Aquatic Sciences

, 80:36 | Cite as

Lentification in Alpine rivers: patterns of diatom assemblages and functional traits

  • E. FalascoEmail author
  • E. Piano
  • A. Doretto
  • S. Fenoglio
  • F. Bona
Research Article


Hydrological alterations in Alpine rivers have been largely increasing due to the combined effects of global climate change and local impacts. Water flow intermittency starts with a process called lentification, which leads to the transformation of the aquatic ecosystem with severe consequences on biotic communities. These consequences have a greater impact in Alpine headwater streams, which are considered important and fragile hotspots of biodiversity and a source of threatened species; the new regime creates conditions to which native biota are poorly adapted. The main aim of our work was to evaluate taxonomical, functional and structural changes of diatom communities in Alpine rivers during the lentification process that precedes a supra-seasonal drought. Contrary to what was expected, communities exposed to river shrinking showed a level of homogeneity comparable to those collected in permanent sections. We therefore hypothesized that lentification created an intermediate disturbance that favoured heterogeneity of assemblages. Conversely, ecological guilds, growth forms and eco-morphological groups varied along temporal and spatial gradients driven by the lentification process. Small, motile and medium-sized low profile species were more abundant during summer, as well as adnate and stalked ones. Lentification limited the presence of high profile guilds and mucous-forming colonies. Droughts in Alpine streams are fairly recent processes, and the dynamics of aquatic communities facing water scarcity are largely unknown. The results we obtained provide important insights towards a more refined functional classification of diatoms for evaluating hydrological alterations.


Bacillariophyceae Hydrological alterations Ecological guilds Growth forms Eco-morphological groups 



This work is part of the research fellowship “From perennial to intermittent: structural and functional responses of benthic diatom communities in Alpine and Appenninic rivers” funded by the Italian Ministry of Research (MIUR) in the framework of the Research Project of National Interest (PRIN) “NO ACQUA”, Grant No. 201572HW8F.

Supplementary material

27_2018_587_MOESM1_ESM.xlsx (44 kb)
Electronic Supplementary Material 1. Complete checklist of diatom taxa detected in the three rivers during the experiment. The first two columns display the name and the OMNIDIA CODE of the taxa. The subsequent columns represent, respectively, the species growth form, the ecological guild to which the species belongs to, its mean biovolume and the eco-morphotype to which the species belongs. The last column shows the results of the Indicator Species Analysis on the following groups: SAMPLING MONTH (March, April, May, June, July, August); HABITAT (microhabitat -MH- or transect -T-); SITE LOCATION (upstream -UP- or downstream -DW- sections); FLOW VELOCITY (V=0 or V>0 m/s) (XLSX 44 KB)
27_2018_587_MOESM2_ESM.xlsx (20 kb)
Electronic Supplementary Material 2. Biological attributes of the diatom communities sampled in the three rivers, throughout the survey. Number of genera and species identified, Shannon diversity index and evenness (out of 400 individuals per sample). Percentage of relative abundance of eco-morphological guilds and growth forms detected in the three rivers throughout the survey. Mean values ± standard deviations are calculated on T and MH samples of both UP-DW sections (XLSX 19 KB)


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Copyright information

© Springer Nature Switzerland AG 2018

Authors and Affiliations

  1. 1.DBIOS, Università degli Studi di TorinoTurinItaly
  2. 2.DISIT, Università del Piemonte OrientaleAlessandriaItaly

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