Dr. Tamara N. Romanuk

B.A., Queen's University (1992)
M.Mar.Sci., University of New South Wales (1995)
Ph.D., McMaster University (2002)
Killam PDF, University of Calgary (2002-2003)
Alberta Ingenuity PDF, University of Calgary (2002-2003)
NSERC PDF, Université du Québec à Montréal (2004-2005)
Research Associate, Pacific Ecoinformatics and Computational Ecology Lab (2004-current)

  • Teaching & Research
  • Students' Research Topics
  • Publications
  • Links   
  • Teaching & Research
    Biodiversity loss, species invasions, food web structure and dynamics, ecosystem functioning

    What are the consequences of declining biodiversity to the functioning of ecosystems? Are diverse communities more stable than depauperate communities? What happens to other species in a community when a species goes extinct? Are there characteristics of invasive species or communities that can be used to predict how invasive a species will be or how resistant a community is to invasion?

    Classes in which Tamara currently teaches:

    Research in my lab focuses on the consequences of changing biodiversity in aquatic food webs. When a species goes extinct there is the potential for complex feedback loops which span population, community, and ecosystem levels.

    The removal of a species can, for example, increase the variability of the remaining species thus increasing the likelihood that stochastic processes such as demographic stochasticity could lead to low population numbers and a cascade of secondary extinctions.

    Another potential effect of removing species from a community is that it might change the way the community processes resources which could, for example, make a community less resilient to the effects to invasive species.

    These research questions, among others, are the core issues of an emerging
    paradigm in ecology known as the biodiversity-ecosystem functioning (BEF) hypothesis. The central tenants of the BEF hypothesis are that an ecosystem with more species will process resources more completely, be more productive, be more stable over time, and be less invasible than an ecosystem with fewer species. Considerable progress has been made over the last few decades on questions related to the BEF debate. Unfortunately, the vast majority of BEF studies have been done on one trophic level (plants) and have not been set in a community context (the trophic level of interest is not explicitly linked to other levels in a food web).

    In my lab we tackle BEF questions using a process-oriented perspective (which means that we are really interested in why these patterns exist -- not just that they do). We use a range of techniques to get at the mechanisms including highly replicated laboratory aquatic microcosm experiments, experiments in the field using natural microcosms such as rock pools and tidal pools, and 'in silico' experiments (which means experiments done in the computer) where we construct model food web communities and subject them to various types of disturbances such as species removals and species invasions as well as environmental disturbances such as increasing temperature and or environmental variability.

    rock pools All of this research is done from a food web perspective which means that the species (in the microcosms) or nodes (in the 'in silico' simulations) are embedded in food web networks. Food web networks track feeding relationships and energy flow between species and are a powerful way to view ecological communities because food webs networks have a topology or structure which can tell us a lot about the particular community we are interested in.

    Examples of Students' Research Topics
    4th year thesis projects
    1. Joint experimental and modeling projects: Team up with another student...one of you will run an empirical experiment and the other will run an " in silico" (i.e. in the computer) experiment dealing with the same question. Possible topics could include entropy and the stability of food web networks, species deletions and secondary extinctions in food web networks, adding horizontal versus vertical diversity in food web networks. Of course you can also go solo and run either an aquatic microcosm experiment or a computer simulation experiment.

    2. Microcosm experiments using zooplankton and phytoplankton. We are interested in any and all questions about the causes and consequences of biodiversity declines.

      Currently recruiting volunteers!

      Volunteer! Meet people! Learn lab techniques! Try out a research topic! Get to know a professor well enough that they can write a kick-ass reference letter for you! Volunteers in my lab will gain experience culturing zooplankton and algae, maintaining experiments, identifying species and sorting samples, entering data and running analyses, taking physicochemical measurements, and helping out collecting the beasts themselves in the field.

      Previous student projects

      Some current and recent thesis and research topics include:

      Ph.D.: Inverse modeling of Arctic polynyas (Olivier Berreville)
      Ph.D.: Salt marsh food webs (Jennifer Frail-Gaultier)
      M.Sc.: Climate change and the robustness of ecological communities along a latitudinal gradient (Constance Tuck)
      M.Sc.: The dynamics of species extinctions (Veronik Campbell)
      M.Sc.: Polar food webs (Mather Carscallen)
      M.Sc. The structure and function of the human microbiome (Marina Ritchie)
      Honors: Comparing stable isotope and binary calculations of trophic position (Kristen Vandenburg)
      Honors: Sequential species invasions (Cashelle Farley)
      PDF: Climate change, metabolic theory, and community structure (Dr. April Hayward)

    Body Ecology subsidies rock pools

    Selected Publications

    Tuck, C. and T.N. Romanuk. Robustness to thermal variability differs along a latitudinal gradient in zooplankton communities. Global Change Biology (in press).

    Carscallen, W.M., K. Vandenburg, J. Lawson and T.N. Romanuk. Predicting trophic position in marine and estuarine food-webs. Ecosphere (in press).

    Campbell, V.C., G. Murphy and T.N. Romanuk. 2011. Experimental design and the outcome and interpretation of diversity-stability relations. Oikos 120: 399-408.

    Romanuk, T.N., A. Hayward and J. Hutchings. 2011. Trophic level scales positively with body size in fishes. Global Ecology and Biogeography 20: 231-240.

    Romanuk, T.N., Vogt, R., Young, A., Tuck, C., and Carscallen, M. 2010. Maintenance of positive diversity-stability relations along a gradient of environmental stress. PLoS ONE 5(4): e10378.   
    Romanuk, T.N., and Levings, C.D. 2010. Reciprocal subsidies and food web pathways leading to chum salmon fry in a temperate marine-terrestrial ecotone. PLoS ONE 5(4): e10073.21.

    Romanuk, T.N., Y. Zhou, U. Brose, E.L. Berlow, R.J. Williams, and N.D. Martinez. 2009. Predicting invasion success in complex ecological networks. Philosophical Transactions of the Royal Society B 364:1743-1754.

    Romanuk, T.N., R.J. Vogt, and J. Kolasa. 2009. Ecological realism and mechanisms by which diversity begets stability. Oikos 118:819-828.

    Romanuk, T.N., B. Beisner, N. Martinez, J. Kolasa. 2006. Non-omnivorous generality promotes population stability. Proceedings B of the Royal Society: Biology Letters 2:374-377.

    Romanuk, T.N., R. Vogt and J. Kolasa. 2006. Eutrophication weakens the stabilizing effect of diversity on community and population variability. Oikos 113:55-66.

    Vogt, R., T.N. Romanuk and J. Kolasa. 2006. A mechanistic examination of species richness-variability relationships in multi-trophic aquatic microcosms. Oikos 113: 55-66

    Romanuk T.N., L. Jackson, J. Post, N. Martinez, E. McCauley. 2006. Food web
    structure along river networks.
    Ecography 28: 1-8.

    Romanuk T.N. and C.D. Levings. 2004. Carbon source partitioning in juvenile Pacific salmon during the estuarine phase. Fisheries Management and Ecology 12: 113-121.

    Romanuk T.N. and C.D. Levings. 2003. Associations between arthropods and
    supralittoral vegetation: dependence of terrestrial and aquatic taxa on vegetation. Environmental
    Entomology 32: 1343-1353.

    Romanuk T.N. and J. Kolasa. 2002. Environmental variability alters the
    relationship between species richness and community variability in
    natural rock pool microcosms
    . Ecoscience 9: 55-62.


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