Abstract: In this paper, physiological reactions to HF exposure by Polygonum chinensis L., Fagopyrum cymosum Meisn and Metasequoia glyptostroboides were studied with top opened field chamber. During the process of HF exposure, stomatal resistance (S.R.), transpiration intensity (T.I), electric conductivity (E.C.) and amount of chlorophyll were measured. It was found that the S.R. of polygonum chinensis L. was higher than that of Fagopyrum cymosum Meisn. What is more, the S.R. of polygonum chinensis in green leaf was higher than that in red leaf. In addition, the difference in sensitivity to HF among different plants was also appeared in tendency and value of E.C. change. Sensitive plants showed much higher E.C. It is considered that to select and determine the appropriate physiological index is one of the important work in biological monitoring of atmospheric pollution.

Key words: HF exposure, Sensitive plant, Physiological change