Thawing seasonal ground ice: An important water source for boreal forest plants in Interior Alaska
Abstract Little is known about the ecological impacts of permafrost degradation on water fluxes in boreal ecosystems, such as those in Interior Alaska. Low plant water stress suggests a reliance on a diversity of water sources. In addition to rainfall, we hypothesize that deep soil water derived fro...
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crwiley:10.1002/eco.1796 2024-09-15T18:11:24+00:00 Thawing seasonal ground ice: An important water source for boreal forest plants in Interior Alaska Young‐Robertson, Jessica M. Ogle, Kiona Welker, Jeffrey M. NSF Hydrology NSF Office of Polar Programs postdoctoral NSF Arctic Natural Sciences DOE SciDAC 2017 http://dx.doi.org/10.1002/eco.1796 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Feco.1796 https://onlinelibrary.wiley.com/doi/pdf/10.1002/eco.1796 en eng Wiley http://onlinelibrary.wiley.com/termsAndConditions#vor Ecohydrology volume 10, issue 3 ISSN 1936-0584 1936-0592 journal-article 2017 crwiley https://doi.org/10.1002/eco.1796 2024-08-20T04:16:20Z Abstract Little is known about the ecological impacts of permafrost degradation on water fluxes in boreal ecosystems, such as those in Interior Alaska. Low plant water stress suggests a reliance on a diversity of water sources. In addition to rainfall, we hypothesize that deep soil water derived from thawing seasonal ground ice (TSGI) supports plants during dry periods. We analyzed water stable isotopes from soils, plants, ice, and rain collected from stable and unstable permafrost sites. We found that TSGI provides a background water source for plants during wet years (at least 10–20%) and a stable source during dry years (at least 30–50%) and early in the growing season (60–80% in wet and dry years). Plant water uptake patterns “track” the soil thawing front, using deep and shallow layers in wet years and deep layers during dry years. This plasticity allows boreal plants to cope with seasonal drought and exploit available water sources. The availability of TGSI depends on the amount of rainfall the prior year and on permafrost stability. Thawing permafrost may reduce the buffering capacity of TGSI due to less seasonal ice from greater drainage and/or a deeper active layer. This study demonstrates the importance of two buffering mechanisms for plants to cope with rainfall variability within boreal forest underlain by permafrost—availability of TSGI and plasticity in water uptake patterns. We suggest that plant utilization of stored water may be why evapotranspiration in northern latitudes can exceed growing season precipitation. Article in Journal/Newspaper Ice permafrost Alaska Wiley Online Library Ecohydrology 10 3 |
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Open Polar |
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Wiley Online Library |
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crwiley |
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English |
description |
Abstract Little is known about the ecological impacts of permafrost degradation on water fluxes in boreal ecosystems, such as those in Interior Alaska. Low plant water stress suggests a reliance on a diversity of water sources. In addition to rainfall, we hypothesize that deep soil water derived from thawing seasonal ground ice (TSGI) supports plants during dry periods. We analyzed water stable isotopes from soils, plants, ice, and rain collected from stable and unstable permafrost sites. We found that TSGI provides a background water source for plants during wet years (at least 10–20%) and a stable source during dry years (at least 30–50%) and early in the growing season (60–80% in wet and dry years). Plant water uptake patterns “track” the soil thawing front, using deep and shallow layers in wet years and deep layers during dry years. This plasticity allows boreal plants to cope with seasonal drought and exploit available water sources. The availability of TGSI depends on the amount of rainfall the prior year and on permafrost stability. Thawing permafrost may reduce the buffering capacity of TGSI due to less seasonal ice from greater drainage and/or a deeper active layer. This study demonstrates the importance of two buffering mechanisms for plants to cope with rainfall variability within boreal forest underlain by permafrost—availability of TSGI and plasticity in water uptake patterns. We suggest that plant utilization of stored water may be why evapotranspiration in northern latitudes can exceed growing season precipitation. |
author2 |
NSF Hydrology NSF Office of Polar Programs postdoctoral NSF Arctic Natural Sciences DOE SciDAC |
format |
Article in Journal/Newspaper |
author |
Young‐Robertson, Jessica M. Ogle, Kiona Welker, Jeffrey M. |
spellingShingle |
Young‐Robertson, Jessica M. Ogle, Kiona Welker, Jeffrey M. Thawing seasonal ground ice: An important water source for boreal forest plants in Interior Alaska |
author_facet |
Young‐Robertson, Jessica M. Ogle, Kiona Welker, Jeffrey M. |
author_sort |
Young‐Robertson, Jessica M. |
title |
Thawing seasonal ground ice: An important water source for boreal forest plants in Interior Alaska |
title_short |
Thawing seasonal ground ice: An important water source for boreal forest plants in Interior Alaska |
title_full |
Thawing seasonal ground ice: An important water source for boreal forest plants in Interior Alaska |
title_fullStr |
Thawing seasonal ground ice: An important water source for boreal forest plants in Interior Alaska |
title_full_unstemmed |
Thawing seasonal ground ice: An important water source for boreal forest plants in Interior Alaska |
title_sort |
thawing seasonal ground ice: an important water source for boreal forest plants in interior alaska |
publisher |
Wiley |
publishDate |
2017 |
url |
http://dx.doi.org/10.1002/eco.1796 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Feco.1796 https://onlinelibrary.wiley.com/doi/pdf/10.1002/eco.1796 |
genre |
Ice permafrost Alaska |
genre_facet |
Ice permafrost Alaska |
op_source |
Ecohydrology volume 10, issue 3 ISSN 1936-0584 1936-0592 |
op_rights |
http://onlinelibrary.wiley.com/termsAndConditions#vor |
op_doi |
https://doi.org/10.1002/eco.1796 |
container_title |
Ecohydrology |
container_volume |
10 |
container_issue |
3 |
_version_ |
1810448997885673472 |