Admit Slip reproducibles for this article are available in [Google doc] and [PDF] formats.
  • After reading the article, students could complete a Consequence Mapping activity. Students should consider all the potential consequences of the alien invasive mountain pine beetles. Ready-to-use Consequence Map reproducibles are available in [Google doc] and [PDF] formats.
  • To learn more about invasive species and understand how they became invasive, students could watch the YouTube video The Threat of Invasive Species.

Teaching Suggestions

  • Teachers could use this article to support the topic of invasive species and ecosystem dynamics. The article defines and differentiates the concepts of alien organisms, introduced species and native species.
  • Prior to reading the article, have students complete an Admit Slip learning strategy. After reading, have students complete the definitions they learned through these resources. Ready-to-use Admit Slip reproducibles for this article are available in [Google doc] and [PDF] formats.
  • After reading the article, students could complete a Consequence Mapping activity. Students should consider all the potential consequences of the alien invasive mountain pine beetles. Ready-to-use Consequence Map reproducibles are available in [Google doc] and [PDF] formats.
  • To learn more about invasive species and understand how they became invasive, students could watch the YouTube video The Threat of Invasive Species.

Learn more

Invasive Species (2017)

Invasive species service and information provided by the Government of Canada

The Threat of Invasive Species (2016) 

TED-Ed video (4:45 min.) that provides facts on invasive species.

The Forest Community 

Information page from the ForSite Forestry Outreach Site about the forest community.

References

Canadian Food Inspection Agency. (2019). Invasive species.

Government of Canada (2019). An invasive alien species strategy for Canada.
 

Natural Resources Canada. (2019). Mountain pine beetle.

Natural Resources Canada. (2019). Mountain pine beetle (factsheet)  

Walther, G. R., Roques, A., Hulme, P. E., Sykes, M. T., Pyšek, P., Kühn, I., ... Settele, J. (2009). Alien species in a warmer world: risks and opportunities. Trends in Ecology and Evolution, 24(12), 686-693. DOI: 10.1016/j.tree.2009.06.008