 |
| Titel |
Heterogeneity of soil carbon pools and fluxes in a channelized and a restored floodplain section (Thur River, Switzerland) |
| VerfasserIn |
E. Samaritani, J. Shrestha, B. Fournier, E. Frossard, F. Gillet, C. Guenat, P. A. Niklaus, N. Pasquale, K. Tockner, E. A. D. Mitchell, J. Luster |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1027-5606
|
| Digitales Dokument |
URL |
| Erschienen |
In: Hydrology and Earth System Sciences ; 15, no. 6 ; Nr. 15, no. 6 (2011-06-06), S.1757-1769 |
| Datensatznummer |
250012849
|
| Publikation (Nr.) |
 copernicus.org/hess-15-1757-2011.pdf |
|
|
|
|
|
| Zusammenfassung |
Due to their spatial complexity and dynamic nature, floodplains provide a
wide range of ecosystem functions. However, because of flow regulation, many
riverine floodplains have lost their characteristic heterogeneity.
Restoration of floodplain habitats and the rehabilitation of key ecosystem
functions, many of them linked to organic carbon (C) dynamics in riparian
soils, has therefore become a major goal of environmental policy. The
fundamental understanding of the factors that drive the processes involved
in C cycling in heterogeneous and dynamic systems such as floodplains is
however only fragmentary.
We quantified soil organic C pools (microbial C and water extractable
organic C) and fluxes (soil respiration and net methane production) in
functional process zones of adjacent channelized and widened sections of the
Thur River, NE Switzerland, on a seasonal basis. The objective was to assess
how spatial heterogeneity and temporal variability of these pools and fluxes
relate to physicochemical soil properties on one hand, and to soil
environmental conditions and flood disturbance on the other hand.
Overall, factors related to seasonality and flooding (temperature, water
content, organic matter input) affected soil C dynamics more than soil
properties did. Coarse-textured soils on gravel bars in the restored section
were characterized by low base-levels of organic C pools due to low TOC
contents. However, frequent disturbance by flood pulses led to high
heterogeneity with temporarily and locally increased C pools and soil
respiration. By contrast, in stable riparian forests, the finer texture of
the soils and corresponding higher TOC contents and water retention capacity
led to high base-levels of C pools. Spatial heterogeneity was low, but major
floods and seasonal differences in temperature had additional impacts on
both pools and fluxes. Soil properties and base levels of C pools in the dam
foreland of the channelized section were similar to the gravel bars of the
restored section. By contrast, spatial heterogeneity, seasonal effects and
flood disturbance were similar to the forests, except for indications of
high CH4 production that are explained by long travel times of
infiltrating water favoring reducing conditions. Overall, the restored
section exhibited both a larger range and a higher heterogeneity of organic
C pools and fluxes as well as a higher plant biodiversity than the
channelized section. This suggests that restoration has indeed led to an
increase in functional diversity. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|