• Journal of Wetlands Research
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• v.24 no.3
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• pp.185-195
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• 2022

This study conducted a survey over spring and autumn from 2014 to 2020 to confirm the ecological characteristics of the size of streams and habitats, centering on the ecological landscape conservation area, and a total 256 species of benthic macroinvertebrates in 105 families, 25 orders, 8 classes, and 5 phyla appeared. In terms of appearance species, by region, the rate of appearance of Ephemeroptera and Trichoptera was high in regions consisting of lotic area and the rate of appearance of Coleoptera and Odonata was high in regions consisting of lentic areas. When comparing the population of Ephemeroptera-Plecoptera-Trichoptera (EPT) groups by region, they were classified into three groups: upstream area, mainstream area, and lentic areas, and it was confirmed that the population ratio of EPT changed as it moved from upstream to downstream. As the stream order increased, the number of species and populations increased. The Shredder group (SH) tended to decrease as the size of stream increased(r=0.9925), and the Collector-Filtering (CF) tended to increase as the size of stream increased(r=0.9319). It was confirmed that the Scraper (SC) replaced each other between species with the same ecological status as it went downstream from upstream, and it is thought that the SC did not differ significantly by stream order. In order to maintain a healthy ecosystem in the designation and management of ecological landscape conservation areas, it is necessary to consider ecological factors such as competition and physico-chemistry factors such as water quality and substrate conditions. Therefore, if the competent authority designated survey areas including buffer areas that include streams and physical habitats of various sizes, it will be advantageous to the conservative area and securing more biological resources.

• Korean journal of applied entomology
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• v.24 no.2 s.63
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• pp.65-70
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• 1985

The locational preference of the brown planthopper (BPH) Nilaparvata lugens ($St{\aa}l$) and the whitebacked plant hopper (WBPH) Sogatella furcifera(Horvath) was studied on rice cultivars IR22 and IR36 as an integral part of subsequent research on insect-fungal pathogen relationships. The BPH was observed to stay consistently on the basal portion while the WBPH showed a general preference for the upper portion regardless of varieties, rice growth stages and insect population density levels. The habitat preference of both species (BPH and WBPH) was found not to be affected by the presence of the other species when both species are present on the same host plant Five rice cultivars with different reactions to BPH biotype 2 were used in the study on BPH-Rhizoctonia solani relationship: IR22 and TN1 (susceptible); Triveni and ASD7 (moderately resistant); and IR42 (resistant). Test plants were inoculated with R. solani (Kuhn) $3{\sim}4$days after insect infestation. Sheath blight disease severity/incidence was significantly higher in the treatment where BPH+R. solani were together than in the treatment with only the pathogen. Symptom expression of the disease in the BPH-pathogen combination was faster and mycelial growth was more profuse inducing the formation of more infection structures. Regardless of varietal reaction to BPH biotype 2, the degree of hopperburn was significantly higher in the combination of the two pests as compared with that of BPH alone. There could be a synergistic relationship between the insect pest and the pathogen indicated by a positive interaction between the two species.

• Journal of Environmental Impact Assessment
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• v.32 no.1
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• pp.1-14
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• 2023

When carrying out development projects around Ardeidae breeding habitats, we intend to devise a plan for sustainable coexistence by presenting measures to select and reduce key evaluation items so that conflicts can be prevented in advance at the environmental impact assessment stage. The results of the study are as follows. The main evaluation items are animal and plant items for preservation of Ardeidae breeding habitats and odor and noise items that can evaluate the effects of odors and noise in Ardeidae breeding habitats. First, the scope of the survey in animals and plants categories is not limited to legal guardian species, but includes egrets breeding and feeding grounds corresponding to major species breeding grounds and migratory birds, and preservation measures are established according to the reduction of the area of breeding and feeding grounds. Second, in the odor category, the irradiation period includes the period when the odor generation is the highest from the end of June to the end of July. The odor evaluation standard is based on the complex odor discharge standard, which is a concentration regulation, and the odor concentration felt by humans shall be 2 to 5OU/m³ and the frequency shall be 2% or less. Third, in the noise category, the timing of the survey is measured every month from May to August, including when the sound of egrets and young birds is combined to maximize noise generation. Since the noise of Ardeidae, a bird in summer, occurs only for a certain period of time, measures are taken to reduce noise by securing separation distances, securing buffer green areas, and installing construction rather than installing artificial structures such as soundproof walls. In order for existing Ardeidae breeding sites to maintain an appropriate density of populations and not move populations elsewhere, it is necessary to manage nesting tree and maintain stable habitat quantity and quality.

• Korean Journal of Environment and Ecology
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• v.37 no.1
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• pp.86-93
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• 2023

This study investigated the ecological characteristics of Odontobutis interrupta at the Geumdang Stream from January to December 2021. The riverbed structure of the species habitat was rich in sand and mud. The water was deep, ranging from 21 to 124 cm, with an average of 48 cm. The stream velocity was slow at 0.24 (0.08-0.36) m/sec. The ratio of females to males was 1:0.98, and the total length of collected individuals ranged from 23 mm to 162 mm. The age according to the total length-frequency distribution as of May indicated that the group with a total length of 23-59 mm was one year old, the group with 60-99 mm was two years old, the group with 100-139 mm was three years old, and the group with 140-162 mm was four years old. As a secondary gender characteristic, the females genital papilla had a cylindrical shape, a hollow inside of the tip, and a longer diameter than males. The males had a cone shape with a pointed end. Sexually mature males had the nuptial color, with a black abdomen and whole body. Some females with a length ranging from 60 to 69 mm and all females 70 mm longer were sexually mature. Some males with a length ranging from 70 to 79 mm and all males 80 mm longer were sexually mature. The spawning season was from May to July, and the water temperature was between 19.6℃ to 29℃ during that period. The prosperous spawning season was June (26℃). The average number of eggs in the ovaries was 2,473 (883-4,955) per matured female, and the matured eggs were yellowish and spherical with a mean diameter of 1.42 (1.20-0.54) mm. The correlation between total length and weight was BW=0.0000006TL^3.21 with the constant a as 0.0000006 and parameter b as 3.21. The condition factor (K) was 1.67 (1.18-2.43) on average, and the slope was 0.116.

• Korean Journal of Environment and Ecology
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• v.37 no.4
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• pp.259-272
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• 2023

This study set up 49 survey areas with an area of about 400 square meters in Abies koreana natural habitat to identify the species composition and vegetation structure of the A. koreana forest in the Mt. Jiri Nation Park, conducted field surveys using phytosociological methods, and performed the cluster analysis using the Two-Way Indicator Species Analysis (TWINSPAN) and Table manipulation. Subsequently, species composition analysis using the importance value, species diversity analysis, DBH analysis, sapling analysis, and similarity analysis was conducted by each cluster type. The cluster analysis classified the A. koreana forest in Mt. Jiri into five clusters, A, B, C, D, and E. The forest was divided into two clusters, Magnolia sieboldii-Dryopteris crassirhizoma-Sasa borealis and Betula ermanii-Solidago virgaurea-Calamagrostis arundinacea. The former was classified as type A and B by Cornus controversa-Hydrangea macrophylla, and the latter was classified as type E, a typical community, and a Sorbus commixta-Rhododendron mucronulatum cluster. And the S. commixta-R. mucronulatum cluster was divided into C type and D type by Picea jezoensis-Ligularia fischeri and Ainsliaea acerifolia. Through vegetation analysis, the importance value of A. koreana, Quercus mongolica, Acer pseudosieboldianum, Fraxinus sieboldiana, and B. ermanii was highly expressed in the A. koreana forest in Mt. Jiri. Regarding species diversity, the results were similar to those reported in other studies of A. koreana forests in Mt. Jiri. The analysis of diameter at breast height (DBH) showed that A. koreana dominated all layers, and the growth of saplings was also good, indicating that the dominance of A. koreana is expected to continue for a while. However, when considering the value of biodiversity that is expected to increase and threats caused by climate change, systematic preservation and management are required to respond to various threats based on continuous monitoring.

• Korean Journal of Ecology and Environment
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• v.56 no.1
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• pp.57-69
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• 2023

The objectives of this study were to analyze the fish community structures and distribution characteristics of fisheries resources in the Osip Stream and Wangpi Stream, fishery resources protection areas. For the study, we conducted fish samplings four times in the two streams from April to October 2019. In Osip Stream and Wangpi Stream, we sampled 31 species and 29 species and the dominant species were Zacco platypus (28.6%) and Squalidus multimaculatus(41.7%), respectively. According to the life type of fish species, primary freshwater species were collected 18 species(58.1%) and 21 species(72.4%), and migration fishes were sampled 4 species (12.9%) and 6 species (20.7%) in Osip Stream and Wangpi Stream, respectively. Fisheries resources species showed high relative abundance in June, and the fish biomass was highest in October. As a results of comparing the previous studies with this study, both rivers showed high biodiversity and were found to maintain stable populations of fishes. According to analysis of tolerance guilds, the proportion of tolerant species, based on the number of individuals, was composed of 14.4% and 1.1% in Osip Stream and Wangpi Stream, respectively. This very low ratio of tolerant species confirmed that both streams have very good physiochemical environment conditions. From the above results, it was judged that the fishery resource protection areas of Osip Stream and Wangpi Stream have high ecological function and preservation value. For sustainable use and management of fishery resource protection areas of Osip Stream and Wangpi Stream, it is suggested that biological disturbance management, fish discharge projects considering environmental capacity, efforts to improve the habitat environment, and establishing a fishery resource protection areas management system were necessary as considerations.

• Korean Journal of Environment and Ecology
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• v.36 no.6
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• pp.603-614
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• 2022

This study investigated the characteristics of fish communities in the Bangtaecheon Stream in Korea from April to October 2020. The survey collected 4,640 fish of 26 species in 9 families from 11 survey stations. The dominant and subdominant species were Rhynchocypris kumgangensis(relative abundance at 31.5%) and Zacco koreanus(27.8%), respectively. The next most abundant species were Ladislavia taczanowskii(15.9%), Pungtungia herzi(4.0%), Brachymystax lenok tsinlingensis(3.7%), Microphysogobio longidorsalis(2.4%), and Zacco platypus(2.3%). Among the collected fish species, 17 (65.4%) were Korean endemic species, 4 (15.4%), including Acheilognathus signifer, Pseudopungtungia tenuicorpa, Gobiobotia brevibarba, and B. l. tsinlingensis,were class II endangered wildlife as designated by the Ministry of Environment, and 1 species, Hemibarbus mylodon, was a natural monument. Moreover, two landlocked species (B. l. tsinlingensisand C. koreanus) were also collected. Additionally, four cold-water species (R. kumgangensis, L. taczanowskii, B. l. tsinlingensis,and Cottus koreanus) were collected, and all of them mainly inhabited the upper and middle streams. Fish community analysis showed a tendency for dominance and uniformity to decrease and abundance and diversity to increase from upstream to downstream and that the community structure was divided into upstream and downstream groups. The river health was rated as excellent (9 stations) and good (2 stations). Compared to the previous studies, three species (Carassius auratus, Leiocassis ussuriensis,and Siniperca scherzeri) appeared in the past but did not appear in this survey, and three species (Opsariichthys uncirostris amurensis, Microphysogobio yaluensis,and Orthrias nudus) that did not appear in the past appeared in this survey. Bangtaecheon Steam is well-preserved, and climate-sensitive species, endangered wildlife, and natural monuments inhabit the stream. Therefore, continuous attention and systematic conservation measures are required.

• Korean Journal of Ecology and Environment
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• v.55 no.1
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• pp.1-9
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• 2022

An estuary is an area where a freshwater river or stream meets the ocean. Even before the importance of the value of estuaries was recognized, the estuary was lost because of large-scale conversion by draining, filling, damming, and dredging. In South Korea, 643 estuaries are located, and the total area is 3,248,300 ha, accounting for 32.5% of the total area of South Korea. Over 35% of Korean estuaries are closed estuaries which are only temporally connected with the sea, either permanently or periodically. Since 2008, in order to preserve the estuary ecosystem and solve major issues in the estuary by accumulating knowledge about the estuarine ecosystem, the Ministry of Environment of Republic of Korea has been conducting the "Estuarine Ecosystem Monitoring and Assessment Project". At 668 sites of 325 estuaries, epilithic diatom, benthic macroinvertebrate, fish, and vegetation are investigated, and the habitat condition of each site is evaluated using the newly developed biotic index. More than 100 researchers annually record 2,097 species of estuaries according to the standardized survey guidelines over the past 14 years and provide strictly managed data necessary for establishing estuaries conservation policies. As a result of bibliometric analysis of 1,195 research articles related to the monitoring and assessment of the estuarine ecosystem, research on pollutants such as heavy metals and sediment control have recently been conducted. "Estuarine Ecosystem Monitoring and Assessment Project" is an ecological monitoring type of long-term mandated monitoring that is usually focused on identifying trends. Although it is difficult to identify the mechanism influencing a change in an ecosystem through long-term mandated monitoring, providing empirical data for supporting evidence-based policy, decision-making, and the management of ecosystems. In order to increase the efficiency of the project, research to investigate the relationship between sediments and pollutants and organisms can be conducted at specific estuaries or sites to compensate for the shortcomings of mandatory monitoring.

• Korean Journal of Ecology and Environment
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• v.55 no.1
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• pp.10-18
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• 2022

This study analyzed the relationship between the community structure of benthic macroinvertebrates and habitat changes in open estuaries among the sites included in the national estuary monitoring program. The estuary survey was conducted under the "Guidelines for Investigation and Evaluation of Biometric Networks" and classified by sea area, 80 places in the East Sea, 102 places in the South Sea, and 19 places in the West Sea were investigated. In a total of 201 open estuaries, benthic macroinvertebrates were identified with 4 phyla, 9 classes, 41 orders, 139 families, 269 species and 196 species in the East Sea, 182 species in the South Sea, and 90 species in the West Sea. The highest population densities were Insecta in the East Sea, the Malacostraca in the South Sea, and the Annelida in the West Sea. Through SIMPER analysis, species contributing to the similarity of benthic macroinvertebrates communities in each sea area were identified. Some species greatly influenced the similarity of clusters. The benthic community in the East Sea was affected by the salinity, so the contribution rate of freshwater species was high. On the other hand, the benthic communities of the South and West Seas showed species compositions are influenced by the substrate composition. As results, the benthic macroinvertebrate community in Korean estuaries was impacted by salinity and substrate simultaneously, and the close relationship with geographical distance was not observed. The result of this study is expected to be used to respond to environmental changes by identifying and predicting changes in the diversity and distribution of benthic macroinvertebrates in Korea estuaries.

• Korean Journal of Heritage: History & Science
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• v.56 no.1
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• pp.132-140
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• 2023

In this study, a total of 21 parts of the head, carapace, and plastron of 21 tortoises were examined to investigate the characteristics of male and female sexual dimorphism of the Reeve's turtle (Mauremys reevesii), a natural monument in Korea. The ratio values of a total of 19 areas were derived from Head Length (HL) and Carapace Length (CL). As a result of comparing the ratio values, it was found that male tortoises had larger head length, head width, and head height than females compared to the size of the carapace. Since females grow eggs inside the body through internal fertilization after mating, female carapaces are judged to be larger than males overall. As a result of statistical analysis of the ratio values of the measured values, Plastron Length (PL), Bridge Length (BL), Gular Length (GL), Interhumeral Length (IH), Interanal Length (IAN), Femoral-Anal seam (FA) and Head Height (HH) showed statistically significant differences. Statistically significant in the part of the plastron, it is judged that the tortoise acts directly on each deck of the plastron as it grows. In addition, the head size of male tortoises was smaller than that of females, but it was found to be larger in proportion. It is considered that the tortoise has a rather large head compared to the body due to the male's habit of shaking his head and courtship behavior before mating. This study, we were able to identify the characteristics of sexual dimorphism in Reeve's turtle. However, since most of them were rescued, it was not possible to accurately determine habitat and age. In the future, if additional studies are conducted on individuals with clear habitats and ages, it is expected that the characteristics of the physical differences that develop as they grow can be identified.