Composition, Richness and Distribution of Ferns and Lycophytes in Different Types of Vegetation in Nayarit, Mexico

It is essential to know the composition and distribution of plant species in ecosystems to devise appropriate management and conservation strategies. In the state of Nayarit, Mexico, there are few floristic and ecological studies of ferns and lycophytes, so the objectives of this study focused on determining the composition, richness, and distribution of both groups of plants at state level. Specimens were collected from 11 vegetation types, in an elevation range of 0 to 2132 m, between 2014 and 2024. The species list was obtained from the identified specimens, consulting previous works, and reviewing herbaria specimens. In addition, the growth habit, geographic distribution, species similarity between vegetation types, and inventory completeness were determined. In general, richness and similarity were high in the cloud, tropical subdeciduous, Quercus, Pinus-Quercus and Pinus forests at high elevations, and were lower in aquatic and secondary vegetation, gallery and tropical deciduous forest, grassland, and mangrove, at lower elevations, where humidity, temperature, and disturbance conditions were more stressful for these plants. In Nayarit, 26 families, 69 genera and 212 species of ferns and lycophytes are distributed; 19 species represented new state records, and four are considered at risk according to Mexican legislation, 17 in IUCN and one in the CITES lists. The most common growth habits were terrestrial (47%) and epipetric (33%); the distribution of most species is restricted to the Neotropics (35.85%) and Mesoamerica (25.47%). The completeness of the inventory (78–88%) suggests an adequate representation of the ferns and lycophytes richness in Nayarit.