Abstract: Ozone is the most important phytotoxic gaseous pollutant in many parts of the world. High level ozone will cause the reduction of crop- and forest outputs. This paper reviewed the research advances in the effects of elevated ozone on the belowground processes of ecosystems, including root growth, root exudation, mycorhizal growth, soil-root respiration, soil enzyme activity, and soil microbiological processes. The significance of this research, the debates in current researches, and the fields and directions needed to be further studied were discussed.

Key words: Red tide, Heterosigma akashiwo, Iron limitation, Fluorescence characteristics