title: Effects of repeated salt pulses on ecosystem structure and functions in a stream mesocosm.
abstract: Rivers and streams affected by mining activities often receive short-term sharp salinity increases due to water-soluble stockpiled materials being washed into receiving water bodies. We conducted a mesocosm study to explore the response of structural (diatom and stream invertebrate communities) and functional descriptors (chlorophyll a concentration, fungal biomass and leaf decomposition) to repeated short salinity pulses (3h of duration, with nominal electrical conductivities of 5, 10 and 15 mS cm(-1)), mimicking the exposure pattern occurring at salt-mine affected rivers. The experiment was conducted in 12 artificial flow-through stream systems over 16 days. The effect of the salt pulses on the ecosystem structure and functioning did not fully match most of our initial hypotheses, with the community response being weaker than predicted. The diatom community was, however, dominated by salt-tolerant species throughout the experiment, showing no consistent response to the treatment. The invertebrate response was associated with statistically significant changes in community structure (i.e. abundance of the different taxa) but no statistically significant changes in taxa richness. The salt pulses affected some functional descriptors of the ecosystem: fungal biomass exhibited a unimodal response to treatment magnitude, algal growth (i.e. chl a biomass) was hampered with increasing conductivity and leaf decomposition was significantly reduced in the high treatment.
authors: Freshwater Ecology and Management (F.E.M.) research group, Departament d'Ecologia, Universitat Barcelona, Diagonal, 643, 08028 Barcelona, Catalonia, Spain; Lytle Lab, Cordley Hall, Oregon State University, Corvallis, OR 97331, USA. Electronic address: mcanedo.fem@gmail.com.
authors: Miguel
authors: M
authors: Cañedo-Argüelles
authors: Functional Aquatic Ecotoxicology, Institute for Environmental Sciences, University of Koblenz-Landau, Fortstrasse 7, D-76829 Landau, Germany; Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, Uppsala, Sweden.
authors: Mirco
authors: M
authors: Bundschuh
authors: Aquatic Ecology Group, Universidad de Murcia, Campus de Excelencia Internacional Regional "Campus Mare Nostrum", Spain.
authors: Cayetano
authors: C
authors: Gutiérrez-Cánovas
authors: Institute of Applied Ecology, University of Canberra, ACT 2601, Australia.
authors: Ben J
authors: BJ
authors: Kefford
authors: Freshwater Ecology and Management (F.E.M.) research group, Departament d'Ecologia, Universitat Barcelona, Diagonal, 643, 08028 Barcelona, Catalonia, Spain.
authors: Narcís
authors: N
authors: Prat
authors: Aquatic Ecosystems, Institute for Food and Agricultural Research & Technology (IRTA), Ctra de Poble Nou, Km 5.5, 43540 Sant Carles de la Rapita, Catalonia, Spain.
authors: Rosa
authors: R
authors: Trobajo
authors: Quantitative Landscape Ecology, Institute for Environmental Sciences, University of Koblenz Landau, Fortstraße 7, 76829 Landau, Germany.
authors: Ralf B
authors: RB
authors: Schäfer
mesh_terms: D000818:Animals; D044822:Biodiversity; D002734:Chlorophyll / Q000032:analysis; D000077194:Chlorophyll A; D017753:Ecosystem; D004784:Environmental Monitoring; D007448:Invertebrates; D045483:Rivers / Q000737:chemistry*; D012965:Sodium Chloride / Q000032:analysis*; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D014874:Water Pollutants, Chemical; D002734:Chlorophyll; D012965:Sodium Chloride; D000077194:Chlorophyll A
keywords: Artificial streams; Ecosystem functioning; Mesocosm; Pulse disturbances; Rivers; Salinity