JFSP Fire Science Exchange Network
Although fuels treatments are generally shown to be effective at reducing fire severity, there is widespread interest in monitoring that efficacy as the climate continues to warm and the incidence of extreme fire weather increases. This paper compared basal area mortality across adjacent treated and untreated sites in the 2021 Dixie Fire of California’s Sierra Nevada.
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Read MoreAlthough vegetation types other than conifer forests make up the majority of burned area in California wildfires, relatively few studies quantify the drivers and patterns of vegetation change in these ecosystems. The impacts of fire exclusion on non-conifer systems remain poorly understood, and the relative influence of fuels compared to factors like climate change or type conversion on fire behavior is largely unknown. To address this knowledge gap, the authors investigated large-scale vegetation change as a possible driver of current trends in fire behavior within mixed-hardwood and shrub-dominated ecosystems in central and coastal Northern California.
Read MoreGiant sequoia (Sequoiadendron giganteum) regeneration is reliant on local surface fires, where episodic pulses of heat desiccate and open their cones, releasing seed onto bare mineral soil. Historically, these fires were characterized as ‘mixed severity’, composed of a large matrix that burned at low or moderate severity interspersed with small forest gaps created by local high severity fire. While sequoia regeneration can flourish within these small, high severity gaps,recent ‘megafires’ have produced unprecedentedly large patches of high severity, where the majority of sequoias as killed. This research aims to help resource managers determine whether and where to replant giant sequoia after high severity wildfire.
Read MoreIdentification and conservation of mature and old-growth forests has become a federal government priority. In California’s Sierra Nevada’s most of the remaining large trees are concentrated on Forest Service and National Park Service lands. We used airborne lidar data to census large (≥30” diameter at breast height (DBH)) and very large (≥40”) trees across three large Sierra landscapes. We found that large trees are either locally absent to rare or are aggregated in stands with 8-20 large trees per acre.
Read MoreThis study explores the effects of historical logging on tree regeneration and successive effects on stand development under a history of fire exclusion. The authors leveraged a silvicultural experiment from the 1920s in the Sierra Nevada mixed-conifer forest of the Stanislaus-Tuolumne Experimental Forest to test if silvicultural objectives of increasing pine stocking rates were met. Combining historical (pre- and post-logging in 1928-1929) and contemporary tree regeneration data along with overstory and microsite conditions, they assessed the impact of logging on pine decline.
Read MoreThis study analyzes tree death in Yosemite National Park and Sequoia/Kings Canyon National Park following the 2012-2016 drought.
Read MoreThis study investigates whether wildfire enables the upslope migration of upper montane conifers into the current range of subalpine conifers in the Sierra Nevada, California.
Read MoreResearchers from Michigan State University and the USFS Fire Behavior Assessment Team used 15 years of immediate pre- and post-fire fuel and wildfire behavior data to identify the role of fire advancement mode and pre-fire environmental drivers (e.g., topography, fire weather, and fuel loadings) on fuel consumption and fire effects in California mixed-conifer forests.
Read MoreIn California’s dry mixed conifer forests, increasingly large high severity wildfires threaten to convert significant areas of forested land into shrub dominated landscapes in the absence of active reforestation, including control of competing vegetation. Previous studies have found that salvage logging and other methods used to prepare a site for reforestation may reduce shrub cover after wildfire. This study investigated the effect of masticated fuel depth on shrub growth where salvage logging and mastication followed high severity wildfire.
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Read MoreThis study uses tree cores gathered at three 4-hectare plots to make inferences about temporal aspects of tree recruitment in pine-dominated ecosystems of the California Sierra Nevada and the Sierra San Petro Martir in northwestern Mexico.
Read MoreIn this paper, the authors quantify change in the extent of mature conifer forests in the southern Sierra Nevada of California during 2011-2020, a decade and ecoregion characterized by compounding severe wildfires and drought follow prolonged fire exclusion.
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Read MoreThis study uses bio-acoustical monitoring to characterize the habitat of mountain quail in the California Sierra Nevada. Findings include that high severity wildfires may promote vegetation structures that are beneficial for mountain quail.
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Read MoreThis study leveraged data collected from 20-year-old forest monitoring plots within fuel treatment units that captured a range of wildfire occurrence (i.e., not burned, burned once, or burned twice) following application of initial thinning treatments and prescribed fire.
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Read MoreA new paper by USGS and partners investigated why some California wildfires are destructive and others are not.
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Read MoreThis synthesis summaries a set of papers the explore the relationship between landscape-level forest resilience and disturbance regimes and provides strategies for the effective forest management of Sierra Nevada mixed-conifer forests
Read MoreIn recent decades white pine blister rust, mountain pine beetle, and fire have increased in extent and caused tree mortality across the western USA. This study used long-term monitoring plots to determine mortality of four white pine species in Sequoia and Kings Canyon National Parks.
Read MoreA recent paper by Scott Stephens and co-authors asserts that conservation of western forests is still possible, and describes sensible, evidence-based strategies to improve forest ecosystem resilience.
Read MoreUnderstanding post-fire tree mortality is important for planning restoration fire treatments that modify fire behavior and effects and models that reflect multiple spatial and temporal scales are effective tools.
Read MoreDo fuel reduction treatments result in restored conditions that align with those found in historically frequent-fire forests of the west? A recent paper sets out to answer that question by examining the principles behind fuel reduction and forest restoration projects and identifying situations where the two approaches align and where they may diverge.
Read MoreThe study used models to predict fire behavior differences according to two primary factors: mid-story density (i.e. the ladder fuel layer) and live fuel moisture. This is relevant for prescribed burns because both of these factors can be modified when conducting burns.
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The California Fire Science Consortium is divided into 4 geographic regions and 1 wildland-urban interface (WUI) team. Statewide coordination of this program is based at UC Berkeley.
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This regional Fire Science Exchange is one of 15 regional fire science exchanges sponsored by Joint Fire Science Program (JFSP).
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