An invasive species is an animal or plant that has populated an ecosystem to the point where it dominates over other plants and animals in the ecosystem. An invasive species can be a species that is not indigenous, meaning that it does not naturally grow in the ecosystem or an indigenous species that dominants the ecosystem and chokes out other species. Invasive species can cause many problems in an ecosystem and need to be controlled and eradicated in some incidences.
Why are Invasive Species a Problem?
There are a number of major problems that invasive species can cause to an environment. In most cases the invasive species has very few or no natural predators and/or competitors in the ecosystem. This means that the invasive species grows unchecked due to easy access to resources and it causes the species to become dominant and destructive. One example of this is the cane toad in Australia. It has no natural predators so has been able to spread in vast numbers across a large portion of the continent.
Invasive species also reduce the ability of native species to compete for the resources in an ecosystem such as food, water and shelter. This is a major problem and can even lead to the extinction of a native species. It can also damage the diversity of the environment as species decrease in number and other animals move out of the area to find more suitable environments. Native species are often displaced by invasive species causing them to find new habitats to live in. The complex food webs that exist in an ecosystem are often unbalanced causing the decline of certain animal and plants and an increase in others.
Invasive species overpopulate an area causing the depletion of minerals and nutrients in an environment. They can also slow or choke waterways to the point where localized flooding and river diversion is caused impacting a number of ecosystems along the river course.
Invasive species also impact humans and economy at large. Some of the ways this occurs are listed below:
- Reduces animal species to hunt – The invasive species changes the natural balance of the ecosystem resulting in either death or displacement of hunted species.
- Reduces plant species that are used to propagate food – As the invasive species takes over then other species are unable to survive due to the competition for food and water.
- Invasive species may damage other crops.
- A number of invasive species have been found to harbor other bacteria and organisms that damage the health of the environment.
- Many invasive plant species cause extra labor as they need to be eradicated prior and during crop propagation.