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Evaluating multiple causes of persistent low microwave backscatter from Amazon forests after the 2005 drought
Amazonia has experienced large-scale regional droughts that affect forest productivity and biomass stocks. Space-borne remote sensing provides basin-wide data on impacts of meteorological anomalies, an important complement to relatively limited ground observations across the Amazon’s vast and remote...
Autores principales: | , , , , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Public Library of Science
2017
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5584941/ https://www.ncbi.nlm.nih.gov/pubmed/28873422 http://dx.doi.org/10.1371/journal.pone.0183308 |
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author | Frolking, Steve Hagen, Stephen Braswell, Bobby Milliman, Tom Herrick, Christina Peterson, Seth Roberts, Dar Keller, Michael Palace, Michael |
author_facet | Frolking, Steve Hagen, Stephen Braswell, Bobby Milliman, Tom Herrick, Christina Peterson, Seth Roberts, Dar Keller, Michael Palace, Michael |
author_sort | Frolking, Steve |
collection | PubMed |
description | Amazonia has experienced large-scale regional droughts that affect forest productivity and biomass stocks. Space-borne remote sensing provides basin-wide data on impacts of meteorological anomalies, an important complement to relatively limited ground observations across the Amazon’s vast and remote humid tropical forests. Morning overpass QuikScat Ku-band microwave backscatter from the forest canopy was anomalously low during the 2005 drought, relative to the full instrument record of 1999–2009, and low morning backscatter persisted for 2006–2009, after which the instrument failed. The persistent low backscatter has been suggested to be indicative of increased forest vulnerability to future drought. To better ascribe the cause of the low post-drought backscatter, we analyzed multiyear, gridded remote sensing data sets of precipitation, land surface temperature, forest cover and forest cover loss, and microwave backscatter over the 2005 drought region in the southwestern Amazon Basin (4°-12°S, 66°-76°W) and in adjacent 8°x10° regions to the north and east. We found moderate to weak correlations with the spatial distribution of persistent low backscatter for variables related to three groups of forest impacts: the 2005 drought itself, loss of forest cover, and warmer and drier dry seasons in the post-drought vs. the pre-drought years. However, these variables explained only about one quarter of the variability in depressed backscatter across the southwestern drought region. Our findings indicate that drought impact is a complex phenomenon and that better understanding can only come from more extensive ground data and/or analysis of frequent, spatially-comprehensive, high-resolution data or imagery before and after droughts. |
format | Online Article Text |
id | pubmed-5584941 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2017 |
publisher | Public Library of Science |
record_format | MEDLINE/PubMed |
spelling | pubmed-55849412017-09-15 Evaluating multiple causes of persistent low microwave backscatter from Amazon forests after the 2005 drought Frolking, Steve Hagen, Stephen Braswell, Bobby Milliman, Tom Herrick, Christina Peterson, Seth Roberts, Dar Keller, Michael Palace, Michael PLoS One Research Article Amazonia has experienced large-scale regional droughts that affect forest productivity and biomass stocks. Space-borne remote sensing provides basin-wide data on impacts of meteorological anomalies, an important complement to relatively limited ground observations across the Amazon’s vast and remote humid tropical forests. Morning overpass QuikScat Ku-band microwave backscatter from the forest canopy was anomalously low during the 2005 drought, relative to the full instrument record of 1999–2009, and low morning backscatter persisted for 2006–2009, after which the instrument failed. The persistent low backscatter has been suggested to be indicative of increased forest vulnerability to future drought. To better ascribe the cause of the low post-drought backscatter, we analyzed multiyear, gridded remote sensing data sets of precipitation, land surface temperature, forest cover and forest cover loss, and microwave backscatter over the 2005 drought region in the southwestern Amazon Basin (4°-12°S, 66°-76°W) and in adjacent 8°x10° regions to the north and east. We found moderate to weak correlations with the spatial distribution of persistent low backscatter for variables related to three groups of forest impacts: the 2005 drought itself, loss of forest cover, and warmer and drier dry seasons in the post-drought vs. the pre-drought years. However, these variables explained only about one quarter of the variability in depressed backscatter across the southwestern drought region. Our findings indicate that drought impact is a complex phenomenon and that better understanding can only come from more extensive ground data and/or analysis of frequent, spatially-comprehensive, high-resolution data or imagery before and after droughts. Public Library of Science 2017-09-05 /pmc/articles/PMC5584941/ /pubmed/28873422 http://dx.doi.org/10.1371/journal.pone.0183308 Text en https://creativecommons.org/publicdomain/zero/1.0/ This is an open access article, free of all copyright, and may be freely reproduced, distributed, transmitted, modified, built upon, or otherwise used by anyone for any lawful purpose. The work is made available under the Creative Commons CC0 (https://creativecommons.org/publicdomain/zero/1.0/) public domain dedication. |
spellingShingle | Research Article Frolking, Steve Hagen, Stephen Braswell, Bobby Milliman, Tom Herrick, Christina Peterson, Seth Roberts, Dar Keller, Michael Palace, Michael Evaluating multiple causes of persistent low microwave backscatter from Amazon forests after the 2005 drought |
title | Evaluating multiple causes of persistent low microwave backscatter from Amazon forests after the 2005 drought |
title_full | Evaluating multiple causes of persistent low microwave backscatter from Amazon forests after the 2005 drought |
title_fullStr | Evaluating multiple causes of persistent low microwave backscatter from Amazon forests after the 2005 drought |
title_full_unstemmed | Evaluating multiple causes of persistent low microwave backscatter from Amazon forests after the 2005 drought |
title_short | Evaluating multiple causes of persistent low microwave backscatter from Amazon forests after the 2005 drought |
title_sort | evaluating multiple causes of persistent low microwave backscatter from amazon forests after the 2005 drought |
topic | Research Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5584941/ https://www.ncbi.nlm.nih.gov/pubmed/28873422 http://dx.doi.org/10.1371/journal.pone.0183308 |
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