John McKay, an associate professor in CSU's Department of Bioagricultureal Sciences and Pest Management, will lead the project - Rhizosphere Observations Optimizing Terrestrial Sequestration (ROOTS) - which will automate the phenotyping of plant roots in agricultural fields and allow researchers to learn more about the genetic composition of the plants based on their roots. "This grant will allow us to scale up our research and look at roots in thousands of research plots and millions of plants," said McKay. "Previously, we were limited by the number of plants we could harvest by hand which meant we lacked the power to identify genes underlying important variation in root traits, including the ideal root systems for maximizing water and nutrient use efficiency." The project will employ two different approaches - pulling the plants out of the ground using a machine currently deployed to examine above-ground material and examing the soil around the plants by using novel, automated sampling the soil throughout the growing season. The researchers are interested in learning which nutrients each plant genotype is using and how much carbon remains in the soil.
Evolution is not easy to measure in a field setting, which is why Ruth Hufbauer, a professor in CSU's Department of Bioagricultural Scineces and Pest Management, and her colleagues Whristopher Weiss-Lehman and Brett Melbourne, from CSU's Department of Ecology and Evoulutionary Biology, used flour beetles (Tribolium castaneum) to observe evolutionary processes in controlled envrironments. The researchers created two different kinds of range expansions - structured, where they allowed beetles to expand across a landscape generation to generation under normal conditions, and shuffled, where each individual beetle was counted in a landscape each generation and then mixed together and put back. By putting the same number of individuals at a given location in a landscape as had originally been there, the researchers were able to reproduce the demographics of the landscape as it was prior to shuffling, while mixing up any genetic structure that have developed. The shuffled beetles moved across the landscape more slowly and more predictably. In contrast, normally structured populations moved faster on average, but with more variation in movement, making them less predictable.
Healthy soil is rich in organic matter, but scientists have yet to fully understand exactly how that organic matter is formed. Colorado State University soil scientist Cynthis Kallenbach has contributed new insight, offering evidence for microbial pathways being the chief originator of the organic matter found in stable soil carbon pools. Kallenbach, a postdoctoral researcher in the Natural Resources Ecology Laboratory, co-authored a recent Nature Communications paper on the topic with Professors Stuart Grandy and Serita Frey of the University of New Hampshire, where Kallenbach completed her Ph.D. She is working now with Matthew Wallenstein, assistant professor in ecosystem science and sustainability in the Warner College of Natural Resources. In the study, which was conducted at University of New Hampshire, Kallenbach et al. suggest that soil organic matter accumulates from inputs of dead microbial cells and microbial byproducts formed when microbes eat plant roots and residues, rather than from plants themselves, as previously thought.[Archive]