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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 FROM AUTHOR]

Climate change may affect temperature, precipitation, snowpack, and fire in the Sierra Nevada, and the effects on various park resources may range from moderate to extreme. But any level of change has ramifications for the day-to-day work of park managers. One technique used by climate scientists and ecologists is dissecting interannual variability into normal and extreme components (i.e., warmer/cooler and wetter/drier) years and comparing differences between those categories. Because the natural range of variability of climate parameters in the Sierra Nevada is larger than recent trends, recent historical highs and lows give us insight into future conditions. Timing of snowpack melt is a key attribute that varies between hot and cool years, and interannual differences in the timing of snowmelt have been shown to have a significant association with fire activity as well as the amount of vegetation converted to smoke and greenhouse gases by fire. This article reviews the implications of these changes for fire management in the context of our current understanding of climate, historical fire suppression, fire frequency, fire severity, and the effects of climate and fire on air quality. We explore positive feedbacks among climate, fire, and air quality that may threaten forests and forest carbon stocks in the Sierra Nevada. We also discuss the potential importance of fire management as a part of an integrated NPS climate response strategy for mitigating threats to air quality, fire ecology, and carbon stock stability as the projected climate changes become manifest. [ABSTRACT FROM AUTHOR]