Using simulation models to project and evaluate post-fire success in restoring sage-grouse habitat over large landscapes
Wildfires are increasingly destroying wildlife habitat in sagebrush (Artemisia species) ecosystems, and managers need approaches to scope the pace and degree to which post-fire restoration actions can re-create habitat in dynamic landscapes. Sagebrush recovery takes a long time, and it can be difficult to anticipate restoration outcomes over large, diverse landscapes that have experienced decades of natural succession and disturbance. It is also challenging to conceptualize projected vegetation in terms of the specific needs of wildlife species.
To help overcome these challenges, scientists at USGS and Colorado State University developed a spatially explicit state-and-transition simulation model (STSMs) framework for sagebrush-steppe landscapes. The framework and approach allowed comparison of habitat restoration outcomes from different post-fire revegetation strategies at larger spatial scales than the revegetation-habitat-recovery model and individual-based model (IBM) developed for Field of Sagebrush Dreams research in the Tuscarora region of Nevada.
USGS Study
Researchers examined how well projected post-fire revegetated landscapes (2018-2068) corresponded to habitat needs for greater sage-grouse (Centrocercus urophasianus) in three Priority Area for Conservation populations (Utah, Nevada, Oregon/California). Recent extensions to STSMs allow continuous variables (for example, percent cover) associated with discrete vegetation states to be tracked and modeled over space and time, letting researchers explicitly model stochastic vegetation cover gain and loss dynamics in simulations. This was useful because continuous values of percent cover are often used to define habitat for sage-grouse (for example, percent sagebrush or perennial grass) and determine revegetation success. To evaluate the potential for post-fire success, scenarios were constructed to contrast the different restoration actions and implementations (seeding or planting revegetation treatments), duration of application (single-, multi-year), and amount of area treated (effort in this study). Researchers also determined potential change in projected habitat classifications after 50 years. By comparing different scenarios of post-fire vegetation recovery with sage-grouse habitat needs, the model and results allow managers to scope the feasibility of site-level revegetation actions scaling up across larger spatial extents to create habitat for sage-grouse populations.
Major Findings
Model projected vegetation outcomes, sage-grouse habitat, and potential for change:
- Across scenarios, sagebrush revegetation actions lead to similar vegetation and habitat outcomes relative to no restoration action being taken.
- Sagebrush regeneration was generally insufficient to meet sage-grouse habitat cover requirements for at least 10 years post-fire.
- Deteriorated sagebrush cover and habitat quality often persisted in burned areas through 50 years post-fire.
Meeting sage-grouse recovery objectives:
- After 50 years, potential for the best habitat conditions for sage-grouse remained low.
- Simulation results indicate existing habitat persisted, but that the sagebrush revegetation alternatives explored didn’t necessarily create broad-scale habitat for sage-grouse.
Management Applications
The model framework and approach could be used to inform management decisions and restoration planning for entire sagebrush communities or targeted to specific species of conservation concern. Some examples for how the projected vegetation and habitat from these models can help land managers and analysts assess the feasibility of creating minimum to high quality habitat for sage-grouse or other target species:
- Integrating model output with monitoring (like TAWS) and prioritization tools (like PReSET) to gauge other restoration benefits that will help policymakers and managers make informed decisions.
- Adapting the STSM to broad or local sagebrush-steppe landscapes or expanding the framework to consider habitat criteria for multiple species, economic and logistic constraints, or additional factors critical to restoration planning.
For More Information
This study has been published in Ecological Modelling: Orning, E.K., J.A. Heinrichs, D.A. Pyke, P.S. Coates, and C.L. Aldridge. 2023. Using state-transition simulation models to scope post-fire success in restoring greater sage-grouse habitat. Ecological Modelling 483:110396. https://doi.org/10.1016/j.ecolmodel.2023.110396.
The project team included Elizabeth Orning, Julie Heinrichs, David Pyke, Peter Coates, and Cameron Aldridge. For further information or to request a briefing on this research, please contact Elizabeth Orning (eorning@usgs.gov).
Linking post-fire sagebrush restoration and sage-grouse habitat recovery
Simulating the influence of sagebrush restoration on post-fire sage-grouse population recovery
Field of Sagebrush Dreams: Planting and Restoring Functional Sagebrush in Burned Landscapes
Wildfires are increasingly destroying wildlife habitat in sagebrush (Artemisia species) ecosystems, and managers need approaches to scope the pace and degree to which post-fire restoration actions can re-create habitat in dynamic landscapes. Sagebrush recovery takes a long time, and it can be difficult to anticipate restoration outcomes over large, diverse landscapes that have experienced decades of natural succession and disturbance. It is also challenging to conceptualize projected vegetation in terms of the specific needs of wildlife species.
To help overcome these challenges, scientists at USGS and Colorado State University developed a spatially explicit state-and-transition simulation model (STSMs) framework for sagebrush-steppe landscapes. The framework and approach allowed comparison of habitat restoration outcomes from different post-fire revegetation strategies at larger spatial scales than the revegetation-habitat-recovery model and individual-based model (IBM) developed for Field of Sagebrush Dreams research in the Tuscarora region of Nevada.
USGS Study
Researchers examined how well projected post-fire revegetated landscapes (2018-2068) corresponded to habitat needs for greater sage-grouse (Centrocercus urophasianus) in three Priority Area for Conservation populations (Utah, Nevada, Oregon/California). Recent extensions to STSMs allow continuous variables (for example, percent cover) associated with discrete vegetation states to be tracked and modeled over space and time, letting researchers explicitly model stochastic vegetation cover gain and loss dynamics in simulations. This was useful because continuous values of percent cover are often used to define habitat for sage-grouse (for example, percent sagebrush or perennial grass) and determine revegetation success. To evaluate the potential for post-fire success, scenarios were constructed to contrast the different restoration actions and implementations (seeding or planting revegetation treatments), duration of application (single-, multi-year), and amount of area treated (effort in this study). Researchers also determined potential change in projected habitat classifications after 50 years. By comparing different scenarios of post-fire vegetation recovery with sage-grouse habitat needs, the model and results allow managers to scope the feasibility of site-level revegetation actions scaling up across larger spatial extents to create habitat for sage-grouse populations.
Major Findings
Model projected vegetation outcomes, sage-grouse habitat, and potential for change:
- Across scenarios, sagebrush revegetation actions lead to similar vegetation and habitat outcomes relative to no restoration action being taken.
- Sagebrush regeneration was generally insufficient to meet sage-grouse habitat cover requirements for at least 10 years post-fire.
- Deteriorated sagebrush cover and habitat quality often persisted in burned areas through 50 years post-fire.
Meeting sage-grouse recovery objectives:
- After 50 years, potential for the best habitat conditions for sage-grouse remained low.
- Simulation results indicate existing habitat persisted, but that the sagebrush revegetation alternatives explored didn’t necessarily create broad-scale habitat for sage-grouse.
Management Applications
The model framework and approach could be used to inform management decisions and restoration planning for entire sagebrush communities or targeted to specific species of conservation concern. Some examples for how the projected vegetation and habitat from these models can help land managers and analysts assess the feasibility of creating minimum to high quality habitat for sage-grouse or other target species:
- Integrating model output with monitoring (like TAWS) and prioritization tools (like PReSET) to gauge other restoration benefits that will help policymakers and managers make informed decisions.
- Adapting the STSM to broad or local sagebrush-steppe landscapes or expanding the framework to consider habitat criteria for multiple species, economic and logistic constraints, or additional factors critical to restoration planning.
For More Information
This study has been published in Ecological Modelling: Orning, E.K., J.A. Heinrichs, D.A. Pyke, P.S. Coates, and C.L. Aldridge. 2023. Using state-transition simulation models to scope post-fire success in restoring greater sage-grouse habitat. Ecological Modelling 483:110396. https://doi.org/10.1016/j.ecolmodel.2023.110396.
The project team included Elizabeth Orning, Julie Heinrichs, David Pyke, Peter Coates, and Cameron Aldridge. For further information or to request a briefing on this research, please contact Elizabeth Orning (eorning@usgs.gov).