• The Korean Journal of Ecology
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• 제26권2호
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• pp.82-86
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• 2003

We investigated the variation in adaptation to growth for four ecotypically-differentiated population of Taraxacum officinale found naturally in temporal environmental heterogeneity. Seeds collected from the four seasons were germinated in incubators and were grown for four months in greenhouse to test genetic variation among biotypes. Biotypes, segregated by seeds collected seasonally, were the part of natural population in Mokpo, South Korea. Each biotype was different in total dry weight of seeds, biomass, and leaf area, confirming previous finding. Differences between biotypes grown under a common environment indicated a genetic basis to their distinct demographic rates. Therefore, biotypes with similar annual rates of growth and contrasting seasonal rates should persist in the population. This differential response suggests that temporal variation in environment may be responsible, in part, for the maintenance of genetic variation within populations.

• 유기물자원화
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• 제18권4호
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• pp.45-53
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• 2010

여러 가지 방법으로 전처리된 느타리 버섯 폐배지에 대한 줄지렁이 개체군의 섭식률 및 생장률을 조사하였다. 갓 발생한 버섯폐배지의 부숙기간을 달리하여 지렁이에게 급이하였을 경우, 20일 이상 부숙된 버섯 폐배지보다 10일 이하로 부숙된 버섯 폐배지에 대한 지렁이 개체군의 섭식량 및 생장률이 높았다. 분변토를 첨가한 버섯폐배지나 질소영양원으로서 요소비료를 첨가하여 부숙한 버섯폐배지는 지렁이 개체군의 섭식률과 생장률을 증대시키지 못하는 것으로 나타났다. 그러나 버섯폐배지를 분쇄하여 공급하였을 경우에는 섭식량 및 생장률이 증가하였다. 특히 분쇄된 버섯폐배지에 미강을 첨가하였을 경우에는 분쇄하지 않은 단순 버섯폐배지보다 생장률이 1.85배 증가하였다.

• Journal of Ecology and Environment
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• 제31권1호
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• pp.9-15
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• 2008

Growth and reproduction of Palaemon serrifer were described and analyzed in a population inhabiting tide pools in warm temperate waters in Korea. The water temperature varied greatly in the tide pools, ranging from 8$^{\circ}C$ to 27.8$^{\circ}C$ Population structure and growth were investigated using size frequency distribution data collected from January to December 2003. Sex ratios fluctuated, but were almost equal during the breeding period. Growth was continuous and size increased gradually throughout the year. Adult females were larger and grew faster than males. von Bertalanffy growth parameters for a one-year sample of females and males were estimated as $L_{i\ddot{A}}$ = 11.32, K = 0.311, $t_0$ = -0.4115 and $L_{i\ddot{A}}$ = 8.36, K = 0.228, $t_0$ = -0.9693 respectively. Breeding was seasonal, starting in May, peaking in August, and finishing by the end of August. The species showed continuous production of successive broods. Laboratory observation showed that females with embryos near hatching had ovaries filled with vitellogenic oocytes ready for spawning. The reproductive output (effort) of each female (mean number of eggs: $552{\sim}1355$) was not high. The mean embryo volume, $0.078mm^3$, is relatively small, indicative of low energy allocation to each embryo. Recruitment of juveniles was closely linked to the breeding period, beginning in September.

• 한국약용작물학회지
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• 제24권1호
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• pp.27-30
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• 2016

Background : This text was conducted to evaluate the distribution, shape characteristics and habitat condition of Crypsinus hastatus in Buyeo Korea. Methods and Results : In Buyeo, Crypsinus hastatus was distributed at an altitude of 31.2 m, a slope of 82.5% and a distance from river water of 27.2 m. The leaf blade was oblong, 2.7 cm long, 1.2 cm wide with a petiole length of 2.3 cm. The total population comprised 2,100 individuals, with the highest proportion being individuals with a leaf blade of length 0.5 - 1 cm. The temperature and light intensity of the growth point were lower, but the humidity higher, than that of growth around. The chemical properties of the soil were as follows: pH 4.42, organic matter 77.99 g/kg, electrical conductivity 0.50 dS/m, nitrate nitrogen 20.50 mg/kg and available phosphate 165.7 mg/kg. Exchangeable cation content of potassium, magnesium, sodium and calcium was 0.35, 0.70, 0.09 and $2.04cmol^+/kg$, respectively. Conclusions : In Buyeo, Crypsinus hastatus was distributed in $5.3m^2$ area of Nakhwaam, Naeseongri and Jeongamri. However, the population of the medicinal resources seemed to decrease owing to the poor environmental conditions of the habitat.

• 암석학회지
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• 제5권2호
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• pp.161-167
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• 1996

The CSD (crystal size distribution) of diopside crystals in the calc-silicate hornfels of the Hwanggangni Formation intruded by the Cretaceous Daeyasan granite shows the patterns of continuous nucleation and growth. There is correlation between the distance from the intrusion contact and the slopes from the linear part of log(population density) vs. size diagrams. In the log(population density) vs. size diagrams of the samples systematically collected from the intrusion contact, two different groups are recognized; the slopes for the samples near the intrusion contact (horizontal distance from the contact less than 50m) are gentler (1500$cm^{-1}$) than those for the samples away from the intrusion contact (2500$cm^{-1}$, distance from the contact greater than 100 m). These differences may reflect the differences in growth rates and crystallization time, or the differences in diopside-forming reactions. All of the log(population density) vs. size diagrams show depletion of smaller crystals. The observed depletion may be due to Ostwald ripening or the changes in nucleation rates as the reactant phases diminishes. Similar grouping is also possible for the observed degree of depletion of smaller crystals; the depletion decreases with increasing distance from the intrusion contact, suggesting temperature-dependent rates of Ostwald ripening.

• Journal of Applied Biological Chemistry
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• 제48권4호
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• pp.161-166
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• 2005

Among 24 isolates of fluorescent Pseudomonads, 5 isolates named as LPT1, LPT2, LPT3, LPT4 and LPT5 were screened in vitro for their nematicidal activity against cyst forming nematode, Heterodera cajani causing patchiness, poor and stunting growth besides discoloration in Sesamum indicum. Second stage juveniles of H. cajani hatched from egg masses were collected from roots of host plant and subjected to fresh and heat-treated culture filtrate of isolates for 24 h. Mortality of H. cajani was recorded on the basis of parameters used for test organism bioassay. Among these isolates, Pseudomonas aeruginosa LPT5 caused maximum mortality towards second stage juvenile of H. cajani in vitro. Five isolates were used as seed coating for the management of cyst forming nematode H. cajani on sesame in green house condition. The strains LPT5 was better than the other strains in reducing the population of H. cajani both in vitro and in vivo. The reduction in cyst and juveniles population was found to be 49 and 60%, respectively when seeds were coated with strain LPT5. Among other strains, LPT4 was also found to inhibit the cyst and juveniles population 12 and 36% respectively. Increases in early vegetative plant growth parameters recorded in both in vitro and in vivo further revealed the significance of indigenous bacteria in comparison to introduced strain.

• 한국균학회소식:학술대회논문집
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• 한국균학회 2014년도 추계학술대회 및 정기총회
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• pp.48-48
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• 2014

Arbuscular Mycorrhizal Fungi(AMF) is widespread symbiont forming mutualistic relationship with plant root in terrestrial forest in ecosystem. They provide improved absorption of nutrient and water, and enhance the resistance against plant pathogen or polluted soil, therefore AM fungi are important for survival and maintaining of individual or community of plant. For last decade, many studies about the functional variation of AM fungi on host plant growth response were showed that different geographic isolates, even same species, have different effect on host plant. However, little was known about functional variation of AM fungal isolates originated single population, which provide important insight about intraspecific diversity of AMF and their role in forest ecosystem. In this study, four AM fungal isolates of Rhizophagus clarus were cultured in vitro using transformed carrot (Daucus carota) root and they showed the difference between isolates in ontogenic characteristics such as spore density and hyphal length. The plant growth response by mycorrhizas were measured also. After 20 weeks from inoculation of these isolates to host plants, dry weight, Root:Shoot ratio, colonization rates and N, P concentration of host plant showed host plant was affected differently by AM fungal isolates. This results suggest that AM fungi have high diversity in their functionality in intraspecific level, even in same population.

• 한국동물위생학회지
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• 제30권3호
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• pp.459-466
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• 2007

The Korean Musk deer (Moschus Moschiferus) is endangered due to heavy hunting and Massive destructions of natural habitat. They are included in CITES appendix II. In addition they are designated as a precious natural product in 1968 and listed as endangered species by the Government and Cultural Heritage Administration. At present, the number of musk deer in Korea is smaller than minimum viable population. Without increment of the population size, natural restoration is impossible. It is necessary to develop the artificial growth and re-enforcement methods in order to conservation Korean musk deer. Furthermore, It is necessary to ensure that we have an adequate individual group for artificial growth and re-enforcement. To ensure that we have an adequate individual group, it is necessary to know ecology of musk deer. This study is conducted to confirm and investigate of habitat of musk deer in order to capture individual musk deer. we investigated, confirmed habitats, found traces and captured using trap and decoy. Captured musk deer is male and 5.5 kg, this have canine tooth of 1.5cm, is estimated 15 months old. After capture, we measured each parts of body and tested to research of parasite infection. Strongyloides papillous was founded in the feces. It is essential to get healthy individual and establish of artificial growth technique.

• ALGAE
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• 제32권4호
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• pp.337-347
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• 2017

Silvetia siliquosa is an ecologically and commercially important brown alga that is harvested from its natural habitats, but its population has recently been diminishing along the Korean coast. To develop new techniques for algal population restoration, we tested two newly developed transplantation methods (using polyethylene ropes and natural rock pieces) at two study sites, Gwanmaedo and Yeongsando, on the southwest coast of Korea, from May to November 2014. The transplants on polyethylene ropes showed significantly greater survival, maturity, and growth than those on natural rocks at both study sites. Newly recruited juveniles (<3 cm) of S. siliquosa increased remarkably from May to December near the transplants on polyethylene ropes and natural rocks.Therefore, we suggest that transplantation using polyethylene ropes is more effective than using natural rocks to restore the population of S. siliquosa in Korea.

• 한국응용곤충학회지
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• 제19권1호
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• pp.31-34
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• 1980

선충 밀도에 따른 피해정도와 피해허용 한계수준을 알기 위하여 Pot시험을 실시한 결과 접종 2개월후부터 밀도별로 생육차가 나타났으며 씨스트 16마리 이상 접종구는 무접종에 비하여 생육과 근류발육이 현저하게 떨어졌다. 또한 접종선충수가 적을수록 증식이 잘되어 수확시의 씨스트수는 처리구간에 별차이가 없었다. 피해 허용한계 밀도는 파종시 토양 500g당 씨스트 20개내외였다.