title: Community ecology theory predicts the effects of agrochemical mixtures on aquatic biodiversity and ecosystem properties.
abstract: Ecosystems are often exposed to mixtures of chemical contaminants, but the scientific community lacks a theoretical framework to predict the effects of mixtures on biodiversity and ecosystem properties. We conducted a freshwater mesocosm experiment to examine the effects of pairwise agrochemical mixtures [fertiliser, herbicide (atrazine), insecticide (malathion) and fungicide (chlorothalonil)] on 24 species- and seven ecosystem-level responses. As postulated, the responses of biodiversity and ecosystem properties to agrochemicals alone and in mixtures was predictable by integrating information on each functional group's (1) sensitivity to the chemicals (direct effects), (2) reproductive rates (recovery rates), (3) interaction strength with other functional groups (indirect effects) and (4) links to ecosystem properties. These results show that community ecology theory holds promise for predicting the effects of contaminant mixtures on biodiversity and ecosystem services and yields recommendations on which types of agrochemicals to apply together and separately to reduce their impacts on aquatic ecosystems.
authors.affiliation: Department of Integrative Biology, University of South Florida, Tampa, FL, 33620.
authors.forename: Neal T
authors.initials: NT
authors.lastname: Halstead
authors.forename: Taegan A
authors.initials: TA
authors.lastname: McMahon
authors.forename: Steve A
authors.initials: SA
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: D016573:Agrochemicals / Q000633:toxicity*; D000818:Animals; D044822:Biodiversity; D058448:Biota / Q000187:drug effects*; D017753:Ecosystem; D005618:Fresh Water; D007448:Invertebrates / Q000187:drug effects; D008954:Models, Biological; D010839:Phytoplankton / Q000187:drug effects; D011156:Population Density
chemical_list: D016573:Agrochemicals
keywords: Contaminant; ecosystem function; ecosystem services; freshwater ecosystem; mesocosm; pesticide