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| Titel |
Biochemical processes of oligotrophic peat deposits of Vasyugan Mire |
| VerfasserIn |
L. I. Inisheva, M. A. Sergeeva |
| Konferenz |
EGU General Assembly 2009
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 11 (2009) |
| Datensatznummer |
250030164
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| Zusammenfassung |
| The problem of peat and mire ecosystems functioning and their rational use is the main
problem of biosphere study. This problem also refers to forecasting of biosphere changes
results which are global and anthropogenic. According to many scientists’ research the
portion of mires in earth carbon balance is about 15% of world’s stock.
The aim of this study is to investigate biochemical processes in oligotrophic
deposits in North-eastern part of Vasyugan Mire. The investigations were made on
the territory of scientific-research ground (56Ë 03´ and 56Ë 57´ NL, 82Ë 22´ and
82Ë 42´ EL). It is situated between two rivers Bakchar and Iksa (in outskirts of
the village Polynyanka, Bakchar region, Tomsk oblast). Evolution of investigated
mire massif began with the domination of eutrophic phytocenosis – Filicinae, then
sedge. Later transfer into oligotrophic phase was accompanied by formation of meter
high-moor peat deposit. The age of three-meter peat deposit reaches four thousand
years.
Biochemical processes of carbon cycle cover the whole peat deposit, but the process
activity and its direction in different layers are defined by genesis and duration of peat
formation. So, the number of cellulose-fermenting aerobes in researched peat deposits
ranges from 16.8 to 75.5 million CFU/g, and anaerobic bacteria from 9.6 to 48.6
million CFU/g. The high number of aerobes is characteristic for high water levels,
organizing by raised bog peats. Their number decreases along the profile in 1.7 - 2
times.
The number of microflora in peat deposit is defined by the position in the landscape
profile (different geneses), by the depth, by hydrothermic conditions of years and individual
months. But microflora activity shows along all depth of peat deposit. We found the same in
the process of studying of micromycete complex structure. There was revealed either active
component micromycete complex – mycelium, or inert one – spores in a meter layer of peat
deposit. If mushrooms spores are observed in all deposit layers, mycelium of mushrooms
deepens into the peat deposit (to 2 meters) within the limits of aerobic (meter) zone
and only in particular months of dry years. The existence of seasonal dynamics of
eukaryotic cells, and also capability of yeast and other groups of micromycetes for
growth, testifies about vital activity of a number of eukaryotic cells at a depth of 2
meters.
Researched peat deposits are biochemically active along the whole profile. But they are
different in a microflora number of individual physiological groups either in items of the
landscape, or in deposit depth. The largest quantity of aerobic cellulose-fermenting
microorganisms is marked during dry years. Anaerobic cellulose-fermenting microorganisms
dominate during wet years. The quantity of microbe biomass increases in bottom lifts
of peat deposits. This fact testifies about viable condition of microbe complex at
depth.
The formation process of carbon dioxide in peat deposits of Vasyugan Mire actively
occurs during dry years and is defined by hydrothermic conditions of a meter layer of peat
deposit. The intensity of CO2 isolation for certain correlates with the temperature in
horizon of 0 – 50 sm. and with bog waters level. The study of gas composition for the
three years showed that the largest concentration of carbon dioxide in peat soils
is marked along the whole profile during a dryer year (0.08 – 2.65 millimole/l),
increasing other years’ level in about 1.5 0 2 times. Emission of carbon dioxide in peat |
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