• Korean Journal of Agricultural and Forest Meteorology
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• v.1 no.1
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• pp.52-59
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• 1999

Vegetation canopy plays an important role in $CO_2$/$H_2$O exchange between the biosphere and the atmosphere by controlling leaf stomata. In this study, rice (Oryza sativa L.), a staple crop in Asia was investigated to formulate its single leaf model of photosynthesis and stomatal conductance. Photosynthesis and stomatal conductance were measured with a portable infrared gas analyzer system. Other plant and meteorological variables were also measured. To evaluate empirical constants in this biochemical leaf model, nonlinear least squares technique was used. The maximum catalytic activity of enzyme and the maximum rate of electron transport were $ 100\mu$㏖ $m^{-2}$ $s^{-1}$ and $140 \mu$㏖ m$^{-2}$ s$^{-1}$ (@ 35$^{\circ}C$), respectively. The empirical constants, m and b, associated with stomatal conductance model were 9.7 and $0.06 m^{-2}$ $s^{-1}$ , respectively. On a leaf scale, agreements between the modeled and the measured values of photosynthesis and stomatal conductance were on average within 20%, and the simulation of diurnal variation was also satisfactory On a canopy scale, the Simple Biosphere model(SiB2) was tested using the derived parameters. The modeled energy fluxes were compared against the micrometeorologically measured fluxes over a rice canopy. Agreements between the modeled and the measured values of net radiation, sensible heat and latent heat fluxes, and $CO_2$ flux (i.e., net canopy photosynthesis) were on average within 25%.

• Korean Journal of Soil Science and Fertilizer
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• v.51 no.2
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• pp.79-89
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• 2018

Subsurface drip irrigation (SDI) system is considered one of the most effective methods for water application. A 2-year field study was conducted to investigate the effect of SDI systems with various dripline spacing (0.7 or 1.4 m) and position (under furrow or ridge) on soybean (Glycine max L.) production at a sandy-loam soil in Miryang, South Korea. For 2016-2017, average grain yield in SDI irrigated plots, $3.16Mg\;ha^{-1}$, was statistically greater than rainfed irrigated plot ($2.63Mg\;ha^{-1}$). Soybean grain yield averaged $3.25Mg\;ha^{-1}$ for the 0.7 m dripline spacing and $3.07Mg\;ha^{-1}$ for the 1.4 m spacing for the two-year period compared to a rainfed irrigated average of $2.63Mg\;ha^{-1}$ for the same period. Soybean treated with SDI system had significantly greater values of normalized difference vegetation index and stomatal conductance, indicating that soybean plants in SDI plots had greater photosynthetic and stomatal activity due to the higher water availability in soil. Irrigation water use efficiency (IWUE) was greatest in the plot of 0.7 m spacing installed under ridge position than any other plot across growing season. Average soil water content in plots with 0.7 m dripline spacing was $0.21m^3\;m^{-3}$ at 5 cm depth layer, which was 45% greater compared to the plots with 1.4 m spacing, even though the gross irrigation amounts were greater in 1.4 m spacing plots. It is concluded that wide dripline spacing (1.4 m) is probably the more economical installation design for SDI system compared to 0.7 m spacing in this study soil because the initial cost for dripline may be reduced with wide spacing design, even though the IWUE is greater in the plot of 0.7 m dripline spacing.

• Journal of Microbiology and Biotechnology
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• v.30 no.9
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• pp.1310-1320
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• 2020

Low-quality soil for land reuse is a crucial problem in vegetation quality and especially to waste disposal sites in mining areas. It is necessary to find suitable materials to improve the soil quality and especially to increase soil microbial diversity and activity. In this study, pot experiments were conducted to investigate the effect of a mixed material of humic acid, super absorbent polymer and biochar on low-quality soil indexes and the microbial community response. The indexes included soil physicochemical properties and the corresponding plant growth. The results showed that the mixed material could improve chemical properties and physical structure of soil by increasing the bulk density, porosity, macro aggregate, and promote the mineralization of nutrient elements in soil. The best performance was achieved by adding 3 g·kg^-1 super absorbent polymer, 3 g·kg^-1 humic acid, and 10 g·kg^-1 biochar to soil with plant total nitrogen, dry weight and height increased by 85.18%, 266.41% and 74.06%, respectively. Physicochemical properties caused changes in soil microbial diversity. Acidobacteria, Bacteroidetes, Chloroflexi, Cyanobacteria, Firmicutes, Nitrospirae, Planctomycetes, and Proteobacteria were significantly positively correlated with most of the physical, chemical and plant indicators. Actinobacteria and Armatimonadetes were significantly negatively correlated with most measurement factors. Therefore, this study can contribute to improving the understanding of low-quality soil and how it affects soil microbial functions and sustainability.

• Journal of People, Plants, and Environment
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• v.24 no.5
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• pp.545-550
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• 2021

Background and objective: With increasing land use intensity in urban areas, apartment buildings have been recognized as a typical type of urban residence. In this study, the impacts of different views through a window on health-related responses were investigated using psychological and physiological parameters. Methods: Photos of three different types of views taken on low (2-12 m), middle (28-35 m), and high (over 54 m) floors of dense apartment building areas were used as visual stimuli. Twenty-two healthy adults participated in the indoor experiment. Semantic differential methods and profile of mood states were used as psychological tools. Autonomic nervous activity was evaluated using blood pressures, pulse rate and heart rate variability (HRV). Results: Analytic data showed different characteristics of psychological and physiological outcomes in three different apartment views. In the analysis of psychological parameters, significantly negative responses to the views on middle floors were found in the subscales of tension-anxiety and anger-hostility, compared to low floors. Significantly positive scores in the subscale of vigor were found on low floors with abundance of vegetation and high floors with a view of the sky. A significantly increased value of HF was found on low floors (2,294.96 ± 169.79), compared to the middle(1,553.45 ± 84.66) and high (1,523.02 ± 70.49) floors. Despite the high scores in openness and vigor, high floor views showed significantly higher LF/HF values (1.83 ± 0.09), the indicator of the sympathetic nervous system, than low (1.30 ± 0.07) and middle floor views (1.34 ± 0.06), which might be related to the unconscious fear of heights. Conclusion: Views from different heights in an apartment building can affect the psychological states of residents. Green space through the window may have a positive health outcome by reducing physiological stress.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2021.04a
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• pp.54-54
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• 2021

The Melanoma Research Coalition reported melanoma affects humans of various races. This study was conducted to confirm the inhibitory effect of melanogenesis in B16 F10 cells of Nypa fruticans Wurmb of ethyl acetate fraction (NEF). Nypa fruticans Wurmb is an important component of the East Asian mangrove vegetation. It belongs to Araceae family. Traditionally, N. fruticans was used to treat various diseases such as asthma, sore throat, liver disease, a pain reliever, and can also be used as sedative and carminative. The present study, the inhibitory effect on melanogenesis was determined by Western blotting and RT-qPCR. The level of expression of tyrosinase, TRP-1, and TRP-2 is regulated by microphthalmia-associated transcription factor (MITF) and cAMP, and cAMP affects the activity of protein kinase A (PKA). Activated PKA stimulates the phosphorylation of cAMP-reactive element-binding protein (CREB) in the nucleus, thereby increasing the amount of MITF expression and enhancing melanogenesis. Western blotting and RT-qPCR analysis showed that NEF treatment decreased the expression of tyrosinase. Similarly, TRP-1 and TRP-2 levels were decreased, which were decreased significantly at compared with the untreated control. Also, NEF attenuated the IBMX mediated increase in the intracellular cAMP level and the phosphorylation of PKA. In conclusion, NEF significantly inhibited the expressions of melanogenesis through cAMP/PKA/CREB signaling pathways.

• Journal of Environmental Impact Assessment
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• v.24 no.3
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• pp.217-232
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• 2015

This study is to examine the section-based stream management with environmental characteristics and user monitoring. In Jeonjucheon, upstream section located near to Jeonju Hanok village has very good water quality and natural stream landscape. In case of mid/down streams, water quality is good and heavy concentration of facility leads to high use rates of these sections. The questionnaire consists of 5 parts: user characteristics, use behavior, citizen participation, importance rank, and Importance-Satisfaction(IS). 383 out of 454 responses with listwise deletion are used for demographic analysis and IS Analysis. In terms of citizen participation through 'ecological experience activity' and 'stream stewardship activity', 'occasional participation' shows the average of 78% in all three sections. For importance rank, the results arranged in order of priority show 'water quality' > 'green corridor' > 'trail' in up/down streams and 'water quality' > 'vegetation management' > 'trail' in midstream. Therefore, 'water quality' appears to be the most important variable among 13 variables. At last, the results of ISA indicate that all 10 variables need to be improved as satisfaction is lower than importance. In addition, 'plant management' variable falls into 'concentrate here' quadrant where importance is high and satisfaction is low.

• Korean Journal of Ecology and Environment
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• v.41 no.spc
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• pp.93-98
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• 2008

We investigated the effect on the removal of BOD, SS, TN and TP and algal growth inhibition of Vegetated Artificial Floating Island (VAFI), by examining microorganism activity and nutrient uptake in the batch test of various conditions: (1) Blank (Control group), (2) VAFI of $0.25m^2$, (3) AFI of $0.25m^2$ which has no vegetation, (4) buoyant plate of $0.25m^2$, (5) buoyant plate of $0.25m^2$ with linear media. The proportion of BOD removal in the VAFI, AFI, buoyant plate and buoyant plate with media were 82.7, 80.8, 45.2% and 59.6% respectively. TN removal in the VAFI, AFI and buoyant plate with media were 51.2, 31.7% and 25.1% respectively. TP removal in the VAFI, AFI, buoyant plate and buoyant plate with media were 23.3, 16.7, 10.0% and 13.3% respectively. Chlorophyll-${\alpha}$ removal in the VAFI was 97.9%. The factors of chlorophyll-${\alpha}$ removal in the VAFI accounted for the shading effect of 35.1%, microorganisms activity of 61%, and plant root of 1.8%.

• Korean Journal of Plant Taxonomy
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• v.38 no.4
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• pp.583-599
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• 2008

Dokdo, small island located in the eastern end of the Korean Peninsula, has been an uninhabited island for long time due to long distance from the land. Moreover, the steep slope of volcanic tuff at Dokdo is well drained for high permeability and Dokdo has few plain areas, swamps and very thin soil layers. In this study, pollen analysis at Dokdo was attempted on the profile of organic sandy soil for the first time in Korea owing to the marine climate environment with high humidity and precipitation including snowfalls in spite of unprofitable condition geologically or geomorphologically. While many historical, political researches have been accumulated for territorial problem of Dokdo with Japan, natural scientific researches with field work are not sufficient, and few paleoecological researches have been done. As a result of pollen analysis, the ratio of the NAP(Non-Arboreal Pollen) and spore was higher than AP(Arboreal Pollen), and the vegetation change existed by showing dramatic decrease of AP at the upper layer. AP was composed of almost Pinus, and a little Alnus, Quercus, Betula, Carpinus, Picea and Ulmus. NAP was composed of Gramineae, Compositae, Chenopodiaceae Cyperaceae, Caryophyllaceae, Liliaceae, Umbelliferae, Artemisia, Lobelia, Rumex, Polygonum. Increase of the NAP such as Gramineae, Artemisia and Chenopodiaceae, they would mostly have been transported from the other areas because agricultural activity is impossible at Dokdo. While one reason of Pinus thunbergii decrease could be regarded as environmental change, the other reason would be lumbering of pine trees by human activity which is adapted to Dokdo environment.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.32 no.1
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• pp.93-106
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• 2014

In this study, Analyze environment of location, investigation into vegetation resources, survey management status and establish to classify the management area for Natural monument No.374 Pyengdae-ri Torreya nucifera forest. The results were as follows: First, Torreya nucifera forest is concerned about influence of development caused by utilization of land changes to agricultural region. Thus, establish to preservation management plan for preservation of prototypical and should be excluded development activity to cause the change of terrain that Gotjawal in the Torreya nucifera forest is factor of base for generating species diversity. Secondly, Torreya nucifera forest summarized as 402 taxa composed 91 familly 263 genus, 353 species, 41 varieties and 8 forms. The distribution of plants for the first grade & second grade appear of endangered plant to Ministry of Environment specify. But, critically endangered in forest by changes in habitat, diseases and illegal overcatching. Therefore, when establishing forest management plan should be considered for put priority on protection. Thirdly, Torreya nucifera representing the upper layer of the vegetation structure. But, old tree oriented management and conservation strategy result in poor age structure. Furthermore, desiccation of forest on artificial management and decline in Torreya nucifera habitat on ecological succession can indicate a problem in forest. Therefore, establish plan such as regulation of population density and sapling tree proliferation for sustainable characteristics of the Torreya nucifera forest. Fourth, Appear to damaged of trails caused by use. Especially, Scoria way occurs a lot of damaged and higher than the share ratio of each section. Therefore, share ratio reduction Plan should be considered through the additional development of tourism routes rather than the replacement of Scoria. Fifth, Representing high preference of the Torreya nucifera forest tourist factor confirmed the plant elements. It is sensitive to usage pressure. And requires continuous monitoring by characteristic of Non-permanent. In addition, need an additional plan such as additional development of tourism elements and active utilizing an element of high preference. Sixth, Strength of protected should be differently accordance with importance. First grade area have to maintenance of plant population and natural habitats. Set the direction of the management. Second grade areas focus on annual regeneration of the forest. Third grade area should be utilized demonstration forest or set to the area for proliferate sapling. Fourth grade areas require the introduced of partial rest system that disturbance are often found in proper vegetation. Fifth grade area appropriate to the service area for promoting tourism by utilizing natural resources in Torreya nucifera forest. Furthermore, installation of a buffer zone in relatively low ratings area and periodic monitoring to the improvement of edge effect that adjacent areas of different class.

• Korean Journal of Environment and Ecology
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• v.22 no.3
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• pp.309-319
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• 2008

Roads are an indicator of anthropogenic activity causing ecosystem disturbances and often lead to habitat fragmentation, habitat loss, and habitat isolation. The Hallasan National Park(153.4$km^2$) on Jeju Island being distinguished for its unique geology, topography, and biota has also been designated as a core area of UNESCO Man and the Biosphere(MAB) Reserve. Although the high conservation value of this park has contributed to a rapid growth of tourists and road construction, landscape changes due to roads have not been examined yet. We used GIS systems to examine the fragmentation pattern caused by roads, in relation to its zonation, elevation, and vegetation. When a buffer was applied to roads(112m width for paved roads and 60m width for both legal and illegal trails), the park consisted of 100 fragments. The ten fragments generated after applying buffer to only paved roads and legal trails ranged from $0.002km^2$ to $38.2km^2$ with a mean of $14.2km^2$, and about 7% of both nature conservation zone and nature environment zone of the park were edge. Fragments in both east and west ends of the park and around the summit exhibited relatively high shape indices with means of 5.19(for 100 fragments) and 7.22(for 10 fragments). All five legal trails are connected to the pit crater of the mountain and vegetation changed from broadleaf forests and conifer forests to grasslands with elevation, consequently resulting in dramatic fragment size reduction in grasslands at high elevation, in particular above 1,400m, where endemic and alpine plants are abundant. These results show that in Hallasan National Park the risks of habitat deterioration and habitat loss due to fragmentation may be more severe in the nature conservation zone dominated by Baengnokdam than in the nature environment zone. Therefore, current road networks of the park appear to fall short of the goal of the national park for ecosystem conservation and protection. Considering that the entire Hallasan National Park also serves as a MAB core area, conservation efforts should focus, first of all, on park rezoning and road management to mitigate habitat fragmentation.