Richness and Distribution of Orchids (Orchidaceae) in the Forests of Mount Busa, Sarangani, Southern Mindanao, Philippines

Orchids are one of the most diverse yet threatened plant families in the world and the Philippines. Despite the new species discoveries of orchids in the country in recent years, diversity and distribution studies are still severely lacking. Here, we provide a list of orchid species found among different forest types in Mount Busa and provide information on the species’ altitudinal and vertical distributions and ornamental use. We recorded 108 species of orchids from 51 genera, of which 53 species are endemic to the Philippines and 15 species are known only to occur on Mindanao island. Species composition differed among forest types, with the MASLEF (mixed advanced secondary lowland evergreen forest) hosting the highest number of orchid species recorded, followed by the UMF (upper montane forest), LMF (lower montane forest), and MESLEF (mixed early secondary lowland evergreen forest). Our results suggest a relatively rich and distinct orchid diversity among different forest types in Mount Busa that reinforces the high conservation value of the mountain range.