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Ecological parameter: rhithral preference (RTI)

Parameter group: region related parameters

Explanation:
The RTI ("Rhithrontypieindex") describes the affinity of a taxon to the rhithral region of a river or stream. Taxa are assigned values between 1 and 5 according to the procedure described in Biss et al. (2002) and the stream zonation classification according to Schmedtje & Colling (1996) and Moog (1995). A high value indicates that a taxon is typically found in the rhithral region of a river.

Biss, R., Kübler, P., Pinter, I. & Braukmann, U. (2002): Leitbildbezogenes biozönotisches Bewertungsverfahren für Fließgewässer (aquatischer Bereich) in der Bundesrepublik Deutschland. Ein erster Beitrag zur integrierten ökologischen Fließgewässerbewertung. Umweltbundesamt Texte 62/02.
Schmedtje, U. & Colling, M. (1996): Ökologische Typisierung der aquatischen Makrofauna. Informationsberichte des Bayerischen Landesamtes für Wasserwirtschaft 4/96, 543 pp.
Moog, O. (ed.) (1995): Fauna Aquatica Austriaca - A Comprehensive Species Inventory of Austrian Aquatic Organisms with Ecological Notes. Federal Ministry for Agriculture and Forestry, Wasserwirtschaftskataster Vienna: loose-leaf binder.


Classification system: metric value (1-5)
A description of the coding system can be found here  Abbreviations/Coding Systems

Abbreviations:
Category name:Abbreviations:Explanation:
rhithral preferenceRTIpreference for the rhithral zone
11taxon with no affinity to the rhithral zone
22taxon with low affinity to the rhithral zone
33taxon with medium affinity to the rhithral zone
44taxon with clear affinity to the rhithral zone
55taxon with high affinity to the rhithral zone
Assigned taxa for each higher systematic unit:
TaxagroupNumber of assigned taxa / total number of taxa - percentage
Bivalvia16 / 77 - 20.7%
Branchiobdellida1 / 8 - 12.5%
Bryozoa11 / 19 - 57.8%
Chironomidae33 / 1315 - 2.5%
Coelenterata1 / 13 - 7.6%
Coleoptera125 / 2678 - 4.6%
Crustacea9 / 270 - 3.3%
Diptera (excl. Chironomidae)109 / 2404 - 4.5%
Ephemeroptera140 / 353 - 39.6%
Gastropoda21 / 241 - 8.7%
Heteroptera8 / 124 - 6.4%
Hirudinea30 / 68 - 44.1%
Megaloptera3 / 6 - 50%
Odonata24 / 174 - 13.7%
Oligochaeta15 / 240 - 6.2%
Planipennia6 / 12 - 50%
Plecoptera127 / 576 - 22%
Porifera6 / 12 - 50%
Trichoptera324 / 1439 - 22.5%
Turbellaria17 / 61 - 27.8%