• Journal of the Korean Institute of Landscape Architecture
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• v.48 no.5
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• pp.1-15
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• 2020

This study was designed to come up with a way of managing a cultural landscape forest by conducting research on the vegetation structure and growth characteristics. This study's target site, which was 45,201㎡ in size, was Pinus densiflora forest for Sugumagi placed at the entrance of Unmun Temple, Sinwon-ri, Unmun-myeon, and Cheongdo-gun in the southernmost part of Gyeongsangbuk-do, Korea. Sugumagi means the water of the valley flows far away, and where no downstream is visible according to feng shui. The historical sources of the Sugumagi Pinus densiflora forest at the entrance of Unmun Temple isn't clear. It waw only found at that location. The Pinus densiflora forest at the entrance of Unmun Temple is located in the waterway in terms of Feng Shui. The present condition of growth was investigated through a grid surveys of 98 trees and Pinus densiflora growth. As a result of the analysis of growth status, Pinus densiflora, Larix leptolepis, Zelkova serrata, Celtis sinensis, and Rhus javanica were distributed in the conopy layer, and 28 species including Ailanthus altissima were grown in the understroy layer, and 92 species, including Ampelopsis brevipedunculata, in the shrub layer. The plant community structure was divided into low, medium and high-density Pinus densiflora forests in the study area, based on the number in the conopy layer and the grade of and the trees analyzed. As a result of the analysis, the Pinus densiflora dominated the low, medium and high-density Pinus densiflora forests, and there were no competitive species. The relative dominance of the low-density Pinus densiflora forests was 46.9% on average, medium-density was 62.6% and 50.2% was found in high-density. The mean species diversity of Shannon in the low-density study was 0.7055, medium-density study was 0.8966 and the average species diversity of Shannon in the high-density study was 0.8317. The analysis of the age and growth of 25 sample trees in the Sugumagi Pinus densiflora forest shows that the distribution of the chest diameter (DBH) of the sample Pinus densiflora is 38 to 77cm with the average chest diameter being 61.1cm. The age was 84-161 years and the average was 114 years. In the Pinus densiflora forest, most(670,659, or 98.3%) of the tree trunk wound was collected for rosins during the Japanese colonia Era, Of the total 670, 659 were Pinus densiflora, 98.3% of the total. 394 were surgically repaired in 2005. For the preservation of the Sugumagi Pinus densiflora forest, dead trees should be replaced with substitute trees appropriate to the middle and south topography. It is demanded that foreign species such as Larix leptolepis in the research area should be removed and Pinus densiflora that underwent surgical operations should be regularly sterilized. It is also emphasized that the management of insecticide is important.

• Journal of Wetlands Research
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• v.22 no.2
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• pp.81-91
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• 2020

As part of method for ecologically utilizing abandoned paddy, potential of the abandoned paddy as a target site for ex-situ conservation of 9 endangered species of different life form was confirmed by considering the nature of rice paddy. In order to create Dum-bung, a component of traditional Korean rice paddy, a part of the abandoned paddy was modified to change the water environment. The seeds, asexual reproductive and sexually reproductive individuals of each endangerd species were transplanted into the abandoned paddy to observe the survival rate and phenological response for 1 year, and then monitored for 2 years. As a result, Hydrophyte 4 taxa (Euryale ferox, Saururus chinensis, Dysophylla yatabeana, Menyanthes trifoliata), Geophyte taxa 1 (Epilobium hirsutum), and Hemicryptophyte taxa 1 (Cicuta virosa) could be introduced into the abandoned paddy. In particular, Euryale ferox, Dysophylla yatabeana, and Menyanthes trifoliata should be introduced into Dum-bung, and Saururus chinensis, Epilobium hirsutum, and Cicuta virosa should be introduced into paddy wetland. Growth of Euryale ferox and Brasenia schreberi was inhibited by herbaceous species, and the growth of Epilobium hirsutum was inhibited by herbivores. Therefore, in order to help efficient settlement of endangered plants introduced in abandoned paddy, it is necessary to remove herbs that inhibit growth and to manage herbivores. In addition, it is necessary to prevent the collapse of paddy bank by planting on the paddy field trees or herbaceous forming vegetation mat. When using abandoned paddy ecologically, it is effective to diversify the moisture environment by creating a Dum-bung to increase biodiversity.

• Journal of Bio-Environment Control
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• v.15 no.2
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• pp.167-172
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• 2006

The objective of this study was to determine the effects of substrate water content and electrical conductivity (EC) on the incidence of brown fruit stem and blossom end rot in glasshouse sweet pepper (Capsicum annuum cv. Special). Three levels of water content and EC had been treated since the first fruit reached 3cm in diameter: that is, 49 (low), 65 (medium), and 86% (high) for water content, and 2.4 (low), 4.2 (medium) and $6.3dS{\cdot}m^{-1}$(high) for EC. Shoot growth was reduced with decreasing water content, and it was lower in both high and low EC treatments than medium EC treatment. Fruit weight at harvest was greater in both medium and hish water content treatments than low water content treatment (158g vs 146g). High EC reduced fruit weight compared to or low EC treatments. The incidence of brown fruit stem increased with increasing water content and with decreasing EC. The highest incidence was shown in the high water content/low EC treatment (38%), which was considerably higher than 2.4% of the low water content/high EC treatment. Blossom end rot occurred in general in the low water content and/or high EC conditions. These results indicated that substrate water content and EC should be controlled differently according to the growth stage, to reduce the incidence of blossom end rot and brown fruit stem in glasshouse sweet pepper. First, to reduce blossom end rot incidence, water content should be maintained high (86%) and EC low ($2.4dS{\cdot}m^{-1}$) until Sweets after fruit set. Secondly, to reduce brown fruit stem incidence, water content should be maintained low (49%) and EC high ($6.3dS{\cdot}m^{-1}$), especially after completion of fruit growth.

• Horticultural Science & Technology
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• v.31 no.5
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• pp.552-557
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• 2013

This study was carried out to investigate the different DIF (day/night temperature differential) treatments on early growth of sweet pepper plants (Capsicum annuum L.) after planting. The DIF treatments were thus as follows. DIF levels are DIF-6 ($20-26^{\circ}C$) and DIF 0 ($23^{\circ}C$), DIF 3 ($24.5-21.5^{\circ}C$) and DIF 6 ($26-20^{\circ}C$). The DIF 3 and DIF 6 treatments significantly increased plant height of the sweet pepper plants during ten weeks after planting compared to DIF-6 and DIF 0. Leaf area per plant of DIF 3 treatment constantly increased and the level was greatest leaf area at ten weeks after planting. Fresh weight per plant treated with DIF-6 was lower and was reduced 74-77% range compared to other treatments. DIF 0 and DIF 3 treatments significantly affected dry weight and percentage of dry matter compared to DIF-6 and DIF 6. Especially DIF 6 treatment significantly decreased from eight weeks after planting. Percentage of dry matter of the leaf treated with DIF 0 and DIF 3 consistently increased from six weeks after planting, however, DIF-6 and DIF 6 treatments dramatically decreased from eight weeks after planting. High levels of DIF management cause growth retardant on early growth of sweet pepper plants, especially when night temperature is higher than day temperature, plants are indicated to be greater growth retardant.

• Korean Journal of Plant Resources
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• v.34 no.4
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• pp.346-361
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• 2021

The range of D. spathulata identified in this survey was between N 35° 24' 58" ~ N 35° 26' 35", E 129° 05' 43" ~ E 129° 07' 04". It is located at an altitude of 98~592 m. The soil pH was strongly acidic in the range of 4.2~4.9, with a canopy openness of 18.56% and a chlorophyll index of 36.74 ± 2.80. As a result of the TWINSPAN analysis, 20 plots of 100 m² each were divided in 4 communities: Pinus densiflora community, Quercus monglica-Diabelia spathulata community, Quercus serrata-Diabelia spathulata community and Carpinus tschonoskii subassociation. The result of species diversity was 0.7615, and evenness and dominance were found to be 0.6077 and 0.3923, respectively. The height of D. spathulata is up to 3.4 m, and the average height is 1.1 m, with most of the species distributed as shrubbery and herbaceous. The average population density of the 20 plots was 1.635 individuals/m², the height range of flowering was 1.0 ~ 1.8 (aver. 1.39 m) and the rate of flowering was 27.37%. It's propagation pattern was mainly formed by extending the rhizome to the side, creating a colony of ground stems.

• Journal of agriculture & life science
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• v.53 no.4
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• pp.19-28
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• 2019

This study was conducted to investigate the effect of nutrient solution strength and duration of nutrient starvation on the growth and development of strawberry (Fragaria x ananassa Duch.) 'Maehyang' and 'Sulhyang' at the flowering stage. Cuttings of runner plants were stuck on November 23th, 2017 and were covered with a layer of black plastic film to block light from penetrating and keep the relative humidity high. The black plastic film was removed after 16 days and rooted plants were cultivated for one month with irrigation of water. The Yamazaki nutrient solution with an electrical conductivity (EC) of 1.85 or 3.71 dS·m-1 (1x or 2x ionic strength, respectively) and pH 5.55 was fed to plants after either 0 (control), 1, 3 or 5 weeks of nutrient starvation to the end of experiment. Plant height in both cultivars decreased gradually with the increase in duration of nutritional starvation. The earlier the nutritional starvation started, the smaller the shoot fresh weight of 'Maehyang'. Hence the greatest shoot fresh weight was obtained in the control which was supplied with the nutrient solution continuously. Shoot fresh weight of 'Sulhyang' was the greatest in 1x ionic strength and one week of nutrient starvation before planting. Although number of flowers on the first flower cluster of 'Maehyang' and 'Sulhyang' showed no significant differences, 'Maehyang' had the greatest number of flowers in the 2x ionic strength solution and one week of nutrient starvation before planting, while 'Sulhyang' had that in the 1x ionic strength treatment. These results suggest that it is considered effective to supply a nutrient solution at a low concentration for a short period of time for increasing the number of flower differentiated on the first flower cluster in both cultivars.

• Journal of Mushroom
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• v.18 no.4
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• pp.317-322
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• 2020

This experiment was conducted to solve the failure of fruiting body production in the bottle cultivation of the oyster mushroom cultivar 'Heuktari'. The effects of incubation temperature on primordium formation and fruiting body yield of the oyster mushroom cultivar 'Heuktari' were investigated. The proper temperature for mycelium growth of 'Heuktari' on potato dextrose agar (PDA) medium is 23-26℃. The mycelial growth of 'Heuktari' was faster than that of Chunchu 2ho. During mycelial culture in sawdust medium, the temperature of the medium in the bottle initially increased, reached the highest point in the middle of the culture, and then decreased. The higher the set temperature, the shorter the incubation period. When the incubation temperatures were 20℃ and 24℃, respectively, the undeveloped primordium formation rates were low (1.8% and 4.2%, respectively). However, the rate of undeveloped primordium formation increased, and the yield decreased at incubation temperatures of 16℃ and 28℃. Mushroom farms that set incubation temperatures to 18℃ and maintained the medium temperature at less than 28℃ showed undeveloped primordium formation rates ranging between 0.3-0.8%. The rate of undeveloped primordium formation increased and the yield decreased in the farms with high incubation temperatures (above 28℃). We found that in order to reduce undeveloped primordium formation, the air inside the incubation room should be circulated continuously so that the temperature of the medium does not rise above 28℃, and dense incubation conditions should be avoided.

• Journal of the Korean Institute of Landscape Architecture
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• v.50 no.2
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• pp.41-63
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• 2022

The purpose of this study is to secure objective and precise data through ecosystem monitoring, to reveal ecological characteristics through comparison and analysis with past survey data, and to accumulate basic data for diagnosing the current situation and predicting changes in the ecosystem. The target site is the 'Quercus mongolica forest on the Buksa-myeon of Namsan', which was designated as an Ecological Landscape Conservation Area (ELCA) of Seoul in July 2006. The research contents are analysis of soil environment change (1986~2016), change of actual vegetation (1978~2016), and change of plant community structure (1994~2016). A total of 8 fixed surveys (400~1,200m²) were established in 1994 and 2000. Analysis items are importance value, species and population, and Shannon's species diversity. The soil environment of Namsan is acidic (pH 4.40 in 2016), which is expected to have a negative impact on tree growth and vegetation structure due to its low capacity for exchangeable cations. Quercus mongolica forest in Namsan is mainly distributed on the northern slopes. The actual vegetation area changed from 49.4% in 1978 → 80.7% in 1986 → 82.4% in 2000 → 88.3% in 2005 → 88.3% in 2009 → 70.3% in 2016. In 2016, the forest decreased by 18% compared to 2009. While there was increased growth of Quercus mongolica in the tree layer from 2009 to 2016, the overall decline in vegetation area was due to logging and fumigation management following the spread of oak wilt in 2012. As for the changes in the plant community structure, Quercus mongolica of the tree layer was damaged by oak wilt, and the potential vegetation that can form the next generation was ambiguous. In the subtree layer, the force of urbanization tree species such as Styrax japonicus, Sorbus alnifolia, and Acer palmatum. was maintained or increased. In the shrub layer, the number of trees and species increased significantly due to the open tree crown, and accordingly, the species diversity of Shannon for woody plants also increased. In Quercus mongolica forest of Namsan, various ecological changes are occurring due to the effects of urban environments such as air pollution and acid rain, the limitation of Quercus mongolica pure forest due to oak wilt, and the introduction of exotic species, thus, it is necessary to establish a management plan through continuous monitoring.

• Korean Journal of Environmental Biology
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• v.42 no.1
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• pp.80-94
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• 2024

This study aimed to examine the morphological characteristics and variation in main traits by comparing the growth of individuals of Ecklonia cava Kjellman(Laminariales, Phaeophyceae) under an aquaculture environment. This survey was conducted from April 2018 to November 2019 at the aquafarm in Jindo-gun, Jeollanam-do(South coast of Korea). To classify the morphology of individuals in the aquaculture farm of E. cava, we investigated fourteen morphological characteristics and calculated four ratios between the measured values. Juvenile individuals showed a simple or oblong lanceolate, and at 3-4 months, a short stipe and holdfast developed, along with a bladelet that developed into the secondary blade form. At 5-7 months, secondary blades were found to develop irregularly on the primary blade. At 8-10 months, the primary blade expanded and secondary blades elongated. At 11-12 months, the secondary blades became oblong. At 13-14 months, the thallus area expanded. At 15-16 months, tertiary blades were formed, the thallus became more complex, the stipe thickened, and the holdfast widened. At 17-18 months, secondary blades clearly developed along with lobes. At 19-20 months, tertiary blades developed and became similar to mature natural blades. In the principal component analysis (PCA), the monthly population of the first year(Q1) and that of the second year(Q2) of the cultured population were divided along PC1, which is related to secondary blade morphological characteristics and the holdfast width. Q2 and natural populations are distributed in descending order of volume in Jeju(J), East Coast(E), and South Coast(S) along PC2, which is related to primary blade and stipe morphological characteristics. The results of this study were judged to offer important criteria for the development of different varieties of E. cava.

• Journal of The Korean Society of Grassland and Forage Science
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• v.5 no.1
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• pp.22-32
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• 1985

Optimum pasture management during the summer season is an important factor to maintain good regrowth and persistence of pasture in Korea. This experiment was carried out to investigate the effects of the cutting management on the dead plant, weed appearance, regrowth and carbohydrate reserves in stubble, and dry matter yield of tall fescue dominated pasture during the mid summer season. For the test, a split plot design with 4 replications was treated with 2 different the third cutting times (July 12 and Aug. 4) as the mainplots, and 3 different cutting heights (3, 6 and 9 cm) at the third cut as the subplots, and the experiment was done at the experimental field of the Livestock Experiment Station, in Suweon, 1984. The results obtained are summarized as follows: 1. Considering the meteorological conditions during the experimental period, the temperature was a little higher by $2^{\circ}C$ than that of average year, especially the first and second decade of August were high. And the precipitation of 1984 tended to be low when compared with the average year. 2. Temperature of soil surface and underground tended to increase by $1-3^{\circ}C$ as the stubble height was low during the summer season. 3. Regrowth leaf length and leaf area after the third cut increased significantly with the high cutting height at the third cut. 4. A significant higher total nonstructural carbohydrate (TNC) content in stubble after the third cut was observed in the high stubble cut on July 12. The results indicate that the high stubble height reserves more carbohydrates for early regrowth stage after the third cut when compared with the low stubble. On Aug. 4, however, the recovery of TNC contents after the third cut was not effective due to high temperature and rainfall. 5. The percentage of dead plant after the third cut was found to be high with the low cutting height during the mid summer season (p<0.05). 6. With the low stubble height on July 12 cut, it was appeared that the percentage of weed was significantly increased (p<0.05), and main weeds appeared after the third cut were Echinochloa crusgalli>Digitaria sanguinalis>Cyperus iria>Rumex crispus, and so on. In case of cut on Aug. 4, weed appearance was no difference at three cutting heights. 7. Dry matter yield at the third cut was increased in the plot of cutting on Aug. 4 and stubble height (p<0.05). However, yields at the fourth and fifth cut were increased with high stubble height (p<0.05), regardless of harvest time. 8. In total dry matter yield after the third cut, there was no significant difference between the cutting time and forage yield. However, total yield on July 12 was increased with the high stubble height (p<0.05). 9. From the above results, it is suggested that the 9 cm cutting height during the mid summer season is the most effective for good regrowth, weed control and forage yield of tall fescue dominated pasture.