Kim, K. D., 2024. The structure and management of invasive plants in Jeju coastal sand dunes, Republic of Korea In: Phillips, M.R.; Al-Naemi, S., and Duarte, C.M. (eds.), Coastlines under Global Change: Proceedings from the International Coastal Symposium (ICS) 2024 (Doha, Qatar). Journal of Coastal Research, Special Issue No. 113, pp. 951-955. Charlotte (North Carolina), ISSN 0749-0208.

Among organisms constituting the coastal dune ecosystem, plants function as primary producers. Primary yields produced by coastal dune plants sustain the survival of many consumers at higher trophic levels. However, the ecosystem of sand dunes in Korea and around the world is being damaged by human activities such as the development of beaches, and as a result, invasive alien species are invading and dominating the world. Therefore, it is necessary to study ecological phenomena of coastal dune plants, especially exotic plants, but related studies are lacking. In this study, 23 major coastal dunes on Jeju Island were selected. In the coastal dunes of Jeju Island, a whole species survey and quadrat survey were carried out on May to September 2022, when the vegetation is clearly represented. Vegetation survey in the field was performed by quadrat establishment and is conducted using Braun-Blanquet method. The proportion of woody and herbaceous in all emerging species was 7.2% and 92.8%, respectively. Annual herbaceous and biennial herbaceous species were mostly native and exotic, and the ratio of native and alien species was similar. In perennial herbs, on the other hand, native species dominated over invasive species and crops. Among the invasive species, Ambrosia artemisiiforia, Hypochaeris radicata, Solidago altissima, Paspalum distichum var. indutum, and Humulus japonicus have emerged as ecosystem disturbing plants. These disturbing plants are on the rise in dune ecosystems. The DCCA(detrended canonical correspondence analysis) based on the vegetation and environment factor matrix showed that the height and covers of the dominant plant species and covers of the exotic plant species explain significantly the variation and distribution of coastal sand dune species on Jeju island. Thus, we may propose a plan to restore the coastal dunes of Jeju island as helping colonization and establishment of mainly sand dune native perennials and trees and eliminating dominant exotic invasive species.