Thursday, April 09, 2015, 4:30PM - 5:30PM
RL-1 room 269
Watching the needles fall: Quantifying canopy change with forest mortality using the remote sensing of snow
Aggressive outbreaks of bark beetles have killed over 600,000 km2 of forest across North America since the 1990s, with wide impacts on hydrologic processes, the carbon cycle, timber production, wildlife, recreation, and an estimated annual economic impact of $1.5 billion. Though spread of the mountain pine beetle has slowed, spruce beetle impacts are growing, with new colonization on 875 km2 of Colorado forest in 2013 alone, and threatening to reach epidemic levels. New methods of identifying this forest mortality are needed. The primary database for beetle impacts is currently the Aerial Detection Survey, compiled by the Forest Service for management purposes by flying helicopters over areas with known impact with skilled observers, who estimate extent and density of beetle-killed trees. This research quantifies canopy extent, and change, with the remote sensing of fractional snow covered area (FSCA) from NASA's Moderate Resolution Imaging Spectroradiometer (MODIS) snow covered area and grain size (MODSCAG) algorithm. Snow cover gives a white backdrop to the forest canopy; FSCA is analogous to the viewable gap fraction (VGF), or fraction of ground surface visible to a satellite. Signature differences in annual time series of FSCA allow quantification of canopy mortality.