Biodiversity, richness and spatial distribution of extant Pteridophytes in Kudremukh National Park, Western Ghats, India

Pteridophyte richness and diversity in Kudremukh National Park (KNP) was assessed using qualitative and quantitative diversity indexing methods, along with the geographic spatial distribution of the extant pteridophyte flora. The field research design employed a stratified random sampling method and was conducted in two phases. Phase 1 included the survey, identification and distribution of the pteridophyte flora and Phase 2 was to study the diversity of the extant pteridophytes throughout the KNP using seven transects. The region exhibited rich and highly diverse (Shannon-Wiener Diversity Index of 3.38), non-homogenous (compared to normal Raunkiaer's frequency curve) stand of 46 different unevenly (evenness index 0.64) distributed pteridophyte flora. The study region was dominated by two unambiguous pteridophyte species of weedy nature (Pteridium aquilinum and Dicranopteris linearis), with a high Simpson's dominance index of 0.96. The study reports eight endemic, two rare, five at risk and seven vulnerable and near-threatened IUCN listed pteridophyte species in the study region. The quantitative diversity indices i.e. frequency, density, abundance, relative abundance and important value index of each extant pteridophyte is calculated. The study also noted that some endemic species such as Osmunda huegeliana and Cyathea nilgirensis present in KNP needed immediate conservation efforts. This study gives an extensive report on the extant pteridophyte flora of KNP and will help future taxonomic surveys and research, as well as conservation and sustenance measures.