Spectral vegetation indices for estimating shrub cover, green phytomass and leaf turnover in a sedge-shrub tundra
Abstract:Using field observations, we determined the relationships between spectral indices and the shrub ratio, green phytomass and leaf turnover of a sedge-shrub tundra community in the Arctic National Wildlife Refuge, Alaska, USA. We established a 50-m × 50-m plot (69.73°N 143.62°W) located on a floodplain of the refuge. The willow shrub (Salix lanata) and sedge (Carex bigelowii) dominated the plot vegetation. In July to August 2007, we established ten 0.5-m × 0.5-m quadrats on both shrub-covered ground (shrub quadrats) and on ground with no shrubs (sedge quadrats). The shrub ratio was more strongly correlated with the normalized difference vegetation index (NDVI, R2 of 0.57) than the normalized difference infrared index (NDII), the soil-adjusted vegetation index (SAVI) or the enhanced vegetation index (EVI). On the other hand, for both green phytomass and leaf turnover, the strongest correlation was with NDII (R 2 of 0.63 and 0.79, respectively).
Document Type: Research Article
Affiliations: 1: Institute of Low Temperature Science, Hokkaido University, W8 N19, Kita-ku, Sapporo 060-0819, Japan 2: International Arctic Research Center, University of Alaska Fairbanks, Fairbanks, Alaska, 99775-7340, USA 3: Graduate School of Environmental Science, Hokkaido University, W5 N10, Kita-ku, Sapporo 060-0810, Japan
Publication date: 2009-01-01