• The Korean Journal of Ecology
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• v.6 no.1
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• pp.33-44
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• 1983

Vegetatiion structure and population dynamcis of pine needle gall midge were investigated from 1980 to 1982 at the southern part of Palgong mountain near Daegu. The results of investigation at the areas of A (pure stand), B(30% mixed forest) adn C(60% mixed forest) were as follow; Vegeation of 3 areas were not classified by the species diversity, but by the unequal distribution of Alnus hirsuta, Robinia pseudo-acacia, Lespedeza cyrtobotrya, Quercus variabilis and vitality of Pinus densiflora at the area C was low, due to shadow by broad-leaf trees. Soil environmental factors at 3 areas not characteristic, but the average of humus contents showed high significance and the order was A

• Journal of Korean Society of Water and Wastewater
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• v.18 no.2
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• pp.242-246
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• 2004

Dissolved air flotation (DAF) is an effective solid/liquid separation process for low density particles, such as algal flocs, humus materials and clay particles produced from low turbidity water. The fraction of humic substances for natural organic matters (NOMs) are considered problematic in water because it can readily react with chlorine to form harmful by-products (trihalomethanes) and can be exposed to undesirable color, tastes and odors in drinking water. A broad class of NOMs includes fulvic acid, humic acid and humin. This paper will discuss the results from a study that performed with a DAF pump process using synthetic wastewater contained humic substance. Batch jar tests were performed to evaluate coagulant dose and recycle ratio on flotation efficiency.

• Journal of Plant Biology
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• v.33 no.3
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• pp.173-182
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• 1990

To investigate the structure of the plant community structure of Mt. Yongmun in Kyonggi-do, fifty-four plots were set up by the clumped sampling method. The classification by TWINSPAN and DCA ordination were applied to the study area in order to classify them into several groups based on woody plant and environmental variables. By both techniques, the plant community were divided into two groups by the aspect. the dominant species of south aspect were Pinus densiflora, Quercus aliena, Q. mongolica, Carpinus laxiflora and of north aspect were Q. ongolica, Fraxinus rhynchophylla. The successional trends of tree species in south aspect seem to be from P. densiflora through Q. serrata, Q. aliena, A. mongolica to C. laxiflora. As a result of the analysis for the relationship between the stand scores of DCA and environmental variables, they had a tendency to increase significantly from the P. densiflora and Q. mongolica community to C. laxiflora and F. rhynchophylla community that was the soil moisture, the amount of soil humus and soil pH.

• Korean Journal of Plant Resources
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• v.11 no.1
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• pp.86-92
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• 1998

The photosynthetic rate (LPS)in the field was higher in the non-shading condition than in the shading. The fertilizer application was somewhat higher than non-fertilizer application. After humus application at 50% sading condition the growth and LPS increased with Ligularia fischeri. The maximum LPS at 80% shading was 22.3${\mu}{\textrm}{m}$mol/m/s with N-fertilizer application . Except Aster tataricus and Solidago virge-aurea. var. asiatic where the maximum LPS at non-shading and N-fertilizer application were 38.68 and 35.28${\mu}{\textrm}{m}$mol/m2/s. While the maximum LPS of Aster scaber was 30.01${\mu}{\textrm}{m}$mol/$m^2$/s at non-shading and non-fertilizer application. the growth rate was higher shading and fertilized conditions than non-shading and non-fertilized . The most effective shading condition was 50% , but leaf ration was highest in the 80% . But a. tataricus was favorable at non-shading and N-feritlized conditions.

• 한국방재학회:학술대회논문집
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• 2008.02a
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• pp.803-806
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• 2008

LEACHN is the computer simulation model which can be used to simulate field-scale N transformations and movement and has three organic pools (plant residue, manure, and soil humus), three inorganic pools (urea, nitrate and ammonium) and plant. Pot experiment operated May to October in 2004. LEACHN simulated the nitrogen movement and transformation in soil using method of PEST and trial and error.

• Korean Journal of Organic Agriculture
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• v.8 no.2
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• pp.97-110
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• 2000

An organic agriculture should be managed by mixed farming in farm unit as a closed recycling system. Due to restricted purchased of fertilizers from outside, organic farmer has to deal with limited amount of nutrient source in farm unit. Especially the supply of the essential nutrient, nitrogen, mostly depends on legumes fixing nitrogen optimizing the site-adapted crop rotation. Dynamics of humus and metabolic plant carbon and active soil carbon compartment in active and passive humuspool by rotation system was explained, and dynamics of potentially mineralizable nitrogen in organic nitrogen and biomass was discussed. It was also discussed comparison of ammonia emission, potential greenhouse effect, primary energy input, acidification potential, CO2 emission between organic and conventional farming, the nitrate-nitrogen dynamic in the soil profile by organic, integrated and conventional farming system. In conclusion, it was suggested for Korean Organic Agriculture that the importance of legumes and green manures in rotation system for increase/maintenance of soil ferfility, and was pointed out the need of investment for environment impact of Korean organic farming implement.

• Journal of Species Research
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• v.8 no.2
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• pp.233-237
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• 2019

Mites in the family Veigaiidae, order Mesostigmata, subclass Acari are widely distributed in subsoil habitats. They are mostly free-living and predaceous on small arthropod eggs and larvae, and prefer habitats with rich organic matters including litter and humus layers of forest soil. The genus Veigaia Oudemans, 1905 of the family Veigaiidae (Acari: Mesostigmata) is one of the ubiquitous genera from the Holarctic Region. Until now, only two genera and five species of the family were recorded from Korea. Here we provide a report of the species Veigaia tibbetsi Farrier, 1957 with detailed redescription. Even though V. tibbetsi had appeared in some ecological literature, this is the first record of this species in Republic of Korea. This species was mostly found from pine forest(Pinus densiflora) of northeastern mountainous parts of the Korean Peninsula, in Gangwon and Gyeongbuk Provinces. We provided some ecological characteristics of the family Veigaiidae, which will help to further exploration of acarine biodiversity.

• Korean Journal of Soil Science and Fertilizer
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• v.21 no.3
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• pp.254-263
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• 1988

Contents and distribution of amino acids in the humic acid and fulvic acid fractions of different types ($R_p$, B, A, P) were investigated. Extracted humic and fulvic acids were purified and analyzed. The results are summarized as the following: (1) Composition of Humus The total humus ($H_T$), amount of humic acid (a), amount of fulvic acid (b), and ${\Delta}logK$ all decrease in the order of $R_p$ > B > A > P type. The same trend was observed in the total nitrogen and carbon. (2) Contents and composition of amino acids in humic acids. 1) The total amounts of amino acids in the humic acid fraction of different types were in the following order for soils under coniferous forest trees: $R_p$ > B > A > P type, but for soils under deciduous forest trees the order was P > A > $R_p$ > B type. There were positive correlationships between total amino acids and total carbon and ${\Delta}logK$ for humic acids from soils under coniferous forest trees, but a negative correlationship was existed. between total amino acids and C/N ratios. No significant correlation was found for samples taken from soils under deciduous forest trees. 2) The ratios of one group of amino acids to the others were compared. The ratios of acidic amino acids were in the order of P > $R_p$ > B > A type. those of neutral amino acids followed the order of $R_p$ > B > A > P type and those of the basic amino acids were in the order of B > A >$R_p$ > P type for soils under coniferous forest trees. Contents of total amino acids were in the order of the neutral > the acidic > the basic amino acids. For the soils under deciduous forest trees the order of the ratio was different. Acidic amino acids followed the order of A > P > B > $R_p$ type, neutral ones followed the order of P > $R_p$ > A > B type, and the basic amino acids did the order of $$P{\geq_-}$$ A > B $$\geq_-$$ $-R_p$ type where the difference was very small. 3) In general aspartic aicd, glycine and glutamic acid were the major components in all samples. Histidine, tyrosine and methionine belonged to the group contained in a small amount. (3) Contents and composition of amino acids in fulvic acids. 1) The total amounts of amino acids of different types of fulvic acids were in the order of $R_p$ > B > P > A type regardless of origin of samples. There were positive correlationships observed between the toal amino acids and total carbon and ${\Delta}logK$ for soils under coniferous forest trees. For soils under deciduous forest trees, positive correlationships were observed among total amino aicds, total nitrogen, total humus ($H_T$), total humic aicd (a), and ${\Delta}logK$, but a negative correlationship existed between total amino acids and C/N ratio. 2) Thr ratio among acidic amino acids, neutral amino acids and basic amino acids of different types were $R_p$ > B > P > A type. In this respect there was no difference between the two soils. 3) In general glycine, aspartic acid, and alanine were the major constituents in all samples of different types, while tyrosine and methionine were contained in a small amount. Virtually no amount of arginine was measured.

• Korean Journal of Agricultural Science
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• v.38 no.1
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• pp.25-30
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• 2011

This study was conducted to investigate changes on burned areas after a forest fire in Geyjoksan which occurred in April 2000. Both soil physicochemical properties and vegetation present were analyzed in burned and unburned sites of pinus densiflora according to two slope aspects(south and north-facing slopes). The results of the analysis are as follows. The appearance species of vegetation were 21, 15 and 18 for burned site, burned site-1 and burned site-2 of pinus densiflora community respectively, indicating that the occurrence of forest fire and slope aspects affect vegetation appearance. The pH values at 0~10cm soil depth of unburned and burned sites of pinus densiflora community were 5.04 and 5.12 respectively with no significant difference between them. Mean organic matter, total nitrogen and available P also had no significant difference. This results indicate that the forest recover its former pH, total nitrogen, mean organic matter and available P over time after a forest fire. North-facing slope had relatively higher soil water content thus implying that its pH values of soil lower than south-facing slope. On the other hand, south-facing slope had high organic matter and available P content of soil as compared to north-facing slope. With south facing slope having high water contents, humus was accumulated due to slow organic matter decomposition. The pH values also decreased due to organic acids from humus. However, we observed that organic matter and P concentration in soil increased.

• Fire Science and Engineering
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• v.26 no.1
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• pp.49-60
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• 2012

The change in fuel moisture in accordance with the number of days after rainfall is an important factor in predicting forest fire dangers and supporting forest fire rangers. Therefore, in order to clear up these forest fire occurrence conditions, forest fire danger levels for surface fuel 0.6 cm or lower, 0.6~3.0 cm, 3.0~6.0 cm, and 6.0 cm or above by fallen leaves layer, humus layer, soil layer, and diameter after rainfall of 5.0 mm and higher in accordance with tree density in 2008, 2009 Spring/Autumn Young Dong region have been analyzed. Research showed an approximate 17 % fuel moisture which is a dangerous forest fire occurrence level after 5 days from rainfall in medium-density areas and 3 days after rainfall in loose-density areas of Spring time in the fallen leaves layer. On the other hand, the humus layer showed a 40 % or higher fuel humidity even after 6 days from rainfall regardless of the season, while the upper and lower parts of the soil layer had a little change. In loose-density areas with 0.6 cm or less surface fuel per diameter in Spring time, the fuel humidity displayed a dangerous level in fire forest occurrence after 3 days, and 4days in medium-density areas, and for loose-density areas with 0.6~3.0 cm surface fuel per diameter in Autumn time it showed a dangerous level in forest fire occurrence after 3 days, and for medium-density areas, 5 days. In the case of 3.0~6.0 cm of fuel moisture per diameter in both Spring and Autumn times, even after 6 days, low and medium-density areas showed that they maintain fuel moisture and therefore the dangers of forest fires were very low, and in the case of 6.0 cm or higher, it showed 25 % or higher fuel moisture even after 6 days from rainfall regardless of the season.