• Korean Journal of Weed Science
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• v.18 no.4
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• pp.356-363
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• 1998

In general weed vegetation analysis has been applied to the study of weed population shift. However, it is a limited tool for understanding a problem region and a specific weed species in a certain area. Recently GIS may be used as an important tool to solve this target or to conduct specific field analysis which enables to introduce a reasonable management strategy. Thus, the GIS study was carried out to understand an integrated weed population changes between 1981 and 1992 in Korea. The nationwide weed survey was performed through the whole rice paddy fields in 1981 and 1992. Weed occurrence was totally different over whole country based on these data. In 1981 a region with high weed occurrence was at western and central areas of Korea in terms of weed population density but this was changed into western and southern area in 1992. In both years there were high weed population density at Taean, Seosan county of Chungnam province in Korea. Thus, this particular area may be needed to introduce a special strategy to reduce weed population density and/or to control problem weed species.

• Journal of Korean Society of Forest Science
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• v.72 no.1
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• pp.27-31
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• 1986

To compare the fungal distribution of matsutake-producing (Tricholoma matsutake) stand with that of non-producing stand, mushrooms on forest floor were collected in September of 1984 from 28-year-old non-producing and 55-year-old matsutake-producing stands of Pinus densiflora in Kangwon Province. A total of 18 fungal species in 12 genera were collected from a non-producing stand, and all the species except one were putative ectomycorrhizal. Common genera in non-producing stand included Suillus, Russula, Lactarius, Hydnum, and Amanita. From a matsutake-producing stand a total of 30 fungal species in 22 genera were collected, of which 22 species were ectomycorrhizal. Common genera in the producing stand included Hydnum, Tricholoma, Laccaria, and Cantharellus. Common species in both stands were six species only. It is concluded that matsutake-producing stand had more diversified fungal population than non-producing stand, probably because of higher contents of organic matters in soil and better development of understory vegetation through the ageing of the stand.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.59 no.1
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• pp.38-46
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• 2014

The purpose of this study was to investigate the effects of sowing time on the bio-active content of major soybean cultivars in a southern region of South Korea. Experiments were carried out in Naju, Jeonnam Province (latitude $35^{\circ}$ 04'N, longitude $126^{\circ}$ 54'E) from 2008 to 2010. The cultivars grown in summer included Saeol-kong and Tawon-kong and those grown in autumn included Taekwang-kong, Pungsannamul-kong, and Cheongja3, respectively. Sowing dates were May 15 and 30, June 15 and 30, and July 15 of each year. Daidzein content was increased in all the test cultivars grown from later sowing, and the contents of genistein and total isoflavone were increased in all the test cultivars except for Cheongja3. On the other hand, glycitein content showed no significant change in any of the test cultivars across the 5 sowing dates except for Tawon-kong. Cyanidin-3-glucoside (C3G) content was significantly increased in Tawon-kong and Cheongja3, and delphinidin-3-glucoside (D3G) and total anthocyanin contents were significantly increased in Tawon-kong. However, pelargonidin-3-glucoside (Pg3G) and petunidin-3-glucoside (Pt3G) contents showed no significant difference in plants sown across the 5 dates. Lutein content in Cheongja3 was between 2.7 and $3.0{\mu}g/g$ based on sowing date and did not vary significantly, while chlorophyll content increased with later sowing and was significantly higher in the cultivars sown on June 30 and July 15. Crude fat content was higher in Taekwang-kong and Cheongja3 when the cultivars were sown earlier; crude fat did not vary in the other test cultivars based on sowing date. Palmitic acid composition was not affected by sowing date in most of the test cultivars. Stearic acid was increased in Saeol-kong, Tawon-kong, and Cheongja3 with later sowing. Oleic acid and linoleic acid were significantly higher in Saeol-kong at an earlier sowing date. The composition of linolenic acid showed significantly increased dates in most of the test cultivars with later sowing. There were no significant differences in carbohydrate and crude protein content across 5 different sowing dates in most of the test cultivars. However, crude protein content was higher in Saeol-kong when sowing occurred earlier, and was higher in Tawon-kong at later sowing dates.

• Korean Journal of Agricultural and Forest Meteorology
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• v.1 no.2
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• pp.127-134
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• 1999

This study was performed to obtain the basic data to present rational silvicultural tending plan. It makes these widely distributed pine-oak mixed stand and each of pure stand in middle province on object of this study and do comparative analysis of light condition about stand parameter and natural regeneration according to each slope(north, west and south) conditions of location in central part of South Korea. Sample plots for pine-oak mixed stand and pine and oak pure stand were established on each of southern, northern and western slopes based upon site and growth conditions of the slope. Sample plot was a circle of 0.05ha with a diameter of 25.24 m. A sample plot has between 30 and 40 tree in it. Total 23 sample plots were established; 9 pure pine stands, 8 pine-oak mixed stands. and 6 pure oak stands across lower, middle, upper parts of slopes. Relative light intensity within a stand was' measured by crown- photo(fish-eye lens; 180$^{\circ}$) system through fish-eye lens and by comparing each plot with the denuded through PAR-sensor. The crown closure ratio of pure pine stand (75%) shows much lower than that of mixed stand (90.9%) and pure oak stand (93%). The relative light intensity within a stand showed an opposite result. The crown closure of mixed stands tended to become gradually low as the slope moves from the north to the south, but the relative light Intensity within the stand tended to rise. By analyzing the relationship between the relative light intensity within a stand and stand parameter, light intensity within a stand tended to decrease as the diameter and N/ha increase. Number of oak seedlings and light intensity within a stand is in a straight-line regression relation. In particular, the number of oak seedlings was the highest in mixed stands on the southern slope. But no single pine seedling was found. The unfavorable conditions of l0cm thick litter layer and low relative light intensity in a stand (ranging between 4% and 8%) is considered to prevent pine seeds from germinating.

• Journal of Wetlands Research
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• v.25 no.4
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• pp.335-344
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• 2023

Brachydiplax chalybea flavovittata, a climate-sensitive biological indicator species, was first observed and recorded at Jeju Island in Korea in 2010. Overwintering was recently confirmed in the Yeongsan River area. This study was aimed to predict the potential distribution patterns for the larvae of B. chalybea flavovittata and to understand its ecological characteristics as well as changes of population under global climate change circumstances. Data was collected both from the Global Biodiversity Information Facility (GBIF) and by field surveys from May 2019 to May 2023. We used for the distribution model among downloaded 19 variables from the WorldClim database. MaxEnt model was adopted for the prediction of potential and future distribution for B. chalybea flavovittata. Larval distribution ranged within a region delimited by northern latitude from Jeju-si, Jeju Special Self-Governing Province (33.318096°) to Yeoju-si, Gyeonggi-do (37.366734°) and eastern longitude from Jindo-gun, Jeollanam-do (126.054925°) to Yangsan-si, Gyeongsangnam-do (129.016472°). M type (permanent rivers, streams and creeks) wetlands were the most common habitat based on the Ramsar's wetland classification system, followed by Tp type (permanent freshwater marshes and pools) (45.8%) and F type (estuarine waters) (4.2%). MaxEnt model presented that potential distribution with high inhabiting probability included Ulsan and Daegu Metropolitan City in addition to the currently discovered habitats. Applying to the future scenarios by Intergovernmental Panel on Climate Change (IPCC), it was predicted that the possible distribution area would expand in the 2050s and 2090s, covering the southern and western coastal regions, the southern Daegu metropolitan area and the eastern coastal regions in the near future. This study suggests that B. chalybea flavovittata can be used as an effective indicator species for climate changes with a monitoring of their distribution ranges. Our findings will also help to provide basic information on the conservation and management of co-existing native species.

• Journal of agricultural medicine and community health
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• v.16 no.1
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• pp.48-60
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• 1991

In a seroepidemiological study in several areas of Korea, the ELISA technique was performed to determine prevalence of some important helminthic diseases in our nation during March $15^{th}$ to June $30^{th}$. 1991. In this survey the serum antibody positive rates of anisakiasis, toxocariasis, clonorchiasis, paragonimiasis, cysticercosis, and sparganosis were measured. Among, 6,704 cases examined, 19.7% showed positive antibody titer at least one of the six items studied. Overall positive antibody rate was 8.1% in anisakiasis, 5.6% in toxocariasis, 3.6% in clonorchiasis, 1.7% in paragonimiasis, 4.5% in cysticercosis, and 2.6% in sparganosis respectively. In Pusan port southeastern part of Korea, antibody positive rate of anisakiasis was 2.9%, and clonorchiasis was 2.8% among 450 examine. In TaeJ$\check{o}$n city, central part of Korea. toxocariasis(6.7%) and anisakiasis(3.7%) showed high serologic positive rate. Of the 875 persons in Chunche$\check{o}$n gun(=province), northern central rural area of South Korea, anisakiasis was revealed as 3.4% seropositivity. In Tonghae port, eastern coast of South Korea. 9.9% of population examined showed positive antibody titer in anisakiasis. Of the 1,122 persons examined in Southern part of Cholla-Namdo(Southwestern coastal area of Korea), anisakiasis was 16.9%, cysticerocosis was 12.7% and the paragonimiasis was 3.3% respectively. In some localized area of Cholla-Pukdo, anisakiasis was 9.3% and cysticekosis was 4.3% among 702 cases examined. In some localized area of Kyungsang-Pukdo, anisakiasis was 10.6%. and toxocariasis was 16.1% among 900 cases examined. And finally, in Cheju-do, southern island of Korea, anisakiasis showed high positive rate(6.7%). Because cross reactions between related helminth group may disturb the analysis of these data, use of further developed techniques such as EITB(enzyme-linked immunoelectrotransfer blot) was considered as a essential tools for the study. We thought that probably most of the positive cases of cysticerosis were taeniasis cases. We can't rule out taeniasis even though EITB was employed as far as crude worm extract or cystic fluid of cysticercus was used as antigen. It was well Known that toxocariasis and anisakiasis also showed cross reactivity. However, the data presented here focus on seropositive rate of several helminthic diseases in Korea, not true prevalence rate of helminthiases, and to wait for more expensive purified antigen in sufficient amount for epidemiologic use is not necessary because increased immunologic sensitivity had little effect on epidemiologic sensitivity. We, here, suggest that ELISA should be applied as soon as possible to the evaluation of prevalence of tissue invading parasitic diseases, and a review of the antibody positive rate obtained in this study would be a basic data for controlling program of parasitic diseases in Korea.

• Economic and Environmental Geology
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• v.44 no.2
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• pp.135-152
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• 2011

Nitrate concentrations in springs at the southern slope of Jeju Island were predicted using multiple linear regression (MLR) of spatial variables including hydrogeological parameters and land use characteristics. Springs showed wide range of nitrate concentrations from <0.02 to 86 mg/L with a mean of 20 mg/L. Spatial variables were generated for the circular buffer when the optimal buffer radius was assigned as 400 m. Selected regression models were tested using the p values and Durbin-Watson statistics. Explanatory variables were selected using the adjusted $R^2$, Cp (total squared error) and AIC (Akaike's Information Criterion), and significance. In addition, mutual linear relations between variables were also considered. Small portion of springs, usually <10% of total samples, were identified as outliers indicating limitations of MLR using circular buffers. Adjusted $R^2$ of the proposed models was improved from 0.75 to 0.87 when outliers were eliminated. In particular, the areal proportion of natural area had the greatest influence on the nitrate concentrations in springs. Among anthropogenic land uses, the influence of nitrate contamination is diminishing in the following order of orchard, residential area, and dry farmland. It is apparent quality of springs in the study area is likely to be controlled by land uses instead of hydrogeological parameters. Most of all, it is worth highlighting that the contamination susceptibility of springs is highly sensitive to nearby land uses, in particular, orchard.

• Journal of Korean Society of Forest Science
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• v.105 no.1
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• pp.12-18
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• 2016

This study was carried out to investigate the change on soil $CO_2$ efflux rates, soil temperature, soil water content and soil pH by thinning intensity treatments (heavy thinning, light thinning, control) of a black pine (Pinus thunbergii Parl.) stand disturbed by pine wilt disease in Wola National Experimental Forests in Jinju, Gyeongnam province. Monthly variations of soil $CO_2$ efflux rates were not significantly different between the thinning and the control treatments (P>0.05). The annual mean soil $CO_2$ efflux rates were $0.58g\;CO_2m^{-2}h^{-1}$ for the light thinning, $0.49g\;CO_2m^{-2}h^{-1}$ for the heavy thinning and $0.45g\;CO_2m^{-2}h^{-1}$ for the control treatments, respectively. There was a significant exponential relation between soil $CO_2$ efflux rates and soil temperature, but no correlation between soil water content or soil pH and soil $CO_2$ efflux rates. The values of $Q_{10}$ were 3.40 for the light thinning, 3.20 for the heavy thinning and 3.06 for the control treatments, respectively. The results indicate that soil $CO_2$ efflux rates in a black pine stand disturbed by pine wilt disease could be affected by thinning treatments.

• Korean Journal of Breeding Science
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• v.40 no.3
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• pp.328-331
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• 2008

Hwangeumnodeul is a new japonica rice cultivar developed from a cross between Milyang165 and HR15151-B-21-3 at Honam Agricultural Research Institute (HARI), NICS, RDA, in 2007. This cultivar has short grains and about 139 days of growth duration from direct seeding to harvesting in the southern plain areas. Culm length of this cultivar is 78 cm and the number of spikelet per panicle is similar to that of the check cultivar, Nampyeongbyeo, while filled grain rate is lower than the check variety. This cultivar is moderately resistant to leaf blast, bacterial blight pathogens of $K_1$, $K_2$ and $K_3$ and stripe virus but susceptible to major virus diseases and insect pests. Milled kernel of Hwanggeumnodeul is translucent with non-glutinous endosperm. This cultivar has about 5.7% and 18.6% of protein and amylose contents, respectively. Palatability of cooked rice of Hwanggeumnodeul is similar to Nampyeongbyeo. Its milling recovery and head rice were 75.6% and 90.0%, respectively. Hwanggeumnodeul yielded 5.69 and 5.61 MT/ha in milled rice at the under wet-direct and dry-direct seeding conditions, respectively which are 17% and 12% higher than the check variety, Juanbyeo. It yielded 5.86 MT/ha, 8% higher than Nampyeongbyeo at the standard fertilizer level of the ordinary transplanting cultivation. "Hwanggeumnodeul" would be adaptable for ordinary transplanting as well as direct seeding in the southern plain including Chungcheong province.

• Korean Journal of Breeding Science
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• v.40 no.3
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• pp.324-327
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• 2008

'Onnuri' is a japonica rice cultivar developed from the cross between 'Milyang 165' and HR14732-B-67-2-3 at Honam Agricultural Research Institute (HARI), NICS, RDA, in 2005. This cultivar has a short grain shape and about 121 days growth duration from transplanting to harvesting in Korean climate condition. In reaction to biotic and abiotic stresses, it shows resistance to blast, bacterial blight pathogen from $K_1$ to $K_3$ and stripe virus, but susceptible to other major diseases and insect pests. The milled kernel of 'Onnuri' is translucent with non-glutinous endosperm. It has about 18.6% of amylose content and better palatability of cooked rice compared with 'Chucheongbyeo' cultivated in Kyunggi province. The milled rice yield of 'Onnuri' is about 5.94 MT/ha under the standard fertilizer level of the ordinary transplanting cultivation. 'Onnuri' would be adaptable to southern plain of Cheonan, middle-northern plain, and southern mid-mountainous of Korea.