We explain what an exotic species is, its difference with the native species and pests. Also, examples of exotic species.
What is an exotic species?
In biology, it is called an exotic species, an introduced species, a non-native species, a foreign species or a non-native species. all those that come from a different geographical or ecological environment, that is, they are not native or autochthonous to the habitat in which they are found, but have arrived there due to migrations or through human beings.
The arrival of exotic species usually permanently modifies the receiving ecosystem, often in unpredictable ways, becoming an invasive species or pest. This is because, coming from a totally different environment, it lacks natural predators and a stable order in the food chains. For this reason, there are ecological protection laws in the world today that limit the transport of animal and plant species from one place to another.
In many cases, however, the exotic species are used as an instrument to modify certain habitats, generally to make them more productive for humans. This work is known as ecosystem engineering.
Exotic species and indigenous species
The difference between autochthonous species, also called native, and foreign or exotic species lies in their belonging to the ecosystem in which they are found. That is to say, the same species can be indigenous in one geographic location or habitat, and exotic in another.
The dilemma between the two is competition for resources. Native species are suited to their environment and therefore they are fully incorporated into the food chains, in a certain state of equilibrium: they have predators and at the same time resources to consume. When an exotic species is taken to that habitat, it can disrupt that balance and cause the eradication of some native species, taking its place in the trophic circuits, thus impoverishing the biodiversity of the region.
Differences between exotic species and pests
Exotic species that arrive at a new habitat or ecosystem and proceed to colonize it, causing the deterioration of the local trophic or ecological balance and the loss of biodiversity, or even the loss of agricultural or rural assets (plantations, flowers, etc.), they are called invasive species or more commonly pests.
This is the case of some species that have been punctually introduced in a certain place and ended up getting out of control, spreading disorderly and killing native species, as well as species that, as a consequence of the imbalance caused by some invasive species, reproduce out of control in the absence of natural predators and end up being abnormally abundant, requiring the introduction of some other exotic species that plays the role of counteracting it and further unbalancing the ecosystem that was initially at peace.
Fortunately, not all exotic species become pests.
Examples of exotic species
Some common exotic species in the world are:
- Cows (Bostaurus). Cows are native to South Asia, but were introduced to the entire world as part of the rise of human livestock and agriculture in all civilizations.
- The wheat (Tricumspp). This Mesopotamian plant species became central in the European diet, and in its various species it was introduced to America by the European colonizers, since there was no native variety.
- The tiger salamanderAmbystomatigrinum). Introduced in the United States to serve as bait for fishermen, this species proliferated to the point of putting the native at risk, AmbystomaCalifornian.
- The royal maple (Acer platanoids). An arboreal plant from Europe, the Caucasus, and Asia Minor, was introduced to the United States and Canada.
- The Asian ladybugHamoniaaxyridis). It is an insect native to Asia, but it was introduced in North America, Europe and South America for natural pesticide purposes, that is, for the biological control of aphids, later becoming a pest that has put native species in check.