posted on 2018-01-30, 11:24authored byClay Prater, Nicole D. Wagner, Paul C. Frost
Declines in environmental calcium (Ca) and phosphorus (P) concentrations have occurred over the past 30 yrs in lakes across the Canadian Shield in southern Ontario, and these reductions appear to be placing strong constraints on populations of Daphnia in this region. Here, we report results from a factorial manipulation of Ca concentrations and food P content under controlled laboratory conditions where we measured resulting changes in daphnid elemental content, individual growth and survival, and life history traits related
to population growth. We found significant effects of Ca- and P-limitation on all variables measured; however, dietary P explained a majority of the variation in daphnid nutrient content and growth. Dietary effects of low P [high food carbon (C): P ratios] on individual Daphnia life-history traits also translated into significant population level effects. Dietary P also explained relatively more experimental variation in population level responses than Ca concentrations. Experimental Ca concentrations most strongly altered daphnid survival
partly due to the use of a lethally low Ca concentration in our experiment. Although recent work examining shifts in zooplankton communities in this region mainly focuses on the effects of Ca-limitation, we show that Ca concentrations and food nutrient content, at levels commonly found on the Canadian Shield,
are both likely to strongly alter Daphnia life-history and populations dynamics. Our results underscore the need to more fully examine how multielemental limitation (e.g., Ca, N, P) affects consumer physiology and life-history given the plausible translation of these effects on the community structure of lake zooplankton.
Funding
This research was supported by a Natural Sciences and Engineering Research Council of Canada (NSERC) Discovery grant to PCF and by
Ontario Graduate Student (OGS) scholarships to CP and NDW.
History
School
Social Sciences
Department
Geography and Environment
Published in
Limnology and Oceanography
Volume
61
Issue
1
Pages
268 - 278
Citation
PRATER, C., WAGNER, N.D. and FROST, P.C., 2016. Effects of calcium and phosphorus limitation on the nutritional ecophysiology of Daphnia. Limnology and Oceanography, 61(1), pp. 268-278.
This work is made available according to the conditions of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0) licence. Full details of this licence are available at: https://creativecommons.org/licenses/by-nc-nd/4.0/
Publication date
2015-10-13
Notes
This is the peer reviewed version of the following article: PRATER, C., WAGNER, N.D. and FROST, P.C., 2016. Effects of calcium and phosphorus limitation on the nutritional ecophysiology of D aphnia. Limnology and Oceanography, 61(1), pp. 268-278., which has been published in final form at https://doi.org/10.1002/lno.10208. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving