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Native and Non-Native Species: Characteristics

Native and Non-Native Species: Characteristics

Author: Sophia Tutorial

Determine the characteristics of native, non-native, and invasive species.

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what's covered
This tutorial will cover the topic of native and non-native species. We will discuss the two different categories of species, the causes of the introduction of invasive species, and their impacts.

Our discussion breaks down as follows:

  1. Native Species
  2. Non-Native Species
  3. Introduction of Invasive Species
  4. Impacts of Invasive Species

1. Native Species

Within an ecosystem or environment, species can be categorized as being either native or non-native. Every species is native to some environment somewhere — a place where that species adapted and evolved over time to that ecosystem's predators, competitors, and limiting factors. As long as a species remains in their originally adapted environment, they're considered native.

You may recall that habitats are the area that a particular species inhabits. Niches are all the biotic and abiotic factors that influence a species. A native species, therefore, occupies specifically adapted habitats and niches in their indigenous environment, and this allows for ecosystem balance and keeps that species' population stabilized.

It is important to note that human disturbances can lead to an overabundance of native species, as a result of removing competitors or other limiting factors.


The killing of wolves allows deer populations to soar.

2. Non-Native Species

Non-native species, also called exotic, introduced, or invasive species, are species living outside their originally adapted environment, either accidentally or intentionally from human activities.

In particular, invasive species are non-native species that are introduced and end up spreading and adversely affecting habitats and biodiversity. This is made possible because invasive species often have few natural predators, competitors, parasites, or diseases outside their original environment. The result is high birth rates and low death rates, allowing them to quickly take over, like the Japanese knotweed, shown below.

Japanese Knotweed

Domesticated species, such as pets, livestock, and certain game animals, are often considered non-native because if or when they escape their domesticated environment, they often become invasive.

3. Introduction of Invasive Species

Exotic or non-native species are often introduced to a new environment accidentally by:

  • Escaping from zoos or botanical gardens
  • Escaping from domesticated agricultural environments
  • Escaping from fish farming
  • Escaping pets
  • Released ballast from ships


Two examples of such incidences include Purple Loosestrife, a plant that escaped from botanical gardens, and English Ivy, which was imported as an agricultural ground cover and quickly became invasive.

Other pathways for species introduction include medicinals imported for health benefits, and accidental pollen transported in travelers' clothes and belongings.

4. Impacts of Invasive Species

Many invasives, such as sparrows, starlings, water hyacinth, and nutria, have also been introduced intentionally; that is, by people not knowing the potential impacts.


Kudzu was planted by the U.S. Soil Conservation Service to reduce soil erosion, and it wasn't until a decade later that people realized it was invasive to the point of smothering many native plants.


The Norway maple was planted as a shade tree but quickly displaced many native maples and overshaded wildflowers.

Remember, non-native species that adversely impact their new environment by altering the balance of their ecosystem in negative or catastrophic ways, are termed invasive species.

Impacts of invasive species include:

  • Displacing or killing native species and contributing to the number of endangered or threatened species
  • Reducing overall ecosystem health and productivity
  • Threatening ecosystem biodiversity
  • Causing a loss of forest and agricultural products
  • Exposing humans and ecosystems to unknown pathogens

Today we learned about two different categories of species: native and non-native species. We discussed the causes of the introduction of non-native — otherwise known as invasive — species, as well as their impacts.

Source: Adapted from Sophia instructor Jensen Morgan, KNOTWEED CC HTTP://BIT.LY/1C565PH