We are interested in topics such as eco-evolutionary dynamics, symbiosis, demography, conservation, and phylogeny. Here are some of our current projects, with sample papers.
Evolution of life histories in response to rapid climate change
We are using long-term demographic monitoring of long-lived plants to assess how sprouting and flowering behavior is likely to change under state-of-the-art climate predictions.
- Shefferson, R.P., R. Mizuta, and M.J. Hutchings. 2017. The evolution of sprouting probability in response to climate change in three dormancy-prone orchid species. Royal Society Open Science 4:160647.
Evolution of mycoheterotrophy
We are analyzing long-term demographic data and parameterizing evolutionary models to understand why so many plant species have evolved to parasitize mycorrhizal fungi, instead of photosynthesizing.
- Shefferson, R.P., M. Roy, U. Puttsepp, and M.-A. Selosse. 2016. Demographic shifts related to mycoheterotrophy and their fitness impacts in two Cephalanthera species. Ecology 97:1452-1462.
- Shefferson, R.P., M.K. McCormick, D.F. Whigham, and J.P. O’Neill. 2011. Life history strategy in herbaceous perennials: inferring demographic patterns from aboveground dynamics of a primarily subterranean, myco-heterotrophic orchid. Oikos 120:1291-1300.
Adaptive dynamics of sprouting
Why can so many photosynthetic plants live for years as rootstock with photosynthesizing? We address this question with both micro-evolutionary and macro-evolutionary methods, including large-scale character evolution reconstruction and game theory.
- Shefferson, R.P., R.J. Warren II, and H.R. Pulliam. 2014. Life history costs make perfect sprouting maladaptive in two herbaceous perennials. Journal of Ecology 102:1318-1328. (In the news)
Mycorrhizal specialization
Some plants obligately depend on mycorrhizal fungi, even for their energy. Yet, these specialists are rarely specialized on just one mycorrhizal fungal species. What determines the breadth of the mycorrhizal interaction, and why do plants and fungi interact with the partners that they have?
- Kartzinel, T.R., D.W. Trapnell, and R.P. Shefferson. 2013. Highly diverse and variable mycorrhizal symbiosis in a rare epiphyte is unrelated to broad biogeographic or environmental features. Molecular Ecology 22:5949-5961.
- Bunch, W.D., C.C. Cowden, N. Wurzburger, and R.P. Shefferson. 2013. Geography and soil nutrients drive the distribution of fungal associations in a lady’s slipper orchid, Cypripedium acaule. Botany (formerly Canadian Journal of Botany) 91:850-856.
Plant and fungal senescence
We generally believe all organisms will senesce if they live long enough, but empirical assessments and some theory suggest otherwise. What determines how senescence evolves across the Tree of Life?
- Salguero-Gómez, R., R.P. Shefferson, and M.J. Hutchings. 2013. Plants do not count… or do they? New perspectives on the universality of senescence. Journal of Ecology 101:545-554.
- Shefferson, R.P. and D.A. Roach. 2013. Longitudinal analysis in Plantago: strength of selection and reverse age analysis reveal age-indeterminate senescence. Journal of Ecology 101:577-584.
Genetic and environmental drivers of plant demography
Why do plant populations vary in demographic response to climatic variation? How does genetic composition interact with environment to determine population dynamics? We work with herbaceous perennials to answer these questions.
- Shefferson, R.P. and D.A. Roach. 2012. The triple helix of Plantago lanceolata: genetics and the environment interact to determine population dynamics. Ecology 93:793-802.
- Brys, R., R.P. Shefferson, and H. Jacquemyn. 2011. Impact of intrinsic and extrinsic variables on flowering and reproductive allocation patterns in a perennial iteroparous grassland herb: a ten-year experiment. Oecologia 166:293-303.
Mark-recapture methodology for dormancy-prone perennials
Plants may not move away from where they are rooted, but they can still be hard to find, especially if they do not need to sprout every year. We have developed methods for estimating demographic parameters in the face of such difficulties.
- Shefferson, R.P., B. K. Sandercock, J. Proper, and S. R. Beissinger. 2001. Estimating dormancy and survival of a rare herbaceous perennial using mark-recapture models. Ecology 82:145-156.