What term describes species that are introduced into an area by human activity?

The term that describes species introduced into an area by human activity is "alien species." These are organisms that are not native to a particular ecosystem or environment and have been brought there through intentional or unintentional human actions. Alien species can be plants, animals, or microorganisms that, once established, may interact with the native species and contribute to changes in the ecosystem.

Understanding the concept behind alien species is essential, as their introduction can sometimes lead to significant ecological impacts, including competition with native species, alteration of habitats, or even disease transmission. This makes the study of alien species crucial in fields like conservation biology and ecology, where the goal is to maintain biodiversity and ecosystem integrity.

While other terms like endemic species refer to species that are native to a specific geographic area and native species apply to those that naturally occur in a region, invasive species specifically refer to alien species that have spread widely and can disrupt local ecosystems, but not all alien species become invasive. Thus, "alien species" is the most accurate term for species introduced by human activities, as it encompasses all such organisms regardless of their impact on the ecosystem.