Research


Below are descriptions of our main research themes and projects. These projects involve close collaborations with other research groups focused on lab or field experiments: The Yvon-Durocher Lab , the Bell Lab , the Woodward Lab , and the Cator Lab .


METABOLISM BIOMECHANICS AND SPECIES INTERACTIONS

All organisms live with two major constraints: their body size, and their body temperature. Both factors govern rates at which individuals gather and use energy (metabolic rate) and thus ultimately, population dynamics and evolutionary fitness. The effects of size and temperature are intimately related. Size influences an individual's ability to maintain stable metabolic temperature (thermoregulate). Temperature in turn, especially in ectotherms, elevates metabolic rate, which scales with body size.We study how body size and temperature together drive interactions between individuals, and what combinations of size and ecophysiological strategies can be successful in different environments. Interactions are important in this context because organismal fitness in the field is determined by consumers exploiting resources (e.g., predators and their prey), mutualists exchanging services (e.g., plants and their pollinators) and competition (e.g., interference among individuals while seeking food). A major area of focus of the lab is currently on understanding rates of adaptation and acclimation to changing environmental temperatures, especially in autotrophs.

POPULATION INTERACTION NETWORKS

Scores of competitive, mutualistic, and consumer-resource interactions between organisms underlie every ecosystem. Altogether, these interactions form large, complex networks that show interesting and sometimes unpredictable ecosystem dynamics. Understanding how these complex systems arise and persist, and how they influence the fate of animals and plants embedded in them, is a fundamental problem that has occupied biologists for almost two centuries. We study how interaction network structure affects populations, and how community-level network structure in turn emerges from assembly of interacting pairs of populations. To quantify interactions, we use metabolic theory to model effects of size- and temperature-mediated constraints on individual organisms. Two main areas of focus currently are species invasions and rates of ecosystem (community) recovery (assembly).

IMPACTS OF CLIMATE CHANGE ON ECOSYSTEM FUNCTION

All organisms live in an environment that varies thermally in space and time, ecologists have always sensed that climate plays a central role in driving ecological and evolutionary dynamics. For example, in the Origin of Species (1859), Darwin emphasizes that climatic fluctuations can interfere with natural selection by imposing physiological stress and destabilizing species interactions. An then, there is the small matter of unprecendented global climatic changes in climate (especially in temperature) currently taking place due to human activities. Building on our work on metabolism and biomechanics underlying species interactions, we study how short-term fluctuations as well as long term directional changes in environmental temperature affect the functioning of whole ecosystems. In particular, current projects