What term describes regions that are particularly rich in endemic species?

The term that describes regions that are particularly rich in endemic species is "hotspots." Biodiversity hotspots are areas that not only have a significant number of unique species that are not found anywhere else in the world but also typically face threats from human activities. These regions are critical for conservation efforts because they hold a substantial amount of biological diversity that is often at risk.

In ecological terms, endemic species are those that are native to a specific location and can be found nowhere else. This means that hotspots often serve as crucial habitats for these species, contributing to global biodiversity. Conservationists focus on these areas to prioritize efforts since protecting hotspots can have a significant impact on conserving unique species and their ecosystems.

The other terms mentioned generally relate to conservation but do not specifically capture the essence of regions rich in endemic species as effectively as "hotspots" does. Conservation areas, protected lands, and critical habitats may contribute to the conservation of biodiversity in various ways, but the term "hotspots" highlights both the richness of unique species and the urgent need for conservation in those areas.