Invasive Plant Council of British Columbia

Why Invasive Plants are a Problem

The IPCBC defines the term “invasive plant” as any invasive alien plant species that has the potential to pose undesirable or detrimental impacts on humans, animals or ecosystems. Invasive plants have the capacity to establish quickly and easily on new sites, and the have widespread negative economic, social and environmental impacts. Many invasive plants in British Columbia are “alien” to North America, and may also be referred to as “non-native”, “exotic” or “introduced” plant species.

Why they are such a threat

Invasive plants pose a threat to our environment and economy due to their great ability as strategists. Invasive plants have a great ability to out-compete our native species for resources for survival such as nutrients, sunlight, and water leading to a crowding out of our native species in their natural environment. Invasive plants also have no natural predators in these environments so essentially, the create an imbalance in nature as native plants offer no competition.

Why it is so critical to take action

Part of an invasive plant’s strategy to ensure its survival lies in its ability to reproduce. In many non-native species, one plant can produce millions of seeds each year and these seeds may not break the next year as they can lie dormant in the seed bank for decades.

Common invasive plant strategies for success:

  • Releasing toxins that are toxic to native species
  • Growing quickly to shade out native species
  • Reproducing both by seed and vegetatively
  • Short lifecycles
  • Lack of palatability for grazing animals

Invasive plants also pose other problems such as:

  • loss of animal habitat (habitat threatened or forage reduced)
  • Decreased water quality and fish habitat
  • increased wildfire hazard

Invasive Plant Strategy for British Columbia - June 2005 - .PPT 17.6MB