Predictions of suitable habitat areas within a specific region can provide important information to assist in the management of invasive plants. Here, we predict the current and future potential distribution of Solidago altissima (tall goldenrod) in South Korea using climatic and topographic variables and anthropogenic activities. We adopt four single models (the generalized linear model, generalized additive model, random forest, and an artificial neural network) and a weighted ensemble model for the projection based on 515 field survey points. The results showed that suitable areas for S. altissima were mainly concentrated in the southwest regions of South Korea, where temperatures are higher than in other regions, especially in the winter season. Solar radiation and Topographic Wetness Index (TWI) were also positively associated with the occurrence of S. altissima. Anthropogenic effects and distances from rivers were found to be relatively less important variables. Based on six selected explanatory variables, suitable habitat areas for S. altissima have expanded remarkably with climate changes. This range expansion is likely to be stronger northward in west coastal areas. For the SSP585 scenario, our model predicted that suitable habitat areas increased from 16,255 km² (16.2% of South Korea) to 44,551 km² (44.4%) approximately over the past thirty years. Our results show that S. altissima is highly likely to expand into non-forest areas such as roadsides, waterfront areas, and abandoned urban areas. We propose that, based on our projection maps, S. altissima should be removed from its current margin areas first rather than from old central population areas.

Invasive alien plants can severely threaten biodiversity and cause economic losses in the agricultural industry; therefore, identifying the critical environmental factors related to the distribution of alien plants plays a crucial role in ecosystem management. In this study, we applied partial least squares regression (PLSR) and geographically weighted regression (GWR) to estimate the important environmental factors affecting the spread of two invasive and expansive plants, Lactuca scariola L. and Aster pilosus Willd., across South Korea. GWR provides more accurate predictions than ordinary least squares regression, and the local coefficients of GWR allow for the determination of the spatial relationships between alien plant distributions and environmental variables. Based on the model’s results, the distributions of these alien species were significantly associated with anthropogenic effects, such as human population density, residential area, and road density. Furthermore, the two alien species can establish themselves in habitats where native plants cannot thrive, owing to their broad tolerance to temperature and drought conditions. This study suggests that urban development and expansion can facilitate the invasion of these species in metropolitan cities.

The number of alien species introduced into South Korea continues to increase over the years. In particular, several plants have been introduced as ornamentals. Ludwigia peploides, which is native to the Americas and Australia, is believed to have been planted as an ornamental aquatic plant called “water primrose” and “primrose”. It spread to natural ecosystems through rivers, and its distribution is gradually expanding in Suwon, Hwaseong, Busan, and Jeju. However, there has been no specific study on the ecological risk of L. peploides introduced into South Korea. This study, therefore, investigates the distribution status and ecological risks of L. peploides in South Korea through field surveys and allelopathic material analysis, as well as assessing abiotic risk factors. The distribution was confirmed at a total of 19 sites, with high-density mats of a single species forming along the water’s edge and on the water surface. The maximum distribution area was 13,922 m² in Chilgok Reservoir in Anseong. Stems and plant fragments transported along waterways were continuously forming colonies through vegetative propagation. When evaluating the overall risk, it is determined that L. peploides has a high potential to cause significant damage to the ecosystem if not managed promptly. Therefore, continuous monitoring is necessary to effectively manage and prevent the habitat expansion of L. peploides. The results of this study are expected to aid in the identification of the current distribution and potential ecological risks of L. peploides in South Korea, providing essential data for ecological risk assessment and the development of effective management strategies.

This study was conducted to provide information on alien species to the specific islands monitored by Ministry of Environment in South Korea, based on the National Survey of Natural Environment of Islands from 2006 to 2020. In the study area, a total 54 taxa, consisting of 17 family, 45 genera, 53 species, one variety, were found. Among them, two species classified as Ecosystem-disturbing species, Humulus japonicus (H. japonicus) Siebold & Zucc. and Ambrosia artemisiifolia (A. artemisiifolia) Linnaeus were found. Alien plants were identified on 127 islands (49.4%), H. japonicus were found on 27 and A. artemisiifolia on six specific islands. The spatial status of alien flora on the specific islands monitored by Ministry of Environment in our data can be basic ecological information for the conservation and management of plant species diversity on the islands.

This study was conducted to provide information on alien species to the Baekdudaegan Protected Area eco-survey by Ministry of Environment in South Korea from 2015 to 2019. The scope of the survey is based on data from 26 subsections out of 44 subsections in five regions, excluding Korea National Park.In the study area, a total 58 taxa, consisting of 16 family, 48 genera, 56 species, two varieties were found. In addition, five species of ecosystem-disturbing species were identified that Ambrosia artemisiifolia, Aster pilosus, Rumex acetosella, Solanum carolinense, Humulus japonicus. However, the habitat of ecosystem-disturbing species could not be confirmed in the subsections of Dakmokjae-Kubusiryeong (designated number, 13-20), Gisdaebaegibong-Doraegijae (designated number, 23, 24), Ihwaryeong-Haneuljae (designated number, 33), and Neuljae-Miljae (designated number, 37). The spatial status of alien flora on the Baekdudaegan Protected Area monitored by Ministry of Environment in our data can be basic ecological information for the conservation and management of plant species diversity on it.