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| Titel |
Responses of diatom communities to hydrological processes during rainfall events |
| VerfasserIn |
Naicheng Wu, Claas Faber, Uta Ulrich, Nicola Fohrer |
| 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 |
250105022
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| Publikation (Nr.) |
 EGU/EGU2015-5702.pdf |
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| Zusammenfassung |
| The importance of diatoms as a tracer of hydrological processes has been recently recognized
(Pfister et al. 2009, Pfister et al. 2011, Tauro et al. 2013). However, diatom variations in a
short-term scale (e.g., sub-daily) during rainfall events have not been well documented
yet.
In this study, rainfall event-based diatom samples were taken at the outlet of the Kielstau
catchment (50 km2), a lowland catchment in northern Germany. A total of nine rainfall events
were caught from May 2013 to April 2014. Non-metric multidimensional scaling (NMDS)
revealed that diatom communities of different events were well separated along
NMDS axis I and II, indicating a remarkable temporal variation. By correlating water
level (a proxy of discharge) and different diatom indices, close relationships were
found. For example, species richness, biovolume (μm3), Shannon diversity and
moisture index01 (%, classified according to van Dam et al. 1994) were positively
related with water level at the beginning phase of the rainfall (i.e. increasing limb of
discharge peak). However, in contrast, during the recession limb of the discharge peak,
diatom indices showed distinct responses to water level declines in different rainfall
events.
These preliminary results indicate that diatom indices are highly related to hydrological
processes. The next steps will include finding out the possible mechanisms of the above
phenomena, and exploring the contributions of abiotic variables (e.g., hydrologic indices,
nutrients) to diatom community patterns. Based on this and ongoing studies (Wu et al.
unpublished data), we will incorporate diatom data into End Member Mixing Analysis
(EMMA) and select the tracer set that is best suited for separation of different runoff
components in our study catchment.
Keywords: Diatoms, Rainfall event, Non-metric multidimensional scaling, Hydrological
process, Indices
References:
Pfister L, McDonnell JJ, Wrede S, Hlúbiková D, Matgen P, Fenicia F, Ector L, Hoffmann
L. 2009. The rivers are alive: on the potential for diatoms as a tracer of water source and
hydrological connectivity. Hydrological Processes 23: 2841-2845.
Pfister L, Wetzel CE, Martínez-Carreras N, Frentress J, Ector L, Hoffmann L, McDonnell
JJ. 2011. Do diatoms run downhill? Using biodiversity of terrestrial and aquatic diatoms to
identify hydrological connectivity between aquatic zones in Luxembourg. AGU Fall
Meeting.
Tauro F, Martínez-Carreras N, Wetzel CE, Hissler C, Barnich F, Frentress J, Ector L,
Hoffmann L, McDonnell JJ, Pfister L. 2013. Fluorescent diatoms as hydrological tracers: a
proof of concept percolation experiment. EGU abstract, EGU2013-7687-4.
van Dam H, Mertens A, Sinkeldam J. 1994. A coded checklist and ecological indicator
values of freshwater diatoms from the Netherlands. Netherlands Journal of Aquatic Ecology
28:117-133. |
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