Research article - Peer-reviewed, 2021
Effects of nitrogen enrichment on zooplankton biomass and N:P recycling ratios across a DOC gradient in northern-latitude lakes
Bergstrom, A-K; Deininger, A.; Jonsson, A.; Karlsson, J.; Vrede, T.Abstract
We used data from whole-lake studies to assess how changes in food quantity (phytoplankton biomass) and quality (phytoplankton community composition, seston C:P and N:P) with N fertilization affect zooplankton biomass, community composition and C:N:P stoichiometry, and their N:P recycling ratio along a gradient in lake DOC concentrations. We found that despite major differences in phytoplankton biomass with DOC (unimodal distributions, especially with N fertilization), no major differences in zooplankton biomass were detectable. Instead, phytoplankton to zooplankton biomass ratios were high, especially at intermediate DOC and after N fertilization, implying low trophic transfer efficiencies. An explanation for the observed low phytoplankton resource use, and biomass responses in zooplankton, was dominance of colony forming chlorophytes of reduced edibility at intermediate lake DOC, combined with reduced phytoplankton mineral quality (enhanced seston N:P) with N fertilization. N fertilization, however, increased zooplankton N:P recycling ratios, with largest impact at low DOC where phytoplankton benefitted from light sufficiently to cause enhanced seston N:P. Our results suggest that although N enrichment and increased phytoplankton biomass do not necessarily increase zooplankton biomass, bottom-up effects may still impact zooplankton and their N:P recycling ratio through promotion of phytoplankton species of low edibility and altered mineral quality.Keywords
Dissolved organic carbon; Light; Nitrogen; Pelagic food web; Food quantity-quality; PhosphorusPublished in
Hydrobiologia2021,
Publisher: SPRINGER
Authors' information
Bergstrom, A-K
Umea University
Deininger, A.
University of Agder
Jonsson, A.
Umea University
Karlsson, J.
Umea University
Swedish University of Agricultural Sciences, Department of Aquatic Sciences and Assessment
Sustainable Development Goals
SDG15 Life on land
UKÄ Subject classification
Ecology
Publication Identifiers
DOI: https://doi.org/10.1007/s10750-021-04689-5
URI (permanent link to this page)
https://res.slu.se/id/publ/113686