• Proceedings of the Korean Society of Crop Science Conference
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• 1997.10a
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• pp.100-101
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• 1997

• Korean Journal of Plant Resources
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• v.17 no.3
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• pp.248-256
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• 2004

Dendropanax morbifera Lev.(Araliaceae), Korean endemic and evergreen small tree is a component of evergreen forest and mainly distributed in sourthern region and islands in Korea. The ecological characteristics of 4 natural stands of D. morbifera.(Sundol, Suak, Hannam, and Sangho populations in Cheju island) were studied. In most of the D. morbifera natural stands, the following tree species appeared predominantly: Castanopsis cuspidata var. sieboldii, Carpinus laxiflora, D. morbifera, Quercus glauca, Quercus myrsinaefolia, Camellia japonica, and Acer pseudo-sieboldianum. Two tree species, such as C. cuspidata var. sieboldii and C. laxiflora appeared in the all investigated stands. D. morbifera occupied 17.2% of the upper story, 12.9% of the middle story, and 10.3% of the lower story, respectively. The distribution patterns by Morisita' s Index showed that D. morbifera was distributed randomly in the three stories. The frequency distribution of DBH D. morbifera species showed reverse J-shaped, therefore it seems to remain as a dominant species.

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 1996.10a
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• pp.81-84
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• 1996

퇴비화온실의 재배환경은 퇴비화 과정중에 발생하는 발효열이나 탄산가스로 인하여 관행온실과는 큰 차이가 있다. 본 연구는 퇴비화과정중에 발생하는 암모니아가스의 동태와 퇴비화에 수반되는 환경의 변화가 토마토의 생육에 어떠한 영향을 미치는지 구명하고자 관행온실과 퇴비화온실의 환경변화를 추적하면서 토마토의 생장과 수량 및 과일의 품질을 비교하였다. (중략)

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 1975.07a
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• pp.110.2-110
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• 1975

성분이 동일한 완제품간장을 3$^{\circ}C$, 15$^{\circ}C$, 5$^{\circ}C$로 각각 달리하여 밑봉과 개봉상태로 1년이상 보존하면서 경시적으로 성분의 변화및 미생물의 동태를 관찰하고 동시에 시판 간장중에 생육하는 미생물을 계측한 결과는 아래와 같다. (1) 총질소, 색도, 비중, 석염의 함량은 저장기간의 경과에 따라 증가 현상을 나타내었으며 고온(3$0^{\circ}C$, 15$^{\circ}C$), 개봉방치 상태에서는 저온(5$^{\circ}C$)밀봉방치 상태에 비하여 증가현상은 현저하였다.(중략)

• Korean Journal of Agricultural and Forest Meteorology
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• v.23 no.2
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• pp.89-99
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• 2021

This study was carried out to understand how factors of decomposition such as quality of the substrate (tree species), forest types, and soil·meteorological conditions affect decomposition rates and dynamics of carbon (C) and nitrogen (N) of branches in adjacent Pinus densiflora and Quercus variabilis stands in Sancheong and J inju in Southern Korea. The branch bags (30 cm × 30 cm) with branch samples (a diameter of 2.0 - 4.0 cm and length of 10 cm) were placed on the forest floor at each stand in May 2018. The branch bags were collected in August and November 2018, February and May 2019, respectively. The decomposition rates of branches in P. densiflora stands were 4.49 % for Sancheong, and 5.75 % for Jinju. Whereas, the decomposition rates in Q. variabilis were 20.01 % for Sancheong, and 24.68 % for Jinju, respectively. The decomposition of branches was more rapid in Q. variabilis compared with P. densiflora in both regions. C and N in decomposed branches were more mineralized in Q. variabilis, whereas C and N were more accumulated in P. densiflora. These results indicated that the decomposition rates, C and N of decomposed branches may be affected by differences in substrate quality such as initial N concentration and C/N ratio rather than differences between both regions including different environmental factors.

• Korean journal of applied entomology
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• v.23 no.1 s.58
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• pp.49-55
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• 1984

This study was carried out to investigate the biological performance of the brownplanthopper, Nilaparvata lugens Stal, reared on rice plants at different growth stages; maximum tillering, booting, heading with and without panicles, and milking. The results obtained are as follows: The rice plants at the maximum tillering stage gave the best in the longevity, oviposition period, and the total number of oviposited eggs for the macropterous females, and the worst with the booting stage. For the brachypterous females, however, the best results were obtained from the rice of which their panicles had removed after heading. There was no significant difference in the hachability of eggs and the developmental period of the nymphs in the next generation, but the nymphal mortality was the highest with the milking stage and the lowest with the maximum tillering and heading stage without panicles. The longest life span was shown in males derived on the maximum tillering stage, and the shortest for milking(macropterous type) or booting (brachypterous type) stages. Coefficientes of variances in longevity and number of eggs for the adults emerged from heading stage without panicles were lower than those with panicles intact, and such trend was more obvious in brachypterous adults, especially for the females. The biological performances of the BPH have close relationship with the translocated organic material at the feeding site which showed considerable difference with the growth stages of the rice.

• Journal of Korean Society of Forest Science
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• v.86 no.1
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• pp.105-111
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• 1997

Root dynamics of a pine stand at Hongcheon, Korea was assayed with two kinds of soil samplers which had been tentatively manufactured to renovate the routine soil sampler, Oakfield soil sampler. Root-mixed soil samples were collected on December of 1995, March, May, August and December of 1996 within each randomly selected 8 plots. The amount of roots collected by the two kinds of soil samplers were not significantly different at the 5% level, which indicated that the renovated sampler was more desirable to be used since the sampler showed efficiencies in time for collection and quantification than the routine sampler. The quantities of total root in 100g soils were 469mg on December of 1995, and 352mg, 473mg, 461mg, 522mg on the following March, May, August and December, respectively. That is, total amount of roots showed the smallest in Spring and reached maximum in early Winter, although the differences were not significant among each season. By the way, the alive roots and dead roots showed significant differences among season, the alive roots took about 90% from May to early December while they decreased down to some 65% from late December to March. The roots of Pinus densiflora S. et Z. took about 46% of total roots although the species comprised 70% of crown layer, and the ratio of fine-roots of the species were higher than that of other species. By the way, the dynamics of total roots and that of alive roots were quite different. Thus, the study for root dynamics such as fine roots which take a major role for mycorrhizae formation or nutrient uptake should not be inferred from the data of total root dynamics but be investigated in detail by dividing them into each class.

• Korean Journal of Environment and Ecology
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• v.35 no.4
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• pp.408-423
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• 2021

We established and monitored survey sites in seven regions of Mt. Jiri to investigate population decline and change of the Korean fir (Abies koreana) over a ten-year period from 2009 to 2018. With the exception of one site (Seseok), the six remaining ones all showed a four-layer stratification structure. The importance value of Korean firs in all of the survey areas decreased significantly by 28.5%, from 55.7% in 2009 to 39.8% in 2018. The average population of objects with a diameter at breast height (DBH) of 5cm or more in all survey sites was 711 objects/ha in 2018, and the cumulative death rate from 2009 to 2018 was 10.8%. Among the death types, DS (dead standing) was the most dominant, comprising 82.4% of the total survey area. However, in Banyabong 1, which had a high gradient of 35°, the death types other than DS accounted for 44.2%. We estimate that A. koreana can maintain a stable population as its distribution type for each diameter class in the Saeseokpyeongjeon site showed a reverse-J shape. The average annual ring growth in all survey sites was 1.09 mm/year, with the most abundant growth observed in the Seseokpyeongjeon site, which was formed mainly by a subtree layer. The growth ring survey showed the estimated average age of A. koreana population in the Byeoksoryeong and Banyabong 1 sites to be 102 and 91 years, respectively, a general downward trend of vitality since 2013.

• The Korean Journal of Ecology
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• v.28 no.5
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• pp.287-293
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• 2005

This study was conducted to evaluate the effect of the conventional pesticide application system on the rice spider community based on the quantitative investigation of arthropod community in the rice fields in Saran area, Hwasung-si, Kyeonggi-do from 1996 to 1998. Spiders were the highest dominant group comprising over 90% of all natural enemies in their density, and showed very stable yearly occurrence. In these fiekds the mean density of spiders was about 10 individuals/$0.25m^2$ during the rice growing season, and three families including Lycosidae, Tetragnathidae and Linyphiidae were very abundant. The colonization of spiders occurred in early season and they showed rapid density increase in mid-season. They maintained the highest density to the late season and their density decreased at harvest season. In the years of the low rice pest occurrence, the disturbance effect on spider community by pesticides were less. Two dominant species, Pirata subpiraticus and Pachygnatha clerki, had different population dynamics; Pirata subpiraticus showed the rapid density increase in the mid-July, and most of them remained immature stages, however, in the case of Pachygnaths clerki population, they rapidly increased in the late August and most of them remained adult stage during the late growing season.

• Journal of Ecology and Environment
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• v.29 no.3
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• pp.205-212
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• 2006

Effects of nitrogen and phosphorus fertilization on nutrient dynamics and litterfall production were determined in adjacent 41-year-old plantations of Pinus rigida Miller and Larix kaempferi Gordon on a similar soil in Yangpyeong, Gyeongggi Province. Litterfall production were significantly different among sampling dates and between the tree species, whereas it was not significantly different among the treatments. Total annual litterfall production was 6,377 kg/ha for P. rigida and 4,778 kg/ha for L. kaempferi, respectively. Litterfall nutrient concentrations of L. kaempferi were higher than those of P. rigida. For both tree species, litterfall nutrient concentrations were highest in summer when the least litterfall production occurred, and lowest in late-autumn when the greatest litterfall production occurred, except for Ca in the L. kaempferi stand. The amount of total organic matter in the forest floor of P. rigida and L. kaempferi plantations were 24,296 kg/ha and 10,763 kg/ha, respectively. Forest floor N and P contents were 126, 10 kg/ha for P. rigida and 102, 8 kg/ha for L. kaempferi, respectively.