Invasive species are a growing threat to Canada’s biodiversity, as climate change is shifting ecosystems creating ideal conditions for invasives to outcompete native species. But there’s hope—by taking simple actions like planting native species, reporting sightings, and supporting conservation efforts, we can help biodiversity fight back.

The threat posed by invasive species on our ecosystems have long been discussed. Not only do they endanger local biodiversity and completely disrupt ecological balance, but they also significantly setback our conservation efforts. These problems are further exacerbated by climate change – as extreme weather events become more frequent and severe due to rising temperatures, invasive species thrive in these different weather patterns, and outcompete native plants and animals. With North American Invasive Species Awareness Week around the corner, let’s explore the state of invasive species in Canada and how you can help protect local biodiversity from their impact.

It is estimated that over 1,400 invasive species – including fish, plants, insects, and invertebrates exist in Canada’s farmlands, forests, and waterways, and cost Canadian billions of dollars each year in lost revenue from the impacts on natural resources. According to the Canadian Environmental Sustainability Indicators: Invasive alien species in Canada Report (2024) invasive species are those harmful alien species whose introduction or spread threatens the environment, the economy, or society, including human health.

It is important to remember that not all “alien” or non-native species are invasive. In fact, there are plenty of plants and animals which are non-native that not only present no threat to our ecosystems, but in fact serve crucial functions in our ecosystems, benefiting wildlife and humans as well. For example, Bull Thistle (Cirsium vulgare) is a non-native plant to Ontario, but is known to be good sources of nectar for pollinating insects, like the eastern giant swallowtail butterfly, as well as a source of seeds for overwintering and resident native birds, like goldfinches.

There are actions that each of us can take to reduce the spread of invasive species, the first takes place right at home in your garden. A common roadblock new gardeners face is where to source plants, seeds and their supplies. It is always good practice to source plants locally, and prioritize native plant species. For an extensive list of nurseries for all the Canadian Municipalities, to source native plants and seeds, visit the Canadian Wildlife Federation’s Canadian Native Plant Suppliers List. Native plants are also a great way to attract beneficial insects which are quintessential for healthy ecosystems as they control invasive species acting as natural predators, they reduce unwanted pests, and aid in seed dispersal and decomposition. For more information and helpful tips on how to support biodiversity from your garden, visit out Gardening for Biodiversity Booklets!

Many conservation groups and local governments or agencies have reporting tools on their website for you to use to report and track invasive species and help with early identification and control efforts. Additionally, consider reaching out to local conservation groups for volunteer opportunities to remove invasive species in your local communities or about ways that you can support ecosystem protection and conservation policies and initiatives.

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