The Structure of Spruce-Fir Tree Stands Mortality Under Impact of the Middle Ural Copper Smelter Emissions
I. E. Bergman1, E. L. Vorobeichik1, V. A. Usoltsev2,3
1Institute of Plant and Animal Ecology, Russian Academy of Sciences, Ural Branch, 8 Marta str., 202, Yekaterinburg, 620144 Russian Federation
2Botanical Garden, Russian Academy of Sciences, Ural Branch, 8 Marta str., 202, Yekaterinburg, 620144 Russian Federation
3Ural State Forest Engineering University, Sibirskii trakt, 37, Yekaterinburg, 620100 Russian Federation
Keywords: industrial pollution, copper smelter, heavy metals, сoarse woody debris, decomposition, tree stand, mortality, dead fallen wood, dead standing trees, Middle Ural
Abstract
The influence of industrial pollution on mortality values (dead fallen wood and dead standing trees) and its distribution by degrees of decomposition were investigated in spruce-fir forest stands in the vicinity of the Middle Ural copper smelter (the city of Revda, Sverdlovsk region). The total mortality and mortality in each size category did not depend on the distance to the source of pollution. At the same time, the amount of dead fallen wood was significantly greater (1.9 times) in the polluted area (2 and 4 km from the smelter) as compared with the background territory (30 km from the smelter). Mortality proportion out of the total number of the trees (both live and dead) did not differ significantly between the sites, although this parameter tended to increase nearer the smelter. The distribution of mortality by size categories revealed significant differences between background territory and site with average level of contamination, as well as background territory and highly contaminated site. Observed differences are associated with an increased proportion of lesser mortality near the smelter (by 15 % and 12 % as compared with areas of background and middle levels of contamination, respectively), as well as because of double-declining of medium- and large-sized mortality near the smelter. The distribution of the living tree stands by size categories also has a connection with level of contamination. The average diameters of the living tree stand and the elements of coarse woody debris (dead fallen wood and dead standing trees) do not differ significantly between sites with different levels of contamination. For the small-sized dead fallen wood, the proportion of weakly decomposed stems increased with the level of pollution, while proportion of strongly decomposed stems decreased. The distribution of medium- and large-sized dead fallen wood on the stages of decomposition does not vary between sites with different levels of pollution.
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