University of Montana Research Chronicles Forest Recovery After Montana’s 2017 Fire Season
October 24, 2022
Introduction:
(EurekAlert) For a researcher who studies wildfire, University of Montana graduate student Kyra Clark-Wolf couldn’t have had better timing.
Clark-Wolf arrived in Missoula to start her graduate studies on the impacts of wildfires on forests at the W.A. Franke College of Forestry & Conservation on July 4, 2017. Eleven days later, a lightning strike sparked the Lolo Peak Fire just south of the city, burning nearly 54,000 acres and leaving lasting and indelible images among Missoulians of dense smoke and flames visible from town.
The impacts of that fire on the forest, as well as the Sunrise Fire burning at the same time west of Missoula, would go on to be central to Clark-Wolf’s doctoral work. Her findings are shared in two papers, the second recently published in Forest Ecology and Management, a leading journal in her field.
“I was curious once the smoke cleared up what was going on in the forest and what the fires left behind,” she said, “and how the effects of ongoing climate change could change forest recovery.”
With support from her adviser, Philip Higuera, professor and director of UM’s PaleoEcology and Fire Ecology Lab, and Kim Davis, a UM research scientist, Clark-Wolf applied for $25,000 in research funding from the federal Joint Fire Science Program and proposed to study how burned landscapes find life again.
Read more here:
https://www.eurekalert.org/news-releases/968951
Abstract:
(Forest Ecology and Management) Climate warming and an increased frequency and severity of wildfires are expected to transform forest ecosystems, in part through altered post-fire vegetation trajectories. Such a loss of forest resilience to wildfires arises due to a failure to pass though one or more critical demographic stages, or “filters,” including seed availability, germination, establishment, and survival. Here we quantify the relative influence of microclimate and microsite conditions on key stages of post-fire seedling demography in two large, lightning-ignited wildfires from the regionally extensive fire season of 2017 in the northern Rocky Mountains, U.S.A. We tracked conifer seedling density, survival, and growth in the first three years post-fire in 69 plots spanning gradients in fire severity, topography, and climate; all plots were limited to within 100 m of a seed source to assure seed availability. Microclimate conditions were inferred based on measurements in a subset of 46 plots. We found abundant post-fire conifer regeneration, with a median of 2,633 seedlings per hectare after three years, highlighting early resilience to wildfire. This robust regeneration was due in part to moderate post-fire climate conditions, supporting high survivorship (>50% on average) of all seedlings tracked over the study period (n = 763). A statistical model based on variables describing potential seed availability, microclimate, fire severity, understory vegetation, and soil nitrogen availability explained 75% of the variability in seedling density among plots. This analysis highlights the overarching importance of fine-scale heterogeneity in fire effects, which determine microclimate conditions and create diverse microsites for seedlings, ultimately facilitating post-fire tree regeneration. Our study elucidates mechanisms of forest resilience to wildfires and demonstrates the utility of a demographic perspective for anticipating forest responses to future wildfires under changing environmental conditions.
Read more here:
https://www.sciencedirect.com/science/ ... a%3Dihub
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