• Journal of Ecology and Environment
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• v.39 no.1
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• pp.11-16
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• 2016

Declines in amphibian populations are occurring worldwide, and have been attributed to many factors, including anthropogenic environmental changes. One of the ramifications of such declines is abnormalities in many amphibian species. A strong association has been detected between human activities and abnormalities in amphibian populations, but studies on this association are largely focused on lentic species. In this study, it was analyzed whether the degree of local human activity was associated with the rate of abnormalities in Bombina orientalis which inhabited lotic environments. We found that the proportions of abnormalities in wild populations of B. orientalis increased, when i) the closest human land use was located within 100 m from the frogs' habitat, and ii) the proportion of human land use within a 300-m radius was high. Our findings suggest that human activity has a negative impact on the fitness of nearby amphibian populations, and that wild populations very close to human-induced disturbance are affected.

• Korean Journal of Remote Sensing
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• v.21 no.5
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• pp.405-415
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• 2005

It is difficult to classify tidal flat surface that is composed of a mixture of mud, sand, water and microphytobenthos. We used a Linear Spectral Unmixing (LSU) method for effectively classifying the tidal flat surface characteristics within a pixel. This study aims at 1) detecting algal mat using LSU in the Saemangeum tidal flats, 2) determining a suitable end-member selection method in tidal flats, and 3) find out a habitual characteristics of algal mat. Two types of end-member were built; one is a reference end-member derived from field spectrometer measurements and the other image end-member. A field spectrometer was used to measure spectral reflectance, and a spectral library was accomplished by shape difference of spectra, r.m.s. difference of spectra, continuum removal and Mann-Whitney U-test. Reference end-members were extracted from the spectral library. Image end-members were obtained by applying Principle Component Analysis (PCA) to an image. The LSU method was effective to detect microphytobenthos, and successfully classified the intertidal zone into algal mat, sediment, and water body components. The reference end-member was slightly more effective than the image end-member for the classification. Fine grained upper tidal flat is generally considered as a rich habitat for algal mat. We also identified unusual microphytobenthos that inhabited coarse grained lower tidal flats.

• Korean Journal of Ichthyology
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• v.31 no.4
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• pp.222-234
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• 2019

Fish community characteristics and habitat aspects of endangered species, Pseudopungtungia tenuicorpa and Acheilognathus signifer were investigated in the Hwayangcheon Stream of Songnisan National Park, a tributary of the Hangang River, Korea from April to October 2018. During this period, there were 29 species of 8 families collected from 11 survey stations using kick nets, cast nets long bag set nets. The dominant and subdominant species were Zacco koreanus (38.81%) and Rhynchocypris oxycephalus (16.64%), respectively. The next most abundant species were Z. platypus (14.28%), Pungtungia herzi (6.92%), Hemibarbus longirostris (4.52%), Pseudogobio esocinus (3.51%), A. signifer (2.31%) and P. tenuicorpa (1.90%). Among the fish collected, 18 species (62.1%) were Korean endemic species. Endangered species were A. signifer, P. tenuicorpa and Gobiobotia brevibarba. From upstream to downstream, the dominance index has gradually decreased, but number of species and individuals, diversity and evenness has gradually increased. Also, river health (index of biological integrity) is assessed as good (St. 1~8) and very good (St. 9~11). Fish communities were divided into four sections by the similarity index based on species and their numbers, i.e., upper section (St. 1~2, 4~5), upper-middle section (St. 3, 6), middle section (St. 7~9) and lower section (St. 10~11). Endangered species, Pseudopungtungia tenuicorpa inhabited in mostly lower section (St. 10~11) with rock and boulder bottoms, and age groups in April estimated from total length indicated that the 44~61 mm group is 1 year old, the 66~81 mm group is 2 years old, the 88~99 mm group is 3 years old, and the 104~107 mm group is more than 4 years old. Also, endangered species, A. signifer inhabited in middle-lower section (St. 7~11) with boulder and cobble bottoms and slow velocity, which the place inhabited by water plants. Meanwhile, their age structure in April estimated from total length indicated that the 30~43 mm group is 1 year old, the 48~58 mm group is 2 years old, the 62~77 mm group is 3 years old, and the 84~100 mm group is more than 4 years old. The sex ratio of female (47) to male (42) was 1 : 0.89.

• Korean Journal of Ichthyology
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• v.25 no.4
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• pp.189-199
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• 2013

The distribution status and habitat characteristics of the endangered species, Lethenteron reissneri were investigated in 2011~2012 in Korea. During the study period, L. reissneri were collected 60 stations among 755 sampling stations investigated. The total numbers of ammocoetes and adults were 208 and 435, respectively from eight stations of the Han River drainage system, four stations of Geum River drainage system, 32 stations of Seomjin and Yeongsan River drainage systems, and 16 stations of Nakdong River drainage system. The Han and Geum river drainage systems, the Sapkyo Stream and independent streams running toward the East Sea were estimated to have suffered sudden reductions of population density, whereas the Seomjin River drainage system showed increased population density compared with historic occurrence records. L. reissneri inhabited the middle-upper stream of clean water with well-developed rapids and lots of aquatic organisms. According to IUCN Red List categories and criteria L. reissneri was assessed to be vulnerable (VU) [B2ab (ii,iii,iv,v);D1] because of the rapid reduction of the occupying areas and the small number of mature individuals. Besides the distribution status and habitat characteristics we discussed the conservation strategies of L. reissneri.

• Korean Journal of Environment and Ecology
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• v.35 no.2
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• pp.98-105
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• 2021

Understanding the migration patterns and habitats of juvenile birds during the post-fledging stage is very important for conservation and management of individuals. The Chinese Egret is an internationally protected species. During the wintering season, they inhabit South-East Asia, such as the Philippines, Malaysia, and Taiwan, and breed in China, Russia, and uninhabited islands on the west coast of Korea. IIn this study, we attached a GPS telemetry tracking device to six juvenile Chinese Egrets breeding on Chilsan Archipelago in 2018 and 2019 to identify habitats by analyzing the home range during the post-fledging stage in the summer season. The individual CE1801 moved north and then returned to the Yeonggwang Baeksu tidal flat area, and CE1802 and CE1803 migrated north and inhabited Taean-gun. In 2019, CE1901 showed a similar pattern to CE1801, and CE1902 migrated southward to the Wando-gun area, while CE1903 moved south to the Sinan-gun area then returned to the Yeonggwang Baeksu tidal flat area, showing KDE 50%. The study results confirmed that the Chinese Egret moved broadly around the flat tidal area on the west coast to find a stable habitat during the post-fledging stage. Efforts to protect the habitat, such as limiting the development of this area and restricting human access, are necessary.

• Korean Journal of Environmental Biology
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• v.19 no.4
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• pp.248-253
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• 2001

These studies were carried out to examine the developmental process of galls caused by aphids in Rhus gavanica and the effects of indole-3-acetic acid (IAA) and ${\alpha}$-naphthalene acetic acid (NAA) on the tannin accumulation in the callus induced from that galls. The results are follows. The development of fist-shaped galls has begun at the beginning of June earlier than the case of finger-shaped galls, and also, the growth of fist-shaped galls has last to September longer than the period of finger-shaped galls. These results indicate that the life cycle and feeding activity of the aphids inhabited in fist-shaped galls were longer and mire active than the case of the aphids inhabited in finger-shaped galls. Tannin contents of fist-shaped galls revealed about 60${\sim}70%$ of total dry weights during the whole growth periods, however, the contents in finger-shaped galls were under 10% at the maximum value. These facts mean that finger-shaped galls seem to be as a habitat of aphids rather than as a major source of tannin such as fist-shaped galls. The growth of callus induced from fist-shaped galls was the most effective in the plot of $10^{-5}$ mole IAA, but the tannin accumulation in callus growth was not even caused in any plots of IAA treatments as wells as in any NAA plots. These results considered that the tannin accumulation in fist-shaped galls may be caused only in specific relation between host plant and life cycle of aphids.

• Korean Journal of Environmental Biology
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• v.25 no.3
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• pp.215-222
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• 2007

DMZ (De-Militalized Zone) in South Korea is world heritage area by passage control of human-being for more than 50 years since 1953. Wild flora and fauna in these area have been protected from any development and/or habitat destruction. However, consideration on ecosystem and nature in the area is becoming higher, and demand for development is raising also. We have reviewed any publications, which are surveyed about ecosystem and interview local residents about wildlife inherit there. Totally 51 species have been reported inhabited DMZ belonging to 17 Families, 6 Orders, so far. National monuments in DMZ are following; Asiatic black bear (Ursus thibetanus), Eurasian otter (Lutra lutra), Musk deer (Moschus moschiferus), KOREAN goral (Nemorhaedus caudatus), flying squirrel (Pteromys volans) and spotted seal (Phoca vitalima). These results would be an essential data to establish management strategy and manuals for conserving native ecosystem, native flora and fauna in DMZ, and also using for registering world heritage area under UNESCO.

• Korean Journal of Ecology and Environment
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• v.42 no.1
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• pp.26-31
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• 2009

Ecological characteristics of Cobitis pacifica inhabited in the Yeongok Stream, Gangwon-do, Korea was investigated from May 2006 to August 2007. The major habitat was composed of sand bottom with current velocities of $0.23{\sim}0.56m\;sec^{-1}$ and depths of $20{\sim}50cm$. The sex ratio of female to male was 1 : 0.93. It was presumed that the spawning season was the period of water temperatures of $25{\sim}27^{\circ}C$. Sexually matured individuals appeared over the two years of age. Frequency analysis of body length indicated that the group with $40{\sim}59mm$ in body length was one-year-old, the group of $60{\sim}89mm$ was two-years-old, the group of $90{\sim}109mm$ was three-years-old, and the group of over 110 mm was four-years-old. The average number of eggs in the ovaries was estimated as 809 per matured female. Main prey items were Ephemeroptera and Diptera.

• Proceedings of the National Institute of Ecology of the Republic of Korea
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• v.2 no.4
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• pp.219-228
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• 2021

During our observations of changes in halophyte distribution in Hampyeong Bay over a period of five years, we found that the distribution area showed a maintenance for Phragmites communis community, a tendency of gradual increase for Zoysia sinica community, gradual decrease for Suaeda maritima community, and disappearance for Limonium tetragonum community during the studied period. The Phragmites communis community stably settled in areas adjacent to land and appeared not to be significantly affected by physical factors (such as tides and waves) or disturbances caused by biological factors (such as interspecific competition). Among studied species, germination time was shown to be the fastest for Suaeda maritima. In addition, this species showed certain characteristics that allowed it to settle primarily in new habitats formed by sand deposition as its growth was not halted under conditions with high amounts of sand and high organic matter content. However, in areas where Zoysia sinica and Suaeda maritima resided together, the area inhabited by Suaeda maritima gradually decreased due to interspecific competition between the two species. This was believed to be the result of a sharp decrease in the germination of Suaeda maritima since May, while the germination of Zoysia sinica was continuously maintained, indicating that the latter had an advantage in terms of seedling competition. In the case of the Limonium tetragonum community, its habitat was found to have been completely destroyed because it was covered by sand. The study area was confirmed to have undergone a large change in topography as tides and waves resulted in sand deposition onto these lands. Hampyeong Bay is considered to have experienced changes in halophyte distribution related to certain complex factors, such as changes in physical habitats and changes in biological factors such as interspecific competition.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.24 no.2
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• pp.85-102
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• 2021

Phytosociological characteristics on Quercus acutissima forests distribution in Daechong-dam basin survey has been carried out using Z.-M. School's methodology and numerical-classification analyses. A total of 43 phytosociological relevés were sampled. Syntaxa were described as Oplismenus undulatifolius-Quercus acutissima community(typicum subcommunity, Phryma leptostachya var. asiatica subcommunity, Ulmus davidiana var. japonica subcommunity), Quercus acutissima community and Quercus variabilis-Quercus acutissima community (typicum subcommunity, Castanea crenata subcommunity). The above three plant communities were classified with species composition reflecting local environmental characteristics of mountain topographies, inclination degrees, and rock exposure rates. Conclusively, those communities were recognized as secondary vegetation affected by high intensity and frequency of human impacts as they inhabited in southward hill lands and low lying grounds in mountains adjacent to human settlements and arable lands. Quercus acutissima community was classified as rural type syntax based on their inlandward distribution and species composition differences from urban forests. Afforest process and natural succession were discussed in relation with habitat environmental elements of Quercus acutissima forest in the survey area.