Mechanisms Driving Climate Change-induced Diversifying Selection in a Dominant Tallgrass Species

EPA Grant Number: FP917240
Title: Mechanisms Driving Climate Change-induced Diversifying Selection in a Dominant Tallgrass Species
Investigators: Avolio, Meghan Lynn
Institution: Yale University
EPA Project Officer: Lee, Sonja
Project Period: September 1, 2010 through August 31, 2013
Project Amount: $111,000
RFA: STAR Graduate Fellowships (2010) RFA Text |  Recipients Lists
Research Category: Academic Fellowships , Fellowship - Global Change


Climate change is predicted to alter global hydrological cycles, including changes in variability of precipitation regimes, which will affect biodiversity, both intra- and inter-specific. My research to date has shown that a decade of altered precipitation patterns increased the genetic diversity of Andopogon gerardii, a dominant C4 grass species. The goal of this research is to mechanistically explain the observed pattern of selection and determine whether these changes in genetic diversity scale up to affect ecosystem productivity.

Global change is expected to result in larger rainfall events that occur less frequently. Understanding their effects on ecosystem biodiversity is essential for determining how climate change will alter the conversion of atmospheric carbon into biomass. Studying the most abundant tallgrass species and focusing on genetic diversity, this research explores how climate induced alterations of plant populations will affect biomass production and is predictive of ecosystem function in future climates.


This research combines both field and greenhouse studies. The first stage of this research was conducted in the field, utilizing an ongoing experiment, the Rainfall Manipulation Plots (RaMPs) at the Konza Prairie Biological Research Station. The RaMPs experiment creates more variable precipitation events in intact tallgrass prairie communities. The field-based research investigated the effect of more variable precipitation patterns on the genetic diversity of a dominant species. The second stage will be conducted in a greenhouse addressing which mechanism is driving the observed patterns in the field, the reduction of soil moisture, an increase in soil moisture variability or their combination. In both the field and greenhouse phenotypic measurements were and will be made on specific genotypes to understand whether there are differences between genotypes in their ability to persist in more variable precipitation regimes.

Expected Results:

Global climate change is predicted to result in rapid evolution of traits as species respond to new climatic conditions. This research has the unique ability to identify traits that have been selected for in a decade long climate change experiment. The results from the on-going field studies and greenhouse experiment will allow for a comprehensive synthesis of differences between genotypes across a range of biological levels of organization. This research will result in a mechanistic explanation of the patterns of selection that have been observed in the field after a decade of experiencing altered precipitation patterns.

Potential to Further Environmental/Human Health Protection
Results from this research can be extrapolated to predict how global change may affect similar terrestrial ecosystems, and by focusing on the ubiquitous and dominant species A. gerardii, this research also has the potential to be useful in the field of biofuels. Insight into future trait selection in A. gerardii will help inform decisions about potential biofuel crops.

Supplemental Keywords:

global climate change, variability, precipitation, genetic diversity, genotypes, Andropogon gerardii, dominant species, C4 grass, tallgrass prairie,

Progress and Final Reports:

  • 2011
  • 2012
  • Final