Connections between ecological research and wildland management are particularly important for fire science as the ecology of wildfire disturbances can have immense consequences for fire management. A critical component of understanding wildfire risk is quantifying live fuel moisture (LFM), a proxy for plant flammability. LFM decreases during dry periods of the year and management agencies monitor LFM to assess current fuel characteristics. Thresholds of LFM across a landscape are used to indicate wildfire risk, allocate resources, and have been shown to relate to wildfire size. Measuring LFM is inherently difficult as on-the-ground plant sampling is time-consuming, and remote sensing data can be highly variable. In California, as LFM changes during the summer drought, so does the physiological status of plants. A means of monitoring plant status is to observe and quantify plant phenology. We collected phenology and live fuel moisture data from two counties in Southern California over 6 years and analyzed the relationship in the context of LFM thresholds of wildfire risk used by ecologists and the US Forest Service.
Results/Conclusions
We found a potential method for estimating LFM by observing the reproductive phenology of a widespread shrub, Adenostoma fasciculatum, in California. By tracking the transition from flowering to fruit ripening, one can reasonably predict the LFM of a stand of shrubs. A robust relationship between LFM and reproductive phenology (p <0.001, adjusted r2 = 0.63) allows for rapid assessment of plant flammability with the potential for large spatial coverage. With simple observations of reproductive phenology, on-the-ground measurements can occur quickly and cover large areas. Our results present an opportunity for expanding our understanding of LFM patterns across landscapes and can aid fire management decisions in California and throughout wildfire-prone regions.