Monday, May 26, 2008 - 11:00 AM
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Functioning of freshwater ecosystems in the south of the russian far east under conditions of a monsoonal climate

Victor Vsevolodovich Bogatov, Institute of Biology and Soil Science, Far Eastern Branch, Russian Academy of Sciences, 159, Pr. 100 let Vladivostoku, Vladivostok, 690022, Russia

The leading role in regulating structural and functional peculiarities of freshwater ecosystems in the south of the Russian Far East carry out extreme natural phenomena (floods, droughts, freezing, extremely biogenic load, etc). Special value in functioning river ecosystems has a spring high water. As a result of passage of thawed snow the reservoir is washed out and, thus, the subsequent biogenic loading on a water-current is reduced. In case of absence of a high water in river systems mass development of seaweed, and the chlorophyll "a" concentration at the end of the spring period 7000 mg per m2 of the bottom area are observed can reach(achieve). It is shown, that the regular consequence of low and high water periods influences favorably the general ecological situation in the rivers. Such consequence allows supporting rather high biological diversity of river communities. In flood-land lakes the primary production of the plankton depends on the value of their flowing and the length of the not floods period. It is established, that annual fish production in the lakes is connected with the average annual plankton chlorophyll "a" concentration and increases by certain limit of the chlorophyll mass (60-80 mg chlorophyll "a" per m3). Effect of the secondary pollution is caused by exceeding of the noted limit.


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