THEORETICAL HABITAT TEMPLETS, SPECIES TRAITS, AND SPECIES RICHNESS - FISH IN THE UPPER RHONE RIVER AND ITS FLOODPLAIN

1. Recent developments in ecological theory concerned with habitat tem plets, species assemblages, and life history traits were examined for the riverine fish communities of the Upper Rhone River, France, in the context of spatial-temporal habitat variability. Relationships among species traits, habitat utilization of species, the relationship betwe en species traits and habitat utilization, and trends of species trait s and species richness in the spatial-temporal variability of the habi tat types were analysed. 2. Relationships among twelve species traits, and utilization of eight habitats were examined for twenty-five fish species using correspondence analysis; the relationship between specie s traits and habitat utilization was investigated by co-inertia analys is. 3. Positive relationships among species traits were observed for s ize, fecundity, and the number of reproductive cycles per individual. However, species were not well differentiated according to the habitat utilization, except for habitats rarely connected with the main chann el (i.e. two types of oxbow lakes). 4. No significant relationship was found between species traits and habitat utilization, nor for either species traits or species richness when examined in the framework of s patial-temporal habitat variability. Only two species traits correspon ded (with slight trends) to predictions in a river habitat templet: (i ) the number of descendants per reproductive cycle increased along wit h temporal variability; and (ii) the number of reproductive cycles per individual was either low or high at low temporal variability and int ermediate at elevated temporal variability. 5. The discrepancy between the predictions of the river habitat templet as well as of the patch dynamics concept and the results observed for the fish in the Upper Rh one was explained in terms of scale problems, the evolutionary ecology of the European fish fauna, and the history of the Rhone River.