Changes in the Spruce Forest Communities Along a Heavy Metal Deposition Gradient on Kola Peninsula

We investigated changes in the community structure of spruce (Picea obovata and P. fennica) forests in the Northern Taiga Region of Russia along a point-source atmospheric deposition gradient of heavy metals on the Kola Peninsula. Study sites were selected in ecologically analogous forest stands at increasing distances from the nickel smelter in Monchegorsk. The heavy metal load at each site was estimated by quantifying metal concentrations in the snow cower. Concentrations of heavy metals in soil, litter and vegetation increased along the gradient of increasing atmospheric deposition. All measured indexes of forest vitality, including species richness and abundance, vertical distribution, and understory structure were adversely affected by pollution.