Evolution that results in a change in the mean or variance of phenotypic traits within a population could have implications for ecological and ecosystem processes. This is most likely when a trait mediates an individual’s interaction with its abiotic and biotic environment and is subject to natural selection. For example a directional shift in the amount of secondary compound that a plant produces could have direct and indirect effects on associated communities and ecosystem processes. These ecological and ecosystem-level modifications could alter the strength and direction of selection on subsequent generations of the focal organism or the associated community members. I will specifically focus on the effect of evolution in plant populations on the soil ecosystem and investigate whether any changes in the ecosystem feedback to alter natural selection on the focal plant population.
Additional Scientific Information
I will establish populations of O. biennis that diverge genetically and phenotypically over time and measure the concurrent change in ecological and ecosystem processes. In the summer of 2012 90 identical populations made of 8 genotypes of O. biennis were planted into a homogenous, ploughed field site at the Koffler Scientific Reserve. These will be divided into 5 evolutionary treatments: i) the control (static) treatment, ii) the increasing total ellagitannin content treatment, iii) the decreasing total ellagitannin content treatment, iv) the increasing phenology index treatment, and v) the decreasing phenology index treatment. Each year I will measure the composition of the aboveground plant and arthropod, and belowground arthropod and microbial communities in each population. Additionally I will measure ecosystem function in each of! the plots by leaf decomposition, nutrient flux, and soil respiration under varying substrates. After some amount of divergence I will look for a feedback between O. biennis genotypes and soil taken from evolutionary treatment plots.
Principal Investigator: Marc Johnson
Researcher(s): Connor Fitzpatrick