Industrial Air Pollution May Have Ecological Consequences
The Athabasca Oil Sands Region in Alberta, Canada, contains boreal forests where epiphytic lichen communities are increasingly at risk from industrial air pollutants emitted by mining, oil extraction, and upgrading operations. (Epiphytics rely on other plants for physical support, growing on trunks and branches rather than rooting themselves to the ground. They are not parasitic because they do not derive any nutrients from their hosts.)
The concentrations of industrial emissions in the Athabasca Oil Sands Region are rising as the area of exploited oil sands and rate of bitumen production continues to expand. Ambient air pollutants of biological importance (ammonia [NH3], nitrogen oxides [NO2], nitric acid [HNO3], and sulfur dixode [SO2]) and atmospheric deposition of nitrogen (N) and sulfur (S) have been monitored by a Forest Service team sponsored by the Wood Buffalo Environmental Association since 2005.
Concentrations of these compounds and N & S deposition decline sharply with distance from the industrial center. Although levels of the measured pollutants do not indicate direct toxic effects to vegetation, sensitive epiphytic lichen communities could be affected by elevated NH3 concentrations. As a consequence, NH3 is of highest importance among the measured pollutants because of its high biological activity and high contribution to nitrogen deposition. In the most polluted areas, elevated N and S deposition may have significant ecological consequences for forests and other ecosystems, such as acidification and changes in the nutritional status of vegetation.
Forest Service Partners