• Korean Journal of Ecology and Environment
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• v.50 no.3
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• pp.295-304
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• 2017

The Ramsar protected area in Ungok wetland, which has been designated since 2011, was described by syntaxonomy and synchorology. Phytocoenon was identified and named by a traditional method of the $Z{\ddot{u}}rich$-Montpellier School and Code of Phytosociological Nomenclature. Habitat-based vegetation classification has identified into twelve syntaxa consisting of 88 taxa in seven vegetation types: Juncus effusus var. decipiens-Salix koreensis community, Caricis-Salicetum subfragilis, Galium spurium var. echinospermon-Phragmites japonica community, Phragmitetum australis, Scirpetum fluviatilis, Leersia japonica-Typha angustifolia community, Juncus diastrophanthus-Juncus effusus var. decipiens community, Leersicetum japonicae, Nymphoido indicae-Trapetum japonicae (typicum, marsiletosum quadrifoliae subass. nova hoc loco, variante Euryale ferox), Nelumbo nucifera community, Utricularia tenuicaulis community, Potamogetonetum crispi. Actual vegetation map was made by using topographical map of scale 1 : 5,000. Habitat-based management on the Ungok wetland vegetation was required, in which there are composed of two major areas such as the back-swamp vegetation and the limnetic vegetation zone.

• Korean Journal of Weed Science
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• v.30 no.4
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• pp.412-420
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• 2010

Weeds are known to cause enormous losses due to their interference in agro ecosystems. Because of environmental and human health concerns, worldwide efforts are being made to reduce the heavy reliance on synthetic herbicides that are used to control weeds. In this regard phytotoxicity of allelochemical sorgoleone, which is a major component of the hydrophobic root exudates of Sorghum bicolor was evaluated in different weed species and also its crop selectivity in greenhouse and field conditions. Sorgoleone strongly inhibited the growth of different weeds by pre-emergence and post-emergence applications both in greenhouse and field conditions. Post-emergence application of sorgoleone on 21-day-old weed seedlings had a greater inhibitory effect than the pre-emergence application. Again, broadleaf weed species were more susceptible than grass species to the application of sorgoleone at both stages of growth. Growth of broadleaf weed species was suppressed by greater than 80% for most of the weed species except a few species and among them the species Rumex japonicus and Galium spurium were completely suppressed at $200{\mu}g\;ml^{-1}$ sorgoleone. Like greenhouse trial, sorgoleone was more effective for broadleaf weed species followed by sedge and grass weed species in the field condition. The growth inhibition of weeds was slightly lower in field condition compared to greenhouse condition. The crop species like rice, barley, wheat, corn, perilla, tomato, soybean and Chinese cabbage were tolerant to sorgoleone while lettuce and cucumber were slightly susceptible to sorgoleone. Consequently, sorgoleone may be applied to control weeds in organic farms without affecting the growth of crop.

• Korean Journal of Weed Science
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• v.31 no.1
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• pp.41-48
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• 2011

This survey of weed population by different soil moisture with paddy-upland rotation was conducted to investigate information on weed flora and its ecology between two years. Weed species were assessed in April : 2009, 2010. Soil samples were taken from each study plot to assess the impact soil moisture on the occurrence and abundance of dominance weed species. Soil water of poorly drained field ranged from 10.2~18.2% more than 11.8~14.3% of somewhat poorly drained field. Weeds of fields composed of 19 species belonging to 12 families. Among 12 families, 6 weed species belonged to Compositae (31.6%) were the biggest family, Cruciferae were 2 species (10.5%), and Rubiaceae were 2 species (10.5%), respectively. Youngia japonica had the highest summed dominance ratio(SDR) (97.0%) and followed by Conyza canadensis (92.1%), Galium spurium (35.3%) and Hemistepta lyrata (28.4%) of somewhat poorly drainage in 2009. Artemisia princeps the highest SDR (100%) and followed by Stellaria alsine(55.2%), Y. japonica (38.3%) and Nasturtium officinale (28.5%) of poorly drainage in 2009. And, Stellaria alsine had the highest SDR (86.8%) and followed by Alopecurus aequalis (77.7%), Astragalus sinicus (68.7%) and Y. japonica (46.3%) of somewhat poorly drainage in 2010. S. alsine the highest SDR (93.7%) and followed by A. aequalis (78.6%), Nasturtium officinale (31.3%) and Y. japonica (30.4%) of poorly drainage in 2010. Simpson's index was calculated to 0.12~0.23, which showed that weed occurrence with different soil moisture in paddy-upland rotation and between years was various. Similarity coefficient between years was 43.0% (2009) and 74.2% (2010), which indicate a low diversity because of the moisture in the agro-ecosystem.