Synthetic Research

Ecology has accumulated an enormous amount of knowledge about individual species, populations, food webs and ecosystems. At the same time, ecological theory has identified many mechanisms capable of explaining how these systems behave. A major challenge is to step back from individual studies and ask whether general ecological rules emerge across species, ecosystems and forms of environmental change.

This is the goal of much of the synthetic research in the McCann Lab.

We combine existing empirical datasets, ecological theory and comparative approaches to look for common mechanisms underlying ecosystem dynamics. Increasingly, this work asks whether apparently different forms of global change produce predictable changes in food-web structure—and whether those structural changes tell us something about the future stability and resilience of ecosystems.

Global Change and the Rewiring of Food Webs

One of the clearest patterns emerging from our synthetic research is that global change does not affect all parts of an ecosystem equally.

Climate change, nutrient pollution, harvesting, invasive species and landscape modification all have spatial and biological signatures. They affect some habitats, species and energetic pathways more strongly than others. As organisms respond, interactions change: consumers shift habitats or resources, some pathways weaken, others strengthen, and the food web becomes rewired.

Our work initially explored this idea in the context of climate change. More recent synthesis led by Dr. Charlotte Ward has shown that this phenomenon appears to extend much more broadly across global change.

Importantly, this rewiring is often asymmetric. Global change can progressively favour particular habitats, species or energetic pathways while weakening alternatives. The result may be an ecosystem increasingly dominated by a smaller number of pathways through which energy flows.

This provides an important connection to our broader work on adaptive capacity. Ecosystems may be resilient partly because organisms have access to multiple resources, habitats and trophic pathways. Global change can erode that resilience when it systematically removes alternatives and channels ecological dynamics in the same direction.

Food Production, Food-Web Structure and Biodiversity

Human food production represents one of the largest ways that people alter ecological systems.

Work led by Dr. Marie Gutgesell, through our collaboration with the Centre for Ecosystem Management, synthesized evidence from both agriculture and fisheries to ask how food production alters the structure and stability of food webs.

Despite obvious differences between farming and fishing, remarkably similar ecological changes can emerge. Food production tends to simplify ecological communities, alter the distribution and strength of species interactions, and modify the energetic structure of food webs.

This work illustrates the power of synthesis: ecological changes that appear specific when examined within individual ecosystems can reveal much more general patterns when considered together.

Life History and Population Dynamics

Another area of our synthetic research asks whether fundamental biological differences among species can predict their population dynamics.

Ecological theory has long suggested that organisms with high potential growth rates can generate more variable, “boom-and-bust” population dynamics. At the same time, life-history theory places species along a fast–slow continuum, ranging from rapidly growing, rapidly reproducing species to slower-growing, longer-lived organisms.

These two large areas of ecological research make an intriguing prediction: should faster species have inherently more variable populations?

Work led by Dr. Reilly O’Connor combines population time series with life-history and trait databases to test this prediction across large numbers of species.

Body size is expected to be an important part of the story because smaller organisms tend to have faster life histories. But we are also interested in variation independent of body size. Two similarly sized species, for example, can differ substantially in metabolism, growth and turnover—and theory predicts that these differences may be reflected in their population dynamics.

This work attempts to connect traits, energetics and population dynamics within a common framework.

Searching for General Rules

Across these projects, our synthetic research has a common objective: to determine whether the enormous biological complexity observed in nature contains general and predictable structure.

Increasingly, we are interested in whether a relatively small number of principles—variation across space and time, energetic constraints, interaction strengths, movement, life history and access to alternative ecological pathways—can explain seemingly different patterns across populations, food webs and ecosystems.

This creates an important feedback between the three major components of research in the McCann Lab. Theory identifies mechanisms. Empirical research asks whether those mechanisms operate in nature. Synthesis asks whether they generalize.

Together, these approaches allow us to move from understanding individual ecological systems toward identifying the broader principles that determine how ecosystems persist, reorganize and sometimes collapse under environmental change.