Macroinvertebrates colonising leaf litter of contrasting quality in a travertine Mediterranean stream
Vivas, S.; Casas, J. J.
Archiv für Hydrobiologie Volume 154 Number 2 (2002), p. 225 - 238
published: May 29, 2002
ArtNo. ESP141015402002, Price: 29.00 €
We investigated the invertebrate assemblages that colonised two types of leaf litter bags, which differed considerably in quality: (1) Mixed-species bags made of leaves from indigenous tree and shrub species (Populus nigra L., Rubus ulmifolius Schott, and Salix atrocinerea Brot.); (2) and bags made of the recalcitrant leaves from the exotic species Platanus orientalis L. The study was conducted at two sites differing in riparian canopy located in the Mediterranean stream Río Vicario, characterised by massive travertine precipitation. The overall density and biomass of invertebrates that colonised the mixed-species bags did not differ significantly from those that colonised the Platanus leaf bags. The same was observed, in general, for the density and biomass of functional feeding groups. The gut content of Leuctra franzi Aub., the most abundant and frequent shredder, showed that only a few individuals (ca. 10 %) had recently consumed leaf litter and only in limited amounts (<15 % leaf remains). furthermore, the mean percentage of leaf remains in the gut of L. franzi from mixed-species bags did not differ significantly from those colonising Platanus-bags, at the more incrusted site. These results suggest that the travertine crust precipitated on decomposing leaves in Río Vicario attenuate the effect of leaf litter quality on the macroinvertebrate assemblages colonising leaf bags.