Peter J. Dillon – 2011

Title: Biogeochemistry - How the movement of chemicals through the Boreal environment can be used to quantify the effects of stressors.

Abstract: The Boreal biome comprising about 60% of Canada‘s land area, includes over 2 million lakes, about 85% of our country’s freshwater and about 25% of global wetlands. Despite the magnitude of this resource, an increasing number of environmental stressors have put it at risk.
The southern part of the biome, including both freshwaters and terrestrial ecosystems, has been affected by acid deposition for at least a half century. Contamination by mercury is widespread throughout the Boreal, and elevated levels of trace organic contaminants of many types are now measurable over much of the area.  Contamination by other metals, once isolated to regions near mining and smelting activities, is more widespread.  In the past few decades, climate change has come to the forefront, and it is clear that the Boreal will be one of the more heavily affected parts of Canada.  Although climate change can directly effect the biological communities of the Boreal, most effects will be mediated through alterations in environmental chemistry.  In addition, climate change can and is altering the response of lakes and their catchments to other stressors, for example, is reducing the rate of recovery of ecosystems from declining acid deposition rates.  For an quantitative understanding of how the Boreal biome responds to changes in the magnitude of stressors, it is critical to have measurements that go beyond simple description of ecosystem properties such as concentrations of various chemicals in different compartments.  Instead, measurement of factors such as the flux or rate of movement of substances between compartments is essential if we are to understand how to minimize the effects of the multiple stressors.  The development of new analytical methodologies such as multi-collector ICP-MS has led to new approaches in studying environmental stressors.  A few of these new methods will be highlighted in this presentation. Brochure - Y-File Article