Dr Sang-hun Oh1, Ms. Yun-Gyeong Choi1, Mr. Su-Chang Yoo1, Mr. Hyun-Jun Kang1, Mr. Geun-Mo Park1
1Daejeon University, Daejeon, South Korea
Biography:
Sang-Hun Oh is a professor of Biology at Daejeon University in South Korea. He is a plant systematist with a specialty in Rosaceae and Orchidaceae. He received a Ph.D. at the University of California, Davis, and continued research on various angiosperms employing molecular systematic approaches at Duke University and Cornell University. He has investigated the origin and evolution of endemic plants on Ulleungdo Island and biodiversity reconstruction of the island's past ecosystem using eDNA methods. He serves as editor-in-chief for the Korean Journal of Plant Taxonomy, an official journal of the Korean Society of Plant Taxonomists.
Abstract:
Ulleungdo Island, located 150 km off of the eastern coast of the Korean peninsula, is a small oceanic island harboring many endemic species. The origin of insular plants and vegetation changes since its formation at ca. 1.8 MYBP are unknown. Understanding past biodiversity records is crucial to reconstructing the historical changes in vegetation associated with climate change. The reconstruction of past biodiversity from geological deposits, particularly in temperate regions, has not been studied. First, we established an environmental DNA (eDNA) analysis method using top soils and conducted the floristic survey. 54 eDNA samples from soil were included from three sites at the Nari Basin, the caldera on Ulleungdo Island. A next-generation sequencing method (Mi-seq) was employed to identify molecular Operational Taxonomic Unit (mOTU) using a two-marker system of the nuclear ITS2 region and chloroplast rbcL. Results of plant mOTU analysis showed that the plant biodiversity of the three sites determined from eDNA is consistent with local flora, indicating that eDNA successfully uncovered the species composition of the sampled site. Second, 40 m of sediment cores were collected by drilling at the Nari Basin to uncover past vegetation by using the eDNA method. eDNA samples are as old as 4,000 years old and successfully produced a biodiversity composition. The results show the changes in broad-leaved deciduous forests over the past 4,000 years. This study is the first report on plant diversity from soil eDNA in the temperate region, providing a valuable tool for the biodiversity study of deeper sediment.