title: "Trophic overyielding": phytoplankton diversity promotes zooplankton productivity.
abstract: Diversity-productivity relationships at the primary producer level have been extensively studied, especially for terrestrial systems. Here, we explore whether the diversity of aquatic primary producers (phytoplankton) has effects on higher trophic levels (zooplankton). We investigated the effect of phytoplankton diversity on an artificial zooplankton community in a laboratory experiment where phytoplankton biomass and elemental composition (carbon-to-phosphorus ratio) were kept constant. Phytoplankton diversity increased the means of both zooplankton growth rate and abundance while suppressing their variability, and sustained higher zooplankton diversity. Likely explanations include resource complementarity effects among phytoplankton species as food entities, as well as niche complementarity effects among Daphnia species as competitors. By affecting the productivity as well as the variability of the next trophic level, biodiversity of primary producers may have far-reaching consequences in aquatic food webs.
authors: Department of Biology, University of Oslo, P.O. Box 1066, Blindern, 0316 Oslo, Norway. Striebel@limnology.eu
authors: Maren
authors: M
authors: Striebel
authors: Gabriel
authors: G
authors: Singer
authors: Herwig
authors: H
authors: Stibor
authors: Tom
authors: T
authors: Andersen
mesh_terms: D000818:Animals; D044822:Biodiversity; D002244:Carbon / Q000737:chemistry / Q000378:metabolism; D003621:Daphnia / Q000502:physiology; D020387:Food Chain; D005618:Fresh Water; D008954:Models, Biological; D010758:Phosphorus / Q000737:chemistry / Q000378:metabolism; D010839:Phytoplankton; D015048:Zooplankton
chemical_list: D010758:Phosphorus; D002244:Carbon