이 연구에서는 파랑 하중을 받는 경사식 방파제의 구조적 안정성을 평가하기 위하여 강도감소법(Strength Reduction Method)을 이 용한 슬립 파괴 해석을 수행하였다. 강도감소법의 신뢰성은 기존의 사면 안정 해석 결과를 유한요소해석 프로그램인 ABAQUS로 재 현함으로써 검증하였다. 또한, 상치 콘크리트에 작용하는 파압 분포를 고려하여 경사식 방파제 내부의 슬립 파괴 거동을 분석하였다. 해석 결과, 이 연구에서 사용한 단면 형상 및 물성 조건 하에서 파고 7m 조건에서 비원형 슬립 파괴면이 발생하였고, 안전율은 약 1.68 로 산정되었다. 추가적으로 Latin Hypercube Sampling을 이용한 불확실성 해석을 수행하여 파고 변화에 따른 경사식 방파제의 취약 도 곡선을 도출하였다. 분석 결과 파고가 증가함에 따라 파괴 확률이 급격히 증가하였으며, 임계 파고는 약 6.85m로 평가되었다. 이 연구는 강도감소법 기반 수치해석이 경사식 방파제의 내파 안정성 및 취약도 평가에 효과적으로 적용될 수 있음을 보여준다.

이 연구는 충격쇄파 하중에 대한 직립식 방파제의 동적 거동을 정밀히 분석하기 위해 유한요소 기반의 2차원 해석 모델을 구축하 였다. 기존의 단순화된 해석 방법이 지닌 한계를 극복하고자, 유체 요소, 비선형 지반 모델, 접촉 비선형성, 에너지흡수경계요소를 포 함한 정밀한 2차원 수치해석 모델을 구축하였다. 또한, 이론적 파압 공식을 기반으로 충격쇄파 하중의 시간이력을 모델링하여 방파 제의 활동량을 평가하였다. 해석 결과, 비선형 지반 모델은 탄성 지반 대비 더 큰 활동량을 유발하는 것으로 나타났으며, PML (Perfectly Matched Layer)은 고정 경계 조건과 비교했을 때 해석 안정성과 정확성을 크게 향상시키는 것으로 나타났다. 이 연구는 직 립식 방파제 설계 및 안전성 평가를 위한 정밀 동적 해석 기술 개발에 기여하며, 극한 조건에서도 방파제 성능을 예측할 수 있는 기반 을 제공할 것으로 기대된다.

This study assessed the genetic outcomes of reintroducing Zacco koreanus into the Bongseonsa Stream by comparing the genetic diversity and population structure of the reintroduced population to those of the original populations from the Jojong and Sudong Streams. The reintroduced population in Bongseonsa Stream retained multiple haplotypes and displayed a mixed genetic composition with the original populations, indicating the reintroduction strategy’s effectiveness. The pairwise genetic differentiation value (FST) suggested that the Jojong Stream population, which is geographically closer and ecologically similar, contributed more to gene flow and potential local adaptation in the reintroduced population. Results from STRUCTURE analysis (K=2) and principal coordinate analysis (PCoA) showed no clear genetic separation among populations, supporting effective genetic integration. However, the relatively small effective population size (Ne) of the reintroduced population raises conserns about potential longterm risks of inbreeding and genetic drift, which could lead to a loss of genetic variation. Overall, the reintroduction successfully established a genetically diverse population in the short term, but continuous monitoring and adaptive management are crucial for maintaining genetic health and ensuring long-term population stability. This study underscores the importance of integrating genetic considerations into freshwater fish restoration programs and provides a reference for developing sustainable population management strategies.

National parks serve as protected areas that ensure the sustainable use of representative natural ecosystems. In South Korea, approximately 46% of the nation’s total species and 65% of its endangered species inhabit national parks. Comprehensive resource surveys have been conducted every 5 years in accordance with the Natural Parks Act to safeguard these invaluable biological resources. However, species identification in these surveys still largely relies on traditional methods, which are time-consuming and labor-intensive, and often subject to investigator bias. This study investigated freshwater fish communities in stream ecosystems at four national parks-Seoraksan, Woraksan, Deogyusan, and Hallyeohaesang-using environmental DNA (eDNA) metabarcoding to evaluate the consistency of its results with those of conventional surveys. A total of 33 fish species (five orders, 11 families) were recorded in both methods. eDNA detected 31 species (detection rate: 93.9%), whereas conventional methods identified 22 species (66.7%). However, species richness values were significantly correlated between the two methods. eDNA exhibited higher detection efficiency (88.7-100.0%) across all parks than conventional methods (64.3-72.2%). Six endangered species were identified in total, four of which (66.7%) were detected by eDNA. The results indicate that eDNA metabarcoding provides a more sensitive, efficient, and reliable tool for assessing freshwater fish diversity in national parks than conventional methods. Overall, eDNA offers a valuable complement or potential alternative to conventional survey methods for the long-term monitoring of freshwater fish biodiversity.

본 연구는 상수리나무(Quercus acutissima) 종자의 발아 효율성과 유묘 생장 특성을 향상시키기 위하여, KNO3 priming 처리 시간(24, 48시간)과 농도(0.5%, 1.0%, 1.5%)를 비교하여 최적 조건을 도출하고자 실시하였다. 충실 종자를 선별한 뒤 KNO3 용액에 priming 처리하여 발아특성과 유묘 생장특성을 평가하였다. 전반적으로 24시간-1.0% KNO3 처리구는 발아율, 발아속도, 발아균일지수 및 유묘 생장 특성에서 대조구보다 유의하게 높은 값을 보였다(p < 0.05). 그러나 농도가 높아지거나 처리 시간이 길어질수록 이러한 효과는 감소하여 대조구와 큰 차이를 보이지 않았다. 이상의 결과를 종합할 때, 상수리나무 종자의 발아 및 초기 유묘 생장에 가장 효과적인 KNO3 priming 조건은 KNO3 1.0%, 24시간 처리인 것으로 판단된다.

Natural populations of numerous species have decreased sharply in recent years, and a number of mammalian species are also now at elevated risk of extinction globally. The long-tailed goral Naemorhedus caudatus, a vulnerable and protected species designated by IUCN (International Union for Conservation of Nature) and CITES (the Convention on International Trade in Endangered Species of Wild Fauna and Flora), is distributed in Northeast Asia including the Korean Peninsula. In South Korea, the Seoraksan National Park is known as the largest core habitat for the long-tailed goral population. In this study, phylogenetic relationships and population genetic features of the Seoraksan goral population were analyzed using fecal samples with both mitochondrial DNA and microsatellite markers. We found that Seoraksan gorals were the most closely related to Russian population, and also found that a unique Seoraksan lineage evolved there. In addition, the Seoraksan goral population showed higher genetic diversity than other South Korean populations, suggesting that this population might represent the most ecologically and evolutionarily important remnants of the long-tailed goral in South Korea. The Seoraksan goral population had a low level of genetic differentiation and a rather single genetic structure, suggesting that non-negligible levels of gene flow might have occurred across populations. Moreover, microsatellite genotype-based individual identification estimated that the population size was ≥81 in the Seoraksan National Park. Findings of our study suggest that effective conservation and restoration actions are needed for long-term conservation of N. caudatus in this protected area.

Biodiversity encompasses species diversity, which includes species richness and species evenness. High species diversity is known to contribute to community stability and the potential for maintaining healthy ecosystem functioning. However, the most commonly used species diversity indices have some limitations, as they require species-specific abundance data for each community. In contrast, phylogenetic diversity measures the evolutionary distances between species within a community, reflecting ecological and/or evolutionary divergences and niche differences, without requiring abundance data. This study assessed biodiversity by calculating phylogenetic diversity indices for freshwater fishes (19 species) and aquatic insects (49 species) at three sites within Seoraksan and Odaesan National Parks. The aquatic insects studied belong to the EPT group (Ephemeroptera, Plecoptera, and Trichoptera), which are widely used as bioindicators of aquatic ecosystems. Two mitochondrial DNA genes were used as molecular markers: COI and cyt b for fish, and COI and 16S rRNA for the EPT - group. Overall, Odaesan National Park exhibited higher phylogenetic diversity in both fishes and aquatic insects compared to Seoraksan National Park, although this difference was not statistically significant. The highest phylogenetic and species diversity were observed for fish at the OD2 site (Woljeong District) and for the EPT group at the OD1 (Gyebangsan) and SA2 (Jangsudae) sites. Correlation analysis revealed that phylogenetic diversity indices were more positively associated with species richness than species diversity indices. This study serves as a pilot project for establishing standardized methods for assessing biodiversity in national park habitats using phylogenetic diversity. It also aims to inform various policies, such as the development of biodiversity assessment systems and the prioritization of protected areas within national parks.

환경오염과 자원 고갈 문제가 심화됨에 따라 재생 가능하고 생분해가 가능한 바이오소재 개발이 지속 가능한 산업 발전의 핵심 과제로 대두되고 있다. 본 연구는 동아시아 지역에서 자생하는 꽝꽝나무(Ilex crenata Thunb.)를 대상으로, 발아 증진 및 순화재배 기술을 체계적으로 정립하여 대량 생산 체계를 구축하고 바이오소재로서의 산업적 활용 가능성을 평가하고자 하였다. 본 연구에서는 GA3, KNO3, NH4NO3, KH2PO4, PEG와 같은 다양한 프라이밍 처리제를 이용하여 꽝꽝나무 종자의 발아 특성과 유묘 생육 특성을 분석하였다. 그 결과, KNO3 50 mM 처리구는 발아율을 99.0%까지 증가시키며 발아 과정을 가속화하는 데 효과적이었다. 그러나 유묘 생육 및 단위면적당 수확량에서는 NH4NO3 200 mM 처리구가 가장 높은 증가를 보였으며, 이는 질소의 두 가지 형태(NH4 +, NO3 -)를 동시에 제공하여 질소 대사를 극대화한 결과로 판단된다. 유묘활력지수(SVI) 또한 NH4NO3 200 mM 처리구에서 254.3±41.6으로 가장 높게 나타났으며, 이는 대량 생산과 바이오소재 원료로의 활용에 적합한 조건으로 확인되었다. 본 연구는 발아 증진 기술 및 초기 생육 안정화를 통해 꽝꽝나무의 대량 재배 가능성을 제시하였으며, 지속 가능한 그린바이오소재 개발에 중요한 기초자료를 제공하였다. 향후 다양한 재배 조건과 종자 특성에 따른 최적화 연구가 추가적으로 필요할 것으로 판단된다.

River estuaries are dynamic and productive ecosystems with high regional biodiversity. Environmental DNA (eDNA) has become a useful approach to assessing biodiversity in aquatic ecosystems. This study was conducted to investigate fish community characteristics and species diversity in two river estuary ecosystems, the Taehwa River and Changwon Stream. We further compared conventional and eDNA metabarcoding analyses of the fish communities. The conventional survey was performed in May, July, and October 2022, while the eDNA analysis was conducted only in May. We observed various fish species with different life histories, including carp, goby, and marine fish. We also found that migratory fish, such as dace Tribolodon hakonensis, sweetfish Plecoglossus altivelis, and eel Auguilla japonica, occurred in the Taehwa River, suggesting high river connectivity. Marine fish species were predominant in the Changwon Stream, as this river is located close to the sea. The diversity indices showed that the Taehwa River generally had higher species richness, evenness, and diversity values than the Changwon Stream. A total of 9-19 species were detected in the conventional survey for the three sites, whereas 11-18 species were found from eDNA analysis. The findings indicate that the sensitivity of eDNA was similar to or higher than that of the conventional method. Our study findings suggest the efficiency and efficacy of eDNA-based fish community monitoring, although with some shortcomings in applying the genetic marker to Korean fish, including no clear-cut distinction for Korean endemic species and/or genetically closely related species groups.

The bitterling (Cyprinidae, Acheilongnathinae) is a temperate freshwater fish with a unique spawning symbiosis with host mussels. Female bitterlings use their extended ovipositors to lay eggs on the gills of mussels through the mussel's exhalant siphon. In the present study, in April of 2020, we investigated spawning frequencies and patterns of three bitterling fish species in host mussel species in the Nakdong River basin (Hoecheon). During field surveys, a total of four bitterling and three mussel species were found. We observed bitterling's spawning eggs/larvae in the three mussel species: Anodonta arcaeformis (proportion spawned: 45.5%), Corbicula fluminea (12.1%), and Nodularia douglasiae (45.2%). The number of bitterlings’ eggs/larvae per mussel ranged from 1 to 58. Using our developed genetic markers, we identified the eggs/ larvae of each bitterling species in each mussel species (except for A. macropterus): A. arcaeformis (spawned by Acheilognathus yamatsutae), C. fluminea (A. yamatsutae and Tanakia latimarginata), and N. douglasiae (A. yamatsutae, Rhodeus uyekii, and T. latimarginata). Approximately 57.6% of N. douglasiae mussel individuals had eggs/ larvae of more than one bitterling species, suggesting that interspecific competition for occupying spawning grounds is intense. This is the first report on bitterling’s spawning events in the Asian clam C. fluminea from Korea; however, it should be ascertained whether bitterling’s embryo undergoes successful development inside the small mussel and leaves as a free-swimming juvenile. In addition, the importance of its conservation as a new host mussel species for bitterling fishes needs to be studied further.

본 연구는 국내 산림생명자원 중 광나무의 대량생산을 위한 기초연구로, Priming 처리에 따른 발아 효율성 및 유묘 생육특성에 미치는 영향을 구명하고자 수행하였다. 종자 Priming처리는 대조구, GA3 (10, 100, 200 ㎎·L-1), Ca (NO3)2 (50, 100, 200 mM), KNO3 (50, 100, 200 mM)를 24시간 처리하여 발아특성을 분석하였고, 순화재배에 따른 생육특성 및 활착률을 조사하여 수확량을 비교·분석하였다. 발아특성은 25℃·KNO3 100 mM에서 발아율이 유의적으로(p<0.001) 높았으며, 평균발아일수는 10.3~18.1일로 15℃에서 대체적으로 빠른 발아일수를 나타냈다(p<0.001). 발아속도 및 발아균일지수 또한 25℃·KNO3 100 mM에서 유의적으로 높은 값을 보였다(p<0.001). 생육특성의 경우 2 5℃·KNO3 100 mM 처리에서 유근 길이(5.1±2.4 ㎝), 초장(5.7±0.7 ㎝), 근장(16.6±2.0 ㎝), 건중량(0.079 g)이 유의적으로 가장 높게 나타났다 (p<0.001). 유묘활력지수 또한 25℃·KNO3 100 mM 처리에서 1418.3으로 높았으며, 가장 높은 수확량(16.8 g/㎡)을 나타냈다. 결과적으로 25℃, KNO3 100 mM 처리 시 실내발아에서 발아효율성을 높일 수 있었으며, 순화재배 시 우수한 유묘 생육을 보여 수확량을 증진시킬 수 있었다.