2012 Annual Report
1a.Objectives (from AD-416):
Quantify grassland carbon, energy, water, and GHG fluxes; grassland phenology, and biophysical and biochemical parameters to improve remote sensing monitoring methods and develop understanding of grassland ecosystem dynamics.
1b.Approach (from AD-416):
In Phase 1, we will deploy two CO2 eddy covariance flux towers, one a fixed position for long-term measurements, and one mobile flux tower for experiments (e.g., livestock grazing, fire, land use change). The eddy covariance flux towers are used to measure CO2, water and energy fluxes at 30-minute intervals. Phenology towers will be co-located with the fixed position eddy flux tower, and the mobile eddy flux tower. The phenology towers will use a webcam system to acquire digital photos to track vegetation dynamics at hourly to daily intervals. To measure biophysical and biochemical parameters, we will put deploy two spectral sensor towers, one co-located with the fixed position eddy flux tower, and the other one is co-located with the mobile eddy flux tower. Spectral sensors measure optical properties of vegetation and soils, which helps interpretation of flux data and supports retrieval of grassland biophysical and biochemical parameters from satellite images. In future phases, we will deploy instrumentation to measure soil moisture dynamics, GHG emissions, an optical sensor track system, and airborne observation systems.
The University of Oklahoma collaborators have purchased the equipment for the permanent greenhouse gas flux tower to be co-located at the El Reno Mesonet site over tall grass prairie and another at an agronomic farm-systems site. The equipment is being tested in the laboratory prior to setting up in the field. The ARS is purchasing methane flux sensors to add to the eddy correlation towers. The ARS research team is developing 5-year land management plans for cow-calf grazing on prairie at the permanent site, and for stock grazing on winter wheat-based forage systems at the agronomic flux site. Data collection will begin in fall of 2012.