Cryocampsis: a biophysical freeze-bending response of shrubs and trees under snow loads
We report a biophysical mechanism, termed cryocampsis (Greek cryo-, cold, + campsis, bending), that helps northern shrubs bend downward under a snow load. Subfreezing temperatures substantially increase the downward bending of cantilever-loaded branches of these shrubs, while allowing them to recove...
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ftpubmed:oai:pubmedcentral.nih.gov:9802243 2023-05-15T14:58:36+02:00 Cryocampsis: a biophysical freeze-bending response of shrubs and trees under snow loads Ray, Peter M Bret-Harte, M Syndonia 2022-07-25 http://www.ncbi.nlm.nih.gov/pmc/articles/PMC9802243/ https://doi.org/10.1093/pnasnexus/pgac131 en eng Oxford University Press http://www.ncbi.nlm.nih.gov/pmc/articles/PMC9802243/ http://dx.doi.org/10.1093/pnasnexus/pgac131 © The Author(s) 2022. Published by Oxford University Press on behalf of National Academy of Sciences. https://creativecommons.org/licenses/by-nc-nd/4.0/This is an Open Access article distributed under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs licence (https://creativecommons.org/licenses/by-nc-nd/4.0/), which permits non-commercial reproduction and distribution of the work, in any medium, provided the original work is not altered or transformed in any way, and that the work is properly cited. For commercial re-use, please contact journals.permissions@oup.com CC-BY-NC-ND PNAS Nexus Biological Health and Medical Sciences Text 2022 ftpubmed https://doi.org/10.1093/pnasnexus/pgac131 2023-01-29T01:34:05Z We report a biophysical mechanism, termed cryocampsis (Greek cryo-, cold, + campsis, bending), that helps northern shrubs bend downward under a snow load. Subfreezing temperatures substantially increase the downward bending of cantilever-loaded branches of these shrubs, while allowing them to recover their summer elevation after thawing and becoming unloaded. This is counterintuitive, because biological materials (including branches that show cryocampsis) generally become stiffer when frozen, so should flex less, rather than more, under a given bending load. Cryocampsis involves straining of the cell walls of a branch’s xylem (wood), and depends upon the branch being hydrated. Among woody species tested, cryocampsis occurs in almost all Arctic, some boreal, only a few temperate and Mediterranean, and no tropical woody species that we have tested. It helps cold-winter climate shrubs reversibly get, and stay, below the snow surface, sheltering them from winter weather and predation hazards. This should be advantageous, because Arctic shrub bud winter mortality significantly increases if their shoots are forcibly kept above the snow surface. Our observations reveal a physically surprising behavior of biological materials at subfreezing temperatures, and a previously unrecognized mechanism of woody plant adaptation to cold-winter climates. We suggest that cryocampsis’ mechanism involves the movement of water between cell wall matrix polymers and cell lumens during freezing, analogous to that of frost-heave in soils or rocks. Text Arctic PubMed Central (PMC) Arctic PNAS Nexus 1 4 |
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PubMed Central (PMC) |
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English |
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Biological Health and Medical Sciences |
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Biological Health and Medical Sciences Ray, Peter M Bret-Harte, M Syndonia Cryocampsis: a biophysical freeze-bending response of shrubs and trees under snow loads |
topic_facet |
Biological Health and Medical Sciences |
description |
We report a biophysical mechanism, termed cryocampsis (Greek cryo-, cold, + campsis, bending), that helps northern shrubs bend downward under a snow load. Subfreezing temperatures substantially increase the downward bending of cantilever-loaded branches of these shrubs, while allowing them to recover their summer elevation after thawing and becoming unloaded. This is counterintuitive, because biological materials (including branches that show cryocampsis) generally become stiffer when frozen, so should flex less, rather than more, under a given bending load. Cryocampsis involves straining of the cell walls of a branch’s xylem (wood), and depends upon the branch being hydrated. Among woody species tested, cryocampsis occurs in almost all Arctic, some boreal, only a few temperate and Mediterranean, and no tropical woody species that we have tested. It helps cold-winter climate shrubs reversibly get, and stay, below the snow surface, sheltering them from winter weather and predation hazards. This should be advantageous, because Arctic shrub bud winter mortality significantly increases if their shoots are forcibly kept above the snow surface. Our observations reveal a physically surprising behavior of biological materials at subfreezing temperatures, and a previously unrecognized mechanism of woody plant adaptation to cold-winter climates. We suggest that cryocampsis’ mechanism involves the movement of water between cell wall matrix polymers and cell lumens during freezing, analogous to that of frost-heave in soils or rocks. |
format |
Text |
author |
Ray, Peter M Bret-Harte, M Syndonia |
author_facet |
Ray, Peter M Bret-Harte, M Syndonia |
author_sort |
Ray, Peter M |
title |
Cryocampsis: a biophysical freeze-bending response of shrubs and trees under snow loads |
title_short |
Cryocampsis: a biophysical freeze-bending response of shrubs and trees under snow loads |
title_full |
Cryocampsis: a biophysical freeze-bending response of shrubs and trees under snow loads |
title_fullStr |
Cryocampsis: a biophysical freeze-bending response of shrubs and trees under snow loads |
title_full_unstemmed |
Cryocampsis: a biophysical freeze-bending response of shrubs and trees under snow loads |
title_sort |
cryocampsis: a biophysical freeze-bending response of shrubs and trees under snow loads |
publisher |
Oxford University Press |
publishDate |
2022 |
url |
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC9802243/ https://doi.org/10.1093/pnasnexus/pgac131 |
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Arctic |
geographic_facet |
Arctic |
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Arctic |
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Arctic |
op_source |
PNAS Nexus |
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC9802243/ http://dx.doi.org/10.1093/pnasnexus/pgac131 |
op_rights |
© The Author(s) 2022. Published by Oxford University Press on behalf of National Academy of Sciences. https://creativecommons.org/licenses/by-nc-nd/4.0/This is an Open Access article distributed under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs licence (https://creativecommons.org/licenses/by-nc-nd/4.0/), which permits non-commercial reproduction and distribution of the work, in any medium, provided the original work is not altered or transformed in any way, and that the work is properly cited. For commercial re-use, please contact journals.permissions@oup.com |
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CC-BY-NC-ND |
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https://doi.org/10.1093/pnasnexus/pgac131 |
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