NOACQUA aims to study biotic community responses and metabolic processes to flow intermittence in both pristine mountain watercourses and lowland drainage channels. The project focus on several aspects of stream ecosystem:
Several groups of benthic flora and fauna will be studied, namely diatoms, macrophytes, meio and macro-invertebrates and fishes. We expect a difference in responses to intermittence for primary productors, invertebrates and fishes.
The alternation of high flows and dry phases is expected to modify biogeochemical cycles in sediments both directly (interaction with atmoshpere) and indirectly (presence/absence of bioturbation processes). During dry phases phosphorous releases and nitrification processes are expected while during the wet phase anaerobic process (i.e. denitrification) will be favoured.
Decomposition rate of Coarse Organic Particulate Matter (CPOM) is expected to be different between intermittent and perennial systems. The presence-absence and abundance of shredder organisms, mainly macroinvertebrates, are predicted to be important during the wet phase.
Pools, hyporheic zones and wet sediments with low hydraulic conductivity are predicted to act as flow refugia for meio-benthos and juvenile macroinvertebrates during the dry phase.
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