Resumen
The French Atlas of Orchids published in autumn 2010 is a large-scale and intensive survey of orchid populations throughout the France territory. The project was directed by the French Orchid Society and involved 3000 specialists in orchids. Overall, more than 110 000 stations were referenced and 160 taxa were reported with their range on 154 maps. This project is original by synthesizing, at large scale, much accurate naturalistic information from local surveys, thanks to a participative approach and on the basis of scientific objectives. Some orchid populations have been recorded for more than 20 years, revealing demographic trends at the scale of the country. Guidelines for application IUCN Red List criteria at regional level have been applied in order to establish The French Red List of orchid species. This represents one of the few examples of IUICN criteria being applied at a regional scale for a plant family. Based on the IUCN categorization about 1 in 5 species is threatened, one as Regionally Extinct (RE), 4 as Endangered (EN) and 23 as Vulnerable (VU). The main extinction risk consists of population size decrease, mostly due to habitat change. Further investigations are needed for the 33 taxa classified as Data Deficient. Most threatened species benefit already from protection regulations. Some recommendations will be drawn in order to conserve orchid species, paying attention to patrimonial and threatened species.