• Journal of Environmental Impact Assessment
• /
• v.32 no.1
• /
• pp.49-59
• /
• 2023

The rapid advance of technology has accelerated global warming. As 50.4 percent of South Korea's population is concentrated in the Seoul Metropolitan Area, which has become a considerable emitter of greenhouse gases, the city's average temperature is expected to increase more rapidly than in other areas in the country. A rise in the average temperature would affect everyday life and urban ecology; thus, appropriate measures to cope with the forthcoming disaster are in need. This study analyzed the changes in plant phenological phases from the past to the present based on temperatures (average temperature of Feb, Mar, April) observed in seven different weather stations nearthe Seoul Metropolitan Area (Ganghwa, Seoul, Suwon, Yangpyeong, Icheon, Incheon, and Paju) and the first flowering dates of Plum tree (Prunus mume), Korean forsythia (Forsythia koreana), Korean rosebay (Rhododendron mucronulatum), Cherry tree (Prunus serrulate), Peach tree (Prunus persica), and Pear tree (Pyrus serotina). Then, RCP (Representative Concentration Pathways) 2.6 and 8.5 scenarios were used to predict the future temperature in the Seoul Metropolitan Area and how it will affect plant phenological phases. Furthermore, the study examined the differences in the flowering dates depending on various strategies to mitigate greenhouse gases. The result showed that the rate of plant phenological change had been accelerated since the 1900s.If emission levels remain unchanged, plants will flower from 18 to 29 earlier than they do now in the Seoul Metropolitan Area, which would be faster than in other areas in the country. This is because the FFD (First Flowering Date), is highly related to temperature changes. The Seoul Metropolitan Area, which has been urbanized more rapidly than any other areas, is predicted to become a temperature warming, forcing the FFDs of the area to occur faster than in the rest of the country. Changes in phenology can lead to ecosystem disruption by causing mismatches in species interacting with each otherin an ecosystem. Therefore, it is necessary to establish strategies against temperature warming and FFD change due to urbanization.

• Korean Journal of Environmental Biology
• /
• v.40 no.2
• /
• pp.164-171
• /
• 2022

Frankliniella occidentalis is an invasive pest insect, which affects over 500 different species of host plants and transmits viruses (tomato spotted wilt virus; TSWV). Despite their efficiency in controling insect pests, pesticides are limited by residence, cost and environmental burden. Therefore, a fixed-precision level sampling plan was developed. The sampling method for F. occidentalis adults in pepper greenhouses consists of spatial distribution analysis, sampling stop line, and control decision making. For sampling, the plant was divided into the upper part(180 cm above ground), middle part (120-160 cm above ground), and lower part (70-110 cm above ground). Through ANCOVA, the P values of intercept and slope were estimated to be 0.94 and 0.87, respectively, which meant there were no significant differences between values of all the levels of the pepper plant. In spatial distribution analysis, the coefficients were derived from Taylor's power law (TPL) at pooling data of each level in the plant, based on the 3-flowers sampling unit. F. occidentalis adults showed aggregated distribution in greenhouse peppers. TPL coefficients were used to develop a fixed-precision sampling stop line. For control decision making, the pre-referred action thresholds were set at 3 and 18. With two action thresholds, N_max values were calculated at 97 and 1149, respectively. Using the Resampling Validation for Sampling Program (RVSP) and the results gained from the greenhouses, the simulated validation of our sampling method showed a reasonable level of precision.

• Journal of agriculture & life science
• /
• v.50 no.2
• /
• pp.73-82
• /
• 2016

Best drought tolerance index was determined through statistics analysis and growth appearance of drought tolerant plants was determined by cultivation in pot and sloping land. For determination of best drought tolerant indicators, RD(Resistant dry days), LD(Leaf area), UTR(Unit transpiration), RWC(Relative water content), RWL(Relative water loss), LA(Leaf area), SN(Stoma unmber) and SA(Stoma area) were carried out by correlation and PCA analysis. RWL and UTR were affected on plant drought tolerance according to comparison among six indices for resistant dry days. The PCs axes separated SA, LA, RD and RWC and SN. UTR was negatively correlated with SA, RWL were also negatively correlated with RWC and SN. RWL and UTR were proved best selection indicator for the selection of drought tolerant species. Ulmus parvifolia, Bidens bipinnata, Patrinia villosa, Kummerowia striata, Arundinella hirta, Artemisia gmelini etc. were selected drought tolerant plants. Shoot growth appearance of drought resistant plants was differed pot and sloping land. Shoot growth and leaf number was no significant differences between the pot and sloping land. However, root growth of drought tolerant plants was all the difference between two cultivation. T/R ratio of drought tolerant plants was also found a big difference. T/R ratio of drought tolerant plants in sloping land was lower than that of pot. These results will be served efficiently plant breeding.

• Korean Journal of Plant Resources
• /
• v.36 no.4
• /
• pp.369-380
• /
• 2023

Developing and breeding improved legume-based food resources require collecting useful genetic traits with heritability even though requiring some time-consuming, costly, and labor intensive. We attempted to infer heritability of nine genetic traits-days to flowering, days to maturity, period from flowering to maturity, the number of seeds per pod, 100-seeds weight, and four contents such as crude protein, crude oil, crude fiber, and dietary fiber-using 455 homologous chloroplast gene sets of six species of legumes. Correlation analysis between genetic trait differences and phylogenetic distance of homologous gene sets revealed that days to flowering, the number of seeds per pod, and crude oil content were influenced by genetic factors rather than environmental factors by 62.86%, 69.45%, 57.14% of correlated genes (P-value ≤ 0.05) and days to maturity showed intermediate genetic effects by 62.42% (P-value ≤ 0.1). The period from flowering to maturity and 100-seeds weight showed different results compared to those of some previous studies, which may be attributed to highly complicated internal (epistatic or additive gene effects) and external effects (cultural environment and human behaviors). Despite being slightly unexpected, our results and method can widely contribute to analyze heritability by including genetic information on mitochondria, nuclear genome, and single nucleotide polymorphisms.

• Journal of Wetlands Research
• /
• v.26 no.1
• /
• pp.62-71
• /
• 2024

To assess the ecological changes of Korean fir (Abies koreana E. H. Wilson) under climate change conditions, growth and physiological responses were analyzed over a 5-year period in a control group (outdoors) and in a treatment group where the temperature and CO2 levels were elevated to closely resemble RCP 4.5 conditions. The results showed an increasing trend in annual branch length of A.koreana in the climate change treatment group over time. While climate change conditions did not significantly impact the morphological differences of A.koreana leaves, they did influence the biomass of the leaves, suggesting that as climate change progresses, the productivity of A.koreana leaves may decline. On the other hand, the chlorophyll content in A.koreana under climate change conditions was higher in the climate change treatment group, whereas the photosynthesis rate, transpiration rate, water use efficiency and stomatal conductance was higher in the control group. This suggests that an environment with elevated temperature and CO2 could influence an increase in stomatal density, but having a negative impact on photosynthetic reactions. Further research on stomatal density under each environmental treatment will be required to confirm this hypothesis. Additionally, as this study only observed changes in leaf biomass, further empirical research should be considered to understand the changes in biomass of A.koreana under climate change conditions. In conclusion, the environmental adaptability of A.koreana is expected to weaken in the long term under elevated temperatures and CO2.

• Korean Journal of Ichthyology
• /
• v.36 no.2
• /
• pp.109-119
• /
• 2024

This study was conducted to investigate the early life history by observing the egg development of Ladislavia taczanowskii in endangered fish and to use it as basic data for species conservation research. The broodstork used in the study was secured from the area of the Hongcheon River in Hongcheon-gun, Gangwon State. The broodstork, who was being raised in the laboratory, selected mature individuals in May 2021 and induced them to spawn by hormone injection. The size of the maturation egg was 1.50~1.79 (average 1.59±0.08, n=30) mm due to the circular invasive egg. The incubation time took 168 hours at 16.5℃ and 109 hours and 30 minutes at 25.5℃. Newly hatched larvae, the consonants had a total length of 5.55~6.31 mm (6.30±6.93, n=30) mm, and the mouth and anus did not open and had egg yolk. 5 days after hatching, the preflexion larvae had a total length of 9.91~10.8 (10.1±0.27, n=30) mm, and the mouth and anus opened, and feeding activities began. 8 days after hatching, the flexion larvae had a total length of 10.3~11.4 (10.8±0.38, n=30) mm, and the end of the vertebrae at the tail fin tip began to bend upward. 10 day after hatching, the postflexion larvae had a total length of 11.8~13.1 (12.3±0.43, n=30) mm, and the end of the vertebrae at the tail tip was completely bent at 45°. 18 days after hatching, the total length of the juveniles was 18.9~23.4 (20.4±1.69, n=30) mm, and the number of fins in each part was fin rays with 10 dorsal fins, 9 anal fins, 22 caudal fins, and 7 ventral fins. As a result of the study, the postflexion larvae showed differences in morphology from other Gobioninae fishes in the upper part of the tail's hypural, the shape of spots on the dorsal vertebrae, the vertical stripes developed on the head, and the irregularly deposited melanophore throughout the body.

• The Korean Journal of Mycology
• /
• v.7 no.1
• /
• pp.13-73
• /
• 1979

These studies were conducted to investigate nutrient sources and supplementary materials of synthetic compost media for Agaricus bisporus culture. Investigation were carried out to establish the optimum composition for compost of Agaricus bisporus methods of out-door fermentation and peakheating with rice straw as the main substrate of the media. The incidence and flora of harmful organisms in rice straw compost and their control were also studied. 1. When rice straw was used as the main substrate in synthetic compost as a carbon source. yields were remarkably high. Fermentation was more rapid than that of barley straw or wheat straw, and the total nitrogen content was high in rice straw compost. 2. Since the morphological and physico-chemical nature of Japonica and Indica types of rice straw are greatly dissimilar. there were apparent differences in the process of compost fermentation. Fermentation of Indica type straw proceeded more rapidly with a shortening the compost period, reducing the water supply, and required adding of supplementary materials for producing stable physical conditions. 3. Use of barley straw compost resulted in a smaller crop compared with rice straw. but when a 50%, barley straw and 50% rice straw mixture was used, the yield was almost the same as that using only rice straw. 4. There were extremely high positive correlations between yield of Agaricus bisporus and the total nitrogen, organic nitrogen, amino acids, amides and amino sugar nitrogen content of compost. The mycerial growth and fruit body formation were severely inhibited by ammonium nitrogen. 5. When rice straw was used as the main substrate for compost media, urea was the most suitable source of nitrogen. Poor results were obtained with calcium cyanamide and ammonium sulfate. When urea was applied three separate times, nitrogen loss during composting was decreased and the total nitrogen content of compost was increased. 6. The supplementation of organic nutrient activated compost fermentation and increased yield of Agaricus bisporus. The best sources of organic nutrients were: perilla meal, sesame meal, wheat bran and poultry manure, etc. 7. Soybean meal, tobacco powder and glutamic acid fermentation by-products which were industrial wastes, could be substituted for perilla meal, sesame meal and wheat bran as organic nutrient sources for compost media. B. When gypsum and zeolite were added to rice straw. physical deterioration of compost due to excess moisture and caramelization was observed. The Indica type of straw was more remarkable in increase of yield of Agricus bisporus by addition of supplementing materials than Japonica straw. 9. For preparing rice straw compost, the best mixture was prepared by 10% poultry manure, 5% perilla meal, 1. 2 to 1. 5% urea and 1% gypsum. At spring cropping, it was good to add rice bran to accelerate heat generation of the compost heap. 10. There was significantly high positive correlation (r=0.97) between accumulated temperature and the decomposition degree of compost during outdoor composting. The yield was highest at accumulated temperatures between 900 and $1,000^{\circ}C$. 11. Prolonging the composting period brought about an increase in decomposition degree and total nitrogen content, but a decrease in ammonium nitrogen. In the spring the suitable period of composting was 20 to 25 days. and about 15 days in autumn. For those periods, the degree of decomposition was 19 to 24%. 12. Compactness of wet compost at filling caused an increase in the residual ammonium nitrogen. methane and organic acid during peak heating. There was negative correlation between methane content and yield (r=0.76)and the same was true between volatile organic acid and yield (r=0.73). 13. In compost with a moisture content range between 69 to 80% at filling. the higher the moisture content, the lower the yield (r=0.78). This result was attributed to a reduction in the porosity of compost at filling the beds. The optimum porosity for good fermentation was between 41 and 53%. 14. Peak heating of the compost was essential for the prevention of harmful microorganisms and insect pests. and for the removal of excess ammonia. It was necessary to continue fer mentatiion for four days after peak heating. 15. Ten species of fungi which are harmful or competitive to Agaricus bisporus were identified from the rice compost, including Diehliomyces microsporus, Trichoderma sp. and Stysanus stemoites. The frequency of occurrance was notably high with serious damage to Agaricus bisporus. 16. Diehliomyces microsporus could be controlled by temperature adjustment of the growing room and by fumigating the compost and the house with Basamid and Vapam. Trichoderma was prevented by the use of Bavistin and Benomyl. 17. Four species of nematodes and five species of mites occured in compost during out-door composting. These orgnanisms could be controlled through peakheating compost for 6 hours at $60^{\circ}C$.

• Journal of Forest and Environmental Science
• /
• v.16 no.1
• /
• pp.82-92
• /
• 2000

The pH, EC and anion of stemflow in Quercus mongolica and Q. variabilis were surveyed and analyzed in order to examine the relationship between watershed conservation function and flood control function of forest in quality and quantity in the Experiment Forests. College of Forest Sciences, Kangwon National University. The results were as follows: 1. pH values of rainfall ranged from 4.47 to 6.55(average: 5.39), and pH values of throughfall ranged from 4.07 to 6.25(average 5.45) for Q. mongolica and from 4.34 to 6.57(average : 5.62) for Q. variabilis, and thus pH values were not different between these two species. Also, pH values of stemflow from Q. mongolica ranged from 4.08 to 6.13(average 5.17) and those of stemflow from Q. variabilis ranged from 3.62 to 6.11(average : 4.68), and pH values of rainfall gave little influence on pH values of stemflow. But, pH values of stemflow in Q. mongolica and Q. variabilis appeard significantly lower in spring and than those in summer and autumn. 2. EC of rainfall was $3.0{\sim}62.6{\mu}s/cm$(average: $18.8{\mu}s/cm$), and EC of throughfall was $5.4{\sim}85.0{\mu}s/cm$(average : $25.1{\mu}s/cm$) for Q. mongolica and $5.0{\sim}253.0{\mu}s/cm$(average : $31.2{\mu}s/cm$) for Q. variabilis. Also, EC of stemflow from Q. mongolica ranged from 9.5 to $500.0{\mu}s/cm$(average : $81.8{\mu}s/cm$) and that of stemflow from Q. variabilis ranged from 11.5 to $534.5{\mu}s/cm$(average : $80.2{\mu}s/cm$). Seasonal EC of rainfall had little variation in the range of 20 to $30{\mu}s/cm$: EC of stemflow showed more than $100{\mu}s/cm$ from March to April and about $30{\mu}s/cm$ in summer period. Seasonal EC of stemflow varied so much and appeared high again from October to November. 3. $Cl^-$, $NO_3{^-}$ and $SO_4{^{2- }}$ concentrations of rainfall and throughfall were from 1 to 15ppm. and $PO_4{^{2- }}$ concentrations showed 0.57ppm and 0.23ppm in rainfall, 0.08ppm in Q. mongolica and 0.14ppm, 0.12ppm and 1.19ppm in Q. variabilis. Also, $Cl^-$, $NO_3{^-}$ and $SO_4{^{2-}}$ concentrations of stemflow were relatively higher than rainfall, and showed differences among seasons. $PO_4{^{2-}}$ concentration of rainfall and throughfall were not possible to observe, but $PO_4{^{2-}}$ concentrations of stemflow ranged from 0.08 to 31.99ppm(average : 3.22ppm) for Q. mongolica and that of stemflow ranged from 0.06 to 12.28ppm(average : 1.93ppm) for Q. variabilis.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
• /
• v.17 no.4
• /
• pp.292-302
• /
• 2012

This paper reviews comparison analysis of current and latest application for stock identification methods of Todarodes pacificus, and the pros and cons of each method and consideration of how to compensate for each other. Todarodes pacificus which migrates wide areas in western North Pacific is important fishery resource ecologically and commercially. Todarodes pacificus is also considered as 'biological indicator' of ocean environmental changes. And changes in its short and long term catch and distribution area occur along with environmental changes. For example, while the catch of pollack, a cold water fish, has dramatically decreased until today after the climate regime shift in 1987/1988, the catch of Todarodes pacificus has been dramatically increased. Regarding the decrease in pollack catch, overfishing and climate changes were considered as the main causes, but there has been no definite reason until today. One of the reasons why there is no definite answer is related with no proper analysis about ecological and environmental aspects based on stock identification. Subpopulation is a group sharing the same gene pool through sexual reproduction process within limited boundaries having similar ecological characteristics. Each individual with same stock might be affected by different environment in temporal and spatial during the process of spawning, recruitment and then reproduction. Thereby, accurate stock analysis about the species can play an efficient alternative to comply with effective resource management and rapid changes. Four main stock analysis were applied to Todarodes pacificus: Morphologic Method, Ecological Method, Tagging Method, Genetic Method. Ecological method is studies for analysis of differences in spawning grounds by analysing the individual ecological change, distribution, migration status, parasitic state of parasite, kinds of parasite and parasite infection rate etc. Currently the method has been studying lively can identify the group in the similar environment. However It is difficult to know to identify the same genetic group in each other. Tagging Method is direct method. It can analyse cohort's migration, distribution and location of spawning, but it is very difficult to recapture tagged squids and hard to tag juveniles. Genetic method, which is for useful fishery resource stock analysis has provided the basic information regarding resource management study. Genetic method for stock analysis is determined according to markers' sensitivity and need to select high multiform of genetic markers. For stock identification, isozyme multiform has been used for genetic markers. Recently there is increase in use of makers with high range variability among DNA sequencing like mitochondria, microsatellite. Even the current morphologic method, tagging method and ecological method played important rolls through finding Todarodes pacificus' life cycle, migration route and changes in spawning grounds, it is still difficult to analyze the stock of Todarodes pacificus as those are distributed in difference seas. Lately, by taking advantages of each stock analysis method, more complicated method is being applied. If based on such analysis and genetic method for improvement are played, there will be much advance in management system for the resource fluctuation of Todarodes pacificus.

• Korean Journal of Weed Science
• /
• v.3 no.1
• /
• pp.14-22
• /
• 1983

To study ecological characteristics of Cyperus serotinus occuring in Korea its propagules were collected from 6 locations from the northern part to the southern part of Korea (Chuncheon, Suweon, Iri, Jeonju, Gwangju, Milyang) in 1981, cultured and replanted 4 times (May 20, June 5, June 20, July 5) in 1982. They flowered from August 10 to August 29 in the plants planted on May 20 and from August 22 to September 4 in the plants planted on July 5. Plant height, number of tillers and top fresh weight were 85-100cm, 375-1,500 tillers/$m^2$ and 500-1,750g/$m^2$, respectively, when they were planted on May 20, and 58-67cm, 300-625 tillers/ $m^2$ and 125-250g/$m^2$, respectively, when they were planted on July S. Weight of seeds and number of rhizomes per plant were 20-50g/$m^2$ and 20.75-61, respectively, whey, they were planted on May 20, and 5-17.5g/$m^2$ and 51.5-80.25 when they were planted on July 5. Local collections showed. the same morphological characteristics at the level of species identification, but there existed variations among the local collections. Cyperus serotinus from Chuncheon and Suweon were longer in the length of inflorescence, than those from Gwangju and Milyang and rhizomes from Chuncheon and Suweon were thicker than the others. Each of local collections may be regarded as different ecotype based on the above mentioned differences in morphology, growth and flowering response to the planting date. The results appear to imply that Cyperus serotinus weeds occuring in various locations of Korea are different one another in competitive ability with rice crop.