What is the Difference Between an Introduced Species and an Invasive Species

The key difference between an introduced species and an invasive species is that an introduced species is a non-native species introduced into an environment by human or other means, while an invasive species is an introduced species that is spread beyond the place of introduction, causing damage to nearby species.

Introduced species and invasive species both are non-native. Non-native species are those that do not naturally occur in the native environment. They are introduced to the native environment as a result of deliberate or accidental human activities. The impact of non-native or introduced species is highly variable. Some, such as invasive species, have a substantial negative effect on the local ecosystem.

CONTENTS

1. Overview and Key Difference
2. What is an Introduced Species 
3. What is an Invasive Species
4. Similarities – Introduced Species and Invasive Species
5. Introduced Species vs Invasive Species in Tabular Form
6. Summary – Introduced Species vs Invasive Species

What is an Introduced Species?

An introduced species is a non-native species introduced into a native environment by human or other means. It is also known as alien species, exotic species, adventive species, immigrant species, foreign species, non-indigenous species, or non-native species. Usually, an introduced species lives outside its native distributional range. It arrives at a native environment by human activity directly or indirectly, either deliberately or accidentally. It can have various effects on the local ecosystem.

Figure 01: An Introduced Species

Introduced species are further divided into subgroups; invasive, acclimatized, adventive, naturalized. Invasive species can cause ecological, economic, and other damages to the local ecosystem. An acclimatized species changes physically or behaviorally in order to adjust to its new local environment. An adventive species is an introduced species that is not permanently established. Moreover, a naturalized species does not need human help to reproduce and maintain their population in the new local environment. Furthermore, some species have been introduced to a local environment deliberately to combat pests. An example is a biocontrol in agriculture. Therefore, the effects of an introduced species on the natural environment have gained much scrutiny from scientists, governments, and farmers recently.

What is an Invasive Species?

An invasive species is an introduced species that is spread beyond the place of introduction, causing damage to nearby species. An invasive species is spread widely or quickly and cause harm to the local environment, human health, economy, and other valued resources. Scientists basically consider a species invasive based on its spread and reproduction rather than other harms it may cause. The transition of an introduced species to an invasive species is well described in the context of plants. Furthermore, approximately 42% of endangered species are at risk due to an invasive species.

Figure 02: An Invasive Species

An invasive species spread to the native environment through various ways – through humans accidentally, wood, shipping palettes and crates that are shipped around the world, ornamental plants, accidentally released pets, etc. Some well-known invasive species are invasive carp, Burmese python, brown marmorated stink bug, zebra mussels, etc.

What are the Similarities Between an Introduced Species and an Invasive Species?

  • Introduced species and invasive species are non-native species.
  • Both species live outside their native distributional range.
  • Both species can be spread by humans unintentionally.
  • They are both termed as new biota.

What is the Difference Between an Introduced Species and an Invasive Species?

An introduced species is a non-native species that is introduced to a native environment by humans or other means, while an invasive species is an introduced species that is spread beyond the place of introduction and causes damage to nearby species. So, this is the key difference between an introduced species and an invasive species. Furthermore, an introduced species may cause a positive or negative impact on the new local environment, while an invasive species always cause negative impacts on the new local environment.

The below infographic lists the differences between introduced species and an invasive species in tabular form for side by side comparison.

Summary – Introduced Species vs Invasive Species

A species that originated somewhere other than its current location is known as non-native species. An introduced species and an invasive species both are non-native. An introduced species is an exotic species that is introduced into a native environment by humans or other means, while an invasive species is introduced species that is spread beyond the place of introduction, damaging nearby species. Thus, this is the key difference between an introduced species and an invasive species