Effects of soil quality and air pollution on the rooting and survival of Salix borealis cuttings

The rooting and survival of Salix borealis cuttings were studied in the surroundings of the Severonikel smelter (Kola Peninsula, NW Russia). In favourable habitats (birch and willow-dominated secondary communities), 22% of the 120 cuttings were successfully established, and 89% of the established cuttings survived up to the fourth year after planting. Cutting survival and vigour were affected by both soil quality and air pollution level. Cutting mortality during the two first weeks after planting depended on soil contamination; in metal-polluted soils it was seven times as high as in clean soils. The detrimental effects of ambient sulphur dioxide became visible after four weeks, whereas survival at the end of the growing season was almost exclusively determined by the nutritional quality of the soil. Cuttings from female genets were more resistant to pollutants than cuttings from male genets; cuttings from the unpolluted site were more tolerant of metals than cuttings from the heavily polluted site. The leaf size of the surviving cuttings was independent of soil, water or air contamination. These preliminary findings seem to indicate that cuttings of S. borealis can be used for the partial revegetation of industrial barrens even at high emission levels.