Oligochaeta of the middle Po River (Italy): principal component analysis of the benthic data
Paoletti, A.; Sambugar, B. (1984). Oligochaeta of the middle Po River (Italy): principal component analysis of the benthic data, in: Bonomi, G. et al. Aquatic Oligochaeta: Proceedings of the 2nd International Symposium on Aquatic Oligochaete Biology, held in Pallanza, Italy, September 21-24, 1982. Developments in Hydrobiology, 24: pp. 145-152. https://dx.doi.org/10.1007/978-94-009-6563-8_25 In: Bonomi, G.; Erséus, C. (Ed.) (1984). Aquatic Oligochaeta: Proceedings of the 2nd International Symposium on Aquatic Oligochaete Biology, held in Pallanza, Italy, September 21-24, 1982. Reprinted from Hydrobiologia, vol. 115. Developments in Hydrobiology, 24. W. Junk Publishers: Dordrecht. ISBN 978-90-6193-775-3; e-ISBN 978-94-009-6563-8. 264 pp. https://dx.doi.org/10.1007/978-94-009-6563-8, more In: Dumont, H.J. (Ed.) Developments in Hydrobiology. Kluwer Academic/Springer: The Hague; London; Boston; Dordrecht. ISSN 0167-8418, more |
| Abstract | The application of principal component analysis to two types of habitat (the benthos of macro-phytes and of central river bed) enabled us to single out some of the factors that affect the dynamics and the structure of the oligochaete population and its various reactions to environ-mental conditions. As regards macrophytes, the distribution of the variables on the basis of the first component is correlated, to a certain extent, with a seasonal factor without any significant differences among sites. The largest population is most closely correlated with the summer months. In fact, we found that the Naididae and Tubificidae species generally develop in larger numbers at higher temperatures. For the Tubificidae, we could detect a precise seasonal cycle. In the central river bed habitat, the first component was correlated with the river discharge, which determines the granulometric characteristics of the sediment; we noticed a correlation among the sites that have the same characteristics, regardless of sampling site or date. The species which correlate most closely among themselves are the Tubificidae Limnodrilus hoffmeisteri, Tubifex tubifex, L. udekemianus and L. profundicola, which are very characteristic of environments that contain abundant organic matter. The second component is correlated with temperature, and hence with the availability of oxygen, which determines the presence and the abundance of more sensitive species. |
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