Impacts of air pollution on far north forest vegetation

• Published in: The Science of the total environment 1995-01, Vol.160-161, p.605-617
• Main Author: Alexeyev, Vladislav A.
• Format: Article
• Language: English
• Subjects: Air pollution; Damage; Health dynamics; Northern forests
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/0048-9697(95)04395-H

As are other parts of the earth, aretic and subarctic territories are influenced by global, regional, and local air pollution. In Europe, the greatest load of airborne contaminants is observed in terrestrial ecosystems of the Kola Peninsula; in Asia, the greatest load is found in ecosystems of the Taimyr Peninsula, where large copper-nickel smelters are functioning. The studies described here for these regions encompassed local and regional deposition of pollutants (mainly sulfates and trace metals); changes in the composition, structure, productivity, and status of forest vegetation; morphological reactions of plant species and their regenerative activity; reforestation processes; successions; element composition of plants and soils; and biological activity of soils. The key findings of long-term studies are as follows. First, the symptoms of plant damage by air and soil pollutants in arctic and temperate zones are the same. Second, plants weakened by natural stresses have lower thresholds of sensitivity to airborn pollutants. Third, rapid destruction of northern plant communities by pollutants is often connected with a wide distribution of sensitive species (e.g., lichens) and previously weakened plants. Fourth, the specific structure of far northern forest and tundra ecosystems (in particular, open canopy and/or thin photosynthetic layer) and the severe climate produce some peculiarities in plant damage, namely (1) a large difference in the rate and intensity of damage to upper and lower parts of plants if the green parts are above or under snow in the winter, (2) simultaneous damage of different parts of stands that are above snow cover, and (3) an increase in the krummholz effect (stunted, low-lying branches) for evergreen coniferous trees. These findings were obtained for conditions of evident airborne contamination. The impact of low level regional pollutants on arctic and subartic vegetation is not sufficiently understood.