제주도 방문 스쿠버다이빙 참여자들의 지각된 서비스품질과 지속의도 간의 관계에서 지각된 가치의 매개효과 검증

홍근혁,이기주,백혜경 한국스포츠학회 2020 한국스포츠학회지 Vol.18 No.2

본 연구의 목적은 제주도를 방문한 스쿠버다이빙 참여자들을 대상으로 서비스품질과 지속의도 간의 관계에서 지각된 가치의 매개효과를 검증하고자 하였다. 연구 대상자들은 2019년 7월~9월까지 스쿠버다이빙 참여를 위해 제주도 를 방문한 다이버 245명이었으며, 이들은 서비스품질, 지속의도, 지각된 가치 검사지를 완료하였다. 수집된 자료는 AMOS 18.0과 SPSS 18.0, PROCESS Macro프로그램을 이용해 분석하였으며 주요 결과는 다음과 같다. 첫째, 서비스 품질의 하위요인(장비, 직원, 시설, 교통편의) 중 장비요인은 지속의도에 직접적인 영향을 미치지는 못했지만 이들의 관계는 지각된 가치의 하위요인(획득적, 감정적, 사회적, 금전적) 중 금전적 가치에 의해 유의한 정(+)의 완전매개효과가 있었다. 둘째, 직원요인은 지속의도에 유의한 정(+)의 영향을 미쳤으며, 이들의 관계는 감정적 가치와 금전적 가치에 의해 부분 매개되었다. 셋째, 시설요인은 지속의도에 직접적인 영향을 미치지 못하였고, 이들의 관계에서 지각된 가치의 간접효과는 없는 것으로 나타났다. 넷째, 교통편의 요인은 지속의도에 직접적인 영향을 미치지 못하였고, 이들의 관계에 서 지각된 가치의 간접효과는 없는 것으로 나타났다. The purpose of this study was to verify the mediated effect of perceived values in the relationship between service quality and sustainability of scuba diving participants who visited Jeju Island. The subjects of the study were 245 divers who visited Jeju Island to participate in scuba diving from July to September 2019, and they completed the questionnaire of service quality, sustainability and perceived value. The collected data were analyzed using the AMOS 18.0, SPSS 18.0 and PROCESS Macro programs, and the main results are as follows. First, there was a positive relationship of complete mediated effect due to monetary value among the sub-factors of perceived value (acquisition, emotional, social and monetary) even though the equipment factors among sub-factors of service quality (equipment, staff, facilities, and transportation) did not directly affect the sustainability, Second, employee factors had a positive effect on sustainability, and their relationships were partially mediated by emotional and monetary values. Third, the facility factors did not directly affect the sustainability, and there was no indirect effect of perceived values in their relationships. Fourth, traffic factors did not directly affect the sustainability, and there was no indirect effect of perceived values in their relationships.

출현 양상 기반 소형호 내 동물플랑크톤 군집의 계절 변동과 다양성 관계

홍근혁,오혜지,최예림,김준완,최범명,장광현,장민호 한국하천호수학회 2023 생태와 환경 Vol.56 No.2

Small ponds, which exhibit unstable succession pattern of plankton community, are less well studied than large lakes. Recently, the importance of small ponds for local biodiversity conservation has highlighted the necessity of understanding the dynamics of biological community. In the present study, we collected zooplankton from three small reservoirs with monthly basis and analyzed their seasonal dynamics. To understand the complicated zooplankton community dynamics of small reservoirs, we categorized zooplankton species into four groups (LALF Group, Low Abundance Low Frequency; LAHF Group, Low Abundance High Frequency; HALF Group, High Abundance Low Frequency; HAHF Group, High Abundance High Frequency) based on their occurrence pattern (abundance and frequency). We compared the seasonal pattern of each group, and estimated community diversity based on temporal beta diversity contribution of each group. The result revealed that there is a relationship between groups with the same abundance but different occurrence frequencies, and copepod nauplii are common important component for both abundance and frequency. On the other hand, species included with LALF Group throughout the study period are key in terms of monthly succession and diversity. LALF group includes Anuraeopsis fissa, Hexarthra mira and Lecane luna. However, groups containing species that only occur at certain times of the year and dominate the waterbody, HALF Group, hinder to temporal diversity. The results of this study suggest that the species-specific occurrence pattern is one key trait of species determining its contribution to total annual biodiversity of given community.

담수산 지각류 Simocephalus serrulatus (Koch, 1841) 생체량 산정 방법 연구

오혜지,홍근혁,최예림,장광현 한국하천호수학회 2023 생태와 환경 Vol.56 No.2

The medium-large cladoceran species Simocephalus spp. predominantly occur in habitats with developed aquatic vegetation. Accordingly, due to Simocephalus' high contribution to zooplankton community biomass in the lake's littoral zone and wetland habitats, estimating their biomass is important to understand the matter cycling based on biological interactions within the aquatic food web. In this study, we reviewed the length–weight regression equations used previously to estimate Simocephalus biomass, directly measured S. serrulatus’ body specification (length, width and area) and their biomass (dry weight) using instruments such as a microscopic digital camera and a microscale, and performed regression analysis between each other. When S. serrulatus biomass was estimated using the equation (Kawabata and Urabe, 1996) presented in 『Biomonitoring Survey and Assessment Manual』, Korea, errors between estimates and measures were relatively large compared to the S. serrulatus species-specific biomass estimate equation developed by Lemke and Benke (2003). In addition, both equations showed not only increasing trends in error (estimate−measure) with increasing S. serrulatus' body length, but also in error variance among similar-sized individuals. The results of regression analysis with dry weight by body specifications indicated that the most appropriate equation for estimating the biomass of S. serrulatus was derived from the width-dry weight exponential regression equation (R2 = 0.9555). The review and development study of such species-specific biomass estimation equations for zooplankton can be used as a tool to understand their role and function in aquatic ecosystem food webs.

종 다양성 평가를 위한 호소 생태계 동물플랑크톤 조사 방법 연구: 희박화 분석(rarefaction analysis)을 이용한 적정 시료 농축 정도 및 부차 시료 추출량의 검증

오혜지,최예림,김현준,홍근혁,박영석,김용재,장광현 한국하천호수학회 2022 생태와 환경 Vol.55 No.4

Through sample-size-based rarefaction analyses, we tried to suggest the appropriate degree of sample concentration and sub-sample extraction, as a way to estimate more accurate zooplankton species diversity when assessing biodiversity. When we collected zooplankton from three reservoirs with different environmental characteristics, the estimated species richness (S) and Shannon’s Hʹ values showed different changing patterns according to the amount of sub-sample extracted from the whole sample by reservoir. However, consequently, their zooplankton diversity indices were estimated the highest values when analyzed by extracting the largest amount of sub-sample. As a result of rarefaction analysis about sample coverage, in the case of deep eutrophic reservoir (Juam) with high zooplankton species and individual numbers, it was analyzed that 99.8% of the whole samples were represented by only 1 mL of sub-sample based on 100 mL of concentrated samples. On the other hand, in Soyang reservoir, which showed very small species and individual numbers, a relatively low representation at 97% when 10 mL of sub-sample was extracted from the same amount of concentrated sample. As such, the representation of sub-sample for the whole zooplankton sample varies depending on the individual density in the sample collected from the field. If the degree of concentration of samples and the amount of subsample extraction are adjusted according to the collected individual density, it is believed that errors that occur when comparing the number of species and diversity indices among different water bodies can be minimized.

호소생태계 건강성 평가를 위한 동물플랑크톤 MMI의 국내 적용 연구

최예림,오혜지,김현준,홍근혁,이대희,곽인실,지창우,박영석,김용재,장광현 한국하천호수학회 2023 생태와 환경 Vol.56 No.1

Recently, Korean government has introduced Multi Metric Indices (MMI) using various bio- community information for aquatic ecosystem monitoring and ecosystem health assessment at the national level. MMI is a key tool in national ecosystem health assessment programs. The MMI consists of indices that respond to different target environmental factors, including environmental disturbance (e.g. nutrients, hydrological and hydraulic situation of site etc.). We used zooplankton community information collected from Korean lakes to estimate the availability of candidate zooplankton MMI indices that can be used to assess lake ecosystem health. First, we modified the candidate indices proposed by the U.S. EPA to suit Korean conditions. The modified indices were subjected to individual index suitability analysis, correlation analysis with environmental variables, and redundancy analysis among indices, and 19 indices were finally selected. Taxonomic diversity was suggested to be an important indicator for all three taxonomic groups (cladoceran, copepod, rotifer), on the other hand, the indices using biomass for large cladocerans and copepods, while the indices using abundance were suggested for small cladocerans and rotifers.

안정동위원소 분석을 활용한 멸종위기종 여울마자와 동서종 돌마자의 영양단계 및 생태적 지위 평가

이대희,오혜지,최예림,홍근혁,백인혁,김근식,장광현,윤주덕 한국하천호수학회 2024 생태와 환경 Vol.57 No.1

In ecosystems within limited resources, interspecific competition is inevitable, often leading to the competitive exclusion of inferior species. This study aims to provide foundational information for the conservation and restoration management of Microphysogobio rapidus by evaluating species’ ecological response to biological factors within its habitat. To understand this relationship, we collected food web organisms from site where M. rapidus coexist with Microphysogobio yaluensis, a specie ecologically similar to M. rapidus, and evaluated the trophic levels (TL), isotopic niche space (INS), and the overlap of INS among fishes within the habitat using stable isotope analysis. Our analysis revealed that the M. rapidus exhibited a higher TL than M. yaluensis, with TL of 2.6 and 2.4, respectively. M. yaluensis exhibited a broad INS, significantly influencing the feeding characteristics of most fish. Conversely, M. rapidus showed a narrow INS and asymmetric feeding relationships with other species, in habitats with high competition levels. This feeding characteristics of M. rapidus indicate that the increase in competitors sharing the similar resources lead to a decrease in available resources and, consequently, is expected to result in a decrease in their density. In ecosystems within limited resources, interspecific competition is inevitable, often leading to the competitive exclusion of inferior species. This study aims to provide foundational information for the conservation and restoration management of Microphysogobio rapidus by evaluating species’ ecological response to biological factors within its habitat. To understand this relationship, we collected food web organisms from site where M. rapidus coexist with Microphysogobio yaluensis, a specie ecologically similar to M. rapidus, and evaluated the trophic levels (TL), isotopic niche space (INS), and the overlap of INS among fishes within the habitat using stable isotope analysis. Our analysis revealed that the M. rapidus exhibited a higher TL than M.yaluensis, with TL of 2.6 and 2.4, respectively. M. yaluensis exhibited a broad INS, significantly influencing the feeding characteristics of most fish. Conversely, M. rapidus showed a narrow INS and asymmetric feeding relationships with other species, in habitats with high competition levels. This feeding characteristics of M. rapidus indicate that the increase in competitors sharing the similar resources lead to a decrease in available resources and, consequently, is expected to result in a decrease in their density.