Distribution of riparian weed species in streams of Sunchon area, Jeonnam, Korea.
The distribution of riparian weed species in streams of rural area, Dong-cheon, Sunchon and Namsu-cheon, Yosu, Jeonnam, Korea Republic was surveyed during May, August and October 2000. The 29 weed species of 15 families were found in the survey areas. Three weed species were identified in submerged weeds (Hydrilla verticillata, Potamogeton crispus and Myriophyllum verticillatum), one in floating-leaved weeds (Trapa japonica), two in free floating weeds (Spirodela polyrhiza and Lemna paucicostata), eight in emerged weeds (Persicaria thunbergii, Oenanthe javanica, Phragmites communis [Phragmites australis], Zizania latifolia [Zizania caduciflora], Scirpus fluviatilis, Scirpus triqueter [Schoenoplectus triqueter], Typha orientalis, Typha angustifolia), and fifteen in water-side weeds (Beckmannia syzigachne, Paspalum distichum var. indutum, Persicaria lapathifolia [Polygonum lapathifolium], Humulus japonicus, Rumex crispus, Rumex obtusifolius, Leersia sayanuka, Phalaris arundinacea, Agropyron tsukushiense var. transiens [Elymus tsukushiensis var. tsukushiensis], Lolium multiflorum, Ranunculus sceleratus, Veronica undulata, Cadamine flexuosa [Cardamine flexuosa], Alisima plantago-aquatica [Alisma plantago-aquatica] var. orientale, and Brassica campestris) by the life form at stream. It consisted of four annual weeds, six biennial weeds and nineteen perennial weeds. The completely dominant species on each survey site were Trapa japonica, Zizania latifolia, Paspalum distichum var. indutum, and Persicaria lapathifolia, Veronica undulata on Dong-cheon, and Phragmites communis, Scirpus fluviatilis, Scirpus triqueter, and Typha orientalis on Namsu-cheon, respectively. Not only the parameters of the riparian soils such as pH, EC, T-N, T-P, Ca, Mg, Na, P2O5, Zn, and Mn but also the parameters of water quality including EC, T-N, T-P, Ca, Na, SS, Cl- and SO42- in Namsu-cheon site were significantly higher than those of Dong-cheon site. It was suggested that the occurrence of riparian weed species may be due to the increased parameters of water quality and soil property in the areas.