Fugen Dou1, Xian Yu2, Chien-lu Ping3, Laodong Guo4, Torre Jorgenson5, and Gary Michaelson3. (1) International Arctic Research Center, 930 Koyukuk Dr., Fairbanks, AK 99775, (2) Department of Mathmatics and Statistics, University of Alaska Fairbanks, 513 Ambler Lane, Fairbanks, AK 99775, (3) University of Alaska-Fairbanks, 533 E Fireweed, Palmer, AK 99645, (4) University of Southern Mississippi, 1020 Balch Blvd. Stennis Space Center, Pearl River, MS 39529-9904, (5) ABR. Inc., Fairbanks, AK 99708
SPATIAL ANALYSIS OF
SOIL ORGANIC CARBON ALONG THE COASTLINE OF NORTHERN ALASKA
Abstract
Coastal erosion plays an
important role in the terrestrial-marine-atmosphere carbon cycle. A total of 268
soil samples, from 48 sites along over 1800-km of coastline in northern Alaska, were collected during the summers of 2005
and 2006. A geographic information
system (GIS) and a geostatistical method (ordinary kriging) were coupled to investigate the spatial variation
of soil organic carbon (SOC) along the coastline. SOC had a large variation
ranging from 0.8 in the river delta to 187.4 kg C m-2 in high bluffs
of organic rich tundra soils. Compared to a 1-D model or a 1-D model using a
shortcut distance, a 2-D model was more suitable to describe SOC content along
the coastline. A Gaussian variogram model was used
because it has less prediction errors than other examined geostatistical
models. The results indicate that soils of the northwestern coastline stored
greater amounts of SOC than those of the northeastern coastline. The estimation
of total SOC along the coastline of northern Alaska was 6.86 x107 kg m-1.
The prediction errors indicated that greater errors were observed in both ends
of the coastline than were observed in other sections, although the range was
from 0.739 to 0.779. Our study suggests that the isotropic 2-D model (Gaussian correlation structure) is a useful
tool for investigating SOC in large scale.
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