Long-term implications of prescribed fire in the western Great Plains: Responses of soil, vegetation, fuel loads and modeled fire behavior
Rangeland Resources Research
Project Number: 5409-21610-001-07
Interagency Reimbursable Agreement
Start Date: Feb 15, 2013
End Date: Sep 30, 2016
Leverage existing studies at Kiowa National Grassland (Forest Service) and Pawnee National Grassland/Central Plains Experimental Range (ARS, Rangeland Resources Research Unit) (including prior investments of infrastructure and maintenance of experimental integrity) by extending them for an additional 3 years to provide land managers with a more robust scientific basis for the use of prescribed fire as a management tool in shortgrass steppe. Of primary interest for both private and public land managers are the long-term implications of prescribed fire in terms of frequency of fires (i.e., the fire return interval) and season (dormant, growing season) on vegetation (forage production, litter, diversity), fuel loads, and soil temperatures and soil moisture. Small mammal community change (local extinction and colonization) and diversity (species richness and abundance) will also be remeasured at the Kiowa site. Moreover, these re-measurements will provide important temporal inputs of variables that can be incorporated into fire behavior models to generate more robust predictive ability across a wide range of environmental conditions. As such, this combined measurement and modeling effort would facilitate more effective attainment of desired and specific management goals on these National Grasslands. Furthermore, this planned research would enhance the capacity of land managers to respond adaptively to climatic variability in these semiarid rangelands through the knowledge of how ecosystem productivity and function may be impacted by environmental (e.g., drought) influences on the effects of fire frequency and season.
The experimental design at the Kiowa National Grassland is completely randomized, with 7 treatments replicated 5 times. Treatments, first implemented in 1997, are composed of a combination of dormant (April)- and growing (July)-season fires and fire return intervals of 3, 6, and 9 years over 18 years and unburned. The experimental design at the Pawnee National Grassland-Central Plains Experimental Range is also completely randomized with 5 treatments replicated 4 times. Treatments, first implemented in 2006, are composed of a combination of dormant (fall) and growing-season (spring) fires and fire return intervals of 1 and 3 years and unburned controls. We will be able to draw solid inferences about the effects of seasonality and frequency of prescribed fire by resampling these 2 studies with proven experimental designs that include solid replication. We will also be able to extend the application of these existing datasets by using both studies in context of a south-north gradient. The opportunity to resample these 2 studies with already existing experimental designs with substantial replications and acquired data from prior prescribed burns permits the drawing of solid inferences about the effects of seasonality and frequency of prescribed fire along a south-north gradient in the shortgrass steppe rather than from a single study site. Including both of these sites broadens the applicability of our findings to the entire rangeland ecosystem, and will therefore be of greater utility to the Forest Service regarding land management on their National Grasslands in shortgrass steppe.