Vegetation type conversion in the US Southwest: frontline observations and management responses

Guiterman, C.H., Gregg, R.M., Marshall, L.A.E. et al. Vegetation type conversion in the US Southwest: frontline observations and management responses. fire ecol 18, 6 (2022). 



Ecosystems in the western US are experiencing transformations, defined here as vegetation type conversions (VTC), as a result of many factors, including land-use change, climate change, and altered fire regimes. To gain a better understanding of the challenges for managing VTC, two workshops were held in 2019 with the goal of bringing together managers, scientists, and practitioners to share their perspectives. 11 case studies and 61 VTC examples were examined in the workshops, and this paper categorized their management responses as 1) reverse change, 2) observe change, or 3) facilitate change. Reversing change pertains to restoring the ecosystem to pre-disturbance conditions and it often involves planting operations that promote resilient ecosystem structure. When recovery efforts aren’t feasible, observing the change is useful for gauging the extent of conversion and informing future management strategies. Facilitating change pushes ecosystems towards the desired trajectory by planting native species that are less susceptible to disturbances such as drought, fire, or invasion. From the VTC examples, the majority were related to high-severity fire events, most resulted in conversion to shrubland, and the most commonly used management strategy was “reverse change”. 


Take Home Points:

  • The most common VTCs found in the Southwest region were forests converting to shrublands and sagebrush converting to invasive-grass-dominated grasslands. The most common driving factor was altered fire frequency and severity. 
  • There are diverse management responses to VTC with no “one-size-fits-all” solution, but developing region-specific intervention strategies and consulting local Tribal communities is a good place to start. 


Management Implications:

  • The RAD framework (resist - accept - direct) is useful for categorizing and analyzing the diverse management responses to VTC. 
  • “Facilitating change” was found to be the least common management response to VTC because it requires many known factors about how the ecosystem will respond to the facilitated change. Expanding knowledge on the complex feedback interactions in ecosystems will help fill this knowledge gap. 
  • “Reversing change” was found to be the most common management response but is often resource intensive, so focusing on small site recovery is recommended.