<p>Appendix 1 - Definitions of microhabitat categories (C1, C2 and C3); x = grain size.</p><p>Microhabitat categories Description Coarse inorganic megalithal, x > 40 cm (C1) macrolithal, 20 < x < 40 cm</p><p>Fine inorganic mesolithal, 6 < x < 20 cm (C2) microlithal, 2 < x < 6 cm akal, 0.2 < x < 2 cm macro-algae, filamentousalgae, algaltufts submerged macrophytes, inclusive moss and Characeae Organic emergent macrophytes (C3) living part of terrestrial plants, fine roots, floating riparian vegetation coarse particulate organic matter</p><p>1 Appendix 2 - Complete list of macroinvertebrate taxa collected within the study area, in alphabetical order.</p><p>MACROINVERTEBRATES Aeshnidae Elmintidae Nematomorpha Agapetus Empididae Nemoura Amphinemoura Epeorus silvicola Odontocerum Ancylidae Epeorus yugoslavicu Perla Anthomyiidae Ephydridae Philopotamus Asellidae Gammaridae Physidae Athericidae Girinidae Piralidae Baetis alpinus Glossosoma Planaridae Baetis muticus Habrophlebia eldae Polycentropus Baetis rhodani Haemopidae Protonemoura Beraea Halipidae Psychodidae Bithynidae Hydracarinae Rhyachophila Blephariceridae Hydraenidae Rhytrogena hybrida Rhytrogena Caenis belfiorei Hydrophilidae semicolorata Caenis macrura Hydropsiche Scirtidae Capnioneura Hydroptilidae Sericostoma Ceratopogonidae Hyrudinidae Serratella ignita Chironomidae Isoperla Simulidae Chloroperla Lasiocephala Sphaeriidae Crunoecia Lepidostoma Stratiomyidae Dendrocoelidae Leuctra Synagapetus</p><p>2 Dinocras Limnephilus Tabanidae Dixidae Limoniidae Taeniopteryx Dryopidae Lumbricidae Tipulidae Dytiscidae Lymnaeidae Tubificidae Ecdyonurus elveticus Micrasema Wormaldia Ecdyonurus venosus Naididae </p><p>3 Appendix 3 - Frequencies (Fr) as % of the inorganic (C1, C2) and organic (C3) microhabitat categories (for acronyms, see Appendix 1) in the three stream sectors (S1 = upstream; S2 = midstream; S3 = downstream) observed in October 2008 (Oct) and Jun 2009 (Jun) in the River Aniene.</p><p>4 5</p>