This report summarizes the most recent results from the Wood Buffalo Environmental Association’s Terrestrial Environmental Effects Monitoring (TEEM) forest health monitoring program. During 1998-2007, WBEA operated the Acid Monitoring Program (AMP) focused on potential adverse effects including acidification of forest soils from sulphur and nitrogen oxides, and detrimental impacts to vegetation. In 1998, TEEM initiated measurement and sampling at a network of 11 jack pine (Pinus banksiana Lamb.) dominated, interior forest stand plots. Additional plots were added between 1999 and 2003, and another cycle of measurement and sampling of soils and vegetation occurred on 13 plots in 2004.
During 2006-2007, the Science Subcommittee (SSC) of TEEM completed a science review of the existing AMP. In 2008 based on science advice, TEEM adopted the source-to-sink approach for effects monitoring by measuring at key points along the emissions, chemical transformation, deposition, and terrestrial receptor pathway. TEEM also adopted the forest health approach to terrestrial monitoring focused on establishing/determining cause-effect relationships between air pollutants and forest ecosystem health in the region. In 2011/12, the enhanced forest health network of 25 plots was sampled.
This report comprises 12 chapters integrating monitoring history, network design, results from air/deposition monitoring, deposition modeling, above- and below-ground biological and chemical measurements made in 2011/12, as well as comparative status of some indicators measured at five plots that were sampled in 1998, 2004 and 2011/12.
The highest passively measured and modeled air concentrations of SO2, NO2, NH3, and HNO3 were reported nearer the industrial operations. Ozone (O3) concentrations, as expected, increased with distance from the sources. Three chapters reporting air quality and deposition of pollutants showed similar patterns of air concentration and spatial deposition for S and N. Two patterns were visible. The first was a west to east pattern resulting in S and N concentrations/ deposition being higher east of the mining and upgrading operations than to the west. There was also a north-south pattern in air concentrations, showing the influence of valley topography on pollutant dispersion. Air quality and deposition measurements indicated that nitrogen and sulphur concentrations/deposition amounts are enhanced within 30 km of the operations, decline with increasing distance from them, and reach background levels ~40-50 km away from main industrial emission sources.
Trace elements in vegetation including heavy metals generally follow the same spatial distribution pattern. Levels of sulphur and nitrogen in jack pine foliage at six plots increased from 1998 to 2012. Nitrogen is being taken up in vegetation, and is not accumulating in mineral soils. Sulphur in soils was correlated with modeled S+N deposition at the LFH, 0-5 and 5-15 and 15-30 cm depths. Neither soil nitrogen nor pH showed any correlation with measured deposition. Soil microflora as well as vascular cover, forb cover and shrub richness were strongly and positively
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related to atmospheric deposition of base cations. There was no correlation between ecosystem variables and S and N as acidifiers because of the importance of base cations which neutralizes the acid inputs. The role of atmospheric nitrogen deposition as a nutrient has the potential to increase in relative importance.
Base cation/aluminum (BC: Al) ratios in the LFH and mineral soil layers were not correlated (P=0.94) with modeled sulphur and nitrogen deposition. The BC: Al ratio ranged from 1 to 5 at twenty of the twenty-one plots sampled. The BC:Al trigger set under the CEMA Acid Deposition Management Framework (http://cemaonline.ca/index.php/cema-recommendations/aciddeposition) was not exceeded, in 2011/12.
Environmental monitoring must never remain complacent, and must always be innovative, adaptive and responsive as is demonstrated in this report. We hope that state of the art monitoring continues to be responsive, and adaptable to continuing oil sands development, and will be fully supported and adequately funded going forward.