Post-Fire Canopy Height Recovery in Canada’s Boreal Forests Using Airborne Laser Scanner (ALS)

Abstract

Canopy height data collected with an airborne laser scanner (ALS) flown across unmanaged parts of Canada’s boreal forest in the summer of 2010 were used—as stand-alone data—to derive a least-squares polynomial (LSPOL) between presumed post-fire recovered canopy heights and duration (in years) since fire (<em>YSF</em>). Flight lines of the > 25,000-km ALS survey intersected 163 historic fires with a known day of detection and fire perimeter. A sequential statistical testing procedure was developed to separate post-fire recovered canopy heights from pre-fire canopy heights. Of the 153 fires with > 5 <em>YSF</em>, 121 cases (89%) could be resolved to a complete or partial post-fire canopy replacement. The estimated LSPOL can be used to estimate post-fire aboveground biomass and carbon sequestration in areas where alternative information is dated or absent. These LIDAR derived findings are especially useful as existing growth information is largely developed for higher productivity ecosystems and not applicable to these ecosystems subject to large wildfires.

Keywords

• airborne laser scanner
• forest fire
• canopy height distribution
• unimodality
• k-means clustering
• aboveground biomass
• carbon sequestration