A species of plant, animal, aquatic life or micro-organism that is not native (to Yukon/an ecosystem) and whose introduction or spread is likely to have net negative effects on our society, our economy, our environment, or our health.

The term “invasive” is reserved for the most aggressive species that reproduce rapidly and cause major changes to the areas where they become established.

An introduced species is, with respect to a particular ecosystem, any species, including its seeds, eggs, spores, or other biological material capable of propagating that species, that is not native to that ecosystem. This means that the species was brought to a new environment by anthropogenic means. All invasive species are introduced species, but not all introduced species are invasive.

An invasive species is any species whose introduction does, or is likely to, cause undesirable or detrimental impacts to humans, animals or ecosystems’. There are different degrees of invasiveness or aggressiveness.

Invasive species are a major threat to biodiversity on the planet. They are more than simply “species out of place”; these introduced species are far-reaching in their impacts, permanently altering landscapes and ecosystem functions. As native plant and animal communities are replaced by invasive species infestations, biodiversity declines and habitats change. The greatest impact is caused by introduced species that change an entire habitat, because many native species thrive only in a particular habitat.

While invasive plants are generally of more serious concern in the Yukon, we also have invasive animals, such as the goldfish (Carassius auratus) and Seven-spotted Lady Beetle (Coccinella septempunctata).

There are 154 introduced plant species in the Yukon. Only 60 are considered invasive and only 20 are on our priority list, meaning they have a high invasiveness rating. These unwanted invaders can negatively impact: rangelands by reducing forage quality and quantity; forestry operations by competing with seedlings for light, nutrients, and water; recreation opportunities by obstructing trails, and reducing aesthetics; and water quality and quantity by increased erosion and sedimentation. Control and management of invasive plants is expensive – the longer we wait the more expensive it will get.

Yukoners are in the enviable position of preventing plant infestations before they become so widespread that control is costly and eradication impossible.

Invasive plants are spread through several key pathways including increased travel and trade; transportation, horticulture, gardening, seed-mixtures (revegetation, birdfeed, wildflower mixes), recreation; and wildlife, livestock, humans, and pets.

For a full list of all introduced species and details about their spread in Yukon:
For a comprehensive list of the invasive species in Yukon: 
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