Biomass and leaf-area index maps derived from SPOT images for Toolik Lake and Imnavait Creek areas, Alaska
Abstract A new emphasis on understanding natural systems at large spatial scales has led to an interest in deriving ecological variables from satellite reflectance images. The normalized difference vegetation index (NDVI) is a measure of canopy greenness that can be derived from reflectances at near...
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Cambridge University Press (CUP)
1995
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Online Access: | http://dx.doi.org/10.1017/s0032247400013644 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0032247400013644 |
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crcambridgeupr:10.1017/s0032247400013644 2024-09-15T18:31:20+00:00 Biomass and leaf-area index maps derived from SPOT images for Toolik Lake and Imnavait Creek areas, Alaska Shippert, Margaret M. Walker, Donald A. Auerbach, Nancy A. Lewis, Brad E. 1995 http://dx.doi.org/10.1017/s0032247400013644 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0032247400013644 en eng Cambridge University Press (CUP) https://www.cambridge.org/core/terms Polar Record volume 31, issue 177, page 147-154 ISSN 0032-2474 1475-3057 journal-article 1995 crcambridgeupr https://doi.org/10.1017/s0032247400013644 2024-07-17T04:02:17Z Abstract A new emphasis on understanding natural systems at large spatial scales has led to an interest in deriving ecological variables from satellite reflectance images. The normalized difference vegetation index (NDVI) is a measure of canopy greenness that can be derived from reflectances at near-infrared and red wavelengths. For this study we investigated the relationships between NDVI and leaf-area index (LAI), intercepted photosynthetically active radiation (IPAR), and biomass in an Arctic tundra ecosystem. Reflectance spectra from a portable field spectrometer, LAI, IPAR, and biomass data were collected for 180 vegetation samples near Toolik Lake and Imnavait Creek, Alaska, during July and August 1993. NDVI values were calculated from red and near-infrared reflectances of the field spectrometer spectra. Strong linear relationships are seen between mean NDVI for major vegetation categories and mean LAI and biomass. The relationship between mean NDVI and mean IPAR for these categories is not significant. Average NDVI values for major vegetation categories calculated from a SPOT image of the study area were found to be highly linearly correlated to average field NDVI measurements for the same categories. This indicates that in this case it is appropriate to apply equations derived for field-based NDVI measurements to NDVI images. Using the regression equations for those relationships, biomass and LAI images were calculated from the SPOT NDVI image. The resulting images show expected trends in LAI and biomass across the landscape. Article in Journal/Newspaper Polar Record Tundra Alaska Cambridge University Press Polar Record 31 177 147 154 |
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Open Polar |
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Cambridge University Press |
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crcambridgeupr |
language |
English |
description |
Abstract A new emphasis on understanding natural systems at large spatial scales has led to an interest in deriving ecological variables from satellite reflectance images. The normalized difference vegetation index (NDVI) is a measure of canopy greenness that can be derived from reflectances at near-infrared and red wavelengths. For this study we investigated the relationships between NDVI and leaf-area index (LAI), intercepted photosynthetically active radiation (IPAR), and biomass in an Arctic tundra ecosystem. Reflectance spectra from a portable field spectrometer, LAI, IPAR, and biomass data were collected for 180 vegetation samples near Toolik Lake and Imnavait Creek, Alaska, during July and August 1993. NDVI values were calculated from red and near-infrared reflectances of the field spectrometer spectra. Strong linear relationships are seen between mean NDVI for major vegetation categories and mean LAI and biomass. The relationship between mean NDVI and mean IPAR for these categories is not significant. Average NDVI values for major vegetation categories calculated from a SPOT image of the study area were found to be highly linearly correlated to average field NDVI measurements for the same categories. This indicates that in this case it is appropriate to apply equations derived for field-based NDVI measurements to NDVI images. Using the regression equations for those relationships, biomass and LAI images were calculated from the SPOT NDVI image. The resulting images show expected trends in LAI and biomass across the landscape. |
format |
Article in Journal/Newspaper |
author |
Shippert, Margaret M. Walker, Donald A. Auerbach, Nancy A. Lewis, Brad E. |
spellingShingle |
Shippert, Margaret M. Walker, Donald A. Auerbach, Nancy A. Lewis, Brad E. Biomass and leaf-area index maps derived from SPOT images for Toolik Lake and Imnavait Creek areas, Alaska |
author_facet |
Shippert, Margaret M. Walker, Donald A. Auerbach, Nancy A. Lewis, Brad E. |
author_sort |
Shippert, Margaret M. |
title |
Biomass and leaf-area index maps derived from SPOT images for Toolik Lake and Imnavait Creek areas, Alaska |
title_short |
Biomass and leaf-area index maps derived from SPOT images for Toolik Lake and Imnavait Creek areas, Alaska |
title_full |
Biomass and leaf-area index maps derived from SPOT images for Toolik Lake and Imnavait Creek areas, Alaska |
title_fullStr |
Biomass and leaf-area index maps derived from SPOT images for Toolik Lake and Imnavait Creek areas, Alaska |
title_full_unstemmed |
Biomass and leaf-area index maps derived from SPOT images for Toolik Lake and Imnavait Creek areas, Alaska |
title_sort |
biomass and leaf-area index maps derived from spot images for toolik lake and imnavait creek areas, alaska |
publisher |
Cambridge University Press (CUP) |
publishDate |
1995 |
url |
http://dx.doi.org/10.1017/s0032247400013644 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0032247400013644 |
genre |
Polar Record Tundra Alaska |
genre_facet |
Polar Record Tundra Alaska |
op_source |
Polar Record volume 31, issue 177, page 147-154 ISSN 0032-2474 1475-3057 |
op_rights |
https://www.cambridge.org/core/terms |
op_doi |
https://doi.org/10.1017/s0032247400013644 |
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Polar Record |
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31 |
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177 |
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147 |
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154 |
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1810472955926282240 |