Interested in watching this video? You have two options:
This video is part of the SER Conference Library. If you want to learn more about this resource please see this guide.
You can purchase a pass for this video on our website.
Already purchased access to this video, or want to redeem credit for a new order? Just enter your order number or email below:
Sign in below to get unrestricted access:
Simon C. Power, G. Matt Davies, Jon D. Bakker
Many ecosystems are currently subject to increased fire frequencies and invasive species introductions. Responses to these disruptions vary between ecosystems. For instance, those with species traits that support rapid regeneration post-fire may be unaffected by increased fire frequency. In contrast, ecosystems lacking such traits may respond by shifting to an alternative state. We investigated whether restoration efforts may reverse such shifts and increase resistance of sagebrush-steppe communities subjected to compounded wildfires and invasion by Bromus tectorum from 1992 to 2017. Community responses were assessed by analyzing changes in species abundances at multiple time points in 37 permanent plots in Washington, USA. The greatest change occurred in communities where the obligate seeding shrub Artemisia tridentata was common (> 25% cover). Repeated fires (up to 4) led to the extirpation of A. tridentata, which was initially replaced by native forbs/grasses and subsequently by B. tectorum. When restoration treatments (herbicide, seeding) were applied following fire, invasive species tended to show reduced dominance. Communities where resprouting grasses/shrubs were common showed the least change. Repeated fires did, however, lead to a gradual but substantial reduction (90% by 2017) in resprouting shrub abundances. Our findings suggest that communities with seeding shrubs that require extended fire intervals (< 30 years) to reestablish, lack resilience to increased fire frequency and are vulnerable to invasion. While restoration did enhance resistance in these communities, their shift to an alternative state suggests that they have evolved a degree of unhelpful resilience that requires sustained fire suppression and restorative interventions.
Conference Presentation, SER2021
Pre-approved for CECs under SER's CERP program