Effects of nutrients and fish on periphyton and plant biomass across a European latitudinal gradient

Research output: Contribution to journalArticle

Abstract

Replicated, factorial mesocosm experiments were conducted across Europe to study the effects of nutrient enrichment and fish density on macrophytes and on periphyton chlorophyll a (chl-a) with regard to latitude. Periphyton chl-a densities and plant decline were significantly related to nutrient loading in all countries. Fish effects were significant in a few sites only, mostly because of their contribution to the nutrient pool. A saturation-response type curve in periphyton chl-a with nutrients was found, and northern lakes achieved higher densities than southern lakes. Nutrient concentration and phytoplankton chl-a necessary for a 50% plant reduction followed a latitudinal gradient. Total phosphorus values for 50% plant disappearance were similar from Sweden (0.27 mg L-1) to northern Spain (0.35 mg L-1), but with a sharp increase in southern Spain (0.9 mg L-1). Planktonic chl-a values for 50% plant reduction increased monotonically from Sweden (30 mu g L-1s) to Valencia (150 mu g L-1). Longer plant growing-season, higher light intensities and temperature, and strong water-level fluctuations characteristic of southern latitudes can lead to greater persistence of macrophyte biomass at higher turbidities and nutrient concentration than in northern lakes. Results support the evidence that latitudinal differences in the functioning of shallow lakes should be considered in lake management and conservation policies.

Details

Authors
  • Eloy Becares
  • Joan Goma
  • Margarita Fernandez-Alaez
  • Camino Fernandez-Alaez
  • Susana Romo
  • Maria R. Miracle
  • Annika Ståhl-Delbanco
  • Lars-Anders Hansson
  • Mikael Gyllström
  • Wouter J. Van de Bund
  • Ellen Van Donk
  • Timo Kairesalo
  • Jaana Hietala
  • Debbie Stephen
  • David Balayla
  • Brian Moss
Organisations
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Ecology

Keywords

  • Mesocosms, Latitude, Shallow lakes, Macrophytes, Periphyton, Nutrients, Fishes
Original languageEnglish
Pages (from-to)561-574
JournalAquatic Ecology
Volume42
Issue number4
Publication statusPublished - 2008
Publication categoryResearch
Peer-reviewedYes