HR: 1340h
AN: B33E-1096    [Abstracts]
TI: Post-fire Changes in Surface Albedo Associated With Vegetation Succession in Boreal Forest Ecosystems
AU: * Lyons, E A
EM: elyons@uci.edu
AF: University of California, Irvine, Croul Hall, Dept. of ESS, Irvine, CA 92697 United States
AU: Jin, Y
EM: yufang@uci.edu
AF: University of California, Irvine, Croul Hall, Dept. of ESS, Irvine, CA 92697 United States
AU: Randerson, J T
EM: jranders@uci.edu
AF: University of California, Irvine, Croul Hall, Dept. of ESS, Irvine, CA 92697 United States
AB: Fire influences surface albedo in boreal regions through several different mechanisms. In post-fire ecosystems, loss of the canopy overstory leads to greater snow cover and higher surface albedos during spring. Also, grasses and deciduous trees that tend to establish in early and intermediate stages of succession have a more reflective canopy than mature black spruce ecosystems. The persistence of these effects is not well known and is important for understanding how changes in boreal disturbance regimes influence climate. Our objective was to assess long-term effects of boreal fire on surface albedo using remote sensing observations. In our analysis, we used MODIS albedo data from the years 2000 through 2004 from interior Alaska. Burn perimeters from 1950 through 2003 were identified by using the Alaska Fire History, 1950-2004, GIS Database. In the first decade after fire, spring albedo (March and April) increased by 0.165 as compared with unburned areas that served as a control. Summer albedo (June and July) shows an initial decrease of 0.023, which recovers in five years, followed by an increase of 0.025. Spring albedo reaches its maximum at nine years since fire while the summer albedo maximum is at 20 years. Both spring and summer albedos recover to pre-fire levels in 49 to 51 years. When converted to radiative forcing, these sustained increases in both summer and winter albedo could offset the heating from greenhouse gasses released during the fire.
DE: 0480 Remote sensing
SC: Biogeosciences [B]
MN: Fall Meeting 2005