Introduced species


July 5, 2022

In biogeography, an introduced species, an alien species, a non-native species or an exotic species is a species of organisms not native to the particular place or area in which it is found.


Introduced species have usually been transported accidentally, or expressly, to a new location by human activities. Introduced species may or may not thrive in the new ecosystem, altering or not the ecological niche of other species. Some have a short life, such as tropical species that manage to thrive during the summer in temperate areas, but die during the winter, such as certain garden plants. Depending on the case, they may or may not have harmful effects on the native species of the places where they have been introduced. A given species can be detrimental to the new ecosystem, producing significant changes in the composition, structure, or processes of the new natural or semi-natural ecosystems in which it thrives. When the introduced species causes such an offense that it endangers biological diversity, threatening native populations, then it is described as an invasive species. Due to their impacts on the ecosystems where some of these species have been introduced they are considered ecosystem engineers.

Types of introductions

The term introduced species refers to species that have been transported beyond their native geographical distribution by human action. Some definitions refer only to those that have managed to acclimatize or naturalize, but these represent a small percentage of the total species introduced. These introductions can be accidental or intentional. Intentionals take place through the action of individuals who believe that this introduction brings some benefit. Accidental ones are secondary consequences of the displacement of human beings. After a species has been introduced a subsequent dispersal can take place without the aid of human actions.

Intentional introductions

Species intentionally transported to other regions can become established in two ways. In the first case by the intentional release of organisms in the new environment. It is difficult to predict which species will be successfully established after their release. In some cases humans have made repeated attempts to introduce to establish a species in the new environment. In these cases it is clear that the establishment of the introduced species has been facilitated by humans. In the second case, certain species that have been transported to new regions, escape their captivity and manage to establish wild populations. Organisms escaped in this category are included because the initial transport was motivated by humans. The ferret is an example of an invasive species that was intentionally introduced to the country of Chile. It has caused great damage to the ecosystem, where rabbits and chickens (also intentionally introduced species) have been harmed. The main reason for introducing species intentionally is economic gain. There are numerous examples of species introduced for agricultural or livestock purposes. Thus, the most numerous and abundant introduced species are agricultural plants and animals. Just mention rice, wheat, corn, soy, among the plants. Cattle, sheep, goats, horses, chickens, dogs and cats are examples of animals introduced in many regions. The domestic bee (Apis mellifera) is another example, it is a highly adaptable species that can naturalize in a wide variety of environments. Examples of introduced species that have become invasive are: rabbits in Australia. Asian carp was introduced to the United States as a possible food source. The apple snails were and