HR: 14:10h
AN: B43F-03    [Abstracts]
TI: The impact of woody plant proliferation on the regional carbon budget in central Oregon
AU: * XIAO, J
EM: jfxiao@email.unc.edu
AF: Department of Geography, University of North Carolina at Chapel Hill, Saunders Hall, Rm 320, Chapel Hill, NC 27599-3220 United States
AU: MOODY, A
EM: aaronm@email.unc.edu
AF: Department of Geography, University of North Carolina at Chapel Hill, Saunders Hall, Rm 320, Chapel Hill, NC 27599-3220 United States
AB: The abundance of woody plants has increased substantially in US savannas, shrublands, and grasslands during the last 150 years. Woody plant proliferation may lead to significant accumulation of carbon in woody biomass, and thus may contribute to the overall US carbon sink. Woody plant proliferation has been documented in the western US, primarily at local scales. The size and distribution of the carbon sink resulting from woody plant proliferation remain uncertain. We investigated the expansion of western juniper in central Oregon and its carbon consequences by combining satellite data and field measurements. We used spectral mixture analysis to estimate percent woody cover from Landsat data for the middle 1970s, the late 1970s, and the early 2000s. The results indicate that the abundance of western juniper has significantly expanded during the past three decades in central Oregon. A pixel-level relationship between total aboveground biomass and canopy cover was developed based on a forest inventory database and field measurements. This pixel relationship was used to estimate carbon stocks in woody biomass from estimates of percent woody cover derived from satellite data. The carbon stocks in woody biomass have significantly increased in central Oregon during the past three decades due to the expansion of western juniper. Our study examined the rates and carbon consequences of woody plant proliferation at a regional scale. Woody plant proliferation has important implications for regional carbon budgets in semi-arid regions.
DE: 0414 Biogeochemical cycles, processes, and modeling (0412, 0793, 1615, 4805, 4912)
DE: 0428 Carbon cycling (4806)
DE: 0439 Ecosystems, structure and dynamics (4815)
DE: 0480 Remote sensing
SC: Biogeosciences [B]
MN: Fall Meeting 2005