Global change exposes plants to environmental stress. Individual plants first respond to these stressful conditions at the molecular level, which then scale up to affect leaf-level physiology and whole plant growth. As each individual responds to new abiotic conditions, the genetic structure of the population will change. I study multiple aspects of an individual's phenotype - from gene regulation through fitness - to understand the mechanisms by which selection changed the genetic structure of a population.
For my dissertation, I studied the mechanisms by which a population of the dominant tall grass Big Bluestem, Andropogon gerardii, adapted to more variable environmental conditions. I continue this research by investigating how a two-year drought affects this same population. My adaptation research takes place at Konza Prairie Biological Station, KS, in the Rainfall Manipulation Plots. I study whether water availability affects an individual's gene regulation, leaf-level physiology, and whole plant carbon accumulation and reproduction and link these individual responses to changes in the population's genotypic composition and genetic diversity. A current focus of this research is to study whether shifts in rainfall mean results in directional selection, while an increase in rainfall variability results in diversifying selection.
Related Research and Collaborators: Melinda Smith, Konza Prairie, Rainfall Manipulation Plots
Populations are made of individual genotypes that express unique phenotypes. As the environment changes with global change, selection acts on an individual's phenotype. Although selection acts on phenotypes, it changes the genetic structure of populations by selecting for genotypes that are best adapted to the new environmental conditions.
- Avolio, M, Beaulieu, J, Smith MD. 2013. Genetic diversity of a dominant C4 grass is altered with increased precipitation variability. Oecologia 171: 571-581.
- Avolio, M and Smith, MD. 2013. Mechanisms of selection: phenotypic differences among genotypes explain patterns of selection in a dominant species. Ecology 94: 953-965.
- Avolio, M and Smith, MD. 2013. Intra-specific responses of a dominant C4 grass to altered precipitation patterns. Plant Ecology 214: 1377-1389.