| Title |
Contrasting effects of an alien worm on benthic N cycling in muddy and sandy sediments |
| Authors |
Benelli, Sara ; Bartoli, Marco ; Ribaudo, Cristina ; Fano, Elisa Anna |
| DOI |
10.3390/w11030465 |
| Full Text |
|
| Is Part of |
Water.. Basel : MDPI. 2019, vol. 11, iss. 3, art. no. 465, p. 1-12.. eISSN 2073-4441 |
| Keywords [eng] |
alien species ; Sparganophilus tamesis ; sediments ; nitrogen ; fluxes ; denitrification |
| Abstract [eng] |
The North American oligochaete Sparganophilus tamesis is widespread in European freshwaters. Its ecological effects on benthic nitrogen (N) biogeochemistry were studied in two contrasting environments: the organic-rich muddy sediments of the eutrophic Mincio River (Italy) and the organic-poor sandy sediments of the oligotrophic Cazaux-Sanguinet Lake (France). Oxygen and inorganic N fluxes and denitrification rates (IPT) were measured by dark incubation of intact cores with different worm biomass. Sediment oxygen demand and denitrification were higher in muddy than in sandy sediments; however, at the two sites, bioturbation by the oligochaetes stimulated differing microbial O2 and NO3− respiration and NH4+ production. In particular, the relative effect of S. tamesis on sediment metabolism was greater in Cazaux-Sanguinet Lake than in the Mincio River. As a result, S. tamesis favored net N loss in the Mincio River, whereas it increased NH4+ recycling and lowered denitrification efficiency in the Cazaux-Sanguinet Lake. Our results suggest that the effects of S. tamesis on N biogeochemistry might differ depending on local trophic settings. These results have implications for the conservation of isoetids in the French Lake, whose persistence can be menaced by oligochaete-induced nutrient mobilization. |
| Published |
Basel : MDPI |
| Type |
Journal article |
| Language |
English |
| Publication date |
2019 |
