Posts by Collection

inprogress

Heckford, T.R., Leroux, S.J., Vander Wal, E., Rizzuto, M., Balluffi­-Fry, J., Rich­mond, I.C., Wiersma, Y.F. [in review] Foliar elemental niche responses of balsam fir (Abies balsamea) and white birch (Betula papyrifera) to differing community types across geographic scales.

McLeod, A. M., Leroux, S. J., Rizzuto, M., Leibold, M. A., Schiesari, L. [in review] Integrating ecosystem and contaminant models to study the spatial dynamics of contaminants.

Rizzuto, M., Leroux, S.J., Schmitz, O.J., Vander Wal, E., Wiersma, Y.F., Heckford, T.R. [submitted] Animal-vectored nutrient flows across resource gradients influences the nature of local and meta-ecosystem functioning.

pastresearch

Activity Budget Scaling in Carnivores

Carnivores live a high-risks, high-rewards life: they eat highly energetic food but it costs a lot of energy to hunt. I used a mathematical models to study how different-sized species respond to these challenges.

Baboon Population Ecology

Baboons live in large group with complex social structures. I worked with behavioural and population ecologist to learn more about how these social groups work.

portfolio

Ecology of Individuals

A snowshoe hare in Terra Nova National Partk. Photo courtesy of T. R. Heckford, CC BY-ND-NC 4.0.

Organisms are the starting point of my research. In particular, I am interested in the constant feedback and feedforward mechanisms they are involved in with each other and their environment. I began my career as a behavioural ecologist working on animal behavior, studying how species interactions modified their activities. Over the years, my interests grew, leading me to investigate what factors influence and constrain animal activities—from biochemistry to the laws of physics. As well, I developed an interest in how researchers and scientists describe and study the interactions among organisms and their environment. I have worked to develop new approaches to better integrate animal ecology in the larger picture of ecosystem functioning and dynamics, using tools that range from isotope analyses to remote sensing products.

Ecology of Ecosystems

Conceptual roadmap to study consumer effects on ecosystem dynamics.
From Ellis-Soto et al. (2021).

Organisms, of course, are not isolated from their enviroment, nor are they just receivers of environmental inputs. They actively influence the environment they live in, shaping it in myriad ways. Identity, condition, activity, density, and diversity of the organisms living in an environment are but a few of the biological factors that can change the non-living world—and in turn be changed by it. This theme made up a substantial portion of my doctoral research and is still a major component of my work. In particular, I am interested in the zoogeochemistry of organisms and how it influences ecosystem structure and functions.

Theoretical Ecology

Diagram of information flows, within and across ecosystems. From Little et al. (2022).

Empirical, field-based research sparked my passion for ecology. However, among fieldwork bouts, I developed an interest in ecological theory and its multiple facets. Theoretical work in ecology is helpful as working on a piece of paper or a computer screen provides something very hard to come by in the field: repeatability and control. I am interested in how mathematical models of ecosystem functioning account for animal activities. I am also working with several stellar researchers to introduce additional currencies in models of ecosystem functioning, to improve our ability to study and predict their dynamics.

publications

2. Rizzuto, M., Leroux, S.J., Vander Wal, E., Wiersma, Y.F., Heckford, T.R., Balluffi-Fry, J. (2019). Patterns and potential drivers of intraspecific variability in the body C, N, P composition of a terrestrial vertebrate, the snowshoe hare (Lepus americanus). Ecology and Evolution, 9, 14453–14464.

Abstract | Full text | Data and code | citation

3. Balluffi-Fry, J., Leroux, S.J., Wiersma, Y.F., Heckford, T.R., Rizzuto, M., Richmond, I.C., Vander Wal, E. (2020). Quantity-quality trade-offs revealed using a multiscale test of herbivore resource selection on elemental landscapes. Ecology and Evolution, 10, 13847–13859.

Abstract | Full text | Data and code | citation

4. Richmond, I. C., Leroux, S.J., Vander Wal, E., Heckford, T.R., Rizzuto, M., Balluffi-Fry, J., Kennah, J., Wiersma, Y.F. (2020). Temporal variation and its drivers in the elemental traits of four boreal plant species. Journal of Plant Ecology, 14, 398–413

Abstract | Full text | Data and code | citation

5. Ellis-Soto, D., Ferraro, K.M., Rizzuto, M., Briggs, E., Monk, J.D., and Schmitz, O.J. (2021) A Methodological Roadmap to Quantify Animal-vectored Spatial Ecosystem Subsidies. Journal of Animal Ecology, 90(7), 1605–1622.

Abstract | Full text | citation

6. Rizzuto, M., Leroux, S.J., Vander Wal, E., Richmond, I.C., Heckford, T.R., Balluffi-Fry, J., Wiersma, Y.F. (2021) Forage stoichiometry predicts the home range size of a small terrestrial herbivore. Oecologia, 197(2), 327–338.

Abstract | Full text | Data and code | citation

7. Heckford, T.R., Leroux, S.J., Vander Wal, E., Rizzuto, M., Balluffi-Fry, J., Richmond, I.C., Wiersma, Y.F. (2022). Spatially explicit correlates of plant functional traits inform landscape patterns of resource quality. Landscape Ecology, 37, 59–80.

Abstract | Full text | Data and code | citation

8. Richmond, I.C., Balluffi-Fry, J., Vander Wal, E., Leroux, S.J., Rizzuto, M., Heckford, T.R., Kennah, J.L., Riefesel, G.R., Wiersma, Y.F. (2022) Individual snowshoe hares manage risk differently: Integrating stoichiometric distribution models and foraging ecology. Journal of Mammalogy, 103(1), 196–208.

Abstract | Full text | Data and code | citation

9. Balluffi-Fry, J., Leroux, S.J., Wiersma, Y.F., Richmond, I.C., Heckford, T.H., Rizzuto, M., Kennah, J.L., Vander Wal, E. (2022) Integrating plant stoichiometry and feeding experiments: state-dependent forage choice and its implications on body mass. Oecologia, 198(3), 579–591

Abstract | Full text | Data and code | citation

10. Little, C.J., Rizzuto, M., Luhring, T.M., Monk, J.D., Nowicki, R.J., Paseka, R.E., Stegen, J.C., Symons, C.C., Taub, F.B., Yan, J.D.L. (2022) Movement with Meaning: Integrating Information into Meta-Ecology. Oikos.

Abstract | Full text | citation

research

Elemental composition of Vertebrates

What chemical elements make up a vertebrate and in what proportions? Working with theoretical, wildlife, and landscape ecologists, I studied the elemental composition of a small vertebrate and how it varies among individuals.

Food quality and consumer home range size

Food quality varies over space and time in natural systems. Animals respond to this variation by making space use decision. I work with data from a small terrestrial herbivore to test if it varies its home range size with variation in its preferred foods’ nutrient content

Nutrient transport by animals

Animals are constantly on the move to find and exploit high quality food patches. These movement, which happen at small spatial scale and on a daily basis, hold the potential to link habitats with different productivities and nutrients availability. I am working to develop a mathematical model to describe these links and their implications for ecosystem dynamics and conservation policies.

Integrating Information in Meta-ecosystems

Information is a fundamental, if understudied, currency of life and is everywhere in nature. I am co-leading a team of researchers from various ecological backgrounds to integrate biological information theory with metaecosystem theory. Our goal is to provide a research framework to help shed light on the role of this currency in shaping natural systems.

Emergent technologies to study animal subsidies across scales

Nutrient transfer across ecosystem boundaries is a fundamental part of ecosystem functioning. Yet, it is quite challenging to study it in the field. I am collaborating with researchers from Yale University to develop a framework to help future studies of this phenomenon.

talks

Rizzuto, M., Carbone, C., Pawar, S. Bio-mechanical constraints on foraging reverse the scaling of activity rate among carnivores.

Published:

Rizzuto, M., Leroux, S. J., Vander Wal, E., Wiersma, Y., Heckford, T. R., Balluffi-Fry, J. Life in a Limiting Environment. Ontogeny and Ecological Stoichiometry of Snowshoe hares (Lepus americanus) in the Boreal Forests of Newfoundland.

Published:

Rizzuto, M., Leroux, S. J., Vander Wal, E., Wiersma, Y., Heckford, T. R., Balluffi-Fry, J. Beyond Diffusion: Animal-Mediated Nutrient Transport at Different Spatial Scales.

Published:

Rizzuto, M., Leroux, S. J., Schmitz, O. J., Vander Wal, E., Wiersma, Y. F., Heckford, T. R. Going against the flow: non-diffusive organismal movement influences local and meta-ecosystem functioning

Published:

teaching

Statistics

Graduate Course, Imperial College London - Silwood Park Campus, Department of Life Sciences, 2014

Behavioural Ecology

Undergraduate Course, Imperial College London, Department of Life Sciences, 2015

Ecology

Undergraduate Course, Imperial College London, Department of Life Sciences, 2015

Models in Biology

Mixed Graduate and Undergraduate Course, Memorial University of Newfoundland, Department of Biology, 2020