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Flora and fauna of Lake Baikal
Scientists point out several features of the flora and fauna of Lake Baikal. The first one is a great biodiversity of them. It was estimated that there are more than 2500 species of fauna and about 1000 species of flora there. At that terrestrial species of plants and animals are not taken into consideration. The second feature is a high degree of endemism, i.e., a significant number of species can be found only in this part of planet; almost 40% of plants and 85% of animals are endemic here. The third feature is the immiscibility of the Baikal species: both plants and animals do not copulate (or practically do not) with their "brothers and relatives" from the nearby water bodies: rivers, streams, small lakes.
The fourth feature of the Baikal flora and fauna is that animals can be found at absolutely all the depths of Lake Baikal, even at maximum ones (the plants are not as they can be found only at the upper water level of the lake), and here there is a unique deep freshwater fauna. The fifth feature of the Baikal flora and fauna is the presence of giant and dwarf species in it; and they differ from the similar species in other water bodies. And, finally, the sixth feature is that the Baikal is characterized by active evolution of organisms: the flora and fauna species go on developing, as they used to throughout all the history of the lake [306, p. 41 – 45].
The Baikal species of flora and fauna somehow deny the well-known Darwin's theory of plants and animals survival in the result of natural culling in the fight against the same species. They live and develop together, and support each other in it (How important this biological reality is for humans now!).
We have already mentioned that the characteristic feature of flora and fauna of Lake Baikal is the high degree of endemism. Let us remind you that endemics are those organisms that are not found outside a definite habitat. Endemic species make up a significant part of animal and plant population of the Baikal. Sometimes they present ancient species preserved in special conditions, but the majority of them are new species that have evolved here. Islands, mountain terrains, deep lakes are rich in endemic species. Endemics can be represented by species, genus, rarely by families, that is by relatively high systemic ranges that depend on the duration of isolation and habitat conditions. Abundance of endemic species in Lake Baikal indicates its significant geological age and duration of isolation.
Since ancient times numerous and diverse wildlife of Lake Baikal and its shores has always been in balance and mutual influence. The interrelation and interdependence of aquatic flora and fauna of Lake Baikal is represented in the concept of the so-called "the lake tree of immortality", "the tree of life" that shows five levels of the lake. The first one is represented by water-plants that get food from sediments and the lake water. The second level is herb plankton. The third level is predatory zooplankton that feeds on grass plankton and microorganisms. The fourth one is small fish that feed on zooplankton. And, finally, the fifth one is food fish and mammals. Thus, all (almost all) biological organisms and chemical elements that are present in the lake take part in the biological process.
According to the number of species the lake does not yield to some seas that are in large excess over it. As B. Dybovsky said after his first excursion on the lake, it was enough to lift a few stones lying near the shore, and you could enrich the systemic zoology with new species.
The Many Faces of Multilingual and Mysterious Baikal. A.D.Karnyshev
A.D. Karnyshev "The Many Faces of Multilingual and Mysterious Baikal"© BSU Publishing House, 2011
Жанр материала: English | Автор(ы): Karnyshev A.D. | Источник(и): The Many Faces of Multilingual and Mysterious Baikal. Ulan-Ude. 2012 | Дата публикации оригинала (хрестоматии): 2011 | Дата последней редакции в Иркипедии: 30 марта 2015
Тематический указатель: Irkipedia English
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