Min-Ju Park1, Yu Cheol Park2, Kang-Hyup Lee3, In Chun Hwang4, Myung-Ok Moon5, Joonhyung Jung6, Bo-Mi Nam6, Narae Yun2P

1Division of Biodiversity Inventory, Honam National Institute of Biological Resources, Mokpo, 58762, Korea; 2Division of Biodiversity Conservation , Honam National Institute of Biological Resources, Mokpo, 58762, Korea; 3Korean Fern Society, Busan 46287, Korea, 4Department of Biology, Jeonbuk National University, Jeonju 34520, Korea; 5Research Institute of Basic Sciences, Jeju National University, Jeju 63243, Korea, 6Division of Taxonomy, Honam National Institute of Biological Resources, Mokpo, 58762, Korea

This study analyzes spore-based reproductive traits of native ferns distributed in island, coastal, and inland regions of Korea, aiming to establish a morphological dataset for taxonomic research and biodiversity conservation. Because fern spores are extremely small and difficult to identify visually, advanced microscopic analysis is required for accurate taxonomic interpretation. Spore morphology of 100 taxa occurring mainly in island and coastal regions was investigated over a two-year period. These taxa represent 23 families 49 genera were examined using living materials and verified voucher specimens collected since 2024. Taxonomic treatment followed the Pteridophyte Phylogeny Group I (PPG I) classification system. Spore characters were documented using standardized English terminology, with quantitative data provided for major diagnostic features, including polar axis length (P), equatorial diameter (E), laesura length, and spore wall ornamentation. Each taxon was illustrated using light microscopy (LM) and field-emission scanning electron microscopy (FE-SEM) images to facilitate detailed comparison. The results were compiled into 「Spore Atlas of Korean Island Ferns I」, providing an essential reference for fern taxonomy, reproductive trait studies, and biodiversity conservation.