Download the full-sized PDF of Climate Change Impacts on Stoichiometry, Phytoplankton, and Zooplankton in Alpine Lake Food WebsDownload the full-sized PDF



Permanent link (DOI):


Export to: EndNote  |  Zotero  |  Mendeley


This file is in the following communities:

Graduate Studies and Research, Faculty of


This file is in the following collections:

Theses and Dissertations

Climate Change Impacts on Stoichiometry, Phytoplankton, and Zooplankton in Alpine Lake Food Webs Open Access


Other title
food webs
alpine lakes
climate change
Type of item
Degree grantor
University of Alberta
Author or creator
Weidman, Raymond Paul
Supervisor and department
Rolf D. Vinebrooke (Department of Biological Sciences, University of Alberta)
David W. Schindler (Department of Biological Sciences, University of Alberta)
Examining committee member and department
Heather C. Proctor (Department of Biological Sciences, University of Alberta)
Beatrix E. Beisner (Département des Sciences Biologiques, Université du Québec à Montréal)
John R. Spence (Department of Renewable Resources, University of Alberta)
Department of Biological Sciences
Date accepted
Graduation date
Doctor of Philosophy
Degree level
The main hypothesis of this study was that warmer and drier conditions affect fishless alpine lakes by increasing (1) phosphorus (P)-availability, (2) P-limited autotrophs versus mixotrophic phytoflagellates, and (3) fast-growing P-limited cladocerans versus slower-growing nitrogen (N)-rich calanoid copepods. To test this hypothesis, I conducted (1) a spatial survey of 16 mountain lakes along 1016 m of elevation (summer water temperatures: 5–17°C) in Alberta; (2) a temporal survey of an alpine lake over 16 y (summer water temperatures: 3–14°C); and (3) a laboratory experiment using two alpine and montane plankton communities subjected to warming (10°C; 17°C) and increased dissolved organic carbon (DOC; +80%). In the lake survey, higher temperatures and decreased lake depth were inferred using structural equation modeling (SEM) to decrease dissolved N:P, which increased chlorophytes and cyanophytes relative to phytoflagellates. Warming suppressed large-bodied cladocerans (Daphnia middendorffiana) and calanoid copepods (Hesperodiaptomus arcticus) and increased small-bodied zooplankton taxa. Small copepods increased relative to small cladocerans; this decreased particulate C:P via increased P-recycling by copepods. In the temporal investigation, SEM revealed that decreased rain reduced flushing of dissolved P, which increased diatoms relative to phytoflagellates in Pipit Lake. Unlike the lake survey, more moderate warming increased D. middendorffiana, while H. arcticus increased with advanced ice-off. Thus, cladocerans increased relative to copepods, which increased particulate C:P via increased P-retention by zooplankton. In the experiment, warming and DOC additions together increased P-availability, which increased autotrophs and offset the negative direct effects of warming and DOC. Warming increased D. middendorffiana but suppressed H. arcticus. Particulate C:P increased with DOC additions and increased cladocerans relative to copepods. These findings partially supported my main hypothesis. Climate effects increased dissolved P-availability, thereby increasing autotrophs relative to phytoflagellates. Shorter-term warming (temporal survey and experiment) increased cladocerans relative to copepods, whereas longer-term warming (spatial survey) suppressed large-bodied zooplankton and increased small taxa. Particulate C:P varied with changes in cladocerans relative to copepods (via P-recycling) and increases in C-rich terrestrial inputs. Findings suggest climate change will increase primary productivity of alpine lakes over several decades by increasing P-availability, and decreasing grazing efficiency as copepods and smaller-bodied zooplankton supercede cladocerans.
Permission is hereby granted to the University of Alberta Libraries to reproduce single copies of this thesis and to lend or sell such copies for private, scholarly or scientific research purposes only. Where the thesis is converted to, or otherwise made available in digital form, the University of Alberta will advise potential users of the thesis of these terms. The author reserves all other publication and other rights in association with the copyright in the thesis and, except as herein before provided, neither the thesis nor any substantial portion thereof may be printed or otherwise reproduced in any material form whatsoever without the author's prior written permission.
Citation for previous publication
Weidman, R.P., D.W. Schindler, and R.D. Vinebrooke 2011. Pelagic Food Web Interactions Among Benthic Invertebrates and Trout in Mountain Lakes. Freshwater Biology 56: 1081-1094.

File Details

Date Uploaded
Date Modified
Audit Status
Audits have not yet been run on this file.
File format: pdf (Portable Document Format)
Mime type: application/pdf
File size: 10176830
Last modified: 2015:10:12 15:48:55-06:00
Filename: Weidman_Raymond_Paul_PhD_thesis_2013.pdf
Original checksum: bb1cec4f4b50a39afa1d2f3910395d18
Well formed: true
Valid: true
File title: TITLE PAGE
File title: Introduction
File author: Paul
Page count: 267
Activity of users you follow
User Activity Date