PrinciplesPrinciples ofofpracticalpractical determinationdetermination::TaxonomyTaxonomy andand pragmatismpragmatism..

Christian Chauvin

I principi della determinazione pratica :tassonomia e pragmatismo.

Giornata mondiale dei fiumi – 20-22 marzo 2006. Imola

What is taxonomic determination?

Assigning a name to an organism

Taxonomic level: Genus? Species? Sub-species or variety?Form?

Giornata mondiale dei fiumi – 20-22 marzo 2006. Imola

Until 90’s: a specialist affair…

Delay,

Now: new tools available from research spheregenomicstatistic morphometry

Poor treatement capacity (only for few samples),

(Cost).

BUT : One group, one specialist,

Giornata mondiale dei fiumi – 20-22 marzo 2006. Imola

Reference books and scientific publications

Abilities required (pre-determination),

Difficult to use,

Access not easy for the generalists,

Not adaptated to a pratical and « on field » use.

Giornata mondiale dei fiumi – 20-22 marzo 2006. Imola

P. BOURRELLY, 1981, 1985, 1990

Giornata mondiale dei fiumi – 20-22 marzo 2006. Imola

Problems to deal with:

Taxonomy is an evolutive notionPeriodical revisions

Some groups are notoriously unstableRanunculus, Mosses

Giornata mondiale dei fiumi – 20-22 marzo 2006. Imola

0

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nb o

f tax

Heterotrophicorganisms(Myceta,bacteria)

Alguae -filamentous,gelatinous or

incrustingthallus

Macro-alguae(Characea)

Alguae -Cyanobacteria

Lichens Bryophytes -Mosses

Bryophytes -Liverworts

Pteridophytes(Ferns,

Horsetails)

Hydrophyticphanerogams

Helophyticphanerogams

Taxa taken into account in IBMR

208 taxa8 vegetal groups

Knowing all the groups needed?

Giornata mondiale dei fiumi – 20-22 marzo 2006. Imola

Applying classical botanical criteria?

Ranunculus sp.Flotting leaves shape,Flower characteristics

? ?

Giornata mondiale dei fiumi – 20-22 marzo 2006. Imola

Mosses:Morphology of sporophytes

? ?

Giornata mondiale dei fiumi – 20-22 marzo 2006. Imola

Routine indicial methods:new requirements

Affordable for non specialist hydroecologists

Covering all groups of a biological element

Not too expensive

Reference documents (guidebooks)

Professionnal training

Means

Giornata mondiale dei fiumi – 20-22 marzo 2006. Imola

What criteria?

Practicals features.None high technic needed

« Field » philosophy.Good efficiency, usable on field (at last in part)

Vegetative criteria.Recognition even if not flowering or fructification

Ecomorphoses considered.Taking in account of the high shape variability

Giornata mondiale dei fiumi – 20-22 marzo 2006. Imola

100 µm

Giornata mondiale dei fiumi – 20-22 marzo 2006. Imola

Guide pratique de détermination générique des algues d’eau douceS. Rodriguez & J.P. Vergon, 1996

Problems of synonymyEstablishing reference lists (national and European levels)Common codification of aquatic taxa

Giornata mondiale dei fiumi – 20-22 marzo 2006. Imola

We need doing choices…Taxonomic levelAccording to the realistic feasibility (e.g. Algae)and the knowledge about autoecology (sub-species, morphoses).

Excluding some groupsToo unstable taxonomy,Evolutive bioindication (e.g. alien and invasive species).

Taking into account practical problemsAggregating very close or undistinguishable speciesEvolutive bioindication (e.g. alien and invasive species).

Hydrobiological routine methodsalso have to consider the available tools…

A relevant method is firstly an applicable method !

Giornata mondiale dei fiumi – 20-22 marzo 2006. Imola

Scientific spherehave to consider routine application…

We need to transfer knowledge to field operators !

Bioassessing water qualityis making both meeting.

Pragmatism

Taxonomy

AssociationFrançaise de Limnologie

Thank you !