Sukachev Forestry Institute of the Siberian Branch of the RAS in the early 1990s launched studies into the impact of discharges from the Norilsk industrial region on the environment (Krasnoyarsk Territory). Other allied institutes: of Biophysics (Krasnoyarsk) and Theory of Light of Atmosphere (Tomsk), Central Siberian Botanical Gardens (Novosibirsk), Scientific and Research Institute of Agriculture of the Far North (Norilsk), the Siberian Regional Scientific and Research Institute of Hydrometeorology (Novosibirsk) have joined in the work since 2001. Drs. Sc. (Biology) A. Abaimov, Yu. Yershov, M. Gladyshev, Cands. Sc. (Biology) M. Telyatnikov, A. Shishkin, Cand. Sc. (Agriculture) V. Ivanov tell about some of the results of their work in the newspaper Science in Siberia of March, 2005.
The territory was divided in three zones according to the level of anthropogenic effects: aside from the air-dust plume of Norilsk enterprises, at the skirts of the latter and finally in its center. Two plain, two submontane and three key mountain areas were surveyed, which gave a comprehensive view of the condition of the region tundra ecosystems. Thus, starting from the first zone, plant development damage was registered. Lichens proved to be the most sensitive to toxic discharges. Less sensitive were mosses, blueberry, and swampy, moderate humid poiums were most resistant. Grasses, some forbs and willow even showed indirect positive responses to pollution.
Gmelin and Siberian larches prevail among the trees in the area under review, though birches and fir trees can also be found. The most important negative natural factors for them are shallow depth of seasonal soil thawing out and unfavorable temperature conditions. Permafrost represents a watertight stratum and determines a low yield of a root layer. The significant portion of dead trees is not a rare thing among local forests, even among relatively safe woodlands it reaches 20 percent. As much as 30-
40 percent of live trees have dry crowns and are extremely frail. Furthermore, as the survey showed, this sad process has started long before the commissioning of the Norilsk metallurgical works.*
The point is that the north tree vegetation is characterized by a higher vulnerability to environmental and technogenic stresses and by low productivity. Thus, the main value of local forests is not in their resource
* See: Ya. Renkas, "Along the Road of Innovations and Investments", Science in Russia, No. 3, 2004. - Ed.
potential, it is in their environmental, soil-protecting function.
During the research the concentration of heavy metals and sulphur was determined in the background territories as well as in the technogenic effect zones and the variability of this index closer to pollution sources. Furthermore it was proved that the harmful effect of these factors on natural ecosystems depends on the shape of terrain, conditions of growth, composition and age of the trees. Their response to the pollution was proved, i.e. change of the crown structure, parts of tree, rate of growth, decrease of reproductive potential and ability for natural regeneration. Needless to say, extremely severe climatic conditions and diversity in microenvironment predetermine different level of forest flora resistance to toxic emissions. The collected data allow to substantiate regional environmental requirements, which specify the permissible pollution loads.
It is necessary to say that the permafrost soil, which is a home for all above-mentioned plants, is highly vulnerable and refractory. The anthropogenic pressure on it results in the accumulation of chemical pollutants from the air (first of all heavy metals, sulphur dioxide). They enter into different chemical reactions, are absorbed by organic material, clay minerals, oxides (iron, aluminum, etc.), and are picked up by vegetation. That is why the main objective was to determine genetic-geographic regularities, cause-effect relationships of soils formation in the northern latitudes, their response to technogenic and natural hazards. Thereby landscape-geochemical and ecological-geochemical approaches were used, based on the theory of integrity and unity of all environmental components (man, rock, soil, flora, fauna, atmosphere, natural waters, etc.) which are interconnected by the flows of energy and substance.
As a result the distribution of heavy metals and sulphur in the soils of the region was established. Let's say, the content of heavy metals and sulphur is drastically increasing and they are being concentrated mostly in the upper root layer (0 - 5 cm) closer to the pollution source. The pollutants are discharged with dust and gas stack ash, are accumulated and absorbed by organic substance. Some portion of these elements penetrates even deeper, where they are carried out to ground and subsurface waters, causing the formation of secondary (technogenic) zones of their dispersal, overlapping the initial (natural) ones.
It is necessary to note that the lowest flat elements of the landscape, accumulating everything that goes from the water-shed area are lakes. By the way, lakes located near Norilsk (due to natural geological characteristics) are defined by a higher natural concentration of metals. The current evaluation system of maximum permissible concentrations, as the inspections confirmed, does not always take into account such special factors for a specific territory. That's why it was necessary to outline the corresponding regional criteria during the survey. Then it was necessary to find out how the pollution would affect the structure and behavior of water ecosystems. To do that the scientists started to study bacterio-, phyto-, zooplankton, the ichtyofauna, including photosynthesis and breathing, recorded vital deviations, not characteristic of transpolar lakes. All this was tentatively classified as a result of anthropogenic effect.
The life of animals in forest tundra is determined by a seasonal activity and a high ecological risk*. The number of species living here in winter is less than a dozen, and exceeds a hundred in summer. Native species of land vertebrates are mainly represented by small mammals, who feel good under the snow. Root vole and different insectivores prevail among them: mole, common, tundra, middle and little shrew. Snow grouse, weasel, arctic fox, mountain hare, lemming are widely spread.
The animals breed fast under favorable conditions. However, if the snow delays in autumn, than the death rate due to hypothermia increases under heavy frosts. The spring thaws are even more harmful, when first the snow turns into slush and then freezes over for a long time, dooming animals to starvation (in this case the population decline, for example, of shrew and lemming continues for 2 - 3 years). Root voles suffer less-they live along brook valleys which are characterized by stable behavior and are rich in grass stand. But sometimes they are also trapped in ecological pitfall-they die during floods. Their population decline leads to a suspension of breeding and migration of birds of prey.
In summer the diversity of fauna will be greatly increased due to water and water-feeding fowl, brushwood and tundra birds (little bunting, blue-throated robin, redpoll, etc.).
White-tailed eagle and pigeon hawk dominate among birds of prey, erne can be often found, peregrine-less often. The causes of migrants arriving for nesting are very complex and not known yet.
Most interesting are the life mode and population conditions of reindeer. Annual migrations for thousands of miles, difficult stream crossings, continued presence of predators, heat and blood sucking insects in summer, anthropogenic obstacles and hunting are responsible for the "fatal" behavior of the animals. However their current population is about a million (which exceeds the estimated capacity of pastures twofold) and so far no decline in population numbers has been registered.**
Nauka v Sibiri (Science in Siberia), 2005
Prepared by Olga BAZANOVA
* See: V. Bolshakov, "'Green Mound' on the Arctic Circle", Science in Russia, No. 5, 2004. - Ed.
** See: Ye. Syroechkovsky, "Reindeer Problems", Science in the USSR, No. 2, 1990. - Ed.
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