Lichen biomonitoring networks in alberta.

Lichen biomonitoring of air pollution has developed over a period of about 150 yr. Several valuable techniques now exist which could complement physical/chemical air quality monitoring programmes. The affects of air pollution and acid rain, in areas such as Alberta, where lichens and bryophytes make up a significant portion of the forest vegetation, must be considered important. In addition, bioaccumulation studies can be used to map the areas of 'heavy metal' deposition, estimate actual depositional rates, and check the accuracy of pollutant dispersion models. Lichen biomonitoring techniques must now be calibrated with more 'glamorous' effects on plant physiology, ecosystem processes, cancer incidence, etc.