ABSTRACT In Mediterranean‐climate shrublands, fire‐return intervals are decreasing, leading to negative impacts on native communities. Most research on this topic has been conducted on woody species, while little is known about the impacts of increased fire frequency on perennial herbaceous species. Geophytes are an ecologically important floral component, contributing to native diversity and often creating conspicuous postfire floral displays. Our long‐term observations of the chaparral geophyte Toxicoscordion fremontii provide information about its life history while offering insights into potential impacts of altered fire regimes. Over two decades and through two wildfires, we tracked individuals in two sites in Santa Barbara County starting in 1990, when half were burned and the other half unburned. Every year through 1999, we measured plant size and reproduction. After a large wildfire in 2009, when both sites burned, a majority of individuals were relocated and plant traits recorded. Most individuals survived the second fire and are long‐lived—lifespan of plants was at least 44 years and possibly over 85 years. Flowering was essentially restricted to the first spring postfire. Flower production was positively correlated to plant size, suggesting growth between fires is crucial. Fruit set did not increase with floral production, suggesting resource limitation. Although this species is fire‐resilient, more frequent burning could have significant negative consequences. Notably, with less time to accumulate carbohydrates available for postfire flowering, seed output and subsequent seedling establishment would be reduced. We recommend further study, including comparisons of postfire reproduction in populations with varying burn histories.
Tyler et al. (Mon,) studied this question.