The Athabasca Oil Sands in Alberta, Canada, is one of the largest point sources of nitrogen oxides in Canada. There are concerns that elevated nitrogen (N) deposition will adversely impact forest ...

Needles on a jack pine branch are browned and curled after the tree was infested with budworm. (Left); A group of jack pine trees that have been infested with jack pine budworm show browned needles on ...