OOS 9-2
Recoupling humans and fire to disrupt social-ecological feedbacks contributing to the loss of grasslands

Tuesday, August 12, 2014: 8:20 AM
204, Sacramento Convention Center
Dirac Twidwell, Agronomy & Horticulture, University of Nebraska, Lincoln, NE

Most modern societal policies and practices governing natural resource management seek to limit variability in extreme disturbance events and operate best under consistent climatic conditions.  Consequently, many disturbance regimes have been greatly altered compared to historical ranges of variability, leading to trophic cascades in food webs, loss of fire dependent species and ecosystems, and biome-level transformations that deplete ecosystem services. I discuss the magnitude with which modern human management systems have constrained fire as an ecosystem process in the Great Plains, followed by numerous case studies I have conducted across the Great Plains biome that demonstrate the potential benefits of restoring variability in fire regimes in ecosystem management. Specifically, I show how the use of high intensity fires during drought is an important pathway needed to collapse woodland states and restore grass-dominated ecosystems – a finding that counters modern conventions that ban the use of fire during drought episodes.


Our recent experimental work demonstrates that fire-dependent grassland ecosystems in the Great Plains are dependent on ecosystem management efforts that fully restore the potential range of variability in fire as a biophysical process.  Targeting high intensity fires led to significantly higher levels of mortality in Juniperus ashei woodlands, Juniperus virginiana woodlands, as well as shrublands dominated by mature, resprouting woody species.  While such an approach directly conflicts with modern anthropogenic values associated with development, infrastructure, food demands, and recreational perspectives in the Great Plains, a novel societal movement (prescribed burn cooperatives) among private citizens has emerged to restore fire to Great Plains grasslands.  We discuss the constraints confronting the movement to reintroduce fire to the Great Plains and how private citizens are overcoming these modern societal constraints in an attempt to restore grassland ecosystems.