Macroinvertebrate community structure in relation to environmental variables in a Swiss glacial stream

Article Article scientifique Article Macroinvertebrate community structure in relation to environmental variables in a Swiss glacial stream eng 2001 author Lods-Crozet Brigitte 26412 author Castella Emmanuel 0000-0002-4115-4124 29171 author Cambin Diana Georgette 25922 author Ilg Christiane 128877 author Knispel Sandra 57309 author Mayor Hélène 722544 1641-1661 10.1046/j.1365-2427.2001.00850.x 0046-5070 1. Benthic macroinvertebrate distribution was examined in relation to channel characteristics (including stability), substratum, hydraulic variables, primary production (chlorophylla) and coarse particular organic matter (CPOM) in an alpine glacial stream, the Mutt (Upper Rhone valley, Switzerland). Co-inertia analysis and canonical correspondence analysis were used to identify the major environmental gradients in¯uencing community variations. 2. The Mutt (length: 3.6 km, altitudinal range: 1800±3099 m a.s.l.) exhibited typical characteristics of a kryal stream. Average summer temperature remained below 2 °C immediately downstream from the snout but was on average 5 °C higher 1700 m downstream. Seasonal variations in water sources were evidenced by the high latesummer(September) contribution of groundwater with increased conductivity. 3. Sixty-six taxa were recorded from the five reaches sampled at three periods (snowmelt,ice melt and low water in late summer) in 1996 and 1997, of which 29 were Chironomidae. Three taxa of Diamesinae were the first colonizers of the stream below the glacier, but 16 taxa, including Ephemeroptera, Plecoptera and Trichoptera, were already recorded 200 m downstream. Water depth, channel slope and Pfankuch's Index of channel stability were strongly correlated with the longitudinal faunal gradient. Maximum temperature, current velocity and water conductivity were also correlated, but to a lesser extent. 4. The rapid incorporation of non-chironomid taxa into the stream community represented a departure from Milner & Petts's (1994) conceptual model of invertebrate succession downstream of glacial margins. The results confirmed that glacial stream communities are primarily driven by physical determinants. Alpine Diamesa Glacial stream Longitudinal zonation Macroinvertebrates Dewey 333.7-333.9 Dewey 550 18 Institut des sciences de l'environnement 0DB 41 Département F.-A. Forel des sciences de l'environnement et de l'eau 153 false 756 Ecology and Aquatic Biology Freshwater biology 46 b6c43522-4844-4101-a2c6-5be95b3fe20d Article (Accepted version) Restricted Lods_Crozet_et_al-2001-Freshwater_Biology.pdf 1207637 application/pdf restrictedAccess Centres et instituts / Institut des sciences de l'environnement Faculté des sciences / Section des sciences de la Terre et de l'Environnement / Département F.-A. Forel des sciences de l'environnement et de l'eau

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Macroinvertebrate community structure in relation to environmental variables in a Swiss glacial stream	Freshwater biology			2001	691	0

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Knispel, Sandra