Aquatic macroinvertebrate assemblages of two contrasting floodplains: The rhǒne and ain rivers, France

Abstract

The study examines the relationship between floodplain aquatic macroinvertebrates and sector-scale parameters such as geomorphology and history of regulation. The assemblages of six groups of invertebrates (Molluscs, Crustaceans, Ephemeroptera, Odonata, Trichoptera, and Coleoptera) were compared in various types of former channels from two contrasting but adjacent floodplain sectors: (1) the Jons sector of the RhBne River where successive meandering and braiding phases has left diversified fluvial forms in the landscape but where the main river is now embanked, and (2) the unregulated Ain River sector where the river is still actively meandering, although this process is being slowed by incision. The results demonstrate little difference in faunal composition between the two sectors but a significant difference in faunal structure. In the Rhbne floodplain, there was a clear distinction between the faunal assemblages together with a high taxa richness at the scale of the sector (dominance of the beta diversity). In the Ain floodplain, the faunal assemblages were overlapping and the taxa richness was high at the sample scale (alpha diversity). Sector-scale spatial patterns of the faunal assemblages along former channels were also distinct: between-channel heterogeneity dominated in the Rhbne, whereas within-channel heterogeneity dominated on the Ain. These results stress the influence of geomorphological and historical determinants on the floodplain communities and, conversely, the relevance of macroinvertebrate assemblages for the assessment, at the landscape scale, of aquatic systems within the floodplains.

Importance of floodplain waters for the conservation of chironomid (Diptera) biodiversity in a 6thorder section of the Garonne river (France)

“…The result was an alteration of the floodplain waters, which progressively filled in and di sappeared (Amoros et al 1987, Finlayson & Moser 1991, Ward & Stanford 1995b. However, the length of time that this takes allows the conservation of these zones within the large river systems and enables the study of their functioning, as for example, on the River Danube (Heiler et al 1994, Tockner & Bretschko 1996, the Rhine and the Meuse rivers in the Netherlands (Van den Brink & Van den Velde 1991) or on the French Haut-Rhóne (Amo ros 1991, Castella et al 1991, Cellot et al 1994). …”

Development of fauna of water beetles (Coleoptera) in waters bodies of a river valley – habitat factors, landscape and geomorphology

“…That is why scientists have been showing a growing interest in relations between river-dwelling fauna and the fauna of other water bodies within the floodplains of rivers (Castella et al, 1984;Stanford et al, 1996;Van den Brink et al, 1996;Stanley et al, 1997;Ward et al, 1999;Robinson et al, 2002;Biesiadka and Pakulnicka, 2004a). Papers describing the faunistic and ecological features of hydrobiont groups are now available, and point to these being shaped by the system's lasting hydrological interconnection (Kajak, 1959;Castella et al, 1984Castella et al, , 1991Castella and Amoros, 1988;Ward et al, 2002;Biesiadka and Kurząt-kowska, 2003;Biesiadka et al, 2004;Biesiadka et al, 2004;Czachorowski, 2004;Jurkiewicz-Karnkowska, 2006;Reckendorfer et al, 2006;Obolewski et al, 2009;Stryjecki and Kowalczyk-Pecka, 2013;Zawal and Kowalik, 2013;Kowalik et al, 2014;Zawal et al, 2016d).…”

“…The question that comes to mind -what are the factors affecting the formation of groups of fauna in river valleys -has been raised not only by hydroentomologists, but also researchers of other groups of organisms (Kajak, 1959;Castella et al, 1984Castella et al, , 1991Castella and Amoros, 1988;Ward, 1998;Ward et al, 2002;Jurkiewicz-Karnkowska, 2006;Reckendorfer et al, 2006;Obolewski et al, 2009). Biesiadka and Pakulnicka (2004a) point out that for water beetles, which are usually perfect fliers and are characterized with high biological dispersal (Bilton, 1994;Lundkvist et al, 2002), faunistic integration between the river and the water bodies located on the floodplain is influenced by two mechanisms: active overflights and migration of beetles in the floodplain area in time of spate.…”

“…Despite this, water environments comprising the cohesive hydrological system may still be distinguished by a certain degree of individualism (Marchese and Ezcurra de Drago, 1992;Pakulnicka and Nowakowski, 2012;Costea et al, 2013;Biesiadka and Pakulnicka, 2004a). These individual features are the result of internal environmental (site) factors, such as type of water body, type of substrate, extent of vegetation, area, age, permanence and water flow speed (Castella et al, 1991;Marchese and Ezcurra de Drago, 1992;Winfield Fairchild et al, 2000;Lundkvist et al, 2001;Oertli et al, 2002;Pakulnicka, 2008;Pakulnicka and Nowakowski, 2012;Pakulnicka et al, 2015a,b).…”

“…In recent decades, scientists have gained a better understanding of just how important landscape factors are to water environments and the groups of macroinvertebrates inhabiting them; those factors including geomorphology, landscape structure and landscape utilization (Castella et al, 1991;Delettre et al, 1992;Richards and Host, 1994;Richards et al, 1996;Delettre and Morvan, 2000;Galic et al, 2013;Zawal et al, 2016b,c). Not any less important are human activities performed on the river itself, a clear example of which can be seen in the studied River Krąpiel (SzlauerŁukaszewska and Zawal, 2014;Bańkowska et al, 2015;Dąbkowski et al, 2016;Stępień et al, 2015;Zawal et al, 2015;2016d;Płaska et al, 2016).…”