A JFSP Fire Science Exchange Network
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Multi-scale analysis of fire effects in alpine treeline ecotones

Date: November 12, 2015
Presenter(s): C. Alina Cansler
Description: Although direct effects of climate change have been studied though observational and experimental methods in alpine treeline ecotones (ATEs), indirect effects due to shifts in disturbance regimes have received less attention, despite evidence that the frequency and extent of large disturbances are increasing in many other ecosystems. At a regional scale, I analyzed wildfires occurring over a 29-year period (1984-2012) in ATEs in eight mountainous ecoregions of the Pacific Northwest and Northern Rocky Mountains. At a local scale, I examined variability in fire severity and changes in plant structure, using data from >500 plots within four alpine treeline ecotones sites in the Cascade Range and Northern Rocky Mountains, which had burned 18-27 years prior. Non-forested areas were less likely to burn and fire increased the proportion of nonforested area. Greater fire severity decreased the abundance of larger, relative to smaller, overstory trees; the latter suffered greater mortality. Of the four common high-elevation tree species observed in burned plots, Abies lasiocarpa had the highest rates of mortality (60%), Larix lyallii had the lowest rate (11%), with intermediate levels in Pinus albicaulis (52%) and Picea engelmannii (37%).
Topic(s): Fire Effects, Ecological - Second Order, Vegetation
Ecosystem(s): Alpine forest/krummholz, Subalpine wet spruce-fir forest, Subalpine dry spruce-fir forest
Type: Webinar
NRFSN number: 14333
Record updated: Jun 29, 2016