• Korean Journal of Environment and Ecology
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• v.16 no.1
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• pp.87-93
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• 2002

The tree of heaven naturalized plant grows in the various habitats of the city. The principal reason is that it is reproduced not only through sexual reproduction but through asexual reproduction. By the spreading of sucker and a bud appearance of the seed it forms a group easily inside the city habitat. The distribution of seed and spreading of the seedlings of the tree of heaven were investigated like the followings. As the result of the sexual reproduction by the seed and hangs in cluster farm, 350 individuals are germinated at the Namsan the best environment, and 50 individuals at Toegyewon Rotary These seeds are dispersed by the effect of wind and geographical factor. Because the northwest wind is blowing mainly from late autumn to early spring, it is dispersed in the south. In Toegyewon Rotary, a slant site, is dispersed mainly by down the site. Compared with width of crown, the seedling of a seed germination are distributed outside more than inside the crown and the seed is spreaded until the maximum 7.5 times of crown width at the investigated area. 1 year seedlings appeared as a group at the place of 2-4 times of the crown (in 20m from the crown, 75% distribution). Considering the distribution by the seed scattering of the tree of heaven, there is a possibility of sudden individual increase even in the deteriorated city environment. So this possibility shows that we need to consider the protection of the city soil, and the species variety decrease resulted from the successful competition to the other species.

• Korean Journal of Agricultural and Forest Meteorology
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• v.5 no.1
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• pp.24-29
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• 2003

This study was conducted to investigate vertical movement properties of precipitation passing forest stands (Pinus densiflora and Pinus rigida stands) in Chunchon, Kangwon-do. The results were as follows: The pH range of precipitation was 4.08∼7.08, and the average pH showed 6.2$\pm$0.7. The average pH of the Pinus densiflora stand showed that the stemflow was 5.9$\pm$0.9, and the throughfall was 6.0$\pm$0.8. The pH value of stemflow and throughfall in the Pinus rigida stand was lower than for the Pinus densiflora stand. Changes of the cation concentrations in two different stands, $Ca^{2+}$, increased more than the $Mg^{2+}$, $K^{+}$, and N $a^{+}$ions. Anions, S $O_{4}$$^{2-}$ and N $O_{3}$$^{[-10]}$ increased more than C $l^{[-10]}$ . Leaching and washout for each species differed by precipitation and influence of tree organs (crown, branch, stem, etc.).etc.).

• Korean Journal of Environment and Ecology
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• v.18 no.4
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• pp.351-358
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• 2004

This study was achieved to investigate the distribution state and the characteristic of Ageratina altissima community in five districts(90.15$\textrm{km}^2$), north of Seoul, Korea. Total distribution area of Ageratina altissima community was 1,860,805$m^2$ and the distribution rate of Ageratina altissima community was 23.7% in Yongsan-gu, Seoul and it was 13.7% in Joong-gu, Seoul including the Namsan-mountain. As a result of correlation between Ageratina altissima community and the actual vegetation, in case of the whole sites Ageratina altissima community was distributed mainly in the Robinia pseudo-acacia forest and in case of Namsan-mountain area it was distributed mainly in the lower layer of the Pinus densiflora forest especially. In case of the whole sites, the distribution ratio of Ageratina altissima community was highest in the Pinus koraiensis forest; on the other hand, it was highest in the Robinia pseudo-acacia forest with planted area excepting the Namsan-mountain. As a result of correlation between Ageratina altissima community and Green Covered Ratio(GCR), the more the distribution ratio of Ageratina altissima community was heigher, the more GCR was higher in case of canopy and understory layer. Especially the distribution ratio of Ageratina altissima community was most high where GCR was over 50%. As a result of correlation between Ageratina altissima community and aspect, Ageratina altissima community was distributed mainly to the west, so we suppose that Ageratina altissima community was distributed mainly in the lower layer of the Robinia pseudo-acacia forest which has fine canopy in the west. We should improve the Robinia pseudo-acacia forest to multi-layer natural forest to control the flourishing Ageratina altissima community in the long term.

• Korean journal of applied entomology
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• v.48 no.4
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• pp.447-451
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• 2009

Locust gall midge (LGM), Obolodiplosis robiniae (Haldeman) (Diptera: Cecidomyiidae), is a cecidomyiid insect forming roll-up galls on leaves of Robinia pseudoacacia Linnaeus (Fabaceae). LGM, known as native to North America, was reported from Korea and Japan in 2002. LGM was observed weekly or biweekly to clarify their voltinism and distribution within the crown of the host tree in two sites of Osan and Siheung in Korea from May to August, 2007. Density of LGM was investigated based on the number of larvae per leaf. Two generations of LGM were observed in Siheung site whereas three generations in Osan site during the present study. The result indicated that LGM had at maximum three generations per year. The density of LGM in Osan was higher in the upper crown of the host trees than middle or lower part. In Siheung, LGMs were distributed more on the exterior of the lower crown than the interior. The average number of larvae per gall was $3.3{\pm}0.1$ and $2.8{\pm}0.1$ individuals per leaf in Osan and Siheung, respectively.

• Horticultural Science & Technology
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• v.32 no.4
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• pp.454-462
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• 2014

This study was carried out to determine the effect of tree height on light transmission, spray penetration, tree growth performance, fruit quality attributes, and labor productivity in the slender-spindle system of 'Hongro'/M.9 apple trees. With increasing tree height, the light penetration into the internal parts of the canopy decreased, especially in the lower canopy. Leaf area index (LAI) increased with increasing tree height, thereby leading to a reduction in the extent of spray penetration into the interior of the canopy. With increasing tree height, shoot growth was more vigorous but produced slender shoots in the upper canopy compared to the lower canopy. Although the soluble solid content and coloration of fruit decreased, there was no difference in fruit firmness and acidity. In addition, the number of final fruit set increased, although the production of large fruit (> 305 g) decreased. The increase in tree height also significantly increased the labor required for practices such as thinning of flowers and fruits, pruning, and harvesting. Nevertheless, this problem of increased in labor input in taller trees would was eased by use of a mechanical lift. Utilizing a lift for thinning the flowers of trees 4.5 m in height saved 14.6 min per tree, compared to the use of ladder. Therefore, it is highly considerable that in order to enhance light transmission and fruit coloration, light conditions should be improved in the internal tree canopy of slender-spindle systems.

• Korean Journal of Environment and Ecology
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• v.26 no.1
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• pp.67-73
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• 2012

This study has compared the different types of forest fire sites and the unburned site at Samcheuk-si Gangwon-do by assessing the amount of litter production, nutrient concentration returned to forest floor from July 2007 through October 2010. The research showed that the average amounts of litterfall produced in the unburned site, the crown fire site(C-1), the crown fire site(C-3) and the ground fire site(G-2) were $7.74{\pm}2.56$, $1.17{\pm}0.67$, $2.97{\pm}0.44$ and $2.92{\pm}0.42ton{\cdot}ha^{-1}{\cdot}yr^{-1}$, respectively. In the unburned site, the average amounts of total nitogen(T-N), total phosphorus(T-P), potassium(K), calcium(Ca) and magnesium(Mg) returned to the forest floor were $22.20{\pm}12.43$, $1.16{\pm}0.46$, $2.68{\pm}1.44$, $16.22{\pm}4.69$ and $1.36{\pm}0.32 kg{\cdot}ha^{-1}{\cdot}yr^{-1}$, respectively whereas those in the crown fire site(C-1) were $3.73{\pm}2.31$, $0.10{\pm}0.09$, $0.27{\pm}0.20$, $2.75{\pm}2.58$ and $0.24{\pm}0.27 kg{\cdot}ha^{-1}{\cdot}yr^{-1}$, respectively. This study showed that the nutrient content returned to forest floor was higher in the following order: unburned site(Un) > crown fire site(C-3) > ground fire site(G-2) > crown fire site(C-1).

• The Korean Journal of Ecology
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• v.26 no.1
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• pp.13-18
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• 2003

We examined water flux, concentrations and contents in nutrients in precipitation, throughfall, stemflow and soil solution in natural deciduous hardwood forest(Quercus variabilis and Q. mongolica) in Chunchon, Kangwon Province. The volume of throughfall was 2∼3% higher in Q. variabilis than in Q. monglica while volume of stemflow, Ao, A and B soil solution was 10∼15% higher in Q. variabilis compared to Q. monglica. Concentrations of K/sup +/ increased in throughfall H while concentrations of Ca/sup 2+/, Mg/sup 2+/ and NO₃/sup -/ increased in Ao soil solution. The former might be related to the canopy leaching and the latter related to leaching and nitrification in Ao horizon. Nutrient concentrations in throughfall, Ao, A and B soil solution decreased with increasing amount of water and especially the decreases in concentrations of K/sup +/, Mg/sup 2+/ and Cl/sup -/ were significant. Nutrient concentrations of Ca/sup 2+/ in Ao soil solution was 1.5 times higher in Q. variabilis than in Q. mongolica. However, there were no significant nutrient concentration differences in throughfall, stemflow and A and B soil solution between the two forest types. Stemflow was less than 10% of total water volume (throughfall + stemflow) to the forest floor, and contribution of stemflow to nutrient cycling seemed to be low in the study forest.

• Journal of agriculture & life science
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• v.44 no.6
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• pp.15-22
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• 2010

This study was carried out to investigate the characteristics of ions in rainwater by stem flow, through fall and rainfall in Pinus thunbergii forest in Ulsan industrial complex area and Mt. Jiri area. pH of rainwater in Ulsan industrial complex area was low as compared with those in Mt. Jiri area. EC of rainwater in Ulsan industrial complex area was mainly high and there was twice difference in stemflow and through fall as compared to Mt. Jiri area. The concentration of major ions in rainwater, especially $Ca^{2+}$ and $Mg^{2+}$ in stem flow were generally high at Ulsan industrial complex area, while anions were high in the order of ${SO_4}^{2-}>{NO_3}^{-}>Cl^-$ in both areas. There was a wide difference in ${SO_4}^{2-}$ concentration in the stem flow between both areas. ${SO_4}^{2-}$ from air pollutants will result into acidification of forest soils and thereafter cause damages on forest ecosystems.

• Journal of Korean Society of Forest Science
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• v.77 no.3
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• pp.303-314
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• 1988

Tong-ri beach has not enough vegetation to be enjoyed by the sea bathers and to be satisfied with preventing the disaster-damages, but mixed forest near the beach can work its funtions and the old forest of Pirus thunbergii $P_{ARL}$. near the beach do a Little. Therefore it is very urgent to plant more trees near the beach for bathers and disaster-damage prevention. This study was carried out for planning an afforestation, with reporting upon the crown amounts and soil properties of disaster-damage prevention forests of P. thunbergii $P_{ARL}$. planted on the coast sand dunes in 1970 and 1976, and with reporting upon the valuation on soil properties of the lands near the beach in order to set the afforestation site. The results are as follows : 1. In disaster-damage prevention forests, crown surface area and crown volume became increasingly greater in proportion to the height. To D.B.H., crown volume also became increasingly greater in proportion, but crown surface area was directly proportional. 2. In comparison to sail characteristics of sand dune, those of the forests were in large quantity in OM, T-N and avail. $SiO_2$, and almost in the same in avail. $P_2O_5$, but in small quantity in exchangeable canons : K, Ca, Mg and Na. 3. EC, Cl and pH were in small value in the forest soils, but CEC was in large value in those soils. 4. Above facts showed that the forests fulfill their functions for preventing disaster-damages and improve their soil properties. 5. The forests have naturally been thinned up to 34% in 17 years and 39% in 11 years, and one can easily pass through the forest(planted in 1970), because of its sufficient clear-length(2.71m) and its space to pass. 6. A plan for afforestation was oracle nut after judging several sites by the evaluation on the soil properties and considering the best relaxation and the prevention of the various disaster-damages upon which were reported in the last issue. 7. Afforestation should be kept for maintaining its appropriate density for best relaxation and disaster-damage prevention.

• Journal of Korean Society of Forest Science
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• v.86 no.3
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• pp.342-351
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• 1997

The objective of this study was to compare acid-neutralizing and buffering capacity of four tree species against soil acidification by acid rain. About 30-year-old forests composed of Pinus rigida, Alnus hirsuta, Quercus mongolica, and Liriodendron tulipifera in a provincial experimental forest located 15km east from Banwol Industrial Complex in Kyonggido were used in this study. Incident precipitation, throughfall and stemflow, and soil samples were collected from May to September, 1996 to analyze their pH and canon concentrations. Internal leaf pH, external acid neutralizing capacity(ENC), and buffering capacity index(BCI) of leaves were also determined. The incident precipitation showed an average pH of 4.56, with the percentage of acid rain incidents being 74%. The average soil pH of the study area was 4.15. The pH of throughfall and stemflow in all four species was higher than that of precipitation except that of the stemflow of Pinus rigida which showed a pH of 3.73. The throughfall of Liriodendron tulipifera showed the highest pH of 5.38. The pH of throughfall and stemflow showed a positive correlation and no correlation, respectively, with precipitations. The most abundant cation in precipitation was Ca. The canon concentraions in throughfall and stemflow decreased in the following order of K, Na, Ca, and Mg. Cation concentrations in stemflow were highest in Lirioendron tulipifera and lowest in Pines rigida. Nutrient leaching from above ground increased with decreasing pH of precipitation. The pH of stemflow showed a positive correlation with ENC and BCI. The highest values in ENC, BCI, soil pH, and soil cation concentrations were observed in Liriodendron tulipifera, while the lowest values were obtained in Pinus rigida, It was concluded that Liriodendron tulipifera had highest neutralizing capacity against acid rain, while Pinus rigida had the lowest capacity and even promoted acidification of soil.