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| Titel |
Modeling approaches to describe H2O and CO2 exchange in mare ecosystems |
| VerfasserIn |
A. Olchev, E. Novenko, E. Volkova |
| Konferenz |
EGU General Assembly 2012
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 14 (2012) |
| Datensatznummer |
250062935
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| Zusammenfassung |
| The modern climatic conditions is strongly influenced by both internal variability of
climatic system, and various external natural and anthropogenic factors (IPCC 2007).
Significant increase of concentration of greenhouse gases in the atmosphere and
especially the growth of atmospheric CO2 due to human activity are considered as
the main factors that are responsible for global warming and climate changes. A
significant part of anthropogenic CO2 is absorbed from the atmosphere by land biota and
especially by vegetation cover. However, it is still not completely clear what is
the role of different land ecosystems and especially forests and mares in global
cycles of H2O and CO2 and what is a sensitivity of these ecosystems to climate
changes.
Within the frameworks of this study the spatial and temporal variability of H2O
and CO2 fluxes in different types of mare ecosystems of the forest-steppe zone in
European part of Russia was described using modeling approaches and results of field
measurements. For this modeling and experimental study the mare ecosystems of Tula region
were selected. The Tula region is located mostly in the forest-steppe zone and it is
unique area for such studies because almost all existed types of mare ecosystems of
Northern Eurasia distinguished by a geomorphological position, water and mineral
supply can be found there. Most mares in Tula region have a relatively small size and
surrounded by very heterogeneous forests that make not possible an application of the
classical measuring and modeling approaches e.g. an eddy covariance technique
or one-dimensional H2O and CO2 exchange models for flux estimation in such
sites.
In our study to describe the radiation, sensible heat, H2O and CO2 exchange between such
heterogeneous mare ecosystems and the atmosphere a three-dimensional model Forbog-3D
and one-dimensional Mixfor-SVAT were applied. The main concept used in the Forbog-3D
and Mixfor-SVAT models is an aggregated description of physical and biological processes at
various hierarchical levels of forest and mire ecosystems: from a single leaf to a tree and an
entire ecosystem. The models consist of the several closely coupled sub-models describing:
transfer of direct and diffuse solar radiation; turbulent exchange of sensible heat, H2O and
CO2 within and above a vegetation cover; transpiration, photosynthesis and respiration of
vegetation and soil; heat and moisture transfer in different soil layers. The models were
validated and applied to describe the H2O and CO2 exchange processes in various mare
ecosystems with different relief position, type of water and mineral supply as well as
vegetation composition. Selected mares are located in different parts of the Tula region
(both in forest and forest-steppe zones) and characterized by different microclimatic
conditions.
The study was supported by grants (11-04-97538-r_center_a, 11-04-01622-a and
11-05-00557-a) of the Russian Foundation for Basic Research (RFBR) and by grant of
Government of Russian Federation N 11.G34.31.0079. |
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