Ozone bioindicatorThis article is part of a larger document. View the larger document here.
Why Is Ozone Important? Ground-level ozone occurs at phytotoxic levels in the United States (Lefohn and Pinkerton 1988). Elevated levels of ozone can cause foliar injury to several tree species, may cause growth loss, and can make trees more susceptible to insects and pathogens (Chappelka and Samuelson 1998). However, tree species have varying degrees of sensitivity to ozone, and ozone can induce foliar injury only if tree stomata are open. Thus, the overall impact of elevated ozone concentrations depends on the amount of ozone, climatic conditions such as drought, and the composition of the forest.