• Journal of the Korean Society of Environmental Restoration Technology
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• v.23 no.3
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• pp.63-79
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• 2020

The present study was to investigate the growth response and nutrient absorption in three willow species (Salix gracilistyla, S. koreensis and S. chaenomeloides) treated with nitrogen source (NH₄⁺:NO₃^- rate; 200:0, 150:50, 100:100, 50:150, 200:0) for a period of 90days. The height, dry weight and chlorophyll contents of three species of willows were found to be highest at 50:150 (NH₄⁺:NO₃^-) treatment. NO₃^--N was more effective than NH₄⁺-N in the early growth of three species of willows. The increase in percentage of NO₃^--N handling, T-N, NO₃^--N in plant tissue increased. The analysis of C, N and mineral content in various parts revealed that the amounts of C, N, K, Ca and Mg were higher in leaves than those in the stems and the roots. However, the amount of NO₃^--N and P were higher in roots than those in the leaves and the stems. Salix koreensis was excellent, followed by S. chaenomeloides and S. gracilistyla in absorption of nitrate nitrogen. Higher percentage of NO₃^--N, the amounts of T-N, NO₃^--N, P₂O₅, K, Na, Ca, and pH in soil were decreased.

• Journal of Korean Society of Forest Science
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• v.78 no.1
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• pp.35-41
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• 1989

The pollen morphology of nine species and one variety of Korean Salix was investigated by means of light and scanning electron microscopy. Pollen grains are tricolpate or tricolporate varying from subprolate or prolate. Based on aperture and sculpture patterns, the pollen morphology of the investigated Korean Salix appeared to exhibit three different types.

• Journal of Ecology and Environment
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• v.33 no.2
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• pp.157-164
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• 2010

We evaluated the restoration effect by introducing willows as a means of controlling invasions of giant ragweed (Ambrosia trifida L.) on a riparian site. Our preliminary survey demonstrated that a problematic exotic species, giant ragweed and the representative riparian species, Salix koreensis are in competitive exclusive relationship. We planted willows at 1 m intervals on the bank of the Dongmun stream at Munsan, Paju, in Central Western Korea as an experimental restoration practice. We installed two 50 m $\times$ 5 m sized restored and non-restored for this experimental study. The non-restored plots were located on river banks, which were covered with concrete blocks and left in itself without any treatment. The height of willow was measured after each of three consecutive growing seasons and compared with the height of the giant ragweed. Although the height of Salix gracilistyla did not achieve the height of the giant ragweed, the height of S. koreensis surpassed that of giant ragweed in the third year after introduction. The results were also reflected in the relative light intensity on the herb layer of willow stand, and thereby the relative light intensities of stands, which were dominated by S. koreensis or restored by introducing S. koreensis, 1.99 $\pm$ 0.33 (%, mean $\pm$ SD) and 1.92 $\pm$ 0.50 (%, mean $\pm$ SD), respectively were lower than those in the stands treated by S. gracilistyla, 3.01 $\pm$ 0.43 (%, mean $\pm$ SD). The giant ragweed stands receive full sunlight as there are no any vegetation layers higher than the herb layer formed by the giant ragweed. As the result of Detrended Correspondence analysis ordination based on naturally established vegetation, the stands dominated by willows and giant ragweed showed different species composition between both stands. The species composition of the restoratively treated sites resembled the reference sites more than the non-treated sites. The species diversity (H') of the sites restored by introducing S. koreensis and S. gracilistyla was higher than the non-restored site dominated by A. trifida. On the basis of our results, the restoration of riparian vegetation equipped with integrated features could contribute not only to the control of exotic plants including giant ragweed but also to ensure the diversity and stability of riverine ecosystems.

• Journal of Ecology and Environment
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• v.30 no.3
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• pp.251-255
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• 2007

Self-thinning was measured in Salix communities on Bam Island in Seoul at various age stages. $D^2H$ was used to estimate tree biomass, where D is stem diameter at breast height or 10 cm height for plants with height <1.5 m, and H is height. A log-log plot of density versus $D^2H$ and correlation analysis indicated a significant relationship between density and biomass with equation 'log $D^2H$ = -1.27 log N + 7.06'. This indicates that self-thinning affects biomass in the Salix community with -1.27 as the thinning coefficient. If we assume a thinning exponent -3/2, then the allometric coefficient of the equation, log w = a log $D^2H$ + b, is 1.18. This is much higher than that for any other species studied in Korea. There were statistically significant relationships between age and density and between age and basal area and these relationships suggest guidelines for transplantation of willows and for the assessment of Salix community restoration projects in riverine wetlands based on standard density, basal area, and age. The results of this study may also increase understanding of succession processes in Salix community restoration in riverine wetlands.

• Journal of the Korean Institute of Landscape Architecture
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• v.15 no.3
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• pp.11-19
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• 1988

The purpose of this study is to investigate ways to control the wind dispersal of contton-wrapped seeds of such poplars and willows as Poplus alba, P. tomentiglandulosa, P. euramericana, P. deltoides, and Salix pseudo-lasiogyne. These trees are hated by many people because of their seeds blowing all over the place during May. These cottony seeds can be nuisance to various types of outdoor activities, pose safely threat to drivers, become fire hazards during prolonged spring dry spells, and cause many types of health hazards of allergy such as sneezing. rhinitis, asthma, and skin rashes. Four control methods can be used to resolve the problem. First, pruning can be a solution, but it is unsatisfactory in terms of costs and outcome. Second, planting of male trees only can be a solution, but it is hard to identify sexes of saplings. Third, female trees can he replaced with other species. But it requires high costs and takes at least ten years to functionally replace the removed ones. As an alternative to such unsatisfactory control methods, the possibility of applying plant growth regulators has been investigated since 1983. During the pre-test, various concentrations and mixtures of them were either sprayed or injected, but failed to achieve any promising results. But the injection of a mixture made up of 0.75g of 2-chloroethane phosphonic acid with 0.2 mg of GA in 300cc water in the end of March produced premature falling of almost all aments and capsules of treated poplars and willows. It was found that the effect of the injection lasts two years. The results of the main experiment of 1987 can be summarized as follows ; First, the injection of the mixture of 2-chloroethane phosphonic acid and GA increases the premature abscisin of aments and capsules, thus reducing the wind dispersal of the cottony seeds of S. pseudolasiogyne, P. tomentiglandulosa, and P. euramericana 1644.09, 1200.61, and 1485.11 times, respectively, than that of the naural abscisin, It is estimated that the average number of wind-blown seeds reduced are approximatively 6,185,100, 4062,900, and 2,830,670 per tree, respectively. Second, the treatment causes no observable side effects on the growth of the samples tested.

• Journal of Bio-Environment Control
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• v.31 no.1
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• pp.35-42
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• 2022

To investigate the effects of ozonated water concentration and soaking time on adventitious root formation of willow, we studied the efficiency of root cuttings in the revegetation technology of biological engineering of willows. The ozonated water concentrations were used for 5 minutes and 2 hours at 1, 5, 10, 15, 20 ppm by soaking method and then the shoot characteristics were observed. The number and length of adventitious roots were determined. The results indicated that 20 ppm of ozonated water for 2 hours and 1 ppm of ozonated water for 5 minutes resulted in leaves turned wither away and no adventitious root production. Considering the appearance, number and length of the adventitious root, soaking willow cuttings into the ozonated water with dissolved ozone concentration, 5 ppm for 2 hours and 10-15 ppm for 5 minutes were suitable for generating adventitious roots.

• Journal of Korean Society of Forest Science
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• v.86 no.2
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• pp.177-185
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• 1997

The influences of fertilizer treatment and clones of five willows and one hybrid poplar on above ground and soil carbon (C) accumulations in a willow bioenergy plantation were studied. The aboveground and soil samples were collected in the winter of 1992 and 1993 from the previously established willow plantation at Tully, New York, U.S.A. in 1987. Half of the plots were fertilized annually with 336kg/ha N, 112kg/ha P, and 224kg/ha K. All trees were harvested annually. The most productive clone, willow clone SV1 with fertilization, accumulated 5.4 and 6.8 t/ha/yr aboveground C contents during the sixth(1992) and seventh(1993) growing seasons, respectively. The average percentage of C in bolewood, bolebark, and branches for the five willow clones and one hybrid poplar clone ranged from 51.1 to 57.5, from 54.0 to 55.4, and from 55.6 to 56.5, respectively, among all treatment combinations. Only tyro of the six clones(SA22 and SA2) responded significantly to the addition of fertilizer by increasing the amount of aboveground C accumulated for the 1992 sampling period(clone-by-fertilizer interaction). No fertilization effect, on aboveground C content, was noted for the 1993 sampling period. No significant fertilization effect on soil C accumulation for all soil sampling depths(0-10, 10-20, and 20-40cm) was found in 1992 and 1993 sampling years. Little clone effect on soil C content was found in 1992 and 1993 sampling years, except at 0-10cm soil depth in 1992. The significant clonal effect on soil C content at 0-10cm soil depth could be because of stone content variation rather than clonal effect. The significant clone-by-fertilizer treatment interaction observed requires that evaluation of response to fertilization by willows be made for each clone individually.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.29 no.4
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• pp.14-26
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• 2011

Imdaejeong Wonlim is located on the verge of Sangsa Village in Sapyeong-ri, Daepyeong-myeon, Hwasun-gun Gyeongsangnam-do toward Northwest. It was planned by Sa-ae, Minjuhyeon in 1862 on the basis of Gobanwon built by Nam Eongi in 16th century against the backdrop of Mt. Bongjeong and facing Sapyeong Stream. As water flows from west to east in the shape of crane, this area is a propitious site standing for prosperity and happiness. This area shows a distinct feature of Wonlim surrounding the Imdaejeong with multi layers as consisting of 5 districts - front yard where landmark stone with engraved letters of 'Janggujiso of Master Sa-ea' and junipers are harmoniously arranged, internal garden of upper pavilion ranging from a pavilion to square pond with a little island in the middle, Sugyeongwon of under pavilionu consisting of 2 ponds with a painting of three taoist hermits, forest of Mt. Bonggeong and external garden including Sapyeong Stream and farmland. According to documentation and the results of on-site investigation, it is certainly proved that Imdaejeong Wonlim was motivated by Byeoseo Wonlim which realized the idea of 'going back to hometown after resignation' following the motives of Janggujiso, a hideout aimed to accomplish the ideology, 'training mind and fostering innate nature,' on the peaceful site surrounded by water and mountain, as well as motives of Sesimcheo(洗心處) to be unified with morality of Mother Nature, etc. In addition, it implies various imaginary landscapes such as Pihangji, Eupcheongdang, square pond with an island and painting of three Taoist hermits based on a notion that 'the further scent flies away, the fresher it becomes,' which is originated from Aelyeonseol(愛蓮說). In terms of technique of natural landscape treatment, divers techniques are found in Imdaejeong Wonlim such as distant view of Mt. Bongjeong, pulling view with an intention of transparent beauty of moonlight, circle view of natural and cultural sceneries on every side, borrowed scenary of pastoral rural life adopted as an opposite view, looked view of Sulyundaero, over looked view of pond, static view in pavilion and paths, close view of water space such as stream and pond, mushroom-and-umbrella like view of Imdaejeong, vista of pond surrounded by willows, imaginary view of engraved letters meaning 'widen knowledge by studying objectives' and selected view to comprise sunrise and sunset at the same time. In the beginning of construction, various plants seemed to be planted, albeit different from now, such as Ginkgo biloba, Phyllostachys spp., Salix spp., Pinus densiflora, Abies holophylla, Morus bombycis, Juglans mandschurica, Paulownia coreana, Prunus mume, Nelumbo nucifera, etc. Generally, it reflected dignity of Confucianism or beared aspect of semantic landscape implying Taoist taste and idea of Phoenix wishing a prosperity in the future. Furthermore, a diversity of planting methods were pursued for such as liner planting for the periphery of pond, bosquet planting and circle planting adopted around the pavilion, spot planting using green trees, solitary planting of monumentally planted Paulownia coreana and opposite planting presenting the Abies holophylla into yin and yang.