HR: 0830h
AN: B11D-0720    [PDF]
TI: Remote Sensing and Modeling of Boreal Forest Regrowth Dynamics
AU: Small, J
EM: jsmall@geog.umd.edu
AF: University of Maryland, Department of Geography, College Park, MD 20742-8225 United States
AU: * Goetz, S J
EM: sgoetz@whrc.org
AF: University of Maryland, Department of Geography, College Park, MD 20742-8225 United States
AU: * Goetz, S J
EM: sgoetz@whrc.org
AF: Woods Hole Research Center, PO Box 296, Woods Hole, MA 02543-0296 United States
AU: Kasischke, E
EM: kk169@umail.umd.edu
AF: University of Maryland, Department of Geography, College Park, MD 20742-8225 United States
AU: Hyer, E
EM: ehyer@geog.umd.edu
AF: University of Maryland, Department of Geography, College Park, MD 20742-8225 United States
AU: Meigs, G W
EM: gmeigs@whrc.org
AF: Woods Hole Research Center, PO Box 296, Woods Hole, MA 02543-0296 United States
AU: Fiske, G W
EM: gfiske@whrc.org
AF: Woods Hole Research Center, PO Box 296, Woods Hole, MA 02543-0296 United States
AB: We are modeling net primary production at high resolution across North America for the time period 1982-2001 on a 10-day interval, and validate the results using an extensive network of compiled and ongoing field measurements. These major determinants of terrestrial carbon dynamics are being analyzed in the context of interannual variability in carbon sequestration by vegetation regrowth across a wide range of burned areas, including intensively studies sites in interior Alaska. The carbon model is driven by AVHRR observational data sets, which we have corrected for orbital drift and various other attenuating factors. The dynamics of vegetation activity and carbon sequestration, as provided by the NPP maps, is being analyzed in the context of linkages between fire, climate, vegetation recovery, and carbon sequestration across the study domain. At the intensively studied sites, measurements of canopy light interception (Fpar), spectral reflectance, and indirect estimates of LAI were made at numerous regrowth sites. Fire severity varied depending on a number of conditions including forest type, topography and site conditions, which affected the regrowth patterns. Aspen, willow, spruce and herbaceous vegetation has regrown in heterogeneous mixtures, heights and densities. Fpar and LAI estimates were made in order to characterize spatial and temporal variability in regrowth and to improve estimates of annual PAR absorption (APAR) at multiple scales, with the intent of modeling net primary production (NPP) from the plot level to Landsat, MODIS and AVHRR resolution. Field measurements were made using a Licor LAI2000, a Decagon model PAR-80 linear ceptometer, "fisheye" photographs, and a set of custom manufactured solar cells which operated nearly continuously through the active growing season. The relationship between the biophysical variables and canopy spectral vegetation indices varies between vegetation types and regrowth stage. The temporal and spatial variability in Fpar and LAI was large across the sites, resulting in a wide range of modeled NPP across scales. The results of these measurements and scaling activities are being assessed in the context of NPP mapping over large areas using satellite estimates of canopy APAR. The linkages between fire disturbance and associated regrowth carbon dynamics have direct relevance numerous ongoing research programs, including the USGCRP North American Carbon Program.
DE: 0315 Biosphere/atmosphere interactions
DE: 0400 Biogeosciences
DE: 1620 Climate dynamics (3309)
DE: 1640 Remote sensing
DE: 1699 General or miscellaneous
SC: Biogeosciences [B]
MN: 2003 Fall Meeting