Svetlana N. Ektova’s research while affiliated with Ural Branch of the Russian Academy of Sciences and other places

This paper represents the results of a comprehen� sive study on the consistent patterns of the functioning (dynamics) of the shrub and northern tundra ecosys� tems of the Yamal Peninsula that have been subjected to long�term anthropogenic impact connected with the traditional reindeer breeding and are now sub� jected to some new influences connected with the development of the oil and gas industry. The study is based on the integration of data accumulated during several decades of investigation of Yamal ecosystems in which we have participated.

Lichens are the most sensitive part of vegetation cover to reindeer grazing. In this study we analyse success of restoration rate of lichen-rich tundra vegetation after ceasing the grazing stress at the Yamal Peninsula. On experimental plots we compare the main parameters of lichen mat (species diversity, total cover, thalii height, biomass, recovery rate) on grazed pastures and fanced sites after 13 years after of its isolation. Our results demonstrate that after intensive overgrazing the lichen species diversity and synusiases structure change very slowly. The rate of the biomass increase of lichens for this period has made 3.8 g m-2 year-1 that makes 3.6% from mass in the year. But this rate is two times lowers than in highly productive lichen communities.

In the article, the problem of development of oil and gas resources and consequence of this process for ecosystems of subarea of the northern subarctic tundra is considered in the example of the Yamal peninsula. These estimates of the main environment-forming and production (resource) functions of tundra natural and territorial complexes in a zone of active development of Bovanenkovsky oil-gas condensate field (OGCF) are presented. Recommendations for the integrated assessment of economic damage from the harm to subarctic ecosystems made by technogenic influence are introduced. The assessment of damage is based on the decrease in economic value of the natural capacity of the territory in the allocated ecological zones (troublesome zone of natural complexes), which development are defined by the stability of ecosystems and intensity of technogenic loadings. Results of an assessment of economic damage to conditions of development of Bovanenkovsky OGCF are given. Results of economic damage assessment for the development conditions of Bovanenkovsky OGCF are given.

The study is focused on the description of the vegetation and the general environment all characteristics of the salt marshes along coasts in the Baydaratskaya Bay there are of the Kara Sea in the southern tundra subzone of Russian Arctic. In tidal salt marsh habitats, several successional stages and types of communities depending on part of tidal zone. The plant communities study areas located close to research stations were represented by 50 species of vascular plant, 15 mosses and 3 lichens. The coastal vegetation tends to be floristically intermediate between the species composition of typical salt marshes communities (obligate and facultative halophytes) and species from adjacent tundra plains which can be able to tolerate occasional flooding by salt water. Zonation of salt marsh vegetation and floristic diversity were compared with the data for northern area of Kara Sea coasts.

Terrestrial ecosystems of the Yamal Peninsula were subjected to the impact of domestic reindeer for several decades: the reindeer husbandry was extensively developed in the traditional nomadic way during the past century and especially recently. The ecosystem dynamics was analyzed by means of computer simulations. It was shown that nomadic reindeer husbandry is the primary cause of the observed degradation of vegetative and lichens cover. Dramatic changes in both productivity and standing crop characteristics indicate the impossibility of keeping on this way of land use under the present industrial and climatic situation in the region. Warming must be fantastically rapid for improving the present situation; global warming seems to be not a sufficient factor for restoration of forage resources in Yamal.The general question we tried to answer was: if global warming (the signs of which seems to be detected since the end of 1950s) may serve as a favoring factor of indigenous manner of land use or not? In the model we supposed that production (per year) of vegetation (lichens mainly) would exponentially increase with the growth of mean ambient temperature. Several model experiments were carried on in the attempt to determine what rate of such changes would be sufficient for keeping the number of reindeer at the modern level (ca. 350000 individuals) without degradation of vegetation. The model experiments showed that these changes have to be much faster that one can reasonably imagine. Therefore, in spite of wide-spread cliché, traditional nomadic reindeer husbandry is not an example of human and vegetation coexistence in harmony at all. Even more, the existent exponential growth of domestic reindeer herds seems to be more dangerous for the natural complexes in the region, than, say, the development of oil and gas industry. The present situation requires significant corrections in ethno-cultural and economical policy in the region, and global worming would not improve the alarming situation.

Currently, 380 000 domestic reindeers are grazed on 106000 km2 of the Yamal peninsula. This unique situation was analyzed from a view of an ecosystem role of indigenous people. Attention was paied to two key points: the impact of overgrazing on (1) vegetation and (2) vertebrates. The results of our 30-years investigations were compared with the published vegetation data from the 1930-ies. In our paper, it is demonstrated, that overgrazing has resulted in a substantial transformation of vegetation, mostly in lichen tundra. Recent situation is close to total extinction of lichen pastures on the Yamal peninsula. Due to overgrazing, total availability of grasses and shrubs have also decreased, in grasses by 1.5-2.0 times, low shrubs - almost 8 times, tall shrubs – 2.0 times. The degradation of vegetation leads to desertification of the peninsula. The area of sandy spots with no vegetation is on average about 5.5% of the peninsula land, however, it could reach up to 19% locally. Overgrazing affected the animal populations too. Since 1990, the peaks of lemmings have never reached former high values and become locally-limited and patchy. This has led to a decrease in the number of predators. The number of other tundra birds decreased as well. The decrease reached almost 2 times lower numbers in geese, 3 times in hygrophillous waders, 5.5 times in Lapland bunting, and 2 times in long-tailed Duck and Willow grouse on watershed. The Nenets themselves can not control reindeer population because of rigid social and psychological attitudes based on their traditions. The main aim of the Nenets reindeer-farming is not to create marketable products for a profit, but increasing the reindeer number of itself. A situation has formed, that, on the one hand, the Nenets are not economically dependent upon the society, and on the other hand, the society contributes to preservation of their traditional farming. The Nenets reindeer-farming, thus become an important factor contributing to rapid transformation of tundra ecosystem.

Morphological and anatomical features of underground organs of 12 species of Magnoliophyta plants growing in the tundra of the Yamal Peninsula were studied. The structural attributes of roots and rhizomes used for their identification and important for understanding of the adaptation of species to extreme conditions were determined.

The systemic approach based mainly on computer simulation has been used to assess the dynamics of ecosystems of the Yamal Peninsula, which have been exposed to the impact of numerous reindeer herds because of extensive development of reindeer breeding during the past decades. This type of development has been demonstrated to result in degradation of vegetation, whose profound changes preclude further development of reindeer breeding in the same way. The current situation requires major amendments to the ethnic-cultural and economic policy in the region. Keywordssimulation–vegetation–reindeer breeding–pasture load–green and lichen forage–vegetation degradation