| Title: | Dam regulation and riverine food-web structure in a Mediterranean river |
| Author(s): | Mor JR; Ruhi A; Tornes E; Valcarcel H; Munoz I; Sabater S; |
| Address: | "Catalan Institute for Water Research (ICRA), Girona, Spain; Department of Evolutionary Biology, Ecology and Environmental Sciences, Universitat de Barcelona, Barcelona, Spain. Electronic address: jrmor@icra.cat. Catalan Institute for Water Research (ICRA), Girona, Spain; Department of Environmental Science, Policy, and Management, University of California, Berkeley, CA 94720-3114, USA. Catalan Institute for Water Research (ICRA), Girona, Spain; Institute of Aquatic Ecology, University of Girona, Girona, Spain. Institute of Aquatic Ecology, University of Girona, Girona, Spain. Department of Evolutionary Biology, Ecology and Environmental Sciences, Universitat de Barcelona, Barcelona, Spain" |
| DOI: | 10.1016/j.scitotenv.2017.12.296 |
| ISSN/ISBN: | 1879-1026 (Electronic) 0048-9697 (Print) 0048-9697 (Linking) |
| Abstract: | "Flow regimes are a major driver of community composition and structure in riverine ecosystems, and flow regulation by dams often induces artificially-stable flow regimes downstream. This represents a major source of hydrological alteration, particularly in regions where biota is adapted to strong seasonal and interannual flow variability. We hypothesized that dam-induced hydrological stability should increase the availability of autochthonous resources at the base of the food web. This, in turn, should favour herbivorous over detritivorous strategies, increasing the diversity of primary consumers, and the food-web width and length. We tested this hypothesis by studying the longitudinal variation in food-web structure in a highly-seasonal Mediterranean river affected by an irrigation dam. We compared an unregulated reach to several reaches downstream of the dam. Hydrological and sedimentological stability increased downstream of the dam, and altered the type and quantity of available resources downstream, prompting a change from a detritus-based to an algae-based food web. The fraction of links between top and intermediate species also increased, and the food web became longer and wider at the intermediate trophic levels. Food-web structure did not recover 14km downstream of the dam, despite a partial restitution of the flow regime. Our results advance the notion that hydrologic alteration affects riverine food webs via additions/deletions of taxa and variation in the strength and distribution of food-web interactions. Thus, flow regulation by dams may not only impact individual facets of biodiversity, but also food-web level properties across river networks" |
| Keywords: | *Biodiversity *Food Chain *Hydrology Mediterranean Region *Rivers Food-web interactions Hydrologic alteration Mediterranean-climate rivers Stream-flow regulation Water stability; |
| Notes: | "MedlineMor, Jordi-Rene Ruhi, Albert Tornes, Elisabet Valcarcel, Hector Munoz, Isabel Sabater, Sergi eng Netherlands 2018/01/01 Sci Total Environ. 2018 Jun 1; 625:301-310. doi: 10.1016/j.scitotenv.2017.12.296. Epub 2017 Dec 28" |
