• Korean Journal of Agricultural and Forest Meteorology
• /
• v.16 no.3
• /
• pp.227-232
• /
• 2014

Ageratina altissima is an invasive plant species known to threaten native plant communities in Korea. A. altissima is thought to invade shady forests from disturbed open areas; however, uncertainty remains as to how shade and litter depth might affect establishment. A study of A. altissima distribution characteristics in areas adjacent to trails was undertaken at Mt. Umyeon in Seoul, Korea. Increasing densities of A. altissima were found to correlate with greater light availability and decreasing litter depth (p < 0.001) within 10 m distance from trail locations and on ridges rather than further within forests and valleys. The effects of soil moisture content, soil gravel content and soil pH on distribution were not found to be significant, suggesting that A. altissima is adaptable to a broad range of soil conditions. Results indicate that forest areas close to trails may be particularly susceptible place to A. altissima invasion, demonstrating the need to carefully consider implications for A. altissima expansion in trail management.

• Korean journal of applied entomology
• /
• v.61 no.4
• /
• pp.539-548
• /
• 2022

In recent decades, the world has entered a new era in terms of the number and variety of biological invasions, due to economic progress and transportation efficiency. Biological invasion is becoming more likely as demand for foreign fresh foods and decorative goods grows. Alien species continue to infiltrate Korea in a variety of ways, and disturb on the insect fauna of Korea. The goal of plant quarantine is to decrease the economic impact of alien pests on the agriculture and forestry industries. In this study, we focused on insects found in imported cut flowers from 1996 to 2020 using pest information system. Overall, 147,160 cut flowers (159 items) were imported into Korea from 69 countries during this time period. Throughout this time, 467 species of insects were found in all imported cut flowers to Korea, total 13,757 detections. They were classified as provisional regulated pests in 273 species, quarantine managed pests in 78 species, and non-quarantine pests in 118 species. Thysanoptera and Hemiptera had the largest number of alien insect detections (more than 80% of the alien insects) among the nine orders. The outcomes of this study have highlighted the need for ongoing inspection activities targeted at preventing quarantine alien pests from entering or incursion in Korea.

• Korean Journal of Environmental Biology
• /
• v.41 no.2
• /
• pp.138-144
• /
• 2023

The main factor of biodiversity decline in major biological populations around the world is invasion of alien species. To protect native species, it is necessary to manage alien species. Recently, to eradicate ecosystem disturbance caused by alien species in Korea, many efforts have been made to capture individuals using nets and purchase captured individuals. However, there is no standard for classifying species due to the form of nest site or external characteristics of eggs of freshwater turtles. Thus, Mauremys reevesii eggs might be discarded due to mistaking as eggs of alien turtles. Based on more data, this study aims to compare and analyze external differences among eggs of Trachemys scripta elegans, Pseudemys concinna, and M. reevesii and use them as reference materials in the process of eradicating alien turtles. This study measured characteristics of eggs of the three turtle species. As a result of comparison, all variables of external characteristics of alien turtles and M. reevesii eggs showed significant differences. The shape of egg was also different, with eggs of T. scripta elegans and P. concinna showing a bicone shape and those of M. reevesii showing an ellipsoid shape. In conclusion, based on results of previous studies and the present study, eggs of M. reevesii, T. scripta elegans, and P. concinna are different in shape and structure. Thus, it is possible to distinguish between M. reevesii and invasive alien turtle using their eggs.

• Korean Journal of Environmental Biology
• /
• v.35 no.1
• /
• pp.57-63
• /
• 2017

This study was conducted to determined the status and geographical distribution of the alien invasive Red-eared slider (Trachemys scripta elegans) turtle on Jeju Island. We found thirty-two Red-eared slider habitats including twenty-five ponds, five agricultural reservoirs, a puddle and a stream. Among those, thirteen sites are newly determined habitats of the turtle. The remaining nineteen are previously reported. However, we could not find any turtles at nine sites, which were documented as turtle habitats in earlier reports. A total of one hundred thirty-three turtles were observed. Among them, we determined that thirty-nine were juvenile turtles, found in nineteen different habitats, indicating estimating that Red-eared sliders produced their progeny in the wild of this island. Because of geographical isolation by the ocean, no freshwater turtle had been found until $19^{th}$ Century. Therefore, the increased number of finding sites and Red-eared sliders indicate the possibility of human release of their pets or for other purposes, and natural propagation in the wild on Jeju Island. Our findings will be useful for management planning to deal with this invasive species, and implementation of a conservation program for native wildlife on Jeju Island.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.28 no.1
• /
• pp.10-18
• /
• 2022

With the increase in world trade through ships, the destruction of the marine ecosystem and socioeconomic damage due to invasive alien species (IAS) are continuously increasing. In particular, marine organisms attached on the hull surface and niche area increase the friction resistance of ships as well as the invasion of non-indigenous species, and causes a decrease in operational efficiency and an increase in GHG (Green House Gas) emissions. The International Maritime Organization (IMO) has recently begun revising guidelines for the control and management of ship's biofouling, and New Zealand and California in the United States are already regulating biofouling management under their own laws. This study investigated the management status of the submerged surface of ships and marine organisms attachments on five international ships entering South Korea, and analyzed species group and coverage (%) of biofouling communities to evaluate the LoF (Level of Fouling) rank. Macroflouling was observed on all ships surveyed, and specially, the adhesion of macro organisms in niche areas such as bow thruster, bilge keels and sea-chest gratings appeared to be at a serious level. This study proposed the management direction our country should take with regard to ship's biofouling and the improvement measures for evaluation of LoF rank and inspection methods of hull and niche ares.

• Korean Journal of Environmental Biology
• /
• v.40 no.1
• /
• pp.1-10
• /
• 2022

Global warming has a major impact on the Earth's precipitation and temperature fluctuations, and significantly affects the habitats and biodiversity of many species. Although the number of alien plants newly introduced in South Korea has recently increased due to the increasing frequency of international exchanges and climate change, studies on how climate change affects the distribution of these alien plants are lacking. This study predicts changes in the distribution of suitable habitats according to RCPs climate change scenarios using the current distribution of the invasive alien plant Conyza sumatrensis and bioclimatic variables. C. sumatrensis has a limited distribution in the southern part of South Korea. Isothermality (bio03), the max temperature of the warmest month (bio05), and the mean temperature of the driest quarter (bio09) were found to influence the distribution of C. sumatrensis. In the future, the suitable habitat for C. sumatrensis is projected to increase under RCP 4.5 and RCP 8.5 climate change scenarios. Changes in the distribution of alien plants can have a significant impact on the survival of native plants and cause ecosystem disturbance. Therefore, studies on changing distribution of invasive species according to climate change scenarios can provide useful information required to plan conservation strategies and restoration plans for various ecosystems.

• Korean Journal of Ecology and Environment
• /
• v.56 no.3
• /
• pp.242-249
• /
• 2023

The aquarium pet trade is a source of potentially invasive crayfish species, which can be subsequently intentionally or unintentionally introduced into new environments. There were 34 species of freshwater crayfish imported into Korea for ornamental purposes. Starting with 1 species in 2008, it shows a trend of continuous increase every year with the maximum of 25 species in 2020. The number of freshwater crayfish imported into Korea for ornamental purposes was 1,172,159, with an annual average of 78,144 being imported. The population also recorded a record high in 2017 with a 38% increase in population imports compared to the previous year. Among the 34 pet crayfish imported into Korea, four species classified as high-risk and managed in the US and Europe were American crayfish (Procambarus clarkii), Cherax quadricarinatus, Cherax cainii, and Cherax destructor. In addition to American crayfish (P. clarkii), 3 types of high-risk invasive crayfish are designated as legally managed species by conducting an ecological risk assessment, raising awareness among importers, retailers and consumers through awareness-raising education on freshwater crayfish, and measures for route management such as species identification and improvement of labeling methods are needed.

• Korean journal of applied entomology
• /
• v.57 no.4
• /
• pp.323-328
• /
• 2018

Despite rising global concerns over the potential impacts of invasive alien species on indigenous species, the consequences of such introductions are lacking. The cabbage seedpod weevil (CSPW, Ceutorhynchus obstrictus) was found invaded into Korea in the early of 1990s. A large-scale survey in Korea reveals that, in about 20 years post-arrival, the invasive CSPW has become the most abundant on rape flowers and spread almost parts of South Korea including Is. Jeju and Is. Ulleung. Its spread is concurrent with the habitat retraction to cruciferous weeds of the native rapseed weevil (RSW, C. albosuturalis). However, Is. Yeoseo located between the mainland and Is. Jeju, showed their ratio with about 1:1. It suggests that the population of CSPW recently entered this island. Although underlying mechanisms of the decline of native species and increase of invaded species remain unknown, the potential roles of exploitative competition cannot be ruled out. Given that invasive weevil can rapidly replace native congeners, increased level of surveillances is demanding to discourage further invasion of othe alien pests.

• Korean Journal of Environment and Ecology
• /
• v.36 no.4
• /
• pp.368-380
• /
• 2022

Biomonitoring of an invasive alien crayfish species, Procambarus clarkii (Girard, 1852), was performed from February to October 2021, along with environmental DNA analysis, at five locations including Wanju-gun, Hampyeong-gun, Naju-si, Gurye-gun, and Cheongju-si. For the investigation, an umbrella-shaped trap for adults and a hand net for young crayfish were used, and 8 to 10L of freshwater was collected for eDNA analysis. The current status and past distributional records of crayfish in Korea were analyzed along with benthic macroinvertebrates at each survey site. As a result of the investigation, a total of 122 individuals were identified, and Hampyeong-gun recorded the largest number of populations with 59 individuals (48.36%) and the highest environmental DNA (eDNA). The frequency of appearance of P. clarkii was highest in May. The ratio of females to males was 21:5, and the body size was 72.2±21.1mm for female, 80.5±15.6mm for male, and 25.3±9.8mm for young crayfish. P. clarkii introduced into Korea is mainly spreading in the southwest region and it has not been observed in Seoul where there had been a record of appearance in the past. No external symbiosis (Branchiobdellida) of P. clarkii has been identified, and P. clarkii that has appeared in Korea was presumed to be imported from Japan. There are more than eight kinds of exotic crayfish distributed in Korea, and among them, the marbled crayfish (P. virginalis) was identified as a harmful species to the ecosystem of Korea by the Ministry of Environment in 2021. The identified species of benthic macroinvertebrates inhabiting the survey area where P. clarkii has appeared were 69 belonging to 39 families, 15 orders, five classes, and three phyla. Among them, Odonata were the most abundant (16 spp.; 24.62%), followed by Coleoptera (11 spp.; 16.92%) and Hemiptera (11 spp.; 16.92%). In the survey area, one Korean endemic species (Rhoenanthus coreanus), one species (Helophorus auriculatus) classified as Near Threatened (NT) on the Korean Red List, and six species of Crustaceans appeared. In the functional feeding group, the predators appeared predominantly while in habitat oriented group, the climbers appeared to be abundant. It was confirmed that P. clarkii in the survey area prefers an area rich in aquatic vegetation with waterside vegetation, and has high resistance to turbid water quality. The omnivore invader P. clarkii is expected to maintain a competitive relationship with carnivorous benthic macroinvertebrates that are predominant in the same species, and is expected to continue to generate ecosystem disturbance along the food chains.

• Journal of Environmental Impact Assessment
• /
• v.27 no.1
• /
• pp.33-55
• /
• 2018

It has been noted that the main cause of biodiversity loss is influx of alien species. Specifically, habitats destruction, economic loss, and human injury are increasing due to invasive alien species. There were 2,167 alien species in Korea. 21 alien species of extraterrestrials including Lycorma delicatula, Solenopsis invicta, Myocastor coypus, and Spartina alterniflora at high risk through ecological risk assessment, are designated as invasive alien species. Alert species, which may have negative impact on ecosystems when they are introduced into the country, are assigned to 127 species through the ecosystem risk evaluation. To list such alien species to prevent invasion of alien species in advance, and to minimize damage caused by imported alien species, a national level management system called the Conservation and Use of Biological deversity Act was established, but there is a lack of a systematic management system in accordance with degree of risk. There is also a risk assessment chart should be developed thatreflects ecological characteristics of each taxon and evaluation criteria in predicting the risk.