• Korean Journal of Ecology and Environment
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• v.47 no.3
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• pp.176-185
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• 2014

There are no population ecological research on the natural monument (No. 191) Jeju Cymbidium kanran in South Korea. In this study, we analyzed the population structure and fine-scale habitat affinity of C. kanran in Sanghyo-dong, Jejudo Island from Oct. 2013 to Feb. 2014. We observed total of 1,237 individuals (4,341 pseudobulbs) of C. kanran (989.6 population $ha^{-1}$) within (1.25 ha) and only 17 (1.4%) individuals were inflorescent. In 60.9% of the entire populations, disease symptoms such as spots and blight leaves were observed. C. kanran populaton exhibited reverse-J shaped size distribution based on leaf area classes as individual size parameter. The three size related attributes of C. kanran (no. of pseudobulb $r_s$=-0.159, no. of leaves $r_s$=-0.148 and leaf arera $r_s$=-0.114) and soil temperature revealed a negative relationship (p<0.0001). Most of C. kanran (95.4%) were grown under Castamopsis cuspidata and spatially, C. kanran were strongly clumped at all distances. Population characteristics of C. kanran in the study area were likely originated from species habitat affinity and successional environment. Through this study, base line data for C. kanran's habitat monitoring was established and conservation measures based on population characteristics were discussed.

• Korean Journal of Ecology and Environment
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• v.47 no.3
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• pp.167-175
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• 2014

This study was conducted to quantify a carbon budget of major vegetation types established in the campus of the National Institute of Ecology (NIE). Carbon budget was measured for Pinus thunbergii and Castanea crenata stands as the existing vegetation. Net Primary Productivity (NPP) was determined by applying allometric method and soil respiration was measured by EGM-4. Heterotrophic respiration was calculated as 55% of total respiration based on the existing results. Net Ecosystem Production (NEP) was determined by the difference between NPP and heterotrophic respiration (HR). NPPs of P. thunbergii and C. crenata stands were shown in $4.9ton\;C\;ha^{-1}yr^{-1}$ and $5.3ton\;C\;ha^{-1}yr^{-1}$, respectively. Heterotrophic respirations of P. thunbergii and C. crenata stands were shown in $2.4ton\;C\;ha^{-1}yr^{-1}$ and $3.5ton\;C\;ha^{-1}yr^{-1}$, respectively. NEPs of P. thunbergii and C. crenata stands were shown in $2.5ton\;C\;ha^{-1}yr^{-1}$ and $1.8ton\;C\;ha^{-1}yr^{-1}$, respectively. Carbon absorption capacity for the whole set of vegetation types established in the NIE was estimated by applying NEP indices obtained from current study and extrapolating NEP indices from existing studies. The value was shown in $147.6ton\;C\;ha^{-1}yr^{-1}$ and it was calculated as $541.2ton\;CO_2ha^{-1}yr^{-1}$ converted into $CO_2$. This function corresponds to 62% of carbon emission from energy that NIE uses for operation of various facilities including the glass domes known in Ecorium. This carbon offset capacity corresponds to about five times of them of the whole national territory of Korea and the representative rural area, Seocheongun. Considered the fact that ongoing climate change was originated from imbalance of carbon budget at the global level, it is expected that evaluation on carbon budget in the spatial dimension reflected land use pattern could provide us baseline information being required to solve fundamentally climate change problem.

• Korean Journal of Ecology and Environment
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• v.47 no.3
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• pp.160-166
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• 2014

This study was aimed at looking into the distribution status and age structure of Abies holophylla population in Sudo-Am temple forest. It was found that a total of 302 individuals of Abies holophylla existed which were more than 2m in height within the study area. Furthermore the population size is one of the largest in the southern region of Korea. The CBH of Abies holophylla ranged from 1.5 cm to 500.8 cm. Age structure of Abies holophylla looks like a gourd-shaped bottle. This means that they have an unstable structure status and do not survive very long. This status results from a variety of factors including, vegetation succession, anthropogenic activities, and global warming. The environmental characteristics of Abies holophylla population was $931{\pm}64.5m$ in mean altitude, $19.2{\pm}8.7^{\circ}$ in mean slope in the northeastern and southeastern area of the slope direction, and $1,324,323{\pm}174,459wh\;m^{-2}$ in average of direct normal irradiation. Among the site environmental factors, the significant ones which influence the potential habitat for Abies holophylla distribution were chosen using the MaxEnt model. According to the results of this study, altitude and slope were found as the important factors. The average value of environmental conditions by ROC analysis were altitude 903.2 m, slope $20.04^{\circ}$, irradiation $1,352.248wh\;m^{-2}$, and the southeastern aspect.

• Journal of the Korean Geographical Society
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• v.41 no.2 s.113
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• pp.150-167
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• 2006

This study was conducted to determine the pedogenesis of dense subsurface horizons (denoted either Bx or Bd) observed within closed depressions and in toeslope positions at loess-covered glacial tillplains in southern Wisconsin. Some of these dense subsurface horizons, especially those occurring within depressions, show a close morphological resemblance to fragipans elsewhere, even though the existence of fragipans has not been previously reported in southern Wisconsin. The spatial occurrence of fragipans was first examined over the landscape to characterize general soil-landscape relationships. Detailed physico-chemical and micromorphological analyses were followed to investigate the development of fragipans within a closed depression along a catenary sequence. The formation of fragipans at the study site is a result of sequential processes of physical ripening and accumulation of colloidal materials. A very coarse prismatic structure with a closely packed soil matrix was formed via physical ripening processes of loess deposited in small glacial lakes and floodplains that existed soon after the retreat of the last glacier. The physically formed dense horizons became hardened by the accumulation of colloidal materials, notably amorphous Si. The accumulation intensity of amorphous Si varies with mass balance relationships, which are governed by topography and local drainage conditions. Well-developed Bx horizons evolve at closed depressions where net accumulation of amorphous Si occurs, but the collapsed layers remain as Bd horizons at other locations where soluble Si has continuously been removed downslope or downvalley. Hydromorphic processes caused by the presence of fragipans are degrading upper parts of the prisms, resulting in the formation of an eluvial fragic horizon (Ex).

• Journal of the Korean Chemical Society
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• v.54 no.5
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• pp.556-566
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• 2010

A new kinetic spectrophotometric method is developed for the measurement of Mn(II) in natural water samples. The method is based on the catalytic effect of Mn(II) with the oxidation of Gallocyanin by $KIO_4$ using nitrilotriacetic acid (NTA) as an activation reagent at 620 nm. The optimum conditions obtained are $4.00{\times}1^{-5}\;M$ Gallocyanin, $KIO_4$, $1.00{\times}10^{-4}\;M$ NTA, 0.1 M HAc/NaAc buffer of pH = 3.50, the reaction time of 5 min and the temperature of $30^{\circ}C$. Under the optimum conditions, the proposed method allows the measurement of Mn(II) in a range of $0.1\;-\;4.0\;ng\;mL^{-1}$ and with a detection limit of down to $0.025\;ng\;mL^{-1}$. The recovery efficiency in measuring the standard Mn(II) solution is in a range of 98.5 - 102%, and the RSD is in a range of 0.76 - 1.25%. The newly developed kinetic method has been successfully applied to the measurement of Mn(II) in both some environmental water samples and certified standard reference river water sample, JAC-0031 with satisfying results. Moreover, few cations and anions interfere with the measurement of Mn(II). Compared with the other catalytic-kinetic methods and instrumental methods, the proposed kinetic method shows fairly good selectivity and sensitivity, low cost, cheapness, low detection limit and rapidity. It can easily and successfully be applied to the real water samples with relatively low salt content and complex matrices such as bottled drinking water, cold and hot spring waters, lake water, river water samples.

• Korean Journal of Environmental Agriculture
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• v.9 no.2
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• pp.133-141
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• 1990

For the purpose of evaluating nutrient loadings into rivers and lakes from agricultural land, especially from paddy fields and also nutrient degradation in drainage channels, the Total Kjeldahl Nitrogen(TKN) and the Total Phosphorus(TP) were investigated in 29.5 ha. paddy fields in Hwa-Sung, Kyong-Ki, Korea, during the period from May 8, 1989 to Sep. 27, 1989. The results of the study can be su㎜arized as follows : 1. Annual inputs into paddy fields were 180 N-kg/ha 46 P-kg/ha. by fertilization, and 15.0 TKN-kg/ha. 10.0 TP-kg/ha. by irrigation, 8.0 TKN-kg/ha. 0.34 TP-kg/ha. by rainfall respectively. The amount of nutrient involved in surface runoff from paddies was 39.0 TKN-kg/ha. 9.2 TP-kg/ha. and in seepage 7.5 TKN-kg/ha. 2.1 TP-kg/ha. respectively 2. In WS1 stream(reach length equals 950m), nutrients decreased 0.31 TKN-mg/L/km, 0.01 TP-mg/L/km and in WS2 stream (reach length equals 750m) which are more meandering and undulating than WS1, the nutrients decreased 0.84 TKN-mg/L/km, 0.11 TP-mg/L/km. From these results, it was concluded that low stream velocity due to meandering and undulation promotes more degradation of nutrient concentrations. 3. For the purpose of decreasing nutrient loads from paddy fields, the amount of fertilizer used needs to be controlled, irrigation weirs need to be constructed in the drainage channels to delay the transportation of nutrients by decelerating the stream velocity and plants such as plantain-lily need to be cultivated in the channel to consume nutrients and therefore enlarge chances of self-purification.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.28 no.4
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• pp.85-97
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• 2010

This study analyzed the distribution, structure and environmental condition of the vegetation of the Chionanthus retusus Lindly et Paxton community at the Wansanchielbong in the Jeonju city to offer basic data for sustainable conservation and ecological management system. And the results are as follows; 1. The average pH of soil at the community was pH 5.69 and it was slightly higher than the average of forest soil pH of Korea. But if the degree of pH will be down, it will be needed some more fertilization of Calcium. 2. The total average for contents of organism was 4.98%. And the nitrate - nitrogen content(mg/kg) of A, B, C, D quadrat was 20.29%, 28.87%, 7.65%, and 23.3% respectively. And there were good condition except quadrat C which was contaminated by amount of earth and sand. 3. The flora of the Chionanthus retusus Lindly et Paxton community was listed as 60 taxa; 37 families, 50 genera, 47 species, 10 varieties and 3 forms. The average appearance species of each Quadrat were A sector 30, B sector 26, C sector 19 and D 19 taxa respectively. 4. Surveyed woody plants in the community were as follows : Chionanthus retusus, Zelkova serrata, Quercus variabilis, Cornus walteri, Robinia pseudo-acacia and those were mixed status. And Chionanthus retusus, Zelkova serrata, Robinia pseudo-acacia, Albizzia julibrisin, Cudrania tricuspidata, Symplocos chinensis for. pilosa were mixed in mid layer trees. Herbaceous plants were founded such as Chionanthus retusus, Zelkova serrata, Robinia pseudo-acacia, Grewia parviflora, Rosa multiflora, Trachelospermum asiaticum was dominant with 35~64% in the ground cover, and Commelina communis, Calamagrostis arundinacea, Dryopteris bissetiana, Lilium lancifolium were founded also. 5. The importance values of Chionanthus retusus was 40.2% in the quadrat A1, 50.2% at quadrat A, 50.0% B1, 45.2% B2, 22.4% C1, 73.6% C2, 33.2% D1 and the total average of I.V. was 44.9%. 6. The average height of surveyed Chionanthus retusus was 5.7m and the average DBH was 12.4cm. The number of trees higher than 2m were 107 and the number of trees lower than 2m were 63. The total numbers of Chionanthus retusus were 170. 7. The age of surveyed Chionanthus retusus were analyzed 42 thru 87 years old and that of Zelkova serrata were 42, Quercus variabilis were 60, Quercus aliena were 48, Robinia pseudo-acacia were 40. 8. The number of trees with DBH 40 through 50cm were 6, and that of 30~39cm were 3, and that of 20~29cm were 16, so the total number that was over 20cm was 25. And there were 70 trees under 10cm of DBH and 63 seedlings. It will be very important data to conserve the habitat that the structure and environmental condition of the Chionanthus retusus Lindly et Paxton community at the Wansanchielbong was stable, and sustainable monitoring will be needed. Now that community is nurse forest of Jeonju City but more positive preservation plan will be needed and assigning monument of city or province also be necessary.

• Korean Journal of Organic Agriculture
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• v.25 no.1
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• pp.135-148
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• 2017

Response Surface Methodology (RSM), which is combining with Plackett-Burman design and Box-Behnken experimental design, was applied to optimize the ratios of the nutrient components for carotenoid production by Rhodobacter sphaeroides PS-24 in liquid state fermentation. Nine nutrient ingredients containing yeast extract, sodium acetate, NaCl, $K_2HPO_4$, $MgSO_4$, mono-sodium glutamate, $Na_2CO_3$, $NH_4Cl$ and $CaCl_2$ were finally selected for optimizing the medium composition based on their statistical significance and positive effects on carotenoid yield. Box-Behnken design was employed for further optimization of the selected nutrient components in order to increase carotenoid production. Based on the Box-Behnken assay data, the secondary order coefficient model was set up to investigate the relationship between the carotenoid productivity and nutrient ingredients. The important factors having influence on optimal medium constituents for carotenoid production by Rhodobacter sphaeroides PS-24 were determined as follows: yeast extract 1.23 g, sodium acetate 1 g, $NH_4Cl$ 1.75 g, NaCl 2.5 g, $K_2HPO_4$ 2 g, $MgSO_4$ 1.0 g, mono-sodium glutamate 7.5 g, $Na_2CO_3$ 3.71 g, $NH_4Cl$ 3.5g, $CaCl_2$ 0.01 g, per liter. Maximum carotenoid yield of 18.11 mg/L was measured by confirmatory experiment in liquid culture using 500 L fermenter.

• Korean Journal of Ecology and Environment
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• v.35 no.3 s.99
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• pp.237-246
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• 2002

Tamjin Dam is built in the upper reaches of the Tamjin River which flows through the Janghung-gun and Gangjin-gun of the Jeollanamdo, Korea. In order to map out a preservation strategy of the fish community from dam construction, We studied the distribution of fish distribution and changes of the habitat environment. we found 49 fish species inhabiting in the downstream and upstream of the Tamjin Dam. Among them, migratory fish were two species sweet smelt, Plecoglossus altivelis and freshwater eel, Anguilla japonica. The Coreoperca kawamebari which designated as a species to be protected by The Ministry of Environment of Korea was also observed. After the dam construction, reservoir would be filled with water and running water system will change to standing water system. Then the habitat and spawning space for mountain torrent fish will be reduced and the migration of migratory fish to upstream will be blocked. Through our study, we proposed several ways to protect fish community. In order to preserve the reduced habitat and spawning area of mountain torrent fish, a fishway has been diagnosed to be built in the shallow reservoir in the entrance of the upriver. The establishment of artificial spawning ground on the riverside has been recommended. In addition, We propose a creation of a shelter for fresh water eel, Anguilla japonica in areas where the depth of the water is about l0m by laying rocks. Since it is difficult for a spawning ground to be formed naturally in the reservoir due to the year-round changes in water level, We suggested a floating spawning facility using an artificial fixture. In the downstream of the dam, a waterway-style habitat and spawning ground in the river and increasing the diversity and abundance of fish fauna in the Tamjin River. A low-cost and highly efficient operational fishway has been recommended so that migratory fish such as Plecoglossus altivelis (sweetfish) can migrate from the lower reaches to the upper reaches of the river.

• Korean Journal of Ecology and Environment
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• v.35 no.3 s.99
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• pp.198-212
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• 2002

A numerical variation and abnormalities were studied on egg bags and embryos of Korean salamander, Hynobius leechii from agricultural habitat. The teratogenic and toxic effects of fungicide benomyl were also investigated with early embryos from non-agricultural habitat. We collected 144 egg bags from agricultural region, and 3418 of early embryos were contained. The lengths of egg bags were varied from 10 to 23 cm and the most frequent length was 19 cm. The number of embryos was varied from 7 to 43, and the most frequent range was 22 to 26. Spontaneous abnormalities were occurred in 406 embryos among 116 egg bags, and 24 kinds of external abnormalities were found. Individuals showing severe external defect were histologically studied and they showed optic dyspalsia, thyroid carcinoma, somatic muscular dysplasia, partial biaxial structure, decrease of red blood cells in the heart, cephalic degeneration and intestinal dysplasia. 385 embryos from non-agricultural region were exposed to 200 nM${\sim}$ 1 ${\mu}$M of benomyl at blastula or gastrula for 12 days. All embryo were dead in the concentration of 1 ${\mu}$M (LD$_{100}$) and 75% of embryos were dead in 800nM of benomyl. Speciflc effect due to benomyl was acrania or cephalic dysplasia and this restult suggests that the benomyl inhibit stongly to the development of neural tissue. These abnormal developments may be caused by antimitotic action, inhibition of tubulin complex, destruction of microtubule, inhibitions of neurulation and closing of neural fold, and by the inhibition of the movement of neural crest cells.