• Korean Journal of Ichthyology
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• v.32 no.2
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• pp.39-48
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• 2020

The slender shinner (Pseudopungtungia tenuicorpa), a tiny freshwater fish of about 8 to 10 cm belonging to Cyprinidae, is an endangered species found only in the Han and Imjin Rivers on the Korean Peninsula. During the breeding season, this species spawns in nests of Coreoperca herzi, a predator of this species, or small crevices on rocks. This unique reproductive ecology can make this species more vulnerable to anthropogenic perturbance that can further limit the places to spawn. Here, mtDNA and microsatellite loci were analyzed to identify the genetic diversity and structure of slender shinners and further to provide the basic data necessary for the conservation planning of this species. A total of 28 polymorphic microsatellite markers were developed using Illumina paired-end sequencing, and 67 slender shinners collected from three localities in the Han River were genotyped using these loci. This species showed a remarkably high level of genetic diversity with mean expected heterozygosity of 0.914 and mean allele number per locus of 27.9, and no signature of drastic demographic decline was detected. As a result of our microsatellite analysis, the genetic structure between the two stems of the Han River, North Han and South Han, was prominent. Such a genetic structure was also evident in the sequence analysis of 14 haplotypes obtained from mtDNA control region. Although slender shinners are only found in very limited areas around the world, the genetic structure indicates that there is a block of gene flow among the populations, which should be reviewed in the future if management and restoration of this species is needed.

• Journal of Korean Society of Forest Science
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• v.109 no.2
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• pp.145-156
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• 2020

In 2000 and 2018, phytosociological surveys were carried out in the forest vegetation of Mt. Yeompo, a representative isolated urban forest in Ulsan city. The trends of change in forest structure, composition, and spatial distribution were compared between years. Total percent coverage per 100 squaremeters of forest vegetation was similar, but natural vegetation showed a 9% increase. The importance of constituent species changed slightly. Specifically, Lindera erythrocarpa and Styrax japonicus showed very high growth rates of 835% and 269%, respectively. Species richness (S) and diversity (H') decreased by about 22% and 8%, respectively. Both S and H' showed slightly higher rates of decrease in artificial compared with natural vegetation. The constituent species life form spectrums were the same in 2000 and 2018 as 'MM-R5-D4-e'. The similarity (Jaccard coefficient) in the species composition of the forest vegetation was almost homogeneous at approximately 75%. The number of indicator species decreased from 16 species in 2000 to 7 species in 2018. This decrease was mostly due to a decline in herbaceous plants, such as Hemicryptophytes, Geophytes, and Therophytes, which are sensitive to disturbances. The spatial distribution of forest vegetation did not change significantly. The number of forest landscape elements (patches) increased by approximately 25% from 537 in 2000 to 721 in 2018, while the average size decreased by about 20% from 1.28 ha in 2000 to 1.03 ha in 2018.

• Journal of the Korean Institute of Landscape Architecture
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• v.45 no.5
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• pp.1-13
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• 2017

This study was intended to provide management directions through the provision of tree spatial information as basic data for the preservation of Gyerim(legal historical site), which is located in Gyeongju city, Gyeonsangnam-do, Korea. As a result of the survey of the entire forest, there are a total of 25 species and 510 individuals growing trees. Of these species, 14 species are native and 14 are introduced species. Apart from Sophora japonica, Zelkova serrata, Celtis sinensis, most of the introduced species were adopted without historical basis after designation as a historical site. By a ratio of 36% to introduced species(including 3% of naturalized species; Ailanthus altissima), the historical heritage was significantly damaged. Gyerim, which has over 2,000 years of history, has a total 15 individuals(2.9%) large trees(over 100cm DBH). Ten of these are Salix glandulosa, and in the past, most of this area was considered a Salix glandulosa forest. Currently, however, there are many small trees(under 20cm DBH) for the next generation of growth and the Salix glandulosa forest will continue to decline. Furthermore, most small trees were afforested, so the historicity and place features as a mythological forest will quickly fade.

• Korean Journal of Ecology and Environment
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• v.56 no.4
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• pp.375-383
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• 2023

To determine the cause of the population decline in Gobiobotia naktongensis, substrate preference and burying behaviour were investigated in this study. In general, the species was shown to prefer a substrate size of 1 mm or less, depending on the flow. In addition, the burying depth varied according to the size of the fish and increased with a decrease in water temperature. Our findings showed that the main cause of the population reduction was the physical changes in the substrate structure due to the dams or barrages construction. Notably, the accumulation of silt and mud in the substrate upon the formation of an upstream lentic water region for structural construction and bed armouring caused by scouring and reduced downstream inflow of fine sediment were deterministic in the fish habitat changes, causing problems in burying. As sand substrate structure is critical for the survival and inhabitation of psammophilous species, efficient strategies should be developed with proper habitat management to reduce the anthropogenic damage

• Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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• 2001.06a
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• pp.1158-1158
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• 2001

Fast and dynamic biochemical, enzymatic and morphological changes occur during the so-called generative development and during the vegetative processes in seeds. The most characteristic biochemical and compositional changes of this period are the formation and decline of storage components or their precursors, the change of their degree in polymerization and an extensive change in water content. The aim of the present study was to detect the maturation processes in seed nondestructively and to verify the applicability of near infrared spectroscopic methods in the measurement of physiological, chemical and biochemical changes in wheat seed. The amount and variation of different water “species” has been changed intensively during maturation. Characteristic changes of three water absorption bands (1920, 1420 and 1150 nm) during maturation were analysed. It was concluded that the free/bound transition of water molecules could be followed sensitively in different region of NIR spectra. Kinetic changes of carbohydrate reserves were characteristic during maturation. An intensive formation and decline of carbohydrate reserves were observed during early stage of maturation (0 -13 days, high energy demand). An accelerated formation of storage carbohydrates (starch) was detected in the second phase of maturation. Five characteristic absorption bands were analysed which were sensitive indicators the changes of carbohydrates occurred during maturation. Precursors of protein synthesis and the synthesis of reserve proteins and their kinetic changes during maturation were followed from NIR spectra qualitative and qualitatively. Dynamic formation of amino acids and the changes of N forms were detected by spectroscopic, chromatographic and by capillary electrophoresis methods. Calibration equations were developed and validated in order to measure the optimal maturation time protein and moisture content of developing wheat seeds. The spectroscopic methods are offering chance and measurement potential in order to detect fine details of physiological processes. The spectra have many hidden details, which can help to understand the biochemical background of processes.

• Ocean and Polar Research
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• v.36 no.1
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• pp.49-57
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• 2014

The seabird plays an important role as one of the indicator species for the status of and changes within marine ecosystems. Therefore, the conservation of seabirds and their habitats is important for maintaining the structure and function of marine ecosystems. Biological invasions affect most ecosystems on oceanic islands. In particular, Rattus spp. is the invasive species with the greatest impact on the seabird population. Introduced predators, like rats, severely affect seabirds and endanger them worldwide. The breeding population of Streaked Shearwaters Calonectris leucomelas in Sasu Island is one of biggest seabird colonies in Korea, and the Norway Rat Rattus norvegicus is known as an alien predator in this island. In this study we investigated rates of burrow occupancy and breeding success of Streaked Shearwaters for 7 years, and the impact of Norway Rats on the breeding success of Streaked Shearwaters breeding in Sasu Island for 4 years. Our results show that the percentage of breeding burrows decreased according to breeding stage during several years in the monitoring period, and that predation by the Norway Rat was the main cause in hatching failures. Consequently, although our results indicate that their breeding population is not likely to decline, Norway Rats have been affecting the breeding status of Streaked Shearwaters on Sasu Island during the last decade.

• Journal of the Korean Institute of Landscape Architecture
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• v.22 no.3
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• pp.79-90
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• 1994

This survey was ocnducted to investgate changes of the plant community structure from 1972 to 1993 in forest of Mt. Kwanak and thirty-five plots that the size of each plot was 10m${\times}$10m(100㎡) were set up and the vegetation analysis was caried out. By the TWINSPAN analysis, the plant community of survey area were divied into Quercus mongolica, Q. mongolica-Pinus densiflora(1), Q. mongolica-P. densiflora(2), Q. acutissima community. The successional trends of the woody species were seemed to be from P. densiflora, Sorbus alnifolia to Q. mongolica in the canopy layer. But the successional trends in the understory and shrub layer were difficult to suppose. The forest vegetation of Mt. Kwanak from 1972 to 1993 was severely decreased in species number and individuals. The sensitive species for the environmental pollution were selected, and the tolerant plants for the acid soil were increased. In comparision with the DBH class distribution from 1972 to 1993, it shows that the ecological succession has stopped. In the analysis of soil characteristics, soil acidification has taken place over last twenty-two years(from pH=5.40 to pH=4.53). The concentration of K+, Ca++ was severly decreased(from K+=0.60m.e./100g to K+=0.06m.e./100g, from Ca++=3.20m.e./100g to Ca++=0.63m.e./100g), which also could seemed to be cause of plant community decline.

• The Korean Journal of Ecology
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• v.25 no.1
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• pp.1-7
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• 2002

The ecological background of a restoration project is complex and difficult to betermine without experimentation. A useful context for experiments is the well-studied process of natural succession, because the factors that drive or inhibit succession are also at work during reclamation (a form of primary succession) and restoration (which often resembles secondary succession). Using experimental studies on urban wasteland reclamation, we have tested for factors that stimulate or inhibit succession during early phases of woodland development in the Northeastern United states. The emphasis has been on mutualisms (seed dispersal, pollination, and mycorrhizae) and microsite limitations in the recruitment, growth, and reproduction of woody plants. Using plantings of seeds, seedlings, and clusters of reproductively mature plants on abandoned landfills, we have observed that (1) soil microsite deficiencies lead to very poor germination (<0.1$\%$) and seedling survival (<0.01$\%$) of most native species; (2) seed dispersal by birds is a significant and reliable source of woody plant recruitment; however (3) proximity effects are strong, with most (up to 95$\%$) of seed rain falling in the vicinity of planted clusters that are closest to putative seed sources; and (4) remnant natural woodlands are critical components of the recruitment process. To emphasize the last point, in one case, we found that the destruction of approximately 50$\%$ of nearby natural woodland vegetation led to a commensurate decline in seed rain. In another case, we found that the species richness of recruits was strictly limited by the species composition of nearby source plant communities, with no evidence of community enrichment by long distance dispersal over 5 years. We conclude from these results that the size and proximity of remnant natural populations are critical considerations when planning reclamation and restoration programs that rely on natural successional processes.

• Korean Journal of Ichthyology
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• v.30 no.3
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• pp.155-160
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• 2018

The distribution aspect and extinction threat evaluation of the endangered species, Cottus hangiongensis were investigated from 2011 to 2017 in Korea for this study. The distribution reports of C. hangiongensis were divided into 1954~1985, 1981~2003, 2004~2012, and 2011~2017. The number of habited streams decreased gradually to 30, 24, 10, and 19 streams, respectively. In this study (2011~2017), C. hangiongensis was newly found in two streams (Ayajincheon and Chuksancheon), but 15 streams that appeared in the past are not in this study. The main habitat of C. hangiongensis was the downstream riffle of clean water with fast velocity and cobble-boulder bottoms. Given this evidence as noted for more than a 30% reduction in population after 2003, due to construction wear, river work and the qualitative decline of the habitat, C. hangiongensis is now considered to be Vulnerable (VU A2ac) based on the IUCN Red List categories and criteria.

• 한국해양학회지
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• v.29 no.4
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• pp.376-382
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• 1994

Seasonal distribution of zooplankton community in Inchon Dock, an artificially closed marine embayment has been studied. Samples were collected monthly during the period from December 1989 to December 1991 at four stations in the dock and compared with that at a single station in neighbouring waters of the Yellow Sea. Copepods dominated both in and outside of the dock all the year round, except in late autumn and early winter when protozoans outnumbered. dominant species were Oithona davisae, Acartia bifilosa, Paracalanus crassirostris, Noctiluca scintillas and Tintinnopsis tubulosa. A sharp decline in the abundance was observed in summer 1990 in the dock apparently due to oxygen deficiency (anoxic condition). Although no distinct deference in the abundance of zooplankton was observed between populations in and outside of the dock except in summer 1990, waters out of the dock showed to have a prosperity in species number throughout the year. Moreover, four species of copepods, Centropages abdominalis, Pseudodiaptomus marinus, Tortanus forcipatus and T. spinicaudatus occurred solely at the outside of the dock.