[A new approach to biodiversity: morphological plasticity of a fresh-water diatom].
Population responses of a planktonic freshwater diatom, Asterionella formosa Hassal, to the hydrodynamic anthropic disturbances were studied at the landscape scale, along a series of nine reservoirs, for a period of 18 months. The analysis of biotic descriptors as cell abundance, cell length and architecture has shown a strong morphological plasticity of this diatom. The morphological variability of A. formosa in response to hydrodynamic conditions favours the colonization of lacustrine freshwater ecosystem for this species. The determination of architectural indices allowed us to distinguish a modification of biodiversity along a disturbance gradient for population level.
Laboratoire d'écologie des eaux continentales méditerranéennes UMR CNRS 6116-IMEP, faculté des sciences et techniques de Saint-Jérôme, case C31, av. Escardrille-Normandie-Niemen, 13397 Marseille, France. celine.bertrand@univ.u-3mrs.fr
Céline
C
Bertrand
Evelyne
E
Franquet
Stéphanie
S
Fayolle
Arlette
A
Cazaubon
D000220:Adaptation, Biological; D017377:Diatoms / Q000254:growth & development / Q000502:physiology / Q000648:ultrastructure*; D017753:Ecosystem; D005618:Fresh Water; D014644:Genetic Variation; D010839:Phytoplankton / Q000502:physiology; D012212:Rheology; D013314:Stress, Mechanical