Robert Warren's research focuses on how species interact in a changing climate. He is not only interested in how habitat drives individual species distributions, but how habitat drives the interactions between species within and across these distributions. Such endeavors include niche theory, dispersal, community ecology, climate change and inferential statistics. Some of his current interests include how the mutualism between plants and seed-dispersing ants changes with climate; how humans facilitation exotic invasive plants; how Native Americans dispersed trees; how habitat facilitates plant pathogens and how ants and termites interact and impact forest decomposition.