Population and community ecology of mutualism and other species interactions
The backbone of my research and scholarship has been on the study of species interactions; especially mutualism, a reciprocally-beneficial species interaction. My ultimate research goal is to develop and study the population ecology of mutualism to raise its status among other inter-species interactions, such predator-prey, host-parasite, and competition.
I have primarily worked with plants and seed-dispersing animals (rodents, birds, ants), bugs and ants that tend and defend them, ants that tend and defend plants, and pollination mutualisms, using both experimental and theoretical methods.
My theoretical and conceptual work has focused on (i) elevating the role of mutualism in the field population ecology, (ii) critiquing classic theoretical models of mutualism population dynamics, and (iii) creating theoretical models of mutualism population dynamics that more realistic with no or little additional complexity.
Acrobat ants (Crematogaster sp.) tend the nectaries of a fishhook barrel cactus (Ferocactus wislizeni). In this mutualism, the ants receive nectar from the plants and the plants are, in turn, defended by the ants.
The ecology of seed dispersal
Seed dispersal was my gateway into ecology. I became interested in how plants move through space and time and the ecological and evolutionary consequences of that movement.
A large part of my dissertation that I have continued to work on is the macroecology of seed-dispersal interactions. In short, we amassed a database of how nearly every species of vascular plant in temperate North America (United States and Canada) is dispersed. We were the first to do so at such a large spatial scale and found some interesting intuitive and non-intuitive patterns, like, the richness of plants dispersed by animals decreases with latitude and that the richness of plants dispersed by animals is negatively dispersed by the richness of animals that disperse them, respectively.
Another large part of my dissertation was focused on how scatter-caching rodents disperse seeds. The two most interesting and useful parts of this study were (i) that I showed that a small-seeded species is not dispersed abiotically like many assumed and (ii) that rodents caching the seeds protected them from fire and enhanced germination in this hyper-diverse group of plants in the fire-prone western United States
Kinnikinnick or bearberry (Arctostaphylos uva-ursi) in fruit on Mount Desert Island, Maine. This is the most widely-distributed member of the genus, with a circumpolar distribution. These fruits are dispersed by birds and rodents, and seed germination is enhanced with fire.
Ant diversity and physiology
To study the population ecology of mutualism, I became interested in ant mutualisms. As a consequence of that, I’ve had to learn about ants and have worked with students to study the community ecology and thermal physiology of ants in Maine.
In the few years I have worked with ants, we have amassed a collection of ants from Maine larger than all the museums in the world combined, and have putatively found species that are both new to Maine, but also New England.
From our unpublished work, we have also found patterns of decreasing diversity, increasing biomass, and decreasing maximum thermal tolerance of ants along elevational gradients.
Because there is great student interest in climate change, we have also begun to study thermal physiology of ants to see how a warmer world would affect ant performance. Our main finding has been that the maximum thermal tolerance of ant species is more strongly correlated with the amount of water in an ant’s body rather than the mass of the ant.
An eastern carpenter ant (Camponotus pennsylvanicus) in a test tube. Photograph by Ashley Conti.
