From cellular respiration to global carbon flux, the movement of materials and energy is a common thread that runs through ecology. While scientists have learned a great deal about energetics at individual and ecosystem scales, comparatively little is known about its role in between. How does variation in organismal energetics affect foraging, competition and local abundance? Can we link individual metabolism to community  structure and diversity?​ To evolutionary trends? 

My work explores these questions. I use energetics as a common currency that links diverse systems, from the ocean to the land, from the Mesozoic to modern ecoystems. I take a synthetic and theoretical approach to ecology, focusing on general mechanisms to explain broad patterns in nature.   

Research  Themes

Endotherms & Ectotherms

I am interested in how metabolic rates and thermoregulation have evolved over geological timescales, and their ecological consequences today. One highly successful but enigmatic group is the non-avian dinosaurs. Were dinosaur warm-blooded or cold-blooded? My analysis of growth rates derived from fossilized bones indicates dinosaur metabolism was intermediate to endothermic birds and ectothermic reptiles, and most similar 'mesothermic' tuna and great white sharks.

What are the advantages and disadvantages of mesothermy? Of endothermy and ectothermy? To better understand their ecological drivers, I am analyzing the energetics and abundances of extant endothermic, mesothermic, and ectothermic predators in the ocean, where interactions between different energetic guilds are common. I have developed theory that links metabolic asymmetries between endotherms and ectotherms to foraging success, and predicts spatial patterns of diversity. 

Individuals to Communities
All communities are comprised of individuals, but moving between ecological scales requires an understanding of how individual traits link to species interactions and local abundance. Forests are ideal systems to make these connections - trees don't move, are easy to count, and metabolic rates like growth can be measured from periodic surveys of trunk diameter. Trees differ in their metabolic rates due to size, but also due to differences in energy investment. For instance, many light-demanding trees allocate photosynthetic energy towards high rates of carbon assimilation and  vertical growth, but at the cost of weaker wood and high mortality when shaded.

This 'live fast - die young' is a common strategy in organisms, but its competitive implications are unclear. When is one strategy more advantageous than another? How does resource availability affect life history diversity and metabolic power? I am working at Barro Colorado Island, Panama and Harvard Forest, MA to link individual to stand-level carbon and light capture, and test theories of energy use at community scales.  
 Picture
A fisheye view of the canopy at Harvard Forest, MA.