Post-fire analysis of Sequoia sempervirens forests on the central coast of California

The public perception of wildfire is that it destroys forests and that all fires should be quickly extinguished. However, fire plays a central role in determining structure, composition, and recruitment in many forest types. In coast redwood forests, the role of fire is not well understood, particularly in the southern part of the range. Observational data suggest that redwoods are relatively unaffected by fire. The sites of three 2008 and 2009 fires were sampled for this study: the Martin Fire in Bonny Doon, California, the Whitehurst Fire near Gilroy, California, and the Lockheed Fire near Swanton, California. Randomly selected ten-meter diameter plots were used to collect data on survivorship and post fire regeneration in order to determine the short-term response of Sequoia sempervirens to fire. Additionally, data were collected on associated tree species in order to compare mortality and regeneration between adjacent forest types. Data collected included mortality, tree height, diameter at breast height, scorch height, percent residual and regenerated canopy cover by species, and the number of basal spouts and seedlings by species. Results indicate that S. sempervirens had the lowest mortality levels, highest crown survival, and greatest regeneration, including canopy regeneration, basal sprouting, and seedling growth of all the species studied. Redwood basal sprouts and redwood seedlings far outnumbered those of associated tree species. However, there was great variability between sites. Variation may be due to differing soils, distance from the ocean, different land uses, fire severity, or a combination of factors

Survival and Recovery Following Wildfire in the Southern Range of the Coast Redwood Forest

Fire plays a central role in determining structure, composition, and recruitment in many forest types. In coast redwood forests, the role of fire is not well understood and scant literature exists on post-fire response, particularly in the southern part of the range. In order to better understand patterns of survival and recruitment following fire for coast redwood (Sequoia sempervirens [lamb. ex D. Don] Endl.) and associated tree species, three sites in the Santa Cruz Mountains, California, USA, were sampled following wildfire. Randomly selected 10 m diameter plots were used to collect data on survivorship and post fire regeneration in order to analyze short-term responses including mortality, crown retention, basal sprouting, canopy regeneration, and seedling production. Results indicated that coast redwood had the lowest percent mortality (11.98 %) and highest mean canopy retention (43.10 %) of all species sampled, followed by Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco) (25.54 %), tanoak (Notholithocarpus densiflorus [Hook. & Arn.] Manos) (23.27 %), combined oak species (Quercus sp.) (6.67 %), and Pacific madrone (Arbutus menziesii Pursh) (4.13 %). In addition, associated species experienced higher survival rates when proximate to coast redwoods. Coast redwood trees also exhibited the highest canopy regeneration (53 %), the highest average density of basal sprouts (3.54 × 104 ha), and the greatest average number of seedlings, ranging from zero to 2.09 × 105seedlings ha-1. Overall, coast redwood appeared to have a balance of fire adaptive features, exceeding all associated species, which allow individual trees to withstand fire, while at the same time promoting recruitment following fire