| Summary: | Live fuel moisture content (<i>LFMC</i>) is an important metric for fire danger ratings. However, there is limited understanding of the physiological control of <i>LFMC</i> or how it varies among co-occurring species. This is a problem for biodiverse yet fire-prone regions such as southern California. We monitored <i>LFMC</i> and water potential for 11 native woody species, and measured ecophysiological traits related to access to water, plant water status, water use regulation, and drought adaptation to answer: (1) What are the physiological mechanisms associated with changes in <i>LFMC</i>? and (2) How do seasonal patterns of <i>LFMC</i> differ among a variety of shrub species? We found that <i>LFMC</i> varied widely among species during the wet winter months, but converged during the dry summer months. Traits associated with <i>LFMC</i> patterns were those related to access to water, such as predawn and minimum seasonal water potentials (Ψ), and water use regulation, such as transpiration. The relationship between <i>LFMC</i> and Ψ displayed a distinct inflection point. For most species, this inflection point was also associated with the turgor loss point, an important drought-adaptation trait. Other systems will benefit from studies that incorporate physiological mechanisms into determining critical <i>LFMC</i> thresholds to expand the discipline of pyro-ecophysiology.
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