Abstract

Mauritius was one of the last places on Earth to be colonized by humans offering one of the most complete history of what native species occurred originally and what was lost, when, and why. This situation can therefore serve as a laboratory to study human impacts in the current age of human-driven species extinction. Mauritius is also one of the most human-impacted places, thereby reflecting what awaits much of the tropics as human impacts intensify. We used available literature, herbarium samples, and personal observations and studies on the Orchidaceae to characterize its diversity, distribution and ecology, and the human-induced threats they face, to better inform their conservation in Mauritius. There are 91 native orchid species from 30 genera recorded on the island. Twenty species (22%) appear extinct, although some may survive undetected. New species and records continue to be added. Only 10% of the species are endemic to Mauritius, and 80% are unique to the south-west Indian Ocean islands. Most species are epiphytic, and the highest diversity occurs in native forests of the wet uplands. Mauritian orchids, particularly the larger ones, face many threats, some inexorably worsening. There exists much room to improve knowledge about Mauritian orchids that would better inform their conservation which is today still very neglected. This includes taxonomic research, detection of ecological patterns and trends, ecology of the species, as well as quantification and hierarchization of threats to prioritize conservation management. Studying Mauritius native orchids helps understand how devastating, sustained, and accelerating the many threats that human activities pose to orchid biodiversity can be and which await other countries currently less human-impacted than Mauritius.