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Abstract The giant sequoia, a serotinous conifer naturally occurring in mixed‐conifer forests of the southern and central Sierra Nevada, California, USA, is the world's largest tree species. Giant sequoia reproduction has been severely lacking over the past century, due to fire exclusion, creating a significant conservation threat. Previous research on postfire sequoia reproduction in high‐severity fire areas, relative to low‐ and moderate‐severity areas, is limited. At 6 years postfire, we investigated giant sequoia reproduction in a high‐severity fire area, and nearby low‐/mixed‐severity fire areas, in the Nelder Grove, which burned in 2017 in the Railroad fire. Postfire giant sequoia reproduction was positively correlated with fire severity in terms of density, height (growth), and proportion (relative to other conifer species), and sequoia seedling/sapling density was positively correlated with percent shrub cover. There was no correlation between distance to live sequoia seed source and density of sequoia reproduction. More research is needed in other mixed‐severity fire areas, with larger high‐severity fire patches, to determine whether a similar postfire response occurs elsewhere.

ABSTRACT Many at‐risk wildlife species depend upon high‐severity fire patches to create “complex early seral forest” (CESF) land cover, characterized by an abundance of snags, downed logs, shrub patches, and regeneration of trees. However, concern has been expressed about whether high‐severity fire might result in persistent type conversion to nonforest, or from pine (Pinus spp.) dominance to forest predominantly consisting of white fir (Abies concolor), Douglas‐fir (Pseudotsuga menziesii), and incense‐cedar (Calocedrus decurrens), as opposed to heterogeneous natural succession and ephemeral occurrence of CESF. If type conversion is common, it could in time harm other at‐risk species that depend on dense, late‐successional forest for some of their habitat needs. I investigated postfire patterns in high‐severity fire patches within yellow pine (Pinus ponderosa and Pinus jeffreyi) and mixed‐conifer forests in California, USA, using field plots evenly spaced along random transects into the interior of patches within fires that occurred from 1999 to 2013. I found natural conifer regeneration in ≥80% of plots, even >300 m into patches. Conifer regeneration was greater closer to low–moderate‐severity areas. Areas with lower conifer regeneration, where CESF would have the greatest longevity—comprised only 4.6% of these fire areas. Pine species dominated regeneration deeper into the interior of large high‐severity patches, and fir–cedar‐dominated at patch edges. Shrubs did not impede conifer regeneration, but greater densities of conifer saplings reduced shrubs, and sapling growth increased with time‐since‐fire. My findings suggest heterogeneous land‐cover patterns are resulting from natural succession in high‐severity fire patches. © 2018 The Wildlife Society.

ABSTRACT The Pacific fisher (Pekania pennanti) is a rare and imperiled forest carnivore, with a genetically distinct and isolated population living in the southern Sierra Nevada mountains of California, USA. Female fishers are of special interest and concern, given their very small numbers and their disproportionately important role in the potential recovery of the population. Using fisher scat detection to assess patterns of habitat use, I conducted analyses regarding use by fishers of unlogged higher severity fire areas at 10–11 years postfire in the 2002 McNally fire area. Contrary to the prevailing current hypothesis regarding fisher postfire habitat use, fishers did not use higher severity fire areas less than low–moderate‐severity areas or unburned forest (n = 77 scats), and female fishers used the large, intense McNally fire area significantly more than unburned forest (n = 12 scats). Female fishers were detected at multiple locations >250 m into the interior of a very large (>5,000 ha), unlogged higher severity fire patch. These results indicate unlogged higher severity fire areas are suitable habitat for fishers, especially female fishers, and suggest a need to revisit current management direction, which emphasizes extensive commercial thinning and postfire logging to reduce fuels and control fire. © 2015 The Wildlife Society.