La Tour du Valat

Institut de recherche pour la conservation des zones humides méditerranéennes

Titre :	Ammonium retention and whole-stream metabolism in cave streams
Auteurs :	K. S. Simon, Auteur ; E. F. Benfield, Auteur
Type de document :	Article
Dans :	Hydrobiologia (482(1-3) AUG 2002)
Article en page(s) :	31-39
Résumé :	We used 4 short-term ammonium releases and 1 whole-stream metabolism estimate to examine nutrient and carbon dynamics in cave streams. Ammonium uptake lengths (34-157 m) in the cave streams fell within the range reported for surface streams. However, uptake lengths in the cave streams were longer than would be expected in surface streams of similar size. Ammonium mass transfer coefficients and uptake rates were much lower in the cave streams than have been measured in surface streams. Differences in ammonium uptake parameters among cave streams were due to both abiotic and biotic factors. Metabolism in the cave stream was relatively low (32.9 g C m(-2) y(-1)), but fell within the range of values reported for surface streams. Benthic organic carbon (BOC) standing stock was low and turned over faster in the cave stream than in most surface streams. Our results suggest cave streams are carbon, but not nutrient, limited and that standard methods and models for nutrient and carbon cycling in surface streams are applicable to cave streams.

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