ABSTRACT In this study a checklist of the stygobiotic crustaceans specifically for Africa is prov... more ABSTRACT In this study a checklist of the stygobiotic crustaceans specifically for Africa is provided for the first time. Several nomenclatorial and taxonomic changes, as well as many new species or localities, have been included in the list since the publication of Stygofauna Mundi (Botosaneanu, 1986), which deeply modifies our knowledge on the biogeography of Africa. The annotated checklist comprises 280 stygobiotic species of crustaceans belonging to 9 orders, 32 families and 103 genera. Information about the endemism and the biogeographical distribution is provided for each of the systematic orders. Cette étude fournit pour la première fois une liste faunistique des crustacés stygobies d'Afrique. Plusieurs modifications dans la nomenclature et la taxinomie et de nombreuses espèces ou localités nouvelles, qui ont profondément modifié notre connaissance de la biogéographie du continent africain, ont été ajoutées à cette liste depuis la publication de Stygofauna Mundi (Botosaneanu, 1986). La liste faunistique annotée comprend 280 espèces de crustacés stygobies appartenant à 9 ordres, 32 familles et 103 genres. Des informations concernant l'endémisme et la distribution biogéographiques ont également été fournies pour chaque ordre systématique.
ABSTRACT * Microbial communities play a central role in the functioning of freshwater ecosystems,... more ABSTRACT * Microbial communities play a central role in the functioning of freshwater ecosystems, but the impact of severe low flow on microbial processes at the floodplain scale is largely unexplored, especially in terms of patterns in decline of water level. The differential responses of benthic and interstitial microbial communities are also unknown. * We explored the structural and functional responses of bacterial and fungal communities to severe low-flow periods at the surface and deep in the sediment of three types of wetland, namely running water, upwelling zones and isolated pools. * The different wetland types exhibited distinct microbial communities but the low-flow period induced homogenisation of community composition among wetland types. Despite a convergence in microbial community composition, the response of microbial processes differed among wetland types during the low-flow period: a decrease in biomass and activity in running water and upwelling sites contrasted with an increase observed in isolated pools. * Microbial communities and processes deep in the sediment appeared less affected by the low-flow period and wetland type, but were not insensitive. Homogenisation of community compositions at 50 cm depth was observed 1 month after the low-flow period, suggesting drivers distinct from those at the surface. Our results demonstrate the predominant effect of environmental conditions on rates of microbial processes as opposed to community composition. * Wetland heterogeneity, in terms of modalities of water level decrease, seems to be important for the maintenance of microbial processes at the floodplain scale in the context of increasing frequency and severity of low-flow periods.
ABSTRACT In this study a checklist of the stygobiotic crustaceans specifically for Africa is prov... more ABSTRACT In this study a checklist of the stygobiotic crustaceans specifically for Africa is provided for the first time. Several nomenclatorial and taxonomic changes, as well as many new species or localities, have been included in the list since the publication of Stygofauna Mundi (Botosaneanu, 1986), which deeply modifies our knowledge on the biogeography of Africa. The annotated checklist comprises 280 stygobiotic species of crustaceans belonging to 9 orders, 32 families and 103 genera. Information about the endemism and the biogeographical distribution is provided for each of the systematic orders. Cette étude fournit pour la première fois une liste faunistique des crustacés stygobies d'Afrique. Plusieurs modifications dans la nomenclature et la taxinomie et de nombreuses espèces ou localités nouvelles, qui ont profondément modifié notre connaissance de la biogéographie du continent africain, ont été ajoutées à cette liste depuis la publication de Stygofauna Mundi (Botosaneanu, 1986). La liste faunistique annotée comprend 280 espèces de crustacés stygobies appartenant à 9 ordres, 32 familles et 103 genres. Des informations concernant l'endémisme et la distribution biogéographiques ont également été fournies pour chaque ordre systématique.
ABSTRACT * Microbial communities play a central role in the functioning of freshwater ecosystems,... more ABSTRACT * Microbial communities play a central role in the functioning of freshwater ecosystems, but the impact of severe low flow on microbial processes at the floodplain scale is largely unexplored, especially in terms of patterns in decline of water level. The differential responses of benthic and interstitial microbial communities are also unknown. * We explored the structural and functional responses of bacterial and fungal communities to severe low-flow periods at the surface and deep in the sediment of three types of wetland, namely running water, upwelling zones and isolated pools. * The different wetland types exhibited distinct microbial communities but the low-flow period induced homogenisation of community composition among wetland types. Despite a convergence in microbial community composition, the response of microbial processes differed among wetland types during the low-flow period: a decrease in biomass and activity in running water and upwelling sites contrasted with an increase observed in isolated pools. * Microbial communities and processes deep in the sediment appeared less affected by the low-flow period and wetland type, but were not insensitive. Homogenisation of community compositions at 50 cm depth was observed 1 month after the low-flow period, suggesting drivers distinct from those at the surface. Our results demonstrate the predominant effect of environmental conditions on rates of microbial processes as opposed to community composition. * Wetland heterogeneity, in terms of modalities of water level decrease, seems to be important for the maintenance of microbial processes at the floodplain scale in the context of increasing frequency and severity of low-flow periods.
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Papers by Christophe Piscart