A study of threatened species of ferns in Gilan province (N Iran) providing a comparison of protective classification of conservation based on IUCN's factors

During an investigation on pteridophytes (ferns) of Guilan province (N Iran), 402 specimens were studied. Of these, 44 species, under 21 genera, belonging to 13 families, were identified. Based on the approved instruction given by the "International Union for the Conservation of Nature and Natural Resources (IUCN)", after performing the filtering stage, 17 species were identified as endangered. The results showed that different threat factors could be considered as an important step to all endangered plants. Deforestation, road-construction, uncontrolled grazing together with invasion of non-indigenous plants, are the most causes considered as threat factors in relation to fern community of the area. It also showed that, out of 44 species that are so far identified from the area, one is considered as critically endangered (CR), five as endangered (EN), five as vulnerable (VU) and six as rare (R) species. In addition, 20 species have suitable population, hence, do not need much attention.