Biological trait structure of macroinvertebrate benthic communities

The faunal assemblage of a river ecosystem integrates the spatial and tempo ral variability of the habitat. Taxa with appropriate combinations of adapt ations, concerning especially traits related to survival and reproduction u se particular habitat types. Consequently, the synthesis of published autec ological information on macroinvertebrate taxa can be used to demonstrate s ome of the environmental changes of an ecosystem. Mesohabitats were sampled in spring and autumn 1993 and 1994 in twelve stud y sites on Ist to 4th order streams in three river catchments located in th e northeast of France. Sites were selected to exhibit high microscale heter ogeneity. Affinities of taxa for modalities of biological traits and/or ecological st rategies were described. The investigation of the relationship between trai ts and distributions of taxa can demonstrate some of the characteristics of both faunal community and environment and provide clear information on cha nges in biotopes across different spatial scales (mesohabitat, station, cat chment basin). The benthic assemblage of each mesohabitat type displayed a specific combination of biological traits. Thus, taxa can provide insights about mesohabitat characteristics in terms of stability, diversity or troph ic potentialities of their potential ecological niches.