This study analyzed the distribution characteristics of invasive alien plants on the islands of the Korean Peninsula. Ten species, Rumex acetosella, Sicyos angulatus, Solanum carolinense, Ambrosia artemisiaefolia var. elatior, Ambrosia trifida, Aster pilosus, Eupatorium rugosum, Hypochaeris radicata, Lactuca scariola, and Paspalum distichum were present on 68 islands. These ecosystem-disturbing invasive alien plants appeared extensively on the islands of Gyeonggi province and Jeollanam province. The proportion of the plants on the inhabited islands (41 places, 2.15 species on average) was higher than that on the uninhabited islands (27 places, 1.07 species on average). This means that the distribution of invasive alien plants was closely related to human activity. The distribution of Ambrosia artemisiaefolia var. elatior (32 islands) and Rumex acetosella (31 islands) was the widest, and there were distinct distribution differences according to species. In the island area, the physical environment is poor compared to the mainland, and the native space is limited. Therefore, when invasive alien species enter and settle on the island, the native island plants can be damaged more than those on the mainland. In this regard, the discussion of the distribution of invasive alien plants in the island region can contribute to the conservation of biodiversity in the region.

This study analyzed the status of climate-change indicator plants native to the main islands of the Korean peninsula, while elucidating their distribution characteristics. Information on flora from over 129 island locations, comprising more than 100 species of native plants, was collected, compiled into a database, and utilized as raw data. The distribution of 193 climate-change indicator plants was confirmed. The distribution area of broadleaf evergreen trees and ferns, including Mallotus japonicus and Cyrtomium falcatum, was relatively wide. In contrast, the distribution of common northern plants such as Corydalis turtschaninovii and Malus baccata was limited. If global warming persists, northern plant distribution is expected to decrease rapidly in the Korean Peninsula island region, while the northern limit line of the southern plants is expected to migrate further northward. During this process, it is likely that the plant congregation structure and species diversity within the island region will change dynamically. In this study, comparative analyses between species and regions were conducted by assessing the relative frequency of their occurrence, and six types of botanical geographic distribution patterns were noted.