• Proceedings of the National Institute of Ecology of the Republic of Korea
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• v.4 no.3
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• pp.104-114
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• 2023

In this study, the distribution, bait preference, hosts, symbionts, habitat status, and cytochrome c oxidase subunit-I sequences of the ant Linepithema humile were analyzed. This species habitat comprised approximately 1.5 km along stone crevices, flower gardens, roadsides, and container yards in the vicinity of Busan station, Korea. Feeding activity of this species was confirmed in 9 species of 7 families of plants. Which was approximately 14% of total flora (63 species of 37 families) in the studied area. Particularly, it was observed that Dendranthema indicum and Camellia japonica were the most frequently visited. Further, we verified that they interacted with four species of aphids. We identified 22 species of ants (17 genera, 4 subfamilies) inhabiting the Busan station area, including L. humile, Tetramorium tsushimae, Nylanderia flavipes and the alien species Paratrechina longicornis. In areas where L. humile was the dominant species, the habitat of local native ants was reduced by approximately 30%. Bait preference was ranked in the following order: jelly, water with glucose (25%), and yogurt, with the highest preference for baits containing sugar and protein. The 630-bp cytochrome c oxidase subunit-I sequences of the local L. humile populations were 99% identical to those of L. humile in the National Center for Biotechnology Information database, and the Argentine ants that invaded Korea had a sequence identical to that of other invasive populations from China, Japan, and New Zealand. As L. humile rapidly increases due to domestic adaptation, continuous monitoring and control strategy for eradication are needed to protect domestic biodiversity.

• Korean Journal of Ecology and Environment
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• v.37 no.2 s.107
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• pp.227-235
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• 2004

Fish fauna and community structure were surveyed in the Nakdong River, Gumi City, Kyeongpook province from April 2001 to July 2002. During the surveyed Period, 39 species, 32 genera belonging to 10 families were collected. Cyprinid fish occupied 64.1% (25 species) and cobitid fish had 7.7% (3 species). Fourteen species(35.9%) of observed species were known as endemic species. The exotic fish was Micropterus salmoides (2.5%) . The dominant species were Zacco platypus (relative abundance: 36.7%) and Opsariichthys uncirorstris amurensis (22.7%). Carassius aurafus and Microphysogobio rapidus were numerous (4.0${\sim}$4.3%). The rare species comprising less than 0.15% were Acheilognathus koreensis, Aphyocypris chinensis, Iksookimia longicorpus, Coreoleuciscus splendidus, Rhinogobius giurinus, Sarcocheilichthys variagatus wakiyae, Silurus asotus astus, and Channa argus. It was found that the population density of carnivorous Opsariichthys uncirostris amurensis increased drastically in the mid-reach of the Nakdong river since it had been introduced from the other native rivers in the middle 1990s. Gobiobotia nakdongensis inhabit riffle (water velocity : 0.43${\sim}$0.67 m $s^{-1}$) of which the river bed is mainly sand. This species is considered to be in need of conservation. As the result of analyzing fish community in the surveyed area, the species diversity, evenness and dominant indices were 1.008, 0.663 and 0.196 respectively. The findings showed that the tributary, which the waterside plants were abundant and had various habitats, had a higher species diversity (1.112) than the main river (0.787). Sand mining had been disturbing the river ecosystem of the study stations 3, 11, 13 & 14, and these stations showed a quite low species diversity (0.421 ${\sim}$0.574).

• Korean Journal of Ecology and Environment
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• v.54 no.2
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• pp.96-101
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• 2021

In this study, we wanted to obtain the information of the ecological impact of alien species on native fish communities. The Ichthyofauna and fish community in Joongchosan Reservoir and Bukchosan Reservoir in Gunsan-si Korea were investigated over the period from March to October 2020. During the survey period, a total of 1,895 individuals representing eight species, five families, and four orders were caught in the Joongchosan Reservoir. In the Bukchosan Reservoir, a total of 171 individuals were caught, representing seven species, five families, and three orders. The dominant species and subdominant species of Joongchosan Reservoir were Pseudorasvora parva (661 individuals, RA: 34.7%), and Rhodeus ocellatus (660 individuals, RA: 34.7%). Conversely, Micropterus salmoides (77 individuals, RA: 45.0%), and Carassius auratus (60 individuals, RA: 35.1%), were the two most common species in the Bukchosan Reservoir. The community indices showed a dominance of 0.697, diversity of 1.483, evenness of 0.713, and species richness of 0.928 in the Joongchosan Reservoir. In comparison, the community indices in the Bukchosan Reservoir showed a dominance of 0.801, diversity of 1.304, evenness of 0.670, and species richness of 1.167. This study confirms that the number of native fishes and the associated community diversity have decreased due to the influence of Micropterus salmoides. This highlights the need for removal of alien species from reservoirs, while simultaneously preventing future introductions.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.27 no.1
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• pp.31-44
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• 2024

The coastal dune ecosystem is one of the ecosystems under the most development pressure in Korea. Therefore, it is necessary to study the ecological location and related ecological phenomena of coastal dune plants, but related studies are lacking. Through this study, we intend to conduct research on the structure and restoration of dune plants, focusing on the coastal dunes in Jeju Island, which are affected by artificial development pressure and the continuous increase in tourists among many coastal dunes in Korea. Ecosystems of coastal sand dunes for vegetation survey in Jeju Island are selected based on naturalness and preservation. In this study, 23 major coastal dunes on Jeju Island including Udo were selected. In the coastal dunes of Jeju Island, a whole species survey and quadrat survey were carried out. The vegetation survey at study sites were conducted on May to September 2022, when the vegetation is clearly visible. At the survey site, the dune area was identified at the beginning and the plant species were recorded until no more new species appeared. Vegetation survey in the field was performed by 103 quadrat establishments and was conducted using Braun-Blanquet method. A total of 277 species appeared, and the most common species were Vitex rotundifolia and Calystegia soldanella. The frequency of both Vitex rotundifolia and Calystegia soldanella was approximately over 90%. The proportion of woody and herbaceous in all emerging species was 7.2% and 92.8%, respectively. The total number of species found in the quadrat survey was 98. As a result of classifying plant communities based on species dominance in the quadrats, it was analyzed into 30 plant communities. The plant communities that appeared with a frequency of 2 or more on the main island of Jeju were Vitex rotundifolia, Imperata cylindrica var. koenigii, Ischaemum antephoroides, Wedelia prostrata, Elymus mollis, Calystegia soldanella, Artemisia scoparia, and Tetragonia tetragonoides. 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 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, preserving native plant communities that are declining and preserving present tree strips of Pinus thunbergii, Litsea japonica, Pittosporum tobira and Vitex rotundifolia.

• Journal of Ecology and Environment
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• v.48 no.1
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• pp.60-73
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• 2024

Background: The available information on terrestrial pest gastropods and their impact on the environment worldwide is scarce and outdated. The present study aimed to address this gap by conducting the first comprehensive survey of pest gastropods in the Nuwara Eliya District, an important vegetable growing area in the highlands of Sri Lanka. Eighty agricultural lands were surveyed over two years by establishing ten 1 m2 sampling plots per crop type in each agricultural land. Geo-coordinates, air temperature, elevation, relative humidity, daily rainfall, soil pH, species richness and abundance were recorded for rainy and non-rainy periods. The relationship between species composition and environmental variables was analyzed using multi-regression models and distribution maps. Results: Out of the 14 species recorded in agricultural lands, nine were identified as exotic pest species. Species abundance (t = 4.69, p < 0.05) and diversity was higher in the rainy period and the dominant species during this period were Bradybaena similaris (t = 2.69, p < 0.05) and Deroceras reticulatum (t = 2. 46, p < 0.05). Eggs and estivating adults were found in soil and under decaying organic matter during the non-rainy period. The exotic species showed broader preferences for the measured environmental factors and showed a wider range in distribution compared to the native species. Variation in pest gastropod composition was significantly accounted for by elevation, relative humidity, soil pH and daily rainfall. Additionally, the species richness and abundance varied across locations due to the combined effects of elevation, crop type and stage, and field type. Conclusions: The study emphasizes the importance of understanding the biology and ecology of gastropod pests to develop effective management strategies. By considering the influence of environmental factors and implementing appropriate soil management techniques, such as targeting specific habitats and crop stages, it is possible to mitigate pest populations and minimize their impact on agricultural lands. Overall, this research contributes valuable insights into the dynamics and interactions of terrestrial gastropods in agricultural ecosystems, supporting sustainable pest management practices.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.14 no.3
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• pp.169-176
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• 2011

The purpose of this study is to examine the ecologically suitable restoration characteristics in riparian slopes constructed by continuous fiber soil reinforced system (Geofiber system) which does not contain the concrete materials. The findings are as follows : (1) as the tested soil was not washed away by rainfalls and floods, Geofiber could replace the concrete wall and gravity stone net bag technique from the civil engineering structural point of view; (2) after one year of the construction, it was monitored that land cover ratio was 80-90%, which indirectly shows that vegetation is safely maintained; and (3) at the same time, 5-8 flora species were found in each test grid and more importantly dominant species have been moved from alien species to native herbaceous plants. From the above findings, Geofiber system is recommendable to restore the riparian slopes in terms of stability and natural landscape points. However, a long term monitering is needed considering flora succession process in a given environment as well as suitability tests should be carried out through the comparative investigations in other environments.

• Journal of the Korean Institute of Landscape Architecture
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• v.15 no.3
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• pp.21-31
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• 1988

This study was executed to investigate the vegetation structure and to propose the administration planning of the Royal Ancestor's Shrine. Five sites sampled in the study area with the clumped sampling method. Pinus koraiensis community covered 27.3% and Quercus aliena community 61.5% of total forest area when considering the actual vegetation. This area of environmental impact grade 3 and 4 area covered 46.9% and it should be restored. The ecological diversity, i.e. species diversity and evenness, showed low class, and especially site 2 which was controlled the user's after 1985 showed the lowest value. Pinus koraiensis community which is a dominant species now in the study area shall be succeed to Quercus aliena community. Robinia pseudoacacia at the eastern wall shall be excluded step by step and it shall be replaced with native species gradually. Ailanthus altissima, Populus ${\times}$ albaglandulosa and Styrax japonica which had higher selection invaded conspicuously the bare land. As the administration planning of the study area, Pinus koraiensis and Styrax japonica shall be thinned out gradually and it shall be replaced with Quercus aliena and Acer palmatum.

• Korean Journal of Environment and Ecology
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• v.24 no.3
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• pp.302-317
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• 2010

In this study, not only to present the management plan but also to verify the effectiveness for a area of improving the landscape and the area of creating the base of bio-inhabitation in Tancheon stream concrete embankment where were practised the vegetation-mat measures for greening via monitoring i.e. restoration progress. The results of monitoring, there were a total of 41 taxa, 18 families, 38 species, 3 varieties in 2006, moreover in the 2007, there were a total of 59 taxa, 19 families, 56 species, 3 varieties and in the period 2008, 64 taxa, 29 families, 59 species, 8 varieties. Therefore, these site has increased the plant spaces year by year. The distribution of vegetation characteristics shows that Miscanthus sacchariflorus and Pennisetum alopecuroides expands their influence in the area of applying the construction method. Those area appears a diversity of native species by the stream deposition at the flood. Thus, its condition is very soundly ecological health and eco-friend. At present, native species have been dominant, however, disturbed species and invasive species can be expected to increase dramatically in the future. Therefore, it is necessary to a long-range monitoring and management for maintaining an environmentally sound aquatic ecosystem. On this area refer to mix the river vegetation of primary succession and disturbed vegetation. For that reason, the method of constructing the vegetation-mat measures for greening in embankment does not need to remove the concrete and can install a coir-mat on the top. It leads to improve the landscape, moreover, it was analysed the such dramatic changes in the vegetation species richness by providing continuous the plant growth basis have a impact on in bio-diversity.

• Korean Journal of Ichthyology
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• v.27 no.2
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• pp.116-132
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• 2015

Freshwater fish fauna and community structure were investigated at 44 stations in upper reach of the Nakdong river, Korea from March to October 2014. During the surveyed period 42 species and 4 types belonging to 34 genera and 14 families were collected. In this collection fishes of Cyprinidae were 17 species and 4 types, most numerous possessing 43.2% of all. There were 17 Korean endemic species including Kichulchoia multifasciata, 3 endangered species such as Koreocobitis naktongensis, Lethenteron reissneri and Brachymystax lenok tsinlingensis and 2 exotic species such as Lepomis macrochirus and Micropterus salmoides. Fish species transferred from other native rivers were 9 species including Hemibarbus mylodon, Coreoleuciscus slpendidus Han river type, Opsariichthys uncirostris amurensis, Iksookimia koreensis and Liobagrus andersoni. Dominant species based on the number of individuals was Rhynchocypris oxycephalus (21.44%) and sub-dominant species were Zacco koreanus NE type (18.55%). The community analysis revealed that the structure of fish community in upper reach of the Nakdong river was very stable and diverse in having diversity 1.101, evenness 0.670, dominance 0.400 and species richness 4.454. Fish community was divided into 5 groups based on similarity indices among surveyed stations such as uppermost, upper I, upper II, mid-upper, middle reach group.

• Korean Journal of Ichthyology
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• v.29 no.3
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• pp.205-217
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• 2017

Fauna of freshwater fish and community structure were investigated at 24 stations in the Hoecheon Stream and some adjacent tributaries of the Nakdonggang River, Korea from July 2016 to August 2017. During the period 42 species and 4 types belonging to 32 genera and 11 families were collected. In this collection fishes of Cyprinidae were 24 species and 4 types, most numerous possessing 59.1% of all. There were 16 Korean endemic species including Acheilognathus yamatsutae and Odontobutis platycephala, 3 endangered species such as Pseudobagrus brevicorpus and Koreocobitis naktongensis (rank I) and Culter brevicauda (rank II) and 2 exotic species such as Micropterus salmoides and Lepomis macrochirus. Fish species transferred from other native rivers were 4 species including Opsariichthys uncirostris amurensis, Hemiculter eigenmanni, Odontobutis interrupta and Tridentiger brevispinis. Dominant species was Zacco koreanus NS type (19.2%) and sub-dominant species was Z. platypus R type (16.1%). The structure of fish community in the Hoecheon Stream was very stable and diverse in having diversity 2.91, evenness 0.77, dominance 0.35 and species richness 4.67. Fish community was divided into 4 groups such as upper, middle, midlower and lower reach group based on similarity among surveyed stations.