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| Titel |
Temporal dynamics of soil aggregates and microbial parameters in permanent and recently established grasslands in the temperate zone |
| VerfasserIn |
Deborah Linsler, Friedhelm Taube, Daniel Geisseler, Rainer Georg Joergensen, Bernard Ludwig |
| Konferenz |
EGU General Assembly 2015
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 17 (2015) |
| Datensatznummer |
250111149
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| Publikation (Nr.) |
 EGU/EGU2015-11234.pdf |
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| Zusammenfassung |
| While changes over time in soil aggregation or microbial parameters are well studied for
arable soils, much less is known about such temporal variations in grassland soils. The
objective of the present study was to determine the changes that occur within one year
(between October 2010 and October 2011) for water-stable aggregate, microbial biomass
carbon (Cmic) and ergosterol (as a proxy for fungal biomass) concentrations of a sandy soil
under a permanent and recently established grasslands The analyzed treatments were (i)
permanent grassland, (ii) grassland re-established after tillage of previous permanent
grassland, and (iii) grassland established on arable land (both in September 2010). Temporal
variations were found for the aggregate distribution and ergosterol concentration in the
permanent grassland. For instance, the concentration of large macroaggregates (>2000
μm) in the surface soil (0-10 cm) varied strongly, with the highest concentration
(mean ± standard error) in October 2011 (666 ± 12 g kg-1) and a 3.2-fold lower
concentration in May 2011. An explanation could be less rainfall and decreasing soil
moisture contents in May compared to October, which may have decreased the
stability of this fraction. A multiple linear regression analysis showed that the large
macroaggregate concentration was well described (R2=0.60) by the gravimetric
moisture content, the Cmic concentration and the pH. After the tillage event in
the grassland and the subsequent grassland renovation, the concentrations of large
macroaggregate, Cmic and ergosterol decreased in the surface soil, while no difference was
found in the soil profile (0-40 cm). In the first year after the conversion of arable
land into grassland, the concentrations of Cmic and ergosterol increased by a factor
of 1.4 and 3.3, respectively, in the surface soil layer, while the macroaggregate
concentration was not affected. This study indicates that the aggregate dynamic in grassland
is not only affected by management but also by environmental conditions. The
fungal biomass seems to be more sensitive to changes in environmental conditions or
grassland management than the microbial biomass because the variations for the
ergosterol concentrations were stronger than those for the Cmic concentrations. |
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