Status and dispersal map of orchid populations of Chréa National Park (southwest of Algiers, Algeria)

In recent years, knowledge about orchids in Algeria has improved, but it remains poorly understood in certain regions, such as the National Park of Chréa (northern Algeria). To study orchids in this area, an inventory was carried out from April 2022 to June 2023 across ten locations within the park, based on systematic surveys and sampling. Nineteen orchid species were identified, including two sub-endemic species. The most represented genus is Ophrys (7 species), followed by Anacamptis, Himantoglossum, Neotinea, and Orchis (2 species each). In total, 378 orchid individuals were recorded. Confirmatory factor analyses (CFA) showed that each group of orchid species is linked to a specific exposition, altitude, and set of co-occurring species. Furthermore, the number of individuals and the size of each orchid population appear to be correlated with local vegetation density. The study area is subject to various disturbances, but many sites reveal remarkably rich flora, particularly orchids. Given the vastness of the park, fieldwork should continue, with a specific focus on hybrids.