WBEA report assesses forest health in the Athabasca Oil Sands Region

Jun 04, 2015

Fort McMurray, Alberta – The Wood Buffalo Environmental Association (WBEA) published a report today, Assessing Forest Health in the Athabasca Oil Sands Region, that summarizes 15 years of results from its Terrestrial Environmental Effects Monitoring forest health monitoring program.

WBEA’s Forest Health monitoring approach determines cause-effect relationships between air pollutants and forest ecosystem function. In 1998 WBEA established a program to determine if emissions of acidifying compounds were having long-term adverse effects on the regional terrestrial environment and, if so, to what extent. Between 2008 and 2011, WBEA embarked on a significant science build. This included adopting an ecological analogue approach to site selection, new biological, physical and chemical indicators, and instrumentation of plots.

By 2011/12, WBEA’s Forest Health Network was significantly expanded to 25 interior jack pine stand plots, 25 forest edge plots for early warning of change prior to a measureable effect, 6 meteorological towers, and passive/active monitoring analyzers.

The report, comprised of twelve chapters, integrates monitoring history, network design, results from air and deposition monitoring, deposition modeling above and below ground biological and chemical measurements made in 2011/2012. It also provides comparisons of indicators measured at five sites that were sampled in 1998, 2004 and 2011/2012.

Dr. Kevin Percy, WBEA Executive Director, says, “Environmental monitoring must never be complacent. It should always be innovative, adaptive and responsive. As such, our approach to forest health monitoring is truly holistic, and this report provides solid scientific data on emissions, pollutant transport, air quality, deposition and source contributions to terrestrial ecosystems.”

Key findings of the report include:

• The highest passively measured and modeled air concentrations of sulphur dioxide (SO2), nitrogen dioxide (NO2), ammonia (NH3), and nitric acid (HNO3) were reported nearer to the oil sands operations.
• Ozone (O3) concentrations, as expected, increased with distance from oil sands operations.
• Similar patterns of air concentrations and spatial deposition for sulphur (S) and nitrogen (N) were reported.
• Air quality and deposition measurements showed that sulphur (S) and nitrogen (N)  concentrations/deposition amounts are enhanced within 30 km of Oil Sands operations, and decline with increasing distance from them.
• Sulphur (S) and nitrogen (N) air concentrations and deposition amounts reach background (very low) levels approximately 40-50 km away from the main oil sands emission sources.
• Trace element and heavy metal concentrations in vegetation generally follow the same spatial distribution pattern.
• There was no correlation between ecosystem variables and sulphur (S) and nitrogen (N) as acidifiers due to the deposition of base cations which neutralizes the acid input.
• Aluminium (Al) toxicity is considered an important factor in forest deterioration caused by soil acidification. A ratio of base cations (BC) to aluminium (Al) in the soil solution is widely used as an indicator for potentially adverse effects on tree health.
• There was no correlation between base cation/aluminum (BC: Al) ratios in the LFH and mineral soil and modeled sulphur (S) and nitrogen (N).
• The BC:Al trigger set under the CEMA Acid Deposition Management Framework (http://cemaonline.ca/index.php/cema-recommendations/acid-deposition) was not exceeded, in 2011/12.

Of the report, Percy states, “The development in the Athabasca Oil Sands Region (AOSR) has been the focus of a lot of attention in recent years, making the information contained within this report all the more important. Data from this report can be used to inform environmental decisions, environmental impact assessments, and stakeholders and the public at large about environmental air quality in the Wood Buffalo region.”

NT3