Benthic and hyporheic invertebrate community responses to seasonal flow recession in a groundwater-dominated stream
Article first published online: 1 OCT 2010
Copyright © 2010 John Wiley & Sons, Ltd.
Special Issue: Ecohydrology on the edge
Volume 4, Issue 4, pages 500–511, July 2011
How to Cite
Stubbington, R., Wood, P. J., Reid, I. and Gunn, J. (2011), Benthic and hyporheic invertebrate community responses to seasonal flow recession in a groundwater-dominated stream. Ecohydrol., 4: 500–511. doi: 10.1002/eco.168
- Issue published online: 19 JUL 2011
- Article first published online: 1 OCT 2010
- Manuscript Accepted: 22 AUG 2010
- Manuscript Received: 12 OCT 2009
- Faculty of Social Sciences and Humanities Research Studentship
- low flows;
- hyporheic refuge hypothesis;
- flow permanence
Natural hydrological variability in lotic ecosystems can include prolonged periods of flow recession. A reduction in discharge is accompanied by abiotic changes in benthic and hyporheic habitats, often including reductions in habitat availability. Whilst the benthic invertebrate community response to low flows is well documented, little research has considered how the composition of the community within the hyporheic zone is affected. We examined benthic and hyporheic invertebrate community composition during flow recession in a temperate karst stream, at sites with contrasting historic flow permanence regimes. Changes in benthic invertebrate community composition primarily reflected changes in habitat availability associated with discharge variability; in particular, the population density of the dominant amphipod, Gammarus pulex, increased as the area of submerged benthic sediments declined. Concurrent significant increases in the hyporheic abundance of G. pulex, and moderate increase in the proportion of the total G. pulex population inhabiting the hyporheic zone were recorded. It is postulated that G. pulex migrated into the hyporheic zone to reduce exposure to intensifying biological interactions in the benthic sediments. An increase in the hyporheic abundance of G. pulex was particularly pronounced at sites with historic intermittent flow, which could be attributed to downwelling stream water dominating vertical hydrologic exchange. The increase in G. pulex abundance reduced community diversity in the benthic sediments, but had no apparent detrimental effects on hyporheic invertebrate assemblages. Copyright © 2010 John Wiley & Sons, Ltd.