HR: 1340h
AN: B43D-1605    [Abstracts]
TI: Carbon Consequences of Positive NDVI Anomalies in North America
AU: * Neigh, C S
EM: neigh@gsfc.nasa.gov
AF: Hydrospheric and Biospheric Processes Laboratory, NASA, Goddard Space Flight Center, Code 614.4, Bldg 33, Greenbelt, MD 20771, United States
AU: * Neigh, C S
EM: neigh@gsfc.nasa.gov
AF: Department of Geography, University of Maryland, College Park, LeFrak Hall, College Park, MD 20741, United States
AU: * Neigh, C S
EM: neigh@gsfc.nasa.gov
AF: Science Systems Application Inc., 10210 Greenbelt Road, Suite 600, Lanham, MD 20706, United States
AU: Carvalhais, N
EM: ncarvalhais@gmail.com
AF: Department of Environmental Science and Engineering, New University of Lisbon, Lisbon, 1600-500, Portugal
AU: Collatz, G J
EM: jcollatz@biome2.gsfc.nasa.gov
AF: Hydrospheric and Biospheric Processes Laboratory, NASA, Goddard Space Flight Center, Code 614.4, Bldg 33, Greenbelt, MD 20771, United States
AB: We present a modeling approach to investigate the carbon consequences of ecosystem disturbance and land cover dynamics in regions of increasing NDVI in North America, which have altered terrestrial patterns of net ecosystem productivity from 1982-2005. Terrestrial carbon fixation and respiration is substantially affected by components of global change (e.g. land cover land use change, and changes in climate variables e.g. warming and drying). The Carnigie-Ames-Stanford approach (CASA) Biosphere model was run on a monthly time interval to simulate seasonal patterns in net plant carbon fixation, biomass and nutrient allocation, litterfall, soil nitrogen mineralization, and microbial CO2 production. CASA is a bucket type model, which allocates carbon between pools based on logarithmic scalars derived from in situ studies of terrestrial mechanistic processes. Carbon was reallocated between pools based on anthropogenic and abiotic disturbances identified with ancillary and remote sensing data (Landsat, Ikonos, aerial photography, agriculture production statistics, and fire and logging data). We developed modules for CASA and simulated expansion of irrigated agriculture, logging and subsequent recovery, warming in the northern latitudes, and fire with subsequent recovery. Simulations with modules initiated predicted altered carbon allocation in ecosystems with disturbance, and sequestration increased in some of our selected study sites during the 24 year (1982-2005) period while others experienced increased soil respiration. The regions investigated represent spatially complex transient pools of carbon in North America vegetation altered by abiotic and anthropogenic land cover conversions which contributed to the terrestrial Northern Hemisphere sink.
DE: 0414 Biogeochemical cycles, processes, and modeling (0412, 0793, 1615, 4805, 4912)
DE: 0429 Climate dynamics (1620)
DE: 0439 Ecosystems, structure and dynamics (4815)
DE: 0466 Modeling
DE: 0480 Remote sensing
SC: Biogeosciences [B]
MN: 2007 Fall Meeting