We assessed the effects of repeated hydropeaking over five consecutive days on the zoobenthic community by manipulating discharge in five experimental flumes directly fed by an Alpine stream. Treatment consisted of two different hydropeaking intensities which increased discharge two- and threefold from baseflow and lasted for 5 h each day. The resulting sudden changes in flow directly affected benthic invertebrates through the induction of catastrophic drift as a direct response to high (hydropeaking) flow conditions, and of behavioural drift in the low, baseflow conditions (at the conclusion of each hydropeaking event) for some taxa. We observed: an initial strong peak in catastrophic drift within the first 3 min of increased discharge, followed by a decreased drift rate throughout the following hours of the experiment; a strong response in the first day of the simulation, with successive days having substantially decreased drift; taxa-specific responses over the short and long-time scales: least-resistant taxa (i.e. Baetis spp.) were removed via the initial catastrophic drift, while more resistant taxa began to behaviourally drift later in each hydropeak (i.e. Simuliidae). Peaks in drift rates corresponded to the initial removal of CPOM which, during low flows, provided habitat and food resource for a high number of individuals and taxa. Quantification of drift responses over time scales larger than the single hydropeaking event underlines the relevance of the typical intermittency and repetition frequency as a stress factor for benthic communities, and that the response to hydropeaking is closely related to the time elapsed since the last perturbation

Bruno, M.C.; Cashman, M.J.; Maiolini, B.; Biffi, S.; Zolezzi, G. (2016). Responses of benthic invertebrates to repeated hydropeaking in semi-natural flume simulations. ECOHYDROLOGY, 9 (1): 68-82. doi: 10.1002/eco.1611 handle: http://hdl.handle.net/10449/24972

Responses of benthic invertebrates to repeated hydropeaking in semi-natural flume simulations

Bruno, Maria Cristina;Maiolini, Bruno;
2016-01-01

Abstract

We assessed the effects of repeated hydropeaking over five consecutive days on the zoobenthic community by manipulating discharge in five experimental flumes directly fed by an Alpine stream. Treatment consisted of two different hydropeaking intensities which increased discharge two- and threefold from baseflow and lasted for 5 h each day. The resulting sudden changes in flow directly affected benthic invertebrates through the induction of catastrophic drift as a direct response to high (hydropeaking) flow conditions, and of behavioural drift in the low, baseflow conditions (at the conclusion of each hydropeaking event) for some taxa. We observed: an initial strong peak in catastrophic drift within the first 3 min of increased discharge, followed by a decreased drift rate throughout the following hours of the experiment; a strong response in the first day of the simulation, with successive days having substantially decreased drift; taxa-specific responses over the short and long-time scales: least-resistant taxa (i.e. Baetis spp.) were removed via the initial catastrophic drift, while more resistant taxa began to behaviourally drift later in each hydropeak (i.e. Simuliidae). Peaks in drift rates corresponded to the initial removal of CPOM which, during low flows, provided habitat and food resource for a high number of individuals and taxa. Quantification of drift responses over time scales larger than the single hydropeaking event underlines the relevance of the typical intermittency and repetition frequency as a stress factor for benthic communities, and that the response to hydropeaking is closely related to the time elapsed since the last perturbation
Hydropeaking
Drift
Macroinvertebrates
Semi-natural flumes
Alpine streams
Hydropower
Hydropeaking
Drift
Macroinvertebrati
Canalette sperimentali
Fiumi alpini
Idroelettrico
Settore BIO/07 - ECOLOGIA
Bruno, M.C.; Cashman, M.J.; Maiolini, B.; Biffi, S.; Zolezzi, G. (2016). Responses of benthic invertebrates to repeated hydropeaking in semi-natural flume simulations. ECOHYDROLOGY, 9 (1): 68-82. doi: 10.1002/eco.1611 handle: http://hdl.handle.net/10449/24972
File in questo prodotto:
File Dimensione Formato  
Bruno_et_al-2016-Ecohydrology.pdf

solo utenti autorizzati

Licenza: Tutti i diritti riservati (All rights reserved)
Dimensione 4.81 MB
Formato Adobe PDF
4.81 MB Adobe PDF   Visualizza/Apri   Richiedi una copia

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10449/24972
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 32
  • ???jsp.display-item.citation.isi??? 40
social impact