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Vegetation Structure and Growth Environmet of Diabelia spathulata (Siebold & Zucc.) Landrein Population in Mt. Cheonseong, Korea (천성산 주걱댕강나무 개체군의 식생구조와 생육환경)

  • Yi, Myung Hoon;Yoo, Sung Tae;Jang, Jeong Gul
    • 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.

The Climatic Influence on Spikelet Formation and Yield of Lowlam Rice II. Climatic Consumptive Effect for Spikelet Formation (수도의 영화수성립과 수량에 미치는 기상환경의 영향에 관한 연구 II. 영화수 성립에 미치는 기상소모효과)

  • Lee, Jong-Chul;Ahn, Su-Bong
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.29 no.4
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    • pp.366-375
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    • 1984
  • In order to confirm the effect of climatic consumption index (C C I) on the number of spikelets and yield of rice, 3 levels of shading rates such as 0, 25, 50% of full light were treated during the tillering stage, reproductive growth stage and ripening period, respectively, in a phytotron controlled with day/ night temperature of 20/10$^{\circ}C$ and 30/20$^{\circ}C$, and field at Crop Experiment Station, Suwon, Korea. The results are as follows: 1. As solar radiation decreased during the reproductive growth stage in 30/20$^{\circ}C$ or field condition, the number of spikelets per panicle was decreased due to the decrease of the number of differentiated secondary rachis branches and spikelets as well as the increase of the number of degenerated secondary rachis branches and spikelets. 2. Our results showed slight negative correlation between C C I of the reproductive growth stage and number of panicles per square meter and number of differentiated secondary rachis branches. On the other hand, there was highly significant positive correlation between C C I of the reproductive growth stage and the number of degenerated secondary rachis branches and spikelets, and negative correlation in number of differentiated spikelets. 3. The shading during the reproductive growth stage did not affect on the percentage of ripened grains and 1000 grains weight of hulled rice, whereas those were decreased with shading during the ripened period. 4. Influence of shading in each growing stage on the yield was severe in the order of ripened period, reproductive growth stage, tillering stage. 5. Respiration rate in Jinheung was higher than that of Tongil at low temperature, but reversed above 30$^{\circ}C$. Respiratory coefficients (Q$\sub$10/) of Tongil and Jinheung were 2.74 and 1.96, respectively. Respiration/ photosynthesis ratio in Jinheung was higher than that of Tongil at low temperature, while higher in Tongil above 32$^{\circ}C$. 6. Transportation of $\^$14/C was restricted at 20/10$^{\circ}C$ in Tongil, however, there was no differences at 30/20$^{\circ}C$ in both Tongil and Jinheung. The influence of shading on the transportation of $\^$14/C did not affect at 20/10$^{\circ}C$, but it was hampered with shading at 30/20$^{\circ}C$ in both varieties.

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Effects of Temperature and Irrigation Intervals on Photosynthesis, Growth and Growth Analysis of Pot-grown Cucumber Seedlings (온도와 관수 주기가 오이 포트 묘의 광합성, 생육 및 생장 해석에 미치는 영향)

  • Jin Hee An;Eun Yong Choi;Yong Beom Lee;Ki Young Choi
    • Journal of Bio-Environment Control
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    • v.32 no.2
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    • pp.148-156
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    • 2023
  • This study was conducted in an indoor cultivation room and chamber where environmental control is possible to investigate the effect of temperature and irrigation interval on photosynthesis, growth and growth analysis of potted seedling cucumber. The light intensity (70 W·m-2) and humidity (65%) were set to be the same. The experimental treatments were six combinations of three different temperatures, 15/10℃, 25/20℃, and 35/25℃, and two irrigation intervals, 100 mL per day (S) and 200 mL every 2 days (L). The treatments were named 15S, 15L, 25S, 25L, 35S, and 35L. Seedlings at 0.5 cm in height were planted in pots (volume:1 L) filled with sandy loam and treated for 21 days. Photosynthesis, transpiration rate and stomatal conductance at 14 days after treatment were highest in 25S. These were higher in S treatments with a shorter irrigation interval than L treatments. Total amount of irrigation water was supplied evenly at 2 L, but the soil moisture content was highest at 15S and lowest at 25S > 15L > 25L, 35S and 35L in that order. Humidity showed a similar trend at 15/10℃ (61.1%) and 25/20℃ (67.2%), but it was as high at 35/25℃ (80.5%). Cucumber growth (plant height, leaf length, leaf width, chlorophyll content, leaf area, fresh weight and dry weight) on day 21 was the highest in 25S. Growth parameters were higher in S with shorter irrigation intervals. Yellow symptom of leaf was occurred in 89.9% at 35S and 35L, where the temperature was high. Relative growth rate (RGR) and specific leaf weight (SLA) were high at 25/20℃ (25S, 25L), RGR tended to be high in the S treatment, and SLA in the L treatment. Water use efficiency (WUE) was high in the order of 25S, 25L > 15S > 15L, 35S, and 35L. As a result of the above, the growth and WUE were high at the temperature of 25/20℃.

Effects on Ginseng Growth and Ginsenoside Content in ICT-based Process Cultivation and Conventional Cultivation (ICT 기반의 공정재배와 관행재배에 있어서 인삼 생장 및 진세 노사이드 함량에 미치는 영향)

  • Kwang Jin Chang;Yeon Bok Kim;Hyun Jung Koo;Hyun Jin Baek;Eui Gi Hong;Su Bin Lee;Jeei Hye Choi;Hyo Yeon Son;Tae Young Kim;Dong Hyun Kim
    • Journal of Practical Agriculture & Fisheries Research
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    • v.25 no.2
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    • pp.12-19
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    • 2023
  • This study conducted an experiment with EC 1.0ms/cm ratio and excellent soil conditions for germination in ICT-based ginseng process cultivation. The first growth survey was conducted before transplantation of ginseng 1-year roots grown by seeding ginseng in the process cultivation, conventional cultivation and a second growth comparison survey was conducted after 3 months of growth. In the results, it was confirmed that ginseng grown in the process cultivation grew more than in the field. As a result of comparing the contents of 11 ginsenosides of 1-year and 2-year-old ginsenosides in the process cultivation and conventional cultivation ginseng, it was confirmed that the content of the process cultivation ginseng was higher than that of practice cultivation ginseng. In conclusion, conventional cultivation ginseng grows due to various factors under the natural cultivation environment, but process cultivation can secure the growth stability of ginseng by allowing stable soil and environmental control, so continuous research is needed in the future.

The Effect of Shading on Pedestrians' Thermal Comfort in the E-W Street (동-서 가로에서 차양이 보행자의 열적 쾌적성에 미치는 영향)

  • Ryu, Nam-Hyong;Lee, Chun-Seok
    • Journal of the Korean Institute of Landscape Architecture
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    • v.46 no.6
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    • pp.60-74
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    • 2018
  • This study was to investigate the pedestrian's thermal environments in the North Sidewalk of E-W Street during summer heatwave. We carried out detailed measurements with four human-biometeorological stations on Dongjin Street, Jinju, Korea ($N35^{\circ}10.73{\sim}10.75^{\prime}$, $E128^{\circ}55.90{\sim}58.00^{\prime}$, elevation: 50m). Two of the stations stood under one row street tree and hedge(One-Tree), two row street tree and hedge (Two-Tree), one of the stations stood under shelter and awning(Shelter), while the other in the sun (Sunlit). The measurement spots were instrumented with microclimate monitoring stations to continuously measure microclimate, radiation from the six cardinal directions at the height of 1.1m so as to calculate the Universal Thermal Climate Index (UTCI) from 24th July to 21th August 2018. The radiant temperature of sidewalk's elements were measured by the reflective sphere and thermal camera at 29th July 2018. The analysis results of 9 day's 1 minute term human-biometeorological data absorbed by a man in standing position from 10am to 4pm, and 1 day's radiant temperature of sidewalk elements from 1:16pm to 1:35pm, showed the following. The shading of street tree and shelter were mitigated heat stress by the lowered UTCI at mid and late summer's daytime, One-Tree and Two-Tree lowered respectively 0.4~0.5 level, 0.5~0.8 level of the heat stress, Shelter lowered respectively 0.3~1.0 level of the heat stress compared with those in the Sunlit. But the thermal environments in the One-Tree, Two-Tree and Shelter during the heat wave supposed to user "very strong heat stress" while those in the Sunlit supposed to user "very strong heat stres" and "exterme heat stress". The main heat load temperature compared with body temperature ($37^{\circ}C$) were respectively $7.4^{\circ}C{\sim}21.4^{\circ}C$ (pavement), $14.7^{\circ}C{\sim}15.8^{\circ}C$ (road), $12.7^{\circ}C$ (shelter canopy), $7.0^{\circ}C$ (street funiture), $3.5^{\circ}C{\sim}6.4^{\circ}C$ (building facade). The main heat load percentage were respectively 34.9%~81.0% (pavement), 9.6%~25.2% (road), 24.8% (shelter canopy), 14.1%~15.4% (building facade), 5.7% (street facility). Reducing the radiant temperature of the pavement, road, building surfaces by shading is the most effective means to achieve outdoor thermal comfort for pedestrians in sidewalk. Therefore, increasing the projected canopy area and LAI of street tree through the minimal training and pruning, building dense roadside hedge are essential for pedestrians thermal comfort. In addition, thermal liner, high reflective materials, greening etc. should be introduced for reducing the surface temperature of shelter and awning canopy. Also, retro-reflective materials of building facade should be introduced for the control of reflective sun radiation. More aggressively pavement watering should be introduced for reducing the surface temperature of sidewalk's pavement.