The effects of Cd2+ ions on the Chl a fluorescence of 5 hydrophytes (e.g. Lemna, Salvinia, Ricciocarp, Nymph, Typha plants) were investigated in order to select Cd2+-sensitive plant species and to get informations on physiological responses of plants to Cd2+ stress. Lemna plants were most sensitive to cadmium stress, while Nymph plants were tolerant. However, in all Cd2+-treated plants, Fv/Fm, the maximum photochemical efficiency of PSⅡ, decreased in proportion to the increase of Cd2+ concentration and treatment time. The Chl a fluorescence transient O-J-I-P was also considerably affected by Cd2+ ions; the fluorescence yield decreased considerably in steps J, I and P in Cd2+ treated plants, although it followed a typical polyphasic rise in non-treated plants. In Lemna plants, the functional parameters, ABS/CS, TRo/CS와 ETo/CS and RC/CS, decreased in proportion to the increase of Cd2+ concentration, while N, Mo and Kn increased. The structural parameters, Φpo, Φpo/(1-Φpo), Plabs, SFlabs, Kp and RC/ABS, also decreased according to the increase of Cd2+ concentration. Consequently, Lemna plants will be useful as a experimental model system to investigate responses of plants. And several functional or structural parameters could be applied to determine quantitatively the physiological states of plants under stresses.

This study was investigated on biodiversity and life forms of plants distributed in 28 wetlands on Jeju city, in order to apply wetlands to nature exploration sites for environmental education. The 131 kinds of the plants were found on 28 wetlands. The plant biodiversity was relatively high in Ban pond, Jeongmool, Mosanimool, Dolgaegi pond, Woot pond, and etc. The 5～6 life forms of plants, relatively high in variousness to other wet lands, were distributed in Mosanimool, Dolgaegi pond, Woot pond, and Yeonhoa pond as well as Jeongmool and Yongsoo reservoir. The 71 kinds, which correspond to 54.2% of plants observed in this study, were identified as hydrophytes. The 4～5 forms of hydrophytes were distributed on 23 wetlands, including Jeongmool, Mosanimool, Yongsoo reservoir, Ban pond, Dolgaegi pond, and etc. In conclusion, 5 wetlands such as Jeongmool, Yongsoo reservoir, Dolgaegi pond, Mosanimool and Woot pond were high in variousness of plant life forms as well as biodiversity of plants. These results suggest that 5 wetlands above could be applied as nature exploration sites. In addition, Korean rare and endangered plants such as Isoetes japonica, Nymphoides coreana, Utricularia japonica and Sparganium stoloniferum in this study need to be conserved.

This study was investigated on the consciousness of middle school students in Jeju city about the environmental education through questionnaire, in order to understand the actual conditions of environmental education and to find out the solutions about them. Middle school students responded that environmental education in school was taken at the class for the special activity or voluntary service, not in regular class and was worked as in the form of the field trip. They generally obtain the knowledge and informations on the environmental problems from mass media such as TV, radio and newspaper than from regular environment class in school. And 36.0% of students perceive that environmental education is needed as a regular class and 31.3% of students perceive that the regular class in school is effective to the environmental education. These results suggest that many students are interested in the regular environment class in school. However, the most of students responded that the regular environment class in school is not worked or is not worked at all, suggesting that the environmental education in middle school is not worked effectively. Most of students prefer to take the environment class in the form of observation or field trip, and they think that observation or field trip is more effective to obtain environmental informations. In conclusion, the special activity such as observation or field trip needs to be supplemented to regular environment class in order to improve the environmental education in middle school more effectively.