Sagebrush Are Not Small Trees: Need and Considerations for Improved, Uniform Burn Severity Assessment in Shrub-Steppe Rangelands

The introduction and proliferation of invasive annual grasses have increased wildfire size and frequency, contributing to the degradation of sagebrush steppe rangelands in the Great Basin of the western United States. The availability of timely and accurate burn severity data following a wildfire is critical for making well-informed postfire management decisions to address this degradation. However, most commonly used burn severity metrics were developed in the context of high biomass, high cover forested systems, which limits their utility in sagebrush steppe. The goal of this paper is to provide an overview of the current state of burn severity assessment in sagebrush steppe communities and to highlight areas for improvement. First, we compared common burn severity metrics, finding differences among them. We then assessed their utility in shrublands and found that most metrics fail to adequately capture key ecological conditions that drive postfire management decisions, such as perennial grass mortality or fine-scale heterogeneity in burn severity. Consequently, we advocate for the development of a standardized procedure that characterizes the state of the postburn plant community in the context of potential successional trajectories under different environmental and management scenarios. Finally, we provide a suite of ecological burn severity indicators that serve as a starting point in capturing the response of rangelands to fire. Most postfire restoration decisions and underlying burn severity estimates in rangelands are made during the weeks following wildfire. However, the effects of wildfire are not always readily apparent immediately after fire, necessitating an adaptive sampling procedure that allows for reassessment of site conditions and adjustments to management strategies. A standardized procedure designed specifically for rangelands is important because it will enable rapid assessment of the indicators relevant to postfire decision-making.