Understanding the Sagebrush Steppe’s Threshold for Transitions Through Resistance and Resilience Models Active
We are investigating ecosystem transitions and thresholds in the sagebrush steppe, studying factors influencing the shift from native to invaded plant communities after disturbances like fire. Our research tests region-wide resistance and resilience models, focusing on real-world recovery patterns, pre-fire conditions, plant succession, and land management treatments.
Background
All ecosystems change over time. These changes can be caused by many things such as fire, human development, or simply due to natural successions from one plant community to another, like when grasses are outcompeted by deeper rooted shrubs. These changes can occur gradually or rapidly. When an ecosystem changes from one dominated by certain types of plants to a different set of species, it is called a transition. A threshold is a tipping point that when crossed causes a transition to take place.
The Fire, Invasion, and Ecology in Sagebrush Steppe (FIREss) lab studies transitions and transition thresholds in the sagebrush steppe. Specifically, our lab studies the factors that contribute to the conversion of native sagebrush and perennial grass communities to invaded communities. We conduct research to understand what makes the sagebrush steppe resistant and resilient to these types of transitions. A resistant community is a community that can withstand the presence of exotic species without being significantly affected or invaded and a resilient community is one that can recover from disturbances and return to its pre-disturbed state. Treatments, like seeding and herbicide spray, can be used by land managers to foster resistant and resilient communities.
Researchers have developed ways of estimating of resistance and resilience across sagebrush steppe of the western United States using computer simulation models. They have found that factors such as soil moisture and average temperature can be used to predict the levels of resistance and resilience a community has. Their models indicate that wetter and cooler landscapes are often more resistant and resilient than hotter and drier places. However, many of these models have not been tested at the small-scale most useful to land managers, most of them are created for region-wide trends. Our team’s research focuses on testing these metrics of resistance and resilience at a management-applicable scale across megafires that collectively cover millions of acres, to see if the models can accurately predict plant recovery in the field. For instance, the FIREss team has assessed post-fire data from the Murphy, Holloway, Rush and Soda wildfires to see how real communities recovered after fire and if resistance and resilience models could explain recovery.
Objectives
The FIRESs Lab is currently conducting research to answer several aspects of transitions, which are further subdivided into three main categories: Pre-Fire Conditions, plant succession, and resistance and resilience.
Regarding Pre-Fire Conditions
- Determine how pre-fire conditions affect post-fire invasion.
- Determine if we can use remotely sensed data to inform us of pre-fire conditions that affect post-fire conditions.
- Identify thresholds in the ratio of invasive grasses to native perennial grasses before a fire that determine post-fire invasion.
Regarding Plant Succession
- Identify the plant communities that exist after fire in the sagebrush steppe and determine how they vary over time.
- Determine if certain native and invasive plant community types are more dominant a few years after fire.
- Determine if certain plant associations that occur after fire tend to get replaced by other plant associations in later years.
Resistance and Resilience
Determine if metrics of resistance and resilience can help predict post-fire vegetation recovery.
We are investigating ecosystem transitions and thresholds in the sagebrush steppe, studying factors influencing the shift from native to invaded plant communities after disturbances like fire. Our research tests region-wide resistance and resilience models, focusing on real-world recovery patterns, pre-fire conditions, plant succession, and land management treatments.
Background
All ecosystems change over time. These changes can be caused by many things such as fire, human development, or simply due to natural successions from one plant community to another, like when grasses are outcompeted by deeper rooted shrubs. These changes can occur gradually or rapidly. When an ecosystem changes from one dominated by certain types of plants to a different set of species, it is called a transition. A threshold is a tipping point that when crossed causes a transition to take place.
The Fire, Invasion, and Ecology in Sagebrush Steppe (FIREss) lab studies transitions and transition thresholds in the sagebrush steppe. Specifically, our lab studies the factors that contribute to the conversion of native sagebrush and perennial grass communities to invaded communities. We conduct research to understand what makes the sagebrush steppe resistant and resilient to these types of transitions. A resistant community is a community that can withstand the presence of exotic species without being significantly affected or invaded and a resilient community is one that can recover from disturbances and return to its pre-disturbed state. Treatments, like seeding and herbicide spray, can be used by land managers to foster resistant and resilient communities.
Researchers have developed ways of estimating of resistance and resilience across sagebrush steppe of the western United States using computer simulation models. They have found that factors such as soil moisture and average temperature can be used to predict the levels of resistance and resilience a community has. Their models indicate that wetter and cooler landscapes are often more resistant and resilient than hotter and drier places. However, many of these models have not been tested at the small-scale most useful to land managers, most of them are created for region-wide trends. Our team’s research focuses on testing these metrics of resistance and resilience at a management-applicable scale across megafires that collectively cover millions of acres, to see if the models can accurately predict plant recovery in the field. For instance, the FIREss team has assessed post-fire data from the Murphy, Holloway, Rush and Soda wildfires to see how real communities recovered after fire and if resistance and resilience models could explain recovery.
Objectives
The FIRESs Lab is currently conducting research to answer several aspects of transitions, which are further subdivided into three main categories: Pre-Fire Conditions, plant succession, and resistance and resilience.
Regarding Pre-Fire Conditions
- Determine how pre-fire conditions affect post-fire invasion.
- Determine if we can use remotely sensed data to inform us of pre-fire conditions that affect post-fire conditions.
- Identify thresholds in the ratio of invasive grasses to native perennial grasses before a fire that determine post-fire invasion.
Regarding Plant Succession
- Identify the plant communities that exist after fire in the sagebrush steppe and determine how they vary over time.
- Determine if certain native and invasive plant community types are more dominant a few years after fire.
- Determine if certain plant associations that occur after fire tend to get replaced by other plant associations in later years.
Resistance and Resilience
Determine if metrics of resistance and resilience can help predict post-fire vegetation recovery.