The California Wildfire & Forest Resilience Task Force (Task Force) has developed regionally-adapted resources to lessen wildfire risk to communities and enhance broader statewide ecosystem resilience. This includes a large set of metrics intended to support a wide range of organizations in prioritizing, planning and/or implementing management actions. The Science Advisory Panel to the Task Force (SAP) was asked to provide expert advice to inform the selection of a subset of “core” metrics for reporting outcomes and progress towards resilience goals. We used survey tools to collect and synthesize the scientific expertise of the SAP as well as other experts regarding existing “Regional Resource Kit” (RRK) metrics as well as potential suggested metrics. This report summarizes the survey process and results. We used two rounds of surveys to collect expert opinion on metrics. Round 1 asked respondents to 1) identify criteria for core metrics, 2) identify metrics from the Regional Resource Kits (RRKs) that were believed to be inadequate based on those criteria, and 3) recommend additional metrics not included in the original set. Round 2 asked respondents to rate the resulting set of 115 metrics. The Round 1 results indicated that selecting a useful set of core metrics depended on their intended application (e.g., planning vs.reporting), the intended audience (e.g., policy makers, scientists, and/or the public), and resilience outcomes (e.g., immediate wildfire risk reduction versus long-term ecological health). In Round 2 we asked respondents to rate each metric on how well it measured each of three broad, overlapping resilience goals identified by the Task Force: 1) reducing wildfire risk, 2) improving ecological integrity, and/or 3) supporting social and/or cultural wellbeing. The Task Force specified the purpose for the metrics: reporting progress to policymakers and the public. Therefore, respondents also evaluated three attributes for each metric: 1) how realistic it was to remeasure (i.e., feasibility), 2) how easy it was to explain to wide audiences (i.e., understandability), and 3) how well it represented the process of interest (i.e., sensitivity). In addition, respondents identified relevant region(s) of California (Sierra Nevada, Southern California, Central Coast, and Northern California) for each metric. For the 115 metrics collectively considered in Round 2 (81 from the RRKs and 34 novel metrics), 66 received an average rating of greater than 4 out of 5 on one or more of the three resilience goals (reduce fire risk, improve ecological resilience, support social/cultural wellbeing). Of these, 13 metrics were rated above 4 out of 5 for two of the three goals, and only “probability of high-severity fire” was rated that highly for all three. Metrics on topics relating to vegetation structure and composition as well as fire behavior and history were most abundant in the RRKs and in our list of highly rated metrics. Topics relating to air quality, water supply, economics, community readiness, environmental justice, and community wellbeing were less abundant in the RRKs and not as highly rated in our surveys; these topic areas could benefit from further expert feedback and development. Top-rated metrics already present in the RRKs included: probability of high severity fire, damage potential in the Wildland-Urban Interface (WUI), standing dead and ladder fuels, vegetative stress during extreme drought, tree mortality, and shrub resilience. Metrics that are not yet in the RRKs but do exist elsewhere include Cal EnviroScreen scores and areas of low potential shrub regeneration. Highly rated novel metrics suggested by the survey respondents include (among others): health outcomes related to air quality/smoke and insurance availability/price. Some considerations for proceeding with selection of core metrics arose through this process. First, metrics selected (and targeted desirable ranges for these metrics) might be ecosystem specific. Second, the tradeoff between the logistical aspects of the metrics (feasibility of remeasurement, understandability) with their scientific accuracy and value needs to be evaluated with the target audience in mind. Third, many metrics can address resilience across multiple topic areas and therefore framing this overlap carefully is important when determining how to track progress towards resilience goals.
