• The Korean Journal of Ecology
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• v.24 no.5
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• pp.281-288
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• 2001

The relationships between the growths of Abies koreana W. and climatic factors were analyzed by the use of tree-ring analysis at the subalpine belt of Mt. Halla National Park. The four cores were extracted from each 21 trees at north-facing slope (1,900m a.s.1.). The site chronology was established on the periods from 1912 to 1999. The growth of A. koreana was very poor, in particular in the years of 1982, 1988 and 1996. Simple correlation was employed to analyze the relationship between the growth of A. koreana and climatic factors. The result of simple correlation indicates that the growth of A. koreana represent positive correlations both with the mean temperatures of April and previous November, and the precipitation of previous December and January. The presence of large number of frost-damaged scars in the individual trees of A. koreana implies that local freezing temperature conditions at Mt. Halla have occurred in 1964, 1965 and 1966. The correlations between the fir chronology SOI(Southern Oscillation Index) of previous January, February and November were significantly positive. The growth ratio of A. koreana demonstrates that this species is sensitive to seasonal variations. As the winter temperature rises, the growth ratio of A. koreana decreases, on the other hand, the increase of autumn temperature accelerates the growth ratio of A. koreana. The growth decline of A. koreana was observed from 51 cores out of the 54 cores, and the overall growth declines have initiated at 1978, 1982 and 1988. Distinct growth decline of A. koreana in the range of 70% is noticed at 34 cores out of the 51 cores. The decline of, A. koreana growth appears to be related to the winter temperature which has increased since mid-1970s.

• Journal of Korean Society of Forest Science
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• v.51 no.1
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• pp.22-35
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• 1981

This study was designed to know difference in degree of dehardening and rehardening respectively by artificial high and low temperature treatments among different clonal seedlings and seedlings from different seed sources of Cryptomeria japonica which have been grown under the cold areas in Japan and Korea. High temperature treatment was done with 15 to $20^{\circ}C$ under 100% relative humidity for one to nine days and low temperature treatment was carried with $-7^{\circ}C$ for one to three days. Occasionaly, high temperature treatment was combined and followed by low temperature treatment. The ability of stem section to delay dehardening by high temperature treatment and/or to hasten rehardening by low temperature treatment was used as an indicator of adaptability under extreme temperature fluctuation in nature. Clones and seedlings from different seed sources which showed greater freezing resistance than others after artificial high and/or low temperature treatments were selected over two to three time periods: early winter, mid winter and early spring in 1977 to 1980. These were Seoul #7, and #9, Namboo #3, and #4, Sung-Kang #11, Chung-Sam #8 and Huek-Suk #9. These selected seedlings might have survival advantage to withstand early and late frost damage, especially the critical frost damage of the basal stem, since it was known to be induced by lowering freezing resistance of the basal part when exposed to the high temperature near the ground during the day. Large variation in freezing resistance and degree of dehardening and rehardening was found among clonal or seed sources and among individuals within a seed source, but was not related to the difference in climatic conditions where the parent trees was selected. These indicated the possibility of future breeding work for more cold resistant family of Cryptomeria japonica.

• Journal of the Korea Organic Resources Recycling Association
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• v.13 no.2
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• pp.107-120
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• 2005

To study the development of solid waste compost to use sewage sludge and paper mill sludge for reclaiming damage soil in forest, the changes of temperature, moisture, chemical properties, heavy metals and harmful compound during the aerobic decomposition were investigated, and the compost decomposition of final products investigated the round paper chromatography method and G.I(Germination index) value. The results were summarized as follows. Temperature was changed a little during early 5days because of air temperature too low. That was rapidly increased to over $50^{\circ}C$ at 4days after first turning and then decreased gradually fallen to $40{\sim}50^{\circ}C$ at 15days after aerobic decomposition in A and C treatments. The second turning was conducted at 18 days after aerobic decomposition, and then the temperature was little changed. At the compare first with terminal product, The moisture content was decreased all treatments but the change was little in A and B treatments. pH was decreased to below 1 in all treatments. EC was increased to below 5dS/m. The content of total carbon, C/N ratio, $NH_4{^+}-N$ were decreased with 4~7%, below 8 and below 500mg/kg in all treatments, respectively. The content of total nitrogen, $NO_3{^-}-N$, CEC were increased with below 0.5%, below 173mg/kg and over $30cmol^+/kg$ in all treatments, respectively. The content of heavy metals and harmful compound were similar during aerobic decomposition and suited to standard of 가 grade in all treatments. The result of round paper chromatography method and G.I. value, The C treatment concluded well aerobic decomposition. Especially, the G.I. value in C treatment was 64.1 and 66.2 at cabbage and grass, respectively.

• Korean Journal of Environment and Ecology
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• v.33 no.1
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• pp.9-15
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• 2019

Artiodactyla, which is an even-toed mammal, widely inhabits worldwide. In recent years, wild Artiodactyla species have attracted public attention due to the rapid increase of crop damage and road-kill caused by wild Artiodactyla such as water deer and wild boar and the decrease of some species such as long-tailed goral and musk deer. In spite of such public attention, however, there have been few studies on Artiodactyla in Korea, and no studies have focused on the trend analysis of Artiodactyla, making it difficult to understand actual problems. Many recent studies on trend used text-mining and co-occurrence analysis to increase objectivity in the classification of research subjects by extracting keywords appearing in literature and quantifying relevance between words. In this study, we analyzed texts from research articles of three countries (Korea, China, and Japan) through text-mining and co-occurrence analysis and compared the research subjects in each country. We extracted 199 words from 665 articles related to Artiodactyla of three countries through text-mining. Three word-clusters were formed as a result of co-occurrence analysis on extracted words. We determined that cluster1 was related to "habitat condition and ecology", cluster2 was related to "disease" and cluster3 was related to "conservation genetics and molecular ecology". The results of comparing the rates of occurrence of each word clusters in each country showed that they were relatively even in China and Japan whereas Korea had a prevailing rate (69%) of cluster2 related to "disease". In the regression analysis on the number of words per year in each cluster, the number of words in both China and Japan increased evenly by year in each cluster while the rate of increase of cluster2 was five times more than the other clusters in Korea. The results indicate that Korean researches on Artiodactyla tended to focus on diseases more than those in China and Japan, and few researchers considered other subjects including habitat characteristics, behavior and molecular ecology. In order to control the damage caused by Artiodactyla and to establish a reasonable policy for the protection of endangered species, it is necessary to accumulate basic ecological data by conducting researches on wild Artiodactyla more.

• Korean Journal of Agricultural and Forest Meteorology
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• v.22 no.4
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• pp.239-249
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• 2020

Rice flour varieties have been developed to replace wheat, and consumption of rice flour has been encouraged. damage related to pre-harvest sprouting was occurring due to a weather disaster during the ripening period. Thus, it is necessary to develop pre-harvest sprouting rate prediction system to minimize damage for pre-harvest sprouting. Rice cultivation experiments from 20 17 to 20 19 were conducted with three rice flour varieties at six regions in Gangwon-do, Chungcheongbuk-do, and Gyeongsangbuk-do. Survey components were the heading date and pre-harvest sprouting at the harvest date. The weather data were collected daily mean temperature, relative humidity, and rainfall using Automated Synoptic Observing System (ASOS) with the same region name. Gradient Boosting Machine (GBM) which is a machine learning model, was used to predict the pre-harvest sprouting rate, and the training input variables were mean temperature, relative humidity, and total rainfall. Also, the experiment for the period from days after the heading date (DAH) to the subsequent period (DA2H) was conducted to establish the period related to pre-harvest sprouting. The data were divided into training-set and vali-set for calibration of period related to pre-harvest sprouting, and test-set for validation. The result for training-set and vali-set showed the highest score for a period of 22 DAH and 24 DA2H. The result for test-set tended to overpredict pre-harvest sprouting rate on a section smaller than 3.0 %. However, the result showed a high prediction performance (R2=0.76). Therefore, it is expected that the pre-harvest sprouting rate could be able to easily predict with weather components for a specific period using machine learning.

• Korean Journal of Agricultural and Forest Meteorology
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• v.24 no.3
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• pp.145-154
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• 2022

Due to abnormal weather conditions caused by climate change, natural disasters and damages are gradually increasing around the world. Global climate change as accompanied by warming is projected to exert adverse impact on production of potato, which is known as cool season crop. Even though, role of potato as a food security crop is expected to increase in the future, the climate change impacts on potato and adaption strategies are not sufficiently established. Therefore, this study was conducted to analyze the damage pattern of potatoes due to high temperature treatment and to evaluate the response of cultivars. T he high temperature treatment (35~38℃) induced heat stress by sealing the plastic house in midsummer (July), and the quantity and quality characteristics of potatoes were compared with the control group. T otal yield, marketable yield (>80 g) and the number of tubers per plants decreased when heat treatment was performed, and statistical significance was evident. In the heat treatment, 'Jayoung' cultivar suffered a high heat damage with an 84% reduction in yield of >80 g compared to the control group. However, in Jopung cultivar, the decrease was relatively small at 26%. Tuber physiological disturbances (Secondary growth, Tuber cracking, Malformation) tended to increase in the heat stress. Under heat conditions, the tubers were elongated overall, which means that the marketability of potatoes was lowered. T he tuber firmness and dry matter content tended to decrease significantly in the heat-treated group. T herefore, the yield and quality of tubers were damaged when growing potatoes in heat conditions. T he cultivar with high heat adaptability was 'Jopung'. T his result can be used as basic data for potato growers and breeding of heat-resistant cultivars.

• Journal of the Korean Institute of Landscape Architecture
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• v.52 no.2
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• pp.110-126
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• 2024

This study conducted a classification of small-scale biological habitats created in Seoul to analyze and synthesize location characteristics, habitat structure, biological habitat functions, and threat factors of representative sites, as well as derive creation and management problems according to the ecological characteristics. The aim was to suggest improvement measures and management items. Data collected through a field survey was used to categorize 39 locations, and 8 representative sites were selected by dividing them into location, water system, and size as classification criteria for typification. Due to the characteristics of each type, the site was created in an area where amphibian movement was disadvantageous due to low or disconnected connectivity with the hinterland forest, and the water supply was unstable in securing a constant flow and maintaining a constant water depth. The habitat structure has a small area, an artificial habitat structure that is unfavorable for amphibians, having the possibility of sediment inflow, and damage to the revetment area. The biological habitat function is a lack of wetland plants and the distribution of naturalized grasses, and threats include the establishment of hiking trails and decks in the surrounding area. Artificial disturbances occur adjacent to facilities. When creating habitats according to the characteristics of each type, it was necessary to review the possibility of an artificial water supply and introduce a water system with a continuous flow in order to connect the hinterland forest for amphibian movement and locate it in a place where water supply is possible. The habitat structure should be as large as possible, or several small-scale habitats should be connected to create a natural waterfront structure. In addition, additional wetland plants should be introduced to provide shelter for amphibians, and facilities such as walking paths should be installed in areas other than migration routes to prevent artificial disturbances. After construction, the management plan is to maintain various water depths for amphibians to inhabit and spawn, stabilize slopes due to sediment inflow, repair damage to revetments, and remove organic matter deposits to secure natural grasses and open water. Artificial management should be minimized. This study proposed improvement measures to improve the function of biological habitats through the analysis of problems with previously applied techniques, and based on this, in the future, small-scale biological habitat spaces suitable for the urban environment can be created for local governments that want to create small-scale biological habitat spaces, including Seoul City. It is significant in that it can provide management plans.

• Journal of Korean Society of Forest Science
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• v.39 no.1
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• pp.47-56
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• 1978

This study aimed to know difference in freezing resistance among different clonal seedlings or different seed source seedlings of Cryptomeria japonica which has been selected where extreme cold prevails in Korea and Japan. The freezing resistance of three 12-50 year old trees was also measured in the experiment. The freezing resistance was measured in different tissue parts: mainly leaf, cambiam and xylem, at three different collection dates in two different collection places during the winter of 1977-1978. The following results and discussions were made: 1. The clonal difference in freezing resistance of Cryptomeria japonica was $9^{\circ}$ to $15^{\circ}C$ in maximum according to the collection place. However, the clonal difference in freezing resistance was not related to the difference in climatic conditions where the parent tree have been growing. This impiled that the natural selection of cold resistant genes in Cryptomeria japonica has not reached its evolutional equilibrium yet since most of the Cryptomeria forest has been established by artificial regeneration. 2. The difference in freezing resistance among leaf, cambium and xylem was not apparent except that leaf of several clones showed higher freezing resistance than cambium or xylem when they collected at mid-winter. The least freezing resistant tissue part, thought its freezing resistance was not measure in all clones and all temperatures were appeared in the apical buds. The new shoot growth was observed in the next spring with being replaced by its dormant or adventitious bud growth when the apical bud was injured dy cold during winter. 3. The freezing resistance of leaf, cambium and xylem was shown high enough so that freezing resistance Cryptomeria clones in this experiment were supposed to be able to survive in cold winter conditions at the middle part of Korea. However, it was reported that the most susceptible tissue part to winter injury was the basal stem, but of which freezing resistance was not-measured in this experiment. Several silvicultural methods for prevention of Cryptomeria seedlings from cold damage were discussed in literature.

• Journal of Korean Society of Forest Science
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• v.58 no.1
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• pp.17-22
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• 1982

During the two-years(1979 to 1980) fertilization trial on 4-year-old chestnut tree plantations, total insolation was diminished in 1980 because of unseasonable weather. In every fertilization treatment plot, especially in the NPK-fertilized plot with magnesium, growth of trees and yield of chestnuts have been increased significantly. The results obtained are as follows: 1) The growth in the NPK-fertilized plot with boron and magnesium was 20 percent higher than in plots fertilized with NPK alone. 2) Although there was some frost damage to trees on November 14, 1979, the 1979 weather was otherwise normal and daily insolation averaged 7 hours from June through september, The 1979 fertilization indices for chesnut yield were 167 for NPK with boron and 207 for NPK with magnesium, as compared with the base index of 100 for NPK alone. 3) In 1980, the second year of the fertilization trial, unseasonable weather decreased the average daily insolation from June through September to 3.8 hours. Under such conditions, the fertilization indices for chestnut yield were 620 for NPK with boron and 741 for NPK with magnesium, and Boron, as compared to the base index of 100 for NPK alone; i.e. the yields of plots treated with NPK and magnesium were 21 percent higher than for plots with NPK and boron and 7 times the yields for plots with NPK alone, But in the trial plot of NPK, yield of chestnut in 1980 decreased compared with 1979, 4) All test plots had natural magnesium levels lower than 0.8me/100gr., and the treatments with NPK and magnesium would have been less apparent on soils with higher magnesium level. The spectacular effects of treatment with NPK and magnesium during periods of low insolation may result from increased chlorophyll production and corresponding increases in active carbon assimilation, which should play an important role in carbohydrate formation.

• Journal of Korean Society of Forest Science
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• v.90 no.6
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• pp.707-716
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• 2001

This study was conducted four ecological survey of field mice of Mt. Chuisuh in Yangsan City, Kyungnam from June, 2000 to March, 2001 for the understanding of field mice damage to forest. The results are obtained as follows. 1. The species of field mice collected were Apodemus agrarius, Apodemus peninsulae and Eothenomys regulus, and Crocidura suaveolens of insectvore. 2. The total collecting rate were 8.1% collected 61 individuals of field mice from 758 trap. 3. The rate among the 61 field mice collected were 45.9% in Apodemus agrarius, 29.5% in Eothenomys regulus, 19.7% in Apodemus peninsulae, and 4.9% in Crocidura suaveolens. 4. The constitution of weight of field mice was 16-51.9g in Apodemus agrarius, 12-25.9g in Apodemus peninsulae, 16-45.9g in Eothenomys regulus, and 12-15.9g in Crocidura suaveolens. 5. The sex ratio of field mice was 48.0% : 52.0% in Apodemus agrarius, 50.0% : 50.0% in Apodemus peninsulae, 55.6% : 44.4% in Eothenomys regulus, and 66.7% : 33.3% in Crocidura suaveolens. 6. The average body lengh was 104.33mm in Eothenomys regulus, 96.04mm in Apodemus agrarius, 94.50mm in Apodemus peninsulae, and 76.33mm in Crocidura suaveolens. 7. The average tail lengh was 92.75mm in Apodemus peninsulae, 80.65mm in Apodemus agrarius, 41.0mm in Crocidura suaveolens, and 40.33mm in Eothenomys regulus. 8. The breeding period of field mice in Mt. Chuisuh presumes from about the early of March to end of October. Specially, The Eothenomys regulus was ascertained the breeding period in December, discovered first time in korea through this experimental study. 9. The average litter size of field mice was 4.5 in Apodemus agrarius, 4.7 in Apodemus peninsulae, and 3.4 in Eothenomys regulus.