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Titel |
Phosphorus status of soils from contrasting forested ecosystems in southwestern Siberia: effects of microbiological and physicochemical properties |
VerfasserIn |
D. L. Achat, M. R. Bakker, L. Augusto, D. Derrien, N. Gallegos, N. Lashchinskiy, S. Milin, P. Nikitich, T. Raudina, O. Rusalimova, B. Zeller, P. Barsukov |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1726-4170
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Digitales Dokument |
URL |
Erschienen |
In: Biogeosciences ; 10, no. 2 ; Nr. 10, no. 2 (2013-02-04), S.733-752 |
Datensatznummer |
250017499
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Publikation (Nr.) |
copernicus.org/bg-10-733-2013.pdf |
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Zusammenfassung |
The Siberian forest is a tremendous repository of
terrestrial organic carbon (C), which may increase owing to climate change,
potential increases in ecosystem productivity and hence C sequestration.
Phosphorus (P) availability could limit the C sequestration potential, but
tree roots may mine the soil deep to increase access to mineral P. Improved
understanding and quantification of the processes controlling P availability
in surface and deep soil layers of Siberian forest ecosystems are thus
required. The objectives of the present study were to (1) evaluate P status
of surface and deep soil horizons from different forest plots in
southwestern Siberia and (2) assess the effects of physicochemical soil
properties, microbiological activity and decomposition processes on soil P
fractions and availability. Results revealed high concentrations of total P
(879–1042 mg kg−1 in the surface mineral soils) and plant-available
phosphate ions. In addition, plant-available phosphate ions accumulated in
the subsoil, suggesting that deeper root systems may mine sufficient
available P for the trees and the potentially enhanced growth and C
sequestration, may not be P-limited. Because the proportions of total organic
P were large in the surface soil layers (47–56% of total P), we
concluded that decomposition processes may play a significant role in P
availability. However, microbiological activity and decomposition processes
varied between the study plots and higher microbiological activity resulted
in smaller organic P fractions and consequently larger available inorganic P
fractions. In the studied Siberian soils, P availability was also controlled
by the physicochemical soil properties, namely Al and Fe oxides and soil pH. |
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