Influence of water level fluctuations in Lake Baikal on animal population of coastal ecosystems
V.A. PRELOVSKII1, I.V. FEFELOV2
1V.B. Sochava Institute of Geography, Siberian Branch, Russian Academy of Sciences, Irkutsk, Russia
2Research Institute of Biology, Irkutsk State University, Irkutsk, Russia
Keywords: hydrological regime, wetlands, animal adaptation, amphibians, birds, mammals
Abstract
The influence of long-term and seasonal fluctuations in the water level of Lake Baikal on species diversity of near-water and waterfowl vertebrates, their population density and breeding success is analyzed, the negative impact is revealed as well as a change in forage specificity and behavioral adaptation of species. The animal population of the coastal ecosystems of Baikal is unique and specific in many respects, as a result of which some aspects of its adaptation to long-term fluctuations in the water level are unique. An analysis was also made of data on changes in the abundance and spatial distribution of terrestrial vertebrates depending on the decrease or increase in the water level. The role of the construction of the Irkutsk hydroelectric power station in changing the structure of the population and the dynamics of the number of vertebrates is revealed. It has been established that in the nesting populations of waterfowl inhabiting the Selenga river delta, the rate of water level rise exceeding 1-2 cm/day causes a significant increase in the death of nests and eggs. Prolonged low water, which covered about 20 years, led to a decrease in the number of waterfowl, gulls and waders, which had previously remained numerous. We collected and analyzed information on the distribution and characteristics of the ecology of more than 120 species of vertebrates, permanently or seasonally living on the coast of Lake Baikal and leading an aquatic or semi-aquatic lifestyle. A zoning of the territory of the coast into 10 regions with different lengths, but with similar natural and climatic conditions, was carried out. 46 key areas have been identified, which are most sensitive to water level fluctuations. For these sites, the species composition of background and rare species of animals was established, and the areas of optimal habitat for animals and the zones of flooding of habitats were determined. The cartographic characteristics of two vulnerable territories of the Baikal coast are given.
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