The chemical mechanisms of plant-soil interactions

The interaction between plants and soils is too often oversimplified for its importance to life on earth. The chemical complexity of this interaction is enormous, but many soil scientists, ecologists, and biogeochemists reduce it to single compounds. This dissertation looks to explore the complexity of the interface of plant roots and soils, termed the rhizosphere, in an effort to better understand the chemical forces that shape terrestrial ecosystems. In two chapters I explore how small genetic differences in plants can lead to vast differences in surrounding soil enzymes and thousands of other metabolites. I show that the trait variation within a plant species can alter pedogenesis (The formation of soils) that may have feedbacks on future generations of plants. In the third chapter I explicitly explore this feedback by examining how plant chemical phenotypes change when exposed to live soils which have been conditioned by populations of a plant with unique phenotypes. As soil metabolomics is a new field, I used my final chapter as a review of the current methods of data analysis with the hope that future soil scientists will join me in exploring the chemical complexity of the soil instead of ignoring it.