What type of ecosystems are particularly threatened by exotic species? Deserts, marine ecosystems, islands, and tropical forests.

Exotic species, also known as invasive species, are particularly threatening to all ecosystems mentioned – deserts, marine ecosystems, islands, and tropical forests – but they pose an exceptional risk to islands and their ecosystems.

Islands are ecosystems with species that have often evolved in isolation, with limited competitive pressures and few predators, parasites or diseases. As a result, these species are highly specialized and may lack defensive strategies that mainland species might have developed. When an exotic species is introduced to an island, whether accidentally or intentionally, the native species may lack the resilience to compete with or defend against the newcomer. This lack of competition can lead to invasive species taking over the island's ecosystem, endangering native species through competition for resources, predation, or the introduction of new diseases.