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Indicator taxa of benthic diatom communities: a case study in Mediterranean streams

A key issue in the implementation of the Water Framework Directive is the classification of streams and rivers using biological quality parameters and type-specific reference conditions. Four groups of stream types were defined in NE Spain on the basis of 152 diatom samples by means of detrended correspondence analysis and classification techniques. Diatom analysis was restricted to epilithic taxa, and the sites included gradients ranging from near-natural streams to sites with poor ecological quality. The main gradient shows a clear separation of sites in relation to the degree of human influence: polluted streams (mainly located in the lowlands) differ from streams in mountainous areas and in the Pyrenees. A second gradient is related to physiographical features. Headwater streams can be distinguished by their catchment geology. The type-specific diatom taxa for the stream types studied were determined by using indicator species analysis (IndVal). The type-specific taxa from near-natural streams are coincident with the indicator taxa for high ecological status. Human impact reduced the typological heterogeneity of the diatom community composition. Overall, the diatom communities in NE Spain exhibit a regional distribution pattern that closely corresponds with that observed in river systems elsewhere. Physiographical differences are only evident in undisturbed sites, while nutrient enrichment and other human disturbances may mask the regional differences in the distribution of diatom communities

© Annales de Limnologie - International Journal of Limnology, 2007, vol. 43, núm. 1, p. 1-11

EDP Sciences

Author: Tornés Bes, Elisabet
Cambra, Jaume
Gomà Martínez, Joan
Leira, M.
Sabater, Sergi
Date: 2007
Abstract: A key issue in the implementation of the Water Framework Directive is the classification of streams and rivers using biological quality parameters and type-specific reference conditions. Four groups of stream types were defined in NE Spain on the basis of 152 diatom samples by means of detrended correspondence analysis and classification techniques. Diatom analysis was restricted to epilithic taxa, and the sites included gradients ranging from near-natural streams to sites with poor ecological quality. The main gradient shows a clear separation of sites in relation to the degree of human influence: polluted streams (mainly located in the lowlands) differ from streams in mountainous areas and in the Pyrenees. A second gradient is related to physiographical features. Headwater streams can be distinguished by their catchment geology. The type-specific diatom taxa for the stream types studied were determined by using indicator species analysis (IndVal). The type-specific taxa from near-natural streams are coincident with the indicator taxa for high ecological status. Human impact reduced the typological heterogeneity of the diatom community composition. Overall, the diatom communities in NE Spain exhibit a regional distribution pattern that closely corresponds with that observed in river systems elsewhere. Physiographical differences are only evident in undisturbed sites, while nutrient enrichment and other human disturbances may mask the regional differences in the distribution of diatom communities
Format: application/pdf
ISSN: 0003-4088 (versió paper)
2100-000X (versió electrònica)
Document access: http://hdl.handle.net/10256/7442
Language: eng
Publisher: EDP Sciences
Collection: Reproducció digital del document publicat a: http://dx.doi.org/10.1051/limn:2007023
Articles publicats (D-CCAA)
Is part of: © Annales de Limnologie - International Journal of Limnology, 2007, vol. 43, núm. 1, p. 1-11
Rights: Tots els drets reservats
Subject: Diatomees
Diatoms
Indicadors biològics
Indicators (Biology)
Anàlisi multivariable
Multivariate analysis
Ecologia fluvial
Stream ecology
Title: Indicator taxa of benthic diatom communities: a case study in Mediterranean streams
Type: info:eu-repo/semantics/article
Repository: DUGiDocs

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