Miranda R. Peterson

Modeling Adaptive Rangeland Management Under Increased Climatic Variability

Rangelands support approximately 50% of the world’s livestock, however, 10-20% of the world’s rangelands have been degraded and the projected increase in climatic variability poses significant management challenges. Simulation models can explore the potential consequences of this increased variability on rangelands under different management schemes. My objective is to use systems modeling to simulate grass and brush dynamics on South Texas rangelands under alternative future climate scenarios and management schemes. My model simulates the effects of different schemes involving rotational grazing and prescribed burns on brush and grass dynamics under present and two future 30-year climate scenarios. Future climate scenarios assume worst-case and moderate CO₂ emissions and are averaged projections for 2080 to 2100. Preliminary results indicate that heavy stocking rates and summer burns reduce grass biomass under all three climate scenarios. Heavy stocking rates and winter burns reduce grass biomass under the current climate, but in future climate scenarios, grass biomass is maintained. This study could be used by South Texas rangeland managers when evaluating future prescribed burning and grazing options.