Perennial grassland ecosystems have the potential to provide Minnesota with locally grown energy sources that reduce greenhouse gas emissions, improve water quality, and provide other important services. It seems likely that such perennial grassland crops will experience climate change in the coming decades, and that in attempts to improve yields farmers would try fertilizing and/or irrigating their grasslands. However the effects of these factors on the potential benefits of alternative biomass crops, including switchgrass monocultures, Miscanthus monocultures and high-diversity prairies, are unstudied and unknown. Soils are the largest storehouse of carbon in Minnesota, and soil carbon sequestration may become a marketed item as part of a carbon cap and trade system. The net effects of warming, fertilization and irrigation on soil carbon storage, though, have not been tested. Similarly, we do not know how either the biomass yields of alternative crops or their susceptibility to invasion by exotic plant species might be impacted by these factors.

This project will use a Fertilization-Irrigation Experiment (consisting of 96 plots) and a Climate Experiment (consisting of 114 plots) to determine how irrigation, fertilization, and climate warming impact yields, carbon sequestration, plant biodiversity, water quality and susceptibility to invasion in grasslands with varying diversity (1, 4, 16 or 32 plant species). An additional Invasion Experiment nested within the first two experiments would also monitor whether Miscanthus, an exotic perennial grass species, poses a threat as pernicious invasive. Our results will be synthesized to find methods for optimizing biofuel production, carbon storage, and habitat restoration.

Project Details