NDVI, biomass, and landscape evolution of glaciated terrain in northern Alaska
Abstract The patterns of the normalized difference vegetation index (NDVI) on three glacial surfaces of different ages in the vicinity of Toolik Lake, Alaska, were examined. NDVI was derived from SPOT multispectral digital data, and the images were stratified according to boundaries on glacial geolo...
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Cambridge University Press (CUP)
1995
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Online Access: | http://dx.doi.org/10.1017/s003224740001367x https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S003224740001367X |
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crcambridgeupr:10.1017/s003224740001367x 2024-06-23T07:50:47+00:00 NDVI, biomass, and landscape evolution of glaciated terrain in northern Alaska Walker, D.A. Auerbach, N.A. Shippert, M.M. 1995 http://dx.doi.org/10.1017/s003224740001367x https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S003224740001367X en eng Cambridge University Press (CUP) https://www.cambridge.org/core/terms Polar Record volume 31, issue 177, page 169-178 ISSN 0032-2474 1475-3057 journal-article 1995 crcambridgeupr https://doi.org/10.1017/s003224740001367x 2024-06-12T04:05:00Z Abstract The patterns of the normalized difference vegetation index (NDVI) on three glacial surfaces of different ages in the vicinity of Toolik Lake, Alaska, were examined. NDVI was derived from SPOT multispectral digital data, and the images were stratified according to boundaries on glacial geology and vegetation maps. Ground-level measurements of NDVI from common vegetation types were also collected, using a portable spectrometer. Late Pleistocene glacial surfaces have lower image-NDVI than older Middle Pleistocene surfaces, and the mean NDVI is correlated with approximate time since deglaciation. The trends are related to differences in NDVI associated with vegetation growing on mineral vs peaty substrates. Nonacidic mineral substrates are more common on the younger landscapes, and acidic peaty soils are more common on the older surfaces. The field-NDVIs of acidic dry, moist, and wet tundra are consistently higher than those of corresponding nonacidic tundra types. These same trends are seen when the SPOT NDVI image is stratified according to vegetation boundaries appearing on two detailed vegetation maps in the region. Above-ground biomass of moist and wet acidic tundra is significantly greater than corresponding nonacidic types. Vegetation species composition was examined along two transects on the oldest and youngest glacial surfaces. Shrub cover is the most important factor affecting the spectral signatures and biomass. Older surfaces have greater cover of shrub-rich tussock tundra and shrub-filled water tracks, and the younger surfaces have more dry, well-drained sites with low biomass and relatively barren nonsorted circles and stripes. These trends are related to paludification and modification of the terrain by geomorphic and geochemical processes. Similar patterns of spectral reflectance have been noted in association with a variety of large-scale natural disturbances in northern Alaska. However, extrapolation of these results to much broader regions of the circumpolar Arctic will require the use ... Article in Journal/Newspaper Arctic Polar Record Tundra Alaska Cambridge University Press Arctic Polar Record 31 177 169 178 |
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Open Polar |
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Cambridge University Press |
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crcambridgeupr |
language |
English |
description |
Abstract The patterns of the normalized difference vegetation index (NDVI) on three glacial surfaces of different ages in the vicinity of Toolik Lake, Alaska, were examined. NDVI was derived from SPOT multispectral digital data, and the images were stratified according to boundaries on glacial geology and vegetation maps. Ground-level measurements of NDVI from common vegetation types were also collected, using a portable spectrometer. Late Pleistocene glacial surfaces have lower image-NDVI than older Middle Pleistocene surfaces, and the mean NDVI is correlated with approximate time since deglaciation. The trends are related to differences in NDVI associated with vegetation growing on mineral vs peaty substrates. Nonacidic mineral substrates are more common on the younger landscapes, and acidic peaty soils are more common on the older surfaces. The field-NDVIs of acidic dry, moist, and wet tundra are consistently higher than those of corresponding nonacidic tundra types. These same trends are seen when the SPOT NDVI image is stratified according to vegetation boundaries appearing on two detailed vegetation maps in the region. Above-ground biomass of moist and wet acidic tundra is significantly greater than corresponding nonacidic types. Vegetation species composition was examined along two transects on the oldest and youngest glacial surfaces. Shrub cover is the most important factor affecting the spectral signatures and biomass. Older surfaces have greater cover of shrub-rich tussock tundra and shrub-filled water tracks, and the younger surfaces have more dry, well-drained sites with low biomass and relatively barren nonsorted circles and stripes. These trends are related to paludification and modification of the terrain by geomorphic and geochemical processes. Similar patterns of spectral reflectance have been noted in association with a variety of large-scale natural disturbances in northern Alaska. However, extrapolation of these results to much broader regions of the circumpolar Arctic will require the use ... |
format |
Article in Journal/Newspaper |
author |
Walker, D.A. Auerbach, N.A. Shippert, M.M. |
spellingShingle |
Walker, D.A. Auerbach, N.A. Shippert, M.M. NDVI, biomass, and landscape evolution of glaciated terrain in northern Alaska |
author_facet |
Walker, D.A. Auerbach, N.A. Shippert, M.M. |
author_sort |
Walker, D.A. |
title |
NDVI, biomass, and landscape evolution of glaciated terrain in northern Alaska |
title_short |
NDVI, biomass, and landscape evolution of glaciated terrain in northern Alaska |
title_full |
NDVI, biomass, and landscape evolution of glaciated terrain in northern Alaska |
title_fullStr |
NDVI, biomass, and landscape evolution of glaciated terrain in northern Alaska |
title_full_unstemmed |
NDVI, biomass, and landscape evolution of glaciated terrain in northern Alaska |
title_sort |
ndvi, biomass, and landscape evolution of glaciated terrain in northern alaska |
publisher |
Cambridge University Press (CUP) |
publishDate |
1995 |
url |
http://dx.doi.org/10.1017/s003224740001367x https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S003224740001367X |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic Polar Record Tundra Alaska |
genre_facet |
Arctic Polar Record Tundra Alaska |
op_source |
Polar Record volume 31, issue 177, page 169-178 ISSN 0032-2474 1475-3057 |
op_rights |
https://www.cambridge.org/core/terms |
op_doi |
https://doi.org/10.1017/s003224740001367x |
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Polar Record |
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31 |
container_issue |
177 |
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169 |
op_container_end_page |
178 |
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1802641703727792128 |