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| Titel |
Establishment area and biogeomorphic feedback window of three pioneer riparian Salicaceae species within a dynamic riparian corridor (Allier River, France) |
| VerfasserIn |
Borbála Hortobágyi, Dov Corenblit, Johannes Steiger, Jean-Luc Peiry |
| Konferenz |
EGU General Assembly 2017
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 19 (2017) |
| Datensatznummer |
250138050
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| Publikation (Nr.) |
 EGU/EGU2017-957.pdf |
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| Zusammenfassung |
| Within riparian corridors, biotic-abiotic feedback mechanisms occur between woody
vegetation which is highly influenced by hydrogeomorphic constraints (e.g. sediment
transport and deposition, shear stress, hydrological variability), fluvial landforms and
morphodynamics, which in turn are modulated by established vegetation. During field
investigations in spring 2015 we analysed on 16 alluvial bars (e.g. point and lateral bars)
within the dynamic riparian corridor of the Allier River, France, the aptitude of three
pioneer riparian Salicaceae tree species (Populus nigra L., Salix purpurea L. and Salix
alba L.) to establish and to act as ecosystem engineers by trapping sediment and
constructing fluvial landforms. Our aim was to empirically identify the preferential
establishment area (EA; i.e. the local areas where species establish) and the preferential
biogeomorphic feedback window (BFW; i.e. where and to what extent the species
affect geomorphology) of these three species on alluvial bars within a river reach
of a length of 20 km. Our results show that the EA and BFW of all three species
significantly varied along the longitudinal, i.e. upstream-downstream exposure on the
alluvial bars, and the transverse gradient, i.e. main channel-floodplain gradient of
hydrological connectivity. In the current context of the Allier River it appeared that
P. nigra, which is the most abundant species, acts as the main engineer species
affecting landform dynamics at the bar scale; S. purpurea establishes and acts as an
ecosystem engineer in the locations on the alluvial bars which are the most exposed to
hydrosedimentary flow dynamics, while S. alba establishes on the bar tail in the vicinity of
secondary channels and affects geomorphology in mixed patches with P. nigra.
Thus, our study underlines the role of functional trait diversity of riparian engineer
species in controlling the extent of fluvial landform construction along geomorphic
gradients within riparian corridors exposed to frequent hydrogeomorphic disturbances. |
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