• Korean Journal of Environmental Biology
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• v.39 no.1
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• pp.108-118
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• 2021

The purpose of this study was to provide baseline ecological data for the conservation of the Manchurian trout habitat through the investigation of the growth status of Brachymystax lenok tsinlingensis, and Pearson's correlation analysis (PCA) between the B. lenok tsinlingensis population and the use of the land around Gyebangcheon stream. Sampling was conducted twice in July, September, and October 2018. During the July and September surveys, 882 individuals belonging to 13 species from six families were collected. The dominant species was Rhynchocypris kumgangensis and the subdominant species was Zacco koreanus. The total number of B. lenok tsinlingensis collected was 99. The results of the length-weight relationship in the B. lenok tsinlingensis population were analyzed with a regression coefficient b value of 3.1272 and a condition factor (k) value of 0.0006. Therefore, the growth condition of B. lenok tsinlingensis was regarded as fairly good. The QHEI(Qualitative habitat evaluation index) value in the B. lenok tsinlingensis habitat was 119.5(±0.5)-153.5(±0.5), indicating optimal-suboptimal conditions. As a result of the HIS (Habitat suitability index) analysis, it was confirmed that the optimal habitat for B. lenok tsinlingensis was 0.45-0.55m and >1 m in water depth, 0.55-0.65 m s^-1 in water velocity, and boulder in the substrate. The ratio of the land use in this study site was analyzed as 66.26-96.31% for forest and grassland areas, 0.00-23.79% for agricultural areas, 0.00-4.19% for urbanized areas, and 3.69-8.87% for others. Correlation analysis of the number of B. lenok tsinlingensis and various factors revealed statistically significant correlations between QHEI and forest and grassland areas, agricultural areas, and urbanized areas.

• The Korean Journal of Quaternary Research
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• v.14 no.1
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• pp.7-31
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• 2000

Quaternary Geological and geophysical investigation was performed at the Eurimji reservoir of Jaechon City in order to interprete depositional environment and genesis of lake sediments. For this purpose, echo sounding, bottom sampling and columnar sampling by drilling on board and GPR survey were employed for a proper field investigation. Laboratory tests cover grain size population analysis, pollen analysis and $^{14}C$ datings for the lake sediments. The some parts of lake bottom sediments anthropogenically tubated and filled several times to date, indicating several mounds on the bottom surface which is difficult to explain by bottom current. Majority of natural sediments were accumulated both as rolling and suspended loads during seasonal flooding regime, when flash flow and current flow are relatively strong not only at bridge area of the western part of Eurimji, connected to stream valley, but at the several conduit or sewage system surrounding the lake. Most of uniform suspend sediments are accumulated at the lake center and lower bank area. Some parts of bottom sediments indicate the existence of turbid flow and mudflow probably due to piezometric overflowing from the lake bottom, the existence of which are proved by CM patterns of the lake bottom sediments. The columnar samples of the lake sediments in ER-1 and ER-3-1 boreholes indicate good condition without any human tubation. The grain size character of borehole samples shows poorly sorted population, predominantly composed of fine sand and muds, varying skewness and kurtosis, which indicate multi-processed lake deposits, very similar to lake bottom sediments. Borehole columnar section, echo sounding and GPR survey profilings, as well as processed data, indicate that organic mud layers of Eurimji lake deposits are deeper and thicker towards lower bank area, especially west of profile line-9. In addition the columnar sediments indicate plant coverage of the Eurimji area were divided into two pollen zones. Arboreal pollen ( AP) is predominant in the lower pollen zone, whreas non-aboreal pollen(NAP) is rich in the upper pollen zone. Both of the pollen zones are related to the vegetation coverage frequently found in coniferous and deciduous broad-leaved trees(mixed forest) surrounded by mountains and hilly areas and prevailing by aquatic or aquatic margin under the wet temperate climate. The $^{14}C$ age of the dark gray organic muds, ER1-12 sample, is 950$\pm$40 years B.P. As the sediments are anthropogenetically undisturbed, it is assumed that the reliability of age is high. Three $^{14}C$ ages of the dark gray organic muds, including ER3-1-8, ER3-1-10, ER3-1-11 samples, are 600$\pm$30 years B.P., 650$\pm$30 years B.P., 800$\pm$40 years B.P. in the descending order of stratigraphic columnar section. Based on the interpretation of depositional environments and formation ages, it is proved that Eurimji reservoir were constructed at least 950$\pm$40 years B.P., the calibrated ages of which ranges from 827 years, B.P. to 866 years B.P. Ancient people utilize the natural environment of the stream valley to meet the need of water irrigation for agriculture in the local valley center and old alluvium fan area.

• Korean Journal of Environment and Ecology
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• v.34 no.5
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• pp.454-465
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• 2020

This study measured the present number of encounters and established the evaluation criterion for the allowable number of encounters in the Seoseokdae summit area (SSA) of Mudeungsan National Park to examine managerial conditions of the number of visitors to the Seoseokdae trail section (STS). Data were obtained from a questionnaire survey of 263 visitors to STS selected through convenient sampling during June 2019. The average number of encounters in SSA was 18.7. Most of the respondents (95.4%) encountered fewer than 30 other visitors. The average maximum number of simultaneous users (AMNSU, measured at 15-minute intervals) in SSA was 13.4 persons (range: 3~31 persons). The AMNSU by the hour was the highest with 21.0 persons at 13-14, followed by 19.8 persons at 11-12, 15.5 persons at 14-15, 15.3 persons at 12-13, 12.3 persons at 10-11, and 10.8 persons at 8-9. Acceptable encounter number (AEN) developed by long-question format (LQF) was 59.2 persons, and that by short-question format (SQF) was 55.1 persons. AEN of the respondents who preferred "near-nature experience" at 27.5 persons was fewer than those who preferred "resort/tourism area like experience" at 46.6 persons. The present number of encounters and AMNUS (range: 3~31 persons) in SSA were fewer than AENs derived from LQF (59.2 persons) and SQF (55.1 persons). Eighty-three percent of the respondents preferred "near-nature experience," while only 10.5% of the respondents preferred "resort/tourism area like experience." 78.4% of the respondents did not perceive that SSA was crowded. The absolute majority of the respondents (92.3%) answered higher personal AEN than the perceived encounter numbers (PEN). The gaps between the personal AEN and the PEN were negatively correlated with perceived crowding.

• Korean Journal of Environmental Biology
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• v.36 no.2
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• pp.180-189
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• 2018

Agricultural landscapes in Korea comprise a large cultivation area of rice paddies, other crops, and forests which surround the cropland and the farmers' residential village. The forests in this agricultural landscape play important roles as ecological corridors and refuges for plants and animals in this agroecosystem. The present study investigated the spatial and temporal diversity patterns among these components of the agroecosystem to provide baseline data that describes how fauna change in the studies system. Insect sampling was conducted at four sites in two regions, Chungcheong (Ockcheon and Geumsan) and Jeonnam (Younggwang and Haenam), from March to August of 2014, using an UV light trap for moths and five pitfall traps for beetles. Beetles comprised 225 species and 2,457 individuals in 35 families, while moths consisted of 141 species and 403 individuals in 17 families. Beetles showed higher diversity in Chungcheong than Jeonnam, while moths showed no difference in diversity between regions. Forests showed the highest number of species and individuals, followed by orchards and rice paddies. The food preference of beetles showed that forests contained a higher proportion of herbivores, while orchards and rice paddies had a higher proportion of carnivores. Temporal changes in moths in the two regions were synchronous, while those of beetles were nonsynchronous. Moths increased from spring to summer across all habitats, especially in rice paddies during summer. Beetles also increased from spring to summer in orchards and rice paddies, although the beetles in the forests increased in the middle of summer. A detailed and long-term study is needed to reveal the causes of different diversity patterns of taxa among the different habitats within the agroecosystems.

• Korean Journal of Ecology and Environment
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• v.38 no.1 s.110
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• pp.45-53
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• 2005

The environmental change of Yong-nup in Mt. Dae-Am, which is located at the northern part of Kangwon-Do, Korea, was assesed with peat sedimentary carbon and nitrogen isotope analysis. The surface layer of the peat (0 ${\sim}$ 5 cm) was 190 year BP, and the middle layers (30 ${\sim}$ 35 cm and 50 ${\sim}$ 55 cm) were 870 year BP and 1900 year BP, respectively. Bulk sedimentation rate was estimated to be about 0.4 mm $year^{-1}$ for 0 cm to 30 cm and 0.15 mm $year^{-1}$ for 35 cm to 50 cm. The $^{14}C$ age of the bottom sediment (75 ${\sim}$ 80 cm) collected and measured in this study was about 1900 year BP, although it was measured that the $^{14}C$ of the lowest bottom sediment in Yong-nup was 4105 ${\pm}$ 175 year BP (GX-23200). Since the $^{14}C$ ages for 50 ${\sim}$ 55 cm and 75 ${\sim}$ 80 cm layers were almost the same as 1890 ${\pm}$ 80 fear BP (NUTA 5364) and 1850 ${\pm}$ 90 year BP (NUTA 5462), respectively, we have estimated that the deep layers (55 ${\sim}$ 80 cm) in the high moor were the original forest soil. The low organic C and N contents in the deeper layers supported the inference. The sediment of 50 ${\sim}$ 55 cm layer contains much sandy material and showed very low organic content, suggesting the erosion (flooding) from the surrounding area. In this context, the Yong-nup, high moor, of Mt. Dae-Am, might have developed to the sampling site at about 1900 year BP. The ${\delta}^{13}C$ values of organic carbon and the ${\delta}^{15}N$ values of total nitrogen in the peat sediments fluctuated with the depths. The profile of ${\delta}^{13}C$ may indicate that the Yong-nup of Mt. Dae-Am have experienced the dry-wet and cool-warm period cycles during the development of the high moor. The ${\delta}^{15}N$ may indicate that the nitrogen cycling in the Yong-nup have changed from the closed (regeneration depending) system to the open (rain $NO_3\;^-$ and $N_2$ fixation depending) system during the development of the high moor.

• Korean Journal of Environment and Ecology
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• v.38 no.2
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• pp.169-177
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• 2024

This study investigated whether population dynamic analysis based on the height characteristics of Abies nephrolepis was feasible. It was necessary because existing population dynamic analyses based on age and diameter at breast height (DBH) made it difficult to reflect the slow growth characteristics of Abies nephrolepis in harsh environments of high altitudes. The limitations of population dynamics analysis based on the age and DBH distribution of Abies nephrolepis in Seoraksan, Odaesan, and Taebaeksan National Parks, where Abies nephrolepis populations are representative, were verified, and the characteristics of height growth were investigated to comprehensively analyze whether a vertical structure based on height could reveal the population dynamics. The result of this study showed some limitations in understanding the population dynamics of Abies nephrolepis based on age distribution due to practical difficulties in sampling all trees and variations in age distribution within the same community depending on factors such as light conditions. Moreover, it was challenging to differentiate the distribution of DBH classes at fine levels, making it difficult to reflect the rapid growth characteristics of Abies nephrolepis when light conditions become suitable after prolonged stays in smaller DBH classes under shade conditions. However, a comprehensive analysis of the height characteristics of Abies nephrolepis revealed that the density corresponding to the population dynamic characteristics of Abies was high and adequately reflected the predominant tree death at similar height stages, as well as the U-shaped population dynamics at the lower stratum. Moreover, it was possible to identify a transition point in height values under shaded conditions, where the annual growth of Abies nephrolepis individuals in the lower stratum increases significantly, indicating that Abies nephrolepis individuals can escape from competition with other shrubs and undergo vigorous growth only at this height level. Therefore, this study confirmed that a vertical structure based on height can be utilized to understand the population dynamics of Abies nephrolepis in high altitudes, and it is expected that future studies on height characteristics can intuitively reveal the maintenance status of Abies nephrolepis populations in the field.

• Journal of Korean Society of Forest Science
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• v.42 no.1
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• pp.1-38
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• 1979

The woody species of Genus Ilex which are endemic to Korea are distributed on limited area due to solely temperature factor. There is some differences according to species, however in general, the evergreen Ilex are found along southern coastal area of Korean Peninsula and near islands where the cold index does not exceed $-5^{\circ}C$. But Ilex macropoda and the variety, only deciduous ones, are grown in temperate zone of the peninsula and some islands. The list of Ilex species of Korea are as follows. Ilex cornuta Lindley et Pax., I. crenata Thunb. var. microphylla Max., I. crenata Thunb., I. rotunda Thunb., I. macropoda Miq., I. macropoda Miq. var. pseudo-macropoda Loensner, I. integra Thunb. The author surveyed the populations of Ilex species as many as possible and data of some characters such as leaf shape, spine, fruit shape, stomata density, sex ratio in natural communities, etc. are collected. Almost all the Ilex species in Korea show sporadic distribution. This means quite small sized populations isolate distantly each other eliminating the change of gene exchange in between. Particularly Ilex conuta and I. crenata show the morphological differentiation among populations as well as significant individual variation within a population. These were true with such characteristics, leaf shape, leaf dimension, leaf margin, fruit shape, spine, and stomata density. The founded are that the fruit length and the stomata density counted on the beneath surface of leaves of Ilex cornuta increased with the decrease of latitude. These are naturally closely related with the cold index values. The table shown below indicates the correlation between mean stomata density per $0.3642mm^2$ and cold index values. These relation however were not observed on Ilex crenata. The most dominated natured in relation to individual variation were outline of leaf, the number of marginal spine, the shape of leaf cross section and the degree of luster of the upper leaf surface. As shown in photos 5~7, these variations are agreed at a glance. There are reports that the development of marginal spines in some Ilex species is associated with the juvenility and topophysis. In present study, these two factors were neglected because of the intended sampling procedure. Of Ilex rotunda, population difference with the characteristics of leaf length is recognized but not for leaf width, petiole length, and fruit size. However, individual variations within a population were significantly large. In case of Ilex integra, only individual differences within population were calculated statistically for such characteristics as leaf length, leaf width, and petiole length. As to natural population, the sex ratio was 1:2 (female to male) for Ilex cornuta, and 1:1 for Ilex crenata. The tendency of more male than female in I. cornuta was agreed to other observations. Preparing the tip cutting of length 10cm, and treating with IBA, then attaching earth ball to the cut end, very successful rooting percentages were obtained. Asexual propagation has the advantages of maintaining the heterozygosity of existing varieties and overcoming the difficulties of delayed seed germination frequently encountered with Ilex species. Considering a great deal of variation in morphological traits, a good possibility of selection breeding for decorative and ornamental purposes exists. At present, these evergreen Ilex are ignored by local people as nuisance weedy shrubs. So the proper protection measures should promptly be taken.

• Korean Journal of Ecology and Environment
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• v.36 no.1 s.102
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• pp.21-28
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• 2003

Community composition and functional feeding groups of aquatic insects according to stream order were investigated from the Gapyeong Creek, a typical mid-sized Korean stream in Gyeonggi -do, Korea, in April 2000. For field investigations, the main watercourse and three major tributaries of the stream that belong to stream order ll to Vll were divided into reaches (ca. $1{\sim}4$ km in distance). Aquatic insects were sampled from one or two sites each reach (total 30 sites) using a Surber sampler ($50{\times}50$cm, mesh 0.75 mm). As a result of the quantitative samplings(two Surber samplings at riffle and pool/run per site; total $2{\times}30$=60 Surber samplings) and additional qualitative samplings, a total of 164 species of aquatic insects in 103 genera, 54 families, and 8 orders were collected from the stream. Those aquatic insects were composed of Trichoptera (56spp.: 34.1%), Ephemeroptera (43 spp.: 26.2%), Diptera (25spp.: 15.2%), Plecoptera (23 spp.: 14.0%), Coleoptera (6 spp.: 3.7%), Odonata (6 spp.:3.7%), Hemiptera (3 spp.: 1.8%), and Megaloptera (2 spp.: 1.2%); EPT-group (122 spp.:74.4%) or EPT-group plus Diptera (147 spp.: 89.6%) occupied most of the aquatic insect community; relatively larger number of species occurred in the mid-stream reaches (order III-Vl). The quantitative samplings throughout the study sites yielded a total of 26,286 individuals of aquatic insects ($136{\sim}2522$ inds./0.5 $m^2$, mean 906.4inds./0.5 $m^2$) that belongs to Ephemeroptera (11,994 inds.: 45.6%), Diptera (8730 inds.:33.2%), Trichoptera (4123 inds.: 15.7%), Plecoptera (1213 inds.: 4.6%), Coleoptera (204 inds.: 0.8%), Odonata (13 inds.: 0.05%), Megaloptera (5 inds.: 0.02%), and Hemiptera (4inds.: inds.: 0.02%); average number of individuals of aquatic insects increased as the stream order increased: average numbers of individuals of Bllecoptera and Trichoptera decreased and increased, respectively, as the stream order increased. Tolerant species such as Chironomidae spp., Uracanthella rufa and Hydropsychidae spp. were particularly abundant in the down stream reaches (order Vll) . Species diversity indices (H`) and dominance indices (Dl) were relatively higher and lower, respectively, in the mid-stream reaches (order $IV{\sim}VI$). Shredders occupied the smallest partand collector-gatherers were most abundant among the functional feeding groups(FFGs); collector-filterers considerably increased in the down stream reaches (orders Vl and VII); scrappers were relatively evenly distributed throughout the stream reaches: predators were relatively more abundant in the uppermost stream reaches(order ll) . Overall, the characteristics of aquatic insect comminity and FFGs in the Gapyeong Creek are largely similar to those in the normal streams of temperate deciduous forest in the northern hemisphere that is explained by the river confineum concept.

• Journal of Korean Society of Forest Science
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• v.16 no.1
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• pp.1-32
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• 1972

By means of the interspecific hybridization in the Sub-genus Diploxylon of the Genus Pinus, $F_1$ hybrids of Pinus rigida${\times}$elliottii, Pinus rigida${\times}$radiata, P. rigida${\times}$serotina and P. densiflora${\times}$thunbergii had been produced. And on the basis of the crossabilities of these hybrids the taxonomic affinities of these pines were examined. And the needle characteristics of these hybrid and the occurence of phenolic substances in these $F_1$ hybrid were also investigated to see the potential usefulness of these characteristics for the diagnosis of the taxonomic affinity. And, the growth performances of the $F_1$ hybrids have also been compared with those of parental species. In order to contribute to the establishment of the hybrid seed orchard the introgression phenomena between P. densiflora and P. thunbergii in the eastern coastal area have also been investigated along with the investigation of the heterozygosity of plus trees of P. densiflora growing in the clone bank in Suwon. And the results were summarized as follows. 1. On the basis of crossabilities as well as on the taxonomic affinities according to the systems of Shaw, Pilger and Duffield, it has been proven that the parental species of those hybrids are of close affinities and range of the fertile hybrid seed production rate was as high as 28-58% in the best hybrid combination (Table 13). 2. Among those hybrids, the ${\times}$ Pinus, rigiserotina hybrid seemed to be most promising in the growth performance exhibiting 109-155% more volume growth compared to the seed parent with the statistic significance of 1% level (Tables 16 and 17). 3. Notwithstanding the fact that the all of the pollen parents are cold tender, all hybrids exhibit cold hardiness as much as their seed parent and it seems to suggest that the characteristics of cold hardiness were transmitted from the seed parent. 4. Though a striking difference in needle length was observed between the parental species of each hybrid, it was difficult to distinguish each hybrid from their seed parent by the needle length except ${\times}$P. rigiserotina which is characterized by long needle which is 65% more longer than the needle of the seed parent (Table 21). 5. With regard to the anatomical characteristics of needle, the hypoderm is apparently thicker in most of the $F_1$ hybrid pines and the characteristics of resin canals are dominated by medial in most $F_1$ hybrid. And, the fibrovascular bundles were apart as were in their seed parent. Therefore it was found to be possible to distinguish the hybrids pines from their parents by the needle characteristics. And, it is to be noticed that the ${\times}$P. densithunbergii was more close to the pollen parent having RDI value of 0.73 (Fig.l, Table 22). 6. It has been demonstrated that ${\times}$P. rigielliottii, ${\times}$P. rigiradiata and ${\times}$P. rigitaeda have a phenolic substance (No.7) of light yellow at Rf-0.46, same as their seed parent, but no trace of phenolic substance was observed in their pollen parent. This fact will serve as an important criteria for early identification of hybridity in progeny testing. However, the fact that both of ${\times}$P. rigiserotina and ${\times}$P. densithunbergii exhibit the same reactions of phenolic substances as well their parental species seems to indicate the close affinities between the parental species of the respective hybrid (Fig.2, Table 23). 7. The separation and the reaction of phenolic substance developed on TLC were found to be same in the same species showing no variations between the individuals, and no variations due to tree part of sampling, tree age or pollen sources. And the reaction was also observed regardless of the not varied by the kind of developing solvent whether it is Aceton-Chloroform (3:7 v/v) or Benzene-Methanol-Acetic acid (90:16:8 v/v). 8. The introgression phenomena of natural Pinus densifiora stand in both east and west coastal area indicates that the major part of the red pines investigated are all heterozygous and the heterozygosity of pines are higher in the west coast than in the east coast(Tables 24 and 25). 9. Based on the RDI, among the plus trees of Pinus densiflora selected in Korea and Japan as well, no pure P. densiflora has been found. Since all of the sample trees of Pinus densiflora were found to be as heterozygous bearing part of the characteristics of P. thunbergii, those red pines were considered to be natural heterotic hybrid pines(Figs. 3 and 4. Tables 26 and 27).