Injuries to Scots pine mycorrhizas and chemical gradients in forest soil in the environment of a pulp mill in Central Finland

• Published in: Water, air, and soil pollution air, and soil pollution, 1996-01, Vol.87 (1/4), p.111-130
• Main Authors: Holopainen, T, Heinonen-Tanski, H, Halonen, A
• Format: Article
• Language: English
• Subjects: air pollution; ammonium nitrogen; Animal, plant and microbial ecology; Applied ecology; Biological and medical sciences; calcium; Cenococcum geophilum; Ecotoxicology, biological effects of pollution; ectomycorrhizae; Effects of pollution and side effects of pesticides on plants and fungi; Fundamental and applied biological sciences. Psychology; mycorrhizal fungi; nitrate nitrogen; nitrification; Non agrochemicals pollutants; Paxillus involutus; phosphorus; Phytopathology. Animal pests. Plant and forest protection; phytotoxicity; Pinus sylvestris; Pollution effects and side effects of agrochemicals on crop plants and forest trees. Other anthropogenic factors; Pollution effects. Side effects of agrochemicals; potassium; pulp and paper industry; roots; soil chemistry; soil fertility; sulfur; sulfur dioxide
• ISSN: 0049-6979; 1573-2932
• DOI: 10.1007/BF00696832

The occurrence and condition of Scots pine mycorrhizas were studied at different distances from a pulp mill in Central Finland. The chemical analyses of the soil humus layer in the vicinity of the mill revealed increased levels of ammonium-nitrogen, sulphur and calcium but unaltered concentrations of phosphorus and magnesium. Higher nitrate levels and nitrification were clearly detected at some sites which had recently been limed. Significant decreases in root ramification index and number of living mycorrhizas were found in a zone 0-0.6 km zone surrounding the factory but these parameters increased with increasing distance. Within a 2 km zone around the mill there were abundant Cenococcum geophilum and Paxillus involutus-type mycorrhizas while lowered frequencies of several other mycorrhizal types were detected. An ultrastructural study revealed changes in several types of mycorrhizas, the clearest of which were increased tannin deposition in cortical cells, intracellular growth of hyphae in cortical cells and the appearance of electron dense accumulations in the vacuoles of the fungal cells. The ultrastructural changes observed were distributed at least to a distance of 3 km from the mill and occurred in the roots of trees that had only a slight loss of needle mass. Nitrogen deposition is suspected to be the primary cause of root decline but atmospheric SO sub(2) through the tree crown is also likely to be a contributing factor.