Great Plains

Ecosystems in the American Great Plains are characterized by mixed croplands and grasslands. These systems are adapted for relatively dry and variable climates, and model parameterizations of drought stress are particularly important. Treatment of landscape heterogeneity is also crucial. One major difference between these systems and forests is the occurrence of vegetation based on C4 photosynthesis, rather than the more common C3. C4 plants include maize (corn) and many tallgrass natives.

We have worked closely with Drs. Joseph Berry (website not found), Shashi Verma, and Niall Hanan(website not found)on model parameterization and simulations at a pair of flux tower sites in Oklahoma and Kansas. The  Ponca City, OK site is in a wheat field, and the Shidler, KS site is in native C4 prairie. Simulations and observations include the effects of seasonal changes in the ratio of C3 to C4 plants on the stable isotopic ratio of CO2 fixed by the mixed canopy.


We are also starting to work with Dr. Margaret Torn (website not found)on mesoscale simulations of land-atmosphere interactions at the ARM-SGP (website not found) site near Lamont, OK. Her group maintains a network of mobile flux tower in various vegetation cover types. They use high-resolution imagery to specify land cover, and then compare simulated fluxes and atmospheric properties to measurements on the flux towers and on a 60 m tower.

Download a copy of a presentation on the ARM-Carbon work by Marc Fischer.