Norton - Research Abstract
PI John Stark, USU Biology, Norton Co-PI, Funded USDA 2007-2011
Cheatgrass establishment results in stable exotic plant communities that resist re-invasion by native perennials. We hypothesize that positive feedbacks resulting from shifts in nutrient cycling and microbial activity are responsible for the long-term persistence of cheatgrass. To test this hypothesis we will revisit a set of restoration plots set up by John Stark (PI) in 1984 in Western Colorado. We will examine the soil microbial structure and nutrient cycling characteristics in these well-replicated experimental plots to determine whether during the past 26 years, cheatgrass-dominated or native perennial-dominated plant communities have 'cultured' different soil characteristics.The study will provide new information on the mechanisms by which cheatgrass establishes stable, persistent plant communities. Through these experiments we will address the CSREES priority of establishing 'mechanisms determining the abundance and distribution of weedy and invasive species on western rangelands. In addition, our results will provide information essential for developing management strategies that will speed the reestablishment of perennial plant species on cheatgrass-dominated rangelands.
Plant-Soil Feedbacks in the Shrub Steppe Ecosystem
Norton Cooperator with Andrew Kulmatiski and Karen Beard
J. Norton will be working with these investigators to characterize microbial communities using next-generation sequencing of phylogenetic and functional genes extracted from the soils from the Washington State manipulative plots. See Kulmatiski A., Beard, K.H. 2011. Long-term plant growth legacies overwhelm short-term plant growth effects on soil microbial community structure. Soil Biology and Biochemistry.