• Korean journal of applied entomology
• /
• v.51 no.2
• /
• pp.149-152
• /
• 2012

The larvicidal activities of Piper nigrum fruit methanol extracts and its constituents against larvae of the diamondback moth, Plutella xylostella, were investigated using the leaf dipping method. Administering the P. nigrum methanol extract resulted in 100 and 97% mortality against diamondback moth larvae at 5.0 and 2.5 mg/mL concentrations, respectively. Larvicidal activities of the P. nigrum fruit-derived piperidine alkaloids, piperine, and N-isobutylamide, as well as pellitorine, guineensine, pipercide, and retrofractamide A against P. xylostella varied according to test compound. Based on the 48 h $LC_{50}$ values, the most toxic compound to diamondback moth larvae was guineensine (0.013 mg/mL) followed by retrofractamide A (0.020mg/mL), pipercide (0.033mg/mL), and pellitorine (0.046 mg/mL). The $LC_{50}$ value of piperine was >0.5 mg/mL.

• The Korean Journal of Mycology
• /
• v.28 no.1
• /
• pp.26-31
• /
• 2000

We isolated genomic clone of FVFD16 and FVFD30 gene specifically expressed during fruit body formation of Flammulina velutipes [(Curt: Fr.) Sing] and determinated the sequences. The FVFD16 gene is including two introns in open reading frame, and FVFD30 gene is including four introns. The introns were matched GT/AG rule. The FVFD16 and FVFD30 genes contained CAAT box with similarity arrange and TATA box. CT-rich region was presented before the transcription start point. FVFD30 gene is investigated that expected the most activity of CCACC arrange. The result of FVFD16 gene analysis showed 80% homology by cDNA clone that is gene family. From the results of genomic southern blot analysis, we presumed more than two copy number gene family of FVFD16 and FVFD30 gene.

• Mycobiology
• /
• v.36 no.4
• /
• pp.249-254
• /
• 2008

Minimal growth inhibitory concentrations (MICs) of chitosan acetate (M.W. 60 kDa) on heterotrophic bacteria (strains MK1, S, and R) isolated from the soft-rotten tissues of Neungee mushroom (Sarcodon aspratus) were measured. The slimy substance produced by the MK1 strain was responsible for the diseased mushroom’s appearance. The S and R strains were members of the Burkholderia cepacia complex. These strains showed different levels of susceptibility toward chitosan acetate. The MIC of chitosan acetate against the MK1 and S strains was 0.06%. The MIC against the R strain was greater than 0.10%. Survival fractions of the MK1 and S strains at the MIC were $3\;{\times}\;10^{-4}$ and $1.4\;{\times}\;10^{-3}$ after 24 h, and $2\;{\times}\;10^{-4}$ and $7\;{\times}\;10^{-4}$ after 48 h, respectively. Survival fractions of the R strain after 24 and 48 hr at 0.1% chitosan acetate were $1\;{\times}\;10^{-2}$ and $6.9\;{\times}\;10^{-3}$, respectively. Compared to the MK1 and S strains, the low susceptibility of the R stain towards chitosan acetate could be due to the ability of the R strain to utilize chitosan as a carbon source. Thirty-eight percent of Neungee pieces treated in a 0.06% chitosan acetate solution for $2{\sim}3$ second did not show any bacterial growth at 4 days, whereas bacterial growth around untreated mushroom pieces occurred within 2 days. These data suggest that chitosan acetate is highly effective in controlling growth of indigenous microorganisms on Neungee. The scanning electron micrographs of the MK1 strain treated with chitosan revealed a higher degree of disintegrated and distorted cellular structures.

• Journal of the Korean Association of Geographic Information Studies
• /
• v.11 no.2
• /
• pp.28-37
• /
• 2008

In this study, we perform land surface monitoring of NDVI (Normalized Difference Vegetation Index) variation by using remote sensing data during 1999-2005 over North Korea, which can't easily access to measure directly land surface characteristics due to one of the world's most closed societies. North Korea forest region has most abundant forest vegetation - so called Lungs of Korea in the Korea peninsula. NDVI represents vegetation activity used in many similar studies. In this study, we detect vegetation variation and analysis factors of the change over North Korea. By using variation of NDVI, we can infer that effect of drought over North Korea, and reduced vegetation indices by typhoon in North Korea. Land surface type except barren ground with decreased NDVI value is considered as when North Korea region was suffering from drought and typhoon effects, which show lower than mean of 7-year NDVI value. Especially, in recently, the food production of North Korea with political and economical issues can be inferred indirectly these trends by using estimated output data from this study.

• Korean Journal of Environmental Biology
• /
• v.38 no.3
• /
• pp.392-403
• /
• 2020

This study analyzed the distribution characteristics of invasive alien plants on the islands of the Korean Peninsula. Ten species, Rumex acetosella, Sicyos angulatus, Solanum carolinense, Ambrosia artemisiaefolia var. elatior, Ambrosia trifida, Aster pilosus, Eupatorium rugosum, Hypochaeris radicata, Lactuca scariola, and Paspalum distichum were present on 68 islands. These ecosystem-disturbing invasive alien plants appeared extensively on the islands of Gyeonggi province and Jeollanam province. The proportion of the plants on the inhabited islands (41 places, 2.15 species on average) was higher than that on the uninhabited islands (27 places, 1.07 species on average). This means that the distribution of invasive alien plants was closely related to human activity. The distribution of Ambrosia artemisiaefolia var. elatior(32 islands) and Rumex acetosella (31 islands) was the widest, and there were distinct distribution differences according to species. In the island area, the physical environment is poor compared to the mainland, and the native space is limited. Therefore, when invasive alien species enter and settle on the island, the native island plants can be damaged more than those on the mainland. In this regard, the discussion of the distribution of invasive alien plants in the island region can contribute to the conservation of biodiversity in the region.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.20 no.4
• /
• pp.63-75
• /
• 2017

This study carried out for establishing the synthetic restoration plan to improve ecological quality of Mt. Mudeung National Park based on the results of conservation value assessment for yellow-throated marten habitats. Yellow-throated marten has significant implications as umbrella species for the wildlife habitats conservation, therefore, this species could be used to ecological restoration plan of the damaged forest ecosystem in Mt. Mudeung National Park. In this study, we diagnosed the quality of yellow-throated marten habitats in Mt. Mudeung National Park based on five natural and two artificial factors. In addition, we evaluated the integrity of each zone divided by trails quantitatively based on land use intensity. As a result, forest landscape quality in Mt. Mudeung National Park was influenced greatly by human activity and the degree was depended on the intensity of trails. Therefore, in this study, we suggested the closing of trails composed of the illegal and 36 legal trails. And then, we modeled the changes of habitats quality of Yellow-throated marten for each closing step. As a result the area of core habitats increased by two times and wildlife habitats quality improved in the whole area of the Mt. Mudeung National Park. As a result, the results of this study indicate that man-made linear landscape elements play a key role in the quality of habitats for predators, which require large habitats area like the Yellow-throated marten. Therefore, in order to establish an ecological restoration plan in the mountainous area, we recommend the concept of the linear landscape should be applied with the concept of area landscape.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.7 no.2
• /
• pp.79-86
• /
• 1987

This study was carried out to investigate the relationships and the variations of agronomic characteristics in the shoot and root part of grasses for the basic data of the development, the management and the utilization of pasture in the forest. This study was conducted with 0% (full sunlight), 25%, 50% and 75% of shading degrees after orchardgrass, timothy, perennial ryegrass, ladino clover and orchardgrass dominated mixture were planted on Aug. 25 in 1984. The results are summarized as follows: 1. Dry matter yield in 25% of shading was increased 3-1 7% compared with 0% (full sunlight), while 50 and 75% of shading were decreased 28-35% and 44-60%, respectively. Dry matter yield of timothy, perennial ryegrass and ladino clover were decreased 10, 8 and 33%, respectively, compared with orchardgrass, but there was little difference between orchard grass and mixture. 2. Root distribution by different shading degrees was the maximum at 25%, followed by 0, 50 and 75% of shading degrees. Root distribution among different species was the maximum at orchardgrass, followed by perennial ryegrass and timothy. Especially, root distribution of timothy was very little compared with different species. And significantly positive correlation was observed in the relationship between root weight and dry matter yield (r=0.8 102**). 3. The physiological activity of root by different shading degrees was declined by more shading. 4. The length and the percentage of blade by different shading degrees was an increase tendency by more shading. The length and the percentage of blade among different species was followed by timothy, perennial ryegrass and orchardgrass, in that order. And the correlation between the percentage of blade and dry matter yield was significantly negative.

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

• Journal of the Korean Association of Geographic Information Studies
• /
• v.6 no.3
• /
• pp.11-20
• /
• 2003

Many-sided approach methods are being demanded to solve environmental problems in urban areas. One of these methods will be to manage forests scattered in urban areas efficiently. This paper is to grasp the change of land use and landscape indices in Mt. Ap, Daegu, and to analyze the change of landscape structure. Mt. Ap is near Daegu Metropolitan, so under unnatural interferences of human activity persistently. The results of above analysis run as follows: First, the north of the case area is connected to forest, and keeps stable equilibrium ecologically, while the other parts of it suffer from rural exodus and side effects of urbanization which has been completed since 1980. Second, according to the area-rate change of each landscape element, a cultivated areas has been converted into urban one, especially Pinus densiflora forests and paddy fields into mixed forests and urban areas. Finally, most of plantations have been converted into deciduous forests and mixed forests in failure of adaption of plants in burned areas rather than owing to factitious interference.

• Korean journal of applied entomology
• /
• v.45 no.2 s.143
• /
• pp.189-194
• /
• 2006

Fumigant toxicity of 18 plant essential oils were tested against the adults of oak longicorn beetle, Moechotypa diphysis. Among them, eucalyptus, rosemary and pennyroyal oils showed 100% mortality and sage oil showed 85% mortality at 10 $\mu\ell/\ell$ (air) dose. Eucalyptus and rosemary oils showed 100% mortality within 6 hr after treatment at 10 $\mu\ell/\ell$ (air) dose. GC and GC/MS analysis of the four essential oils and bioassay of their components revealed that 1,8-cineole (a major component of eucalyptus, rosemary and sage oils), thujone (a major component of sage oil) and pulegone (a major component of pennyroyal oil) showed higher adulticidal activity than others.