HR: 0800h
AN: B21A-0022    [Abstracts]
TI: Remotely sensed vicennial changes of green phytomass, Salix cover, and leaf turnover in a sedge-shrub tundra, Arctic National Wildlife Refuge, Alaska
AU: * Kushida, K
EM: kkushida@lowtem.hokudai.ac.jp
AF: Institute of Low Temperature Science, Hokkaido University, W 8 N 19, Kita-ku, Sapporo, 060-0819, Japan
AU: Kim, Y
EM: kimyw@iarc.uaf.edu
AF: International Arctic Research Center, University of Alaska Fairbanks, Koyukuk Drive 930, Fairbanks, AK 99775, United States
AU: Tsuyuzaki, S
EM: tsuyu@ees.hokudai.ac.jp
AF: Graduate School of Environmental Science, Hokkaido University, W 5 N 10, Kita-ku, Sapporo, 060-0510, Japan
AU: Watanabe, M
EM: mwatana@cneas.tohoku.ac.jp
AF: Center for Northeast Asian Studies, Tohoku University, Kawauchi 41, Aoba-ku, Sendai, 980-8576, Japan
AU: Kadosaki, G
EM: kadosaki.gaku@jaxa.jp
AF: Earth Observation Research Center, Japan Aerospace Exploration Agency, Sengen 2-1-1, Tsukuba, 305-8505, Japan
AU: Sawada, Y
EM: ysawada@lowtem.hokudai.ac.jp
AF: Institute of Low Temperature Science, Hokkaido University, W 8 N 19, Kita-ku, Sapporo, 060-0819, Japan
AU: Ishikawa, M
EM: mishi@ees.hokudai.ac.jp
AF: Graduate School of Environmental Science, Hokkaido University, W 5 N 10, Kita-ku, Sapporo, 060-0510, Japan
AU: Fukuda, M
EM: mfukuda@lowtem.hokudai.ac.jp
AF: Institute of Low Temperature Science, Hokkaido University, W 8 N 19, Kita-ku, Sapporo, 060-0819, Japan
AB: We obtained the relationship between spectral indices, green phytomass, Salix - non-Salix ratio, and leaf turnover in a sedge-shrub tundra, Arctic National Wildlife Refuge (ANWR), Alaska based on the field observations of spectral reflectance and phytomass, and we used Landsat TM images acquired in July of 1986, 1994, and 2006 and the time series of NOAA AVHRR (Advanced Very High Resolution Radiometer) for evaluating the vicennial changes. 51% of Beaufort coastal plain, Alaska was occupied by lowland moist sedge-shrub tundra, lowland wet sedge tundra, riverine moist sedge-shrub tundra, and riverine wet sedge tundra, where willow shrubs and sedges dominate. We set a 50-m × 50-m plot located on the floodplain of Jago River in ANWR. Shrub (Salix lanata L.) and sedge (Carex bigelowii Torr.) dominated in the plot. Ten 0.5-m × 0.5-m quadrates (Salix} quadrates) were set on the Salix cover and ten 0.5-m × 0.5-m quadrates (non-Salix quadrates) were set on the ground that was not covered with Salix lanata. Salix lanata in each of the Salix quadrates was harvested, and the leaf area index (LAI) and the oven-dried weights of the photosynthetic (leaf) and non-photosynthetic parts were measured. After harvesting Salix, other green plants were harvested and the oven-dried weights of the plants were measured. The Salix quadrates were spectrally measured with a spectroradiometer at a wavelength of 350 - 2500 nm before and after harvesting Salix and after harvesting other green plants. Non-Salix quadrates were also spectrally measured with the spectroradiometer. The coefficients of determination (R²) of the green phytomass, Salix - non-Salix ratio, and leaf turnover estimations from the spectral indices were 0.63, 0.57, and 0.79, respectively. These estimations were used for evaluating the vicennial changes using the satellite data.
DE: 0428 Carbon cycling (4806)
DE: 0439 Ecosystems, structure and dynamics (4815)
DE: 0475 Permafrost, cryosphere, and high-latitude processes (0702, 0716)
DE: 0476 Plant ecology (1851)
DE: 0480 Remote sensing
SC: Biogeosciences [B]
MN: 2007 Fall Meeting