Lepori, Fabio and Barbieri, Alberto and Ormerod, Steve J. (2003) Effects of episodic acidification on macroinvertebrate assemblages in Swiss Alpine streams. Freshwater Biology, 48 (10). pp. 1873-1885. ISSN 00465070
Full text not available from this repository.Abstract
1. Despite long-standing ecotoxicological evidence that episodes of acidification in streams are important biologically, there is still uncertainty about their effects on invertebrate communities. We surveyed 20 streams in an acid sensitive Alpine area (Canton Ticino, Switzerland), where episodes are driven by snowmelt in spring and by rainstorms at other times of the year. Samples of water and macroinvertebrates were collected in pre-event conditions (winter and summer) and during periods of high flow (spring and autumn). 2. Using pH, [Ca2+] and [Aln+], streams were clustered into six acid–base groups that were either well buffered (groups 4–6), soft-water with stable pH (group 3), or poorly buffered with low pH at high flow (groups 1 and 2). 3. Severe episodes occurred during snowmelt, when the group 1 streams became acidic with pH down to 5.0 and [Aln+] up to 140 μg L−1. pH declined to 6.2 in streams of group 2, but remained > 6.6 in groups 3–6. 4. Detrended canonical correspondence analysis showed that the streams sensitive to episodes (groups 1 and 2) had different invertebrate assemblages from well-buffered sites (groups 4 and 5) or soft-water stable streams (group 3), with faunal differences largest following spring snowmelt. Empididae, Isoperla rivulorum, Rhithrogena spp. and Baetis spp. were scarce in streams sensitive to episodes (groups 1 and 2). By contrast, Amphinemura sulcicollis was scarcer in hard-water streams (groups 4–6). Taxonomic richness was lower in the episodic streams of group 1 than in other streams. 5. Together, these results indicate clear biological differences between acid-sensitive streams with similar low-flow chemistry but contrasting episode chemistry. Severe episodes of acidification appear to affect macroinvertebrate assemblages in streams in the southern Swiss Alps.
Item Type: | Scientific journal article, Newspaper article or Magazine article |
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Subjects: | Biological Sciences > Biology > Marine/Freshwater biology > Freshwater biology Biological Sciences > Biology > Ecology Biological Sciences > Biology > Ecology > Ecosystem ecology & land use Physical sciences > Chemistry > Environmental chemistry |
Department/unit: | Dipartimento ambiente costruzioni e design > Istituto scienze della Terra |
Depositing User: | Fabio Lepori |
Date Deposited: | 26 Jul 2021 08:39 |
Last Modified: | 26 Jul 2021 08:40 |
URI: | http://repository.supsi.ch/id/eprint/12682 |
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