Project Number: 6206-11220-005-07
Start Date: Oct 01, 2009
End Date: Aug 31, 2014
Our approach focuses on a large-scale field study that will provide information for parameterizing a plant growth model (ALMANAC) and a coupled soil-plant-atmosphere biogeochemistry model (SPAB). Replicated 0.63 ha (1.5 ac) plots will be planted with three treatments: 1. Switchgrass (Panicum virgatum) in monoculture, 2. Coastal bermudagrass (Cynodon dactylon L.) in monoculture, and 3. Native prairie polyculture of 30 native prairie species, including common dominant C4 grasses and numerous forbs. Nitrogen fertilizer will be added to half the switchgrass and coastal bermudagrass plots and subplots within the native prairie plots (150 lb N ac-1). Subplots within each planting treatment will be irrigated to replace evapotranspiration to minimize water limitation of plant and soil processes by minimizing seasonal and interannual variability in water availability. Additional subplots will be planted with seeds of a widespread introduced invasive grass, Sorghum halapense (Johnsongrass), to test invasibility. Measurements of plant biomass and its bioenergy potential, plant community composition, plant and soil pools and fluxes of carbon and nitrogen, microclimate, and soil moisture will be conducted to quantify differences in ecosystem service provision among these treatments. Field data will be used to parameterize two models: 1. ALMANAC: This plant growth model will simulate plant biomass production and will be calibrated and verified for each planting treatment. Additional simulations will be run to predict production under environmental scenarios beyond those represented in the experiment. 2. SPAB: This coupled soil-plant-atmosphere biogeochemistry model will predict long-term probability distributions of soil carbon storage.