A JFSP Fire Science Exchange Network
Bringing People Together & Sharing Knowledge in the Northern Rockies

Vegetation recovery since the 2003 wildfires in western Montana

Date: April 28, 2015
Presenter(s): Andrew T. Hudak
Description: Various metrics of vegetation recovery following wildfire are useful measures of ecosystem resilience, yet few studies have quantified vegetation recovery ten or more years post-fire. Conventional wisdom is that recovery time to pre-fire condition will be slower as a function of burn severity but will also vary between forest types. Extensive and severe wildfires in 2003 burned through all western Montana forest types. As part of a rapid response project, we collected field and remotely sensed data immediately post fire, as well as one year later, on the Cooney Ridge, Black Mountain 2, Robert, and Wedge Canyon fires. A decade later, we revisited most field sites to collect repeat measures of vegetation cover and species richness. We also tracked recovery annually using vegetation indices derived from Landsat time series. The LandTrendr approach was applied to reduce Landsat time series indices to measures of the date and magnitude of burn severity as well as the magnitude and duration of vegetation change since disturbance. We found that vegetation ten years later still had not reached pre-fire conditions, but comes closest to doing so in areas of low severity, has farther to go in areas burned at moderate severity, and has farthest to go in high burn severity areas. Thus, the rate of vegetation recovery differs little between severity classes, but the magnitude and duration of vegetation recovery are in proportion to the initial burn severity, which is consistent with a “dose-response” type of relationship. LandTrendr appears to provide a consistent and powerful approach to quantifying disturbance and recovery trajectories over the long term. We conclude that it may be feasible to project recovery rates forward, to predict when sites are expected to be restored to their prefire condition, as a function of initial burn severity, topography, climate, and vegetation type.
Topic(s): Fire Effects, Ecological - Second Order, Vegetation, Fire Regime, Fire Intensity / Burn Severity
Ecosystem(s): None
Type: Webinar
NRFSN number: 14878
Record updated: Jul 31, 2018