Plants, animals, or microorganisms are considered invasive species if they are capable of causing severe damage in areas outside their normal range. They can harm the economy, the environment, or human health once they become established. Note: Not all non-native species are invasive, and sometimes even native species can be considered invasive or undesirable.
Invasive species usually don't spread very fast on their own, but are often spread inadvertently (but very quickly) by humans. Seeds can get stuck in vehicle or bike tires, the tread on our shoes, or even on our clothes or pets. We might even buy an attractive (but invasive) plant at a nursery. We could spread invasive pests when transporting firewood. Or if we don't clean, drain, and dry our watercraft, we could spread invasive species between waterbodies.
Most of the invasive species in county parks are aquatic or terrestrial plants, though we do have other invasive pests like Emerald Ash Borer in Story County.