Weeds are problem plants that can destroy the natural environment. Most weeds are introduced species, but they can also be native species growing outside their natural area.
Weeds are one of the biggest threats to biodiversity – along with pest animals, land clearing and habitat destruction.
Unlike native plants, introduced weeds have fewer natural predators or diseases in their new environment. This gives them an advantage over native species.
Weeds compete with native plants for nutrients, sunlight and water. Some weeds can smother and kill native plants, prevent regeneration, or change the structure and function of an environment. Weeds can affect native animals that depend on native plants for their food and shelter.