title: Fungicide-induced declines of freshwater biodiversity modify ecosystem functions and services.
abstract: Although studies on biodiversity and ecosystem function are often framed within the context of anthropogenic change, a central question that remains is how important are direct vs. indirect (via changes in biodiversity) effects of anthropogenic stressors on ecosystem functions in multitrophic-level communities. Here, we quantify the effects of the fungicide chlorothalonil on 34 species-, 2 community- and 11 ecosystem-level responses in a multitrophic-level system. At ecologically relevant concentrations, chlorothalonil increased mortality of amphibians, gastropods, zooplankton, algae and a macrophyte (reducing taxonomic richness), reduced decomposition and water clarity and elevated dissolved oxygen and net primary productivity. These ecosystem effects were indirect and predictable based on changes in taxonomic richness. A path analysis suggests that chlorothalonil-induced reductions in biodiversity and top-down and bottom-up effects facilitated algal blooms that shifted ecosystem functions. This work emphasises the need to re-evaluate the safety of chlorothalonil and to further link anthropogenic-induced changes in biodiversity to altered ecosystem functions.
authors.affiliation: Department of Integrative Biology, University of South Florida, Tampa, FL 33620, USA. tamcmaho@mail.usf.edu
authors.forename: Taegan A
authors.initials: TA
authors.lastname: McMahon
authors.forename: Neal T
authors.initials: NT
authors.lastname: Halstead
authors.forename: Steven
authors.initials: S
authors.lastname: Johnson
authors.forename: Thomas R
authors.initials: TR
authors.lastname: Raffel
authors.forename: John M
authors.initials: JM
authors.lastname: Romansic
authors.forename: Patrick W
authors.initials: PW
authors.lastname: Crumrine
authors.forename: Jason R
authors.initials: JR
authors.lastname: Rohr
mesh_terms: D000818:Animals; D044822:Biodiversity; D005068:Eutrophication; D005659:Fungicides, Industrial; D009570:Nitriles
chemical_list: D005659:Fungicides, Industrial; D009570:Nitriles; C005806:tetrachloroisophthalonitrile