Monitoring atmospheric deposition of pollutant with mosses around point-sources and across the landscape in eastern Canada
(1) Université de Moncton, (2) Université du Québec en Abitibi-Témiscamingue
Air pollutants from natural and anthropogenic sources, such as heavy metals, are deposited in ecosystems, with adverse effects on both ecosystems and human health. Air quality monitoring in Canada is concentrated around urban areas or emission points, leaving gaps in rural areas. Bryomonitoring, a bio-monitoring technique using mosses, offers a complement to such monitoring. This technique has been used in Europe for several decades, while its use in Canada is still recent. I will present the results of three projects in which we are deploying this technique. First, we launched Canada's first provincial bryomonitoring study to map atmospheric deposition in New Brunswick (NB). We collected mosses at 207 sites to identify regions affected by various trace metal elements. In standardized protocols, a minimum distance from trees is specified since the forest canopy can act as a sink or source of elements. This impact appears to be greater in arid regions than in humid ones, where precipitation releases dust accumulation in the canopy. We therefore established 11 sites in southern NB and found that the impact of trees was minimal for six of the eight heavy metals analyzed. This will enable us to evaluate different approaches to fostering the community involvement necessary for the sustainability of this type of program. Finally, little is known about the indirect impacts of mining, particularly in the boreal forest. We aim to determine the spatial footprint of six mines at different stages of development in Quebec's boreal forest. The spatial footprint of active mines extends to around 500 m from the mine, but this distance varies according to the elements and prevailing winds. The results of these studies have local, provincial, and national significance, filling spatial gaps in air quality data for different regions of Canada. In addition, the mining project will help reduce the environmental impacts of mining activities in the boreal forest.
Keywords: bryomonitoring, moss, boreal forest, Canada, trace metals, mining industry
