Resilience theory posits that critical ranges of variation in disturbance regimes are necessary for the persistence of many ecological states. In Great Plains grasslands, variation in fire regimes has been minimized, or fire has been removed entirely, to increase harvest efficiency for production systems. This major departure in anthropogenic fire use – from fire-promoting to elimination or simplification of fire - has driven undesirable regime shifts from grassland to woody dominance and the loss of multiple unique ecosystem services. Even with this reality, fire has not been restored as a self-reinforcing feedback in Great Plains grasslands at broad scales. In this paper, I introduce findings from the Loess Canyon Experimental Landscape, an innovative approach to grassland restoration that centers on the use of extreme fire (defined as fires exhibiting sudden and erratic changes in fire behavior and that lead to collapse and reorganization of ecological states) to restore grassland dominance in a 75,000 ha ecoregion that has been converted to Juniperus woodland. This experimental landscape is now the largest scale restoration of extreme fires as a fundamental component of rangeland management in the entire Great Plains biome, and the intent is to transform away from an undesirable regime change and facilitate self-reorganization of the previous grassland regime.
Results/Conclusions
Transforming away from an undesired regime shift from grassland to non-resprouting juniper woodland required extreme fires that overcame hysteretic effects resulting from stabilizing feedbacks in the juniper woodland state. Less intense fires, which are typically used in practice to reinforce grassland persistence, were incapable of overcoming the resilience of the new, woody regime. By implementing a series of extreme fire events, conservation targets are being enhanced. Early evidence points to positive trajectories for grassland birds and the endangered burying beetle at scales that are not possible with alternative restoration techniques (e.g. mechanical removal of trees). Logistical and economical constraints preclude restoration success for those intenstive mechanical techniques at broader scales. These social considerations have important implications for how to operationalize resilience and transform away from undesirable regime shifts at broader spatial extents.