Alnus viridis ssp. Fruticosa modulates local conditions to influence intra and interspecies growth
Dissertation (Ph.D.) University of Alaska Fairbanks, 2023 The Arctic is warming rapidly due to anthropogenic greenhouse gas emissions. Concurrent with warming, some Arctic plant communities have transformed from short statured evergreen and graminoid shrub tundra to tall deciduous shrubs in recent d...
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Online Access: | http://hdl.handle.net/11122/14953 |
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ftunivalaska:oai:scholarworks.alaska.edu:11122/14953 2024-04-28T08:07:11+00:00 Alnus viridis ssp. Fruticosa modulates local conditions to influence intra and interspecies growth Drew, Jackson W. Bret-Harte, Marion Syndonia Ruess, Roger W. Drown, Devin M. Buchwal, Agata 2023-12 http://hdl.handle.net/11122/14953 en_US eng http://hdl.handle.net/11122/14953 Department of Biology and Wildlife Alder Global warming Arctic regions North Slope Betula nana Birch Willows Shrubs Shrubland ecology Doctor of Philosophy in Biological Sciences Dissertation phd 2023 ftunivalaska 2024-04-10T14:05:37Z Dissertation (Ph.D.) University of Alaska Fairbanks, 2023 The Arctic is warming rapidly due to anthropogenic greenhouse gas emissions. Concurrent with warming, some Arctic plant communities have transformed from short statured evergreen and graminoid shrub tundra to tall deciduous shrubs in recent decades. As warming continues, plant-plant interactions will likely change and influence future community composition. Alnus viridis ssp. fruticosa (Siberian alder) is rapidly expanding across Arctic regions and is particularly important because Siberian alder is the Arctic's only large N-fixing shrub, may alter N-cycling to further influence both C-cycling and community composition as it spreads. This dissertation addressed two main questions to better understand how Arctic deciduous shrub communities have changed, and may continue to change as Arctic warming proceeds. First, how did the climate sensitivity of Siberian alder's growth change over the past century (1920 - 2017), and how did climate sensitivity change as Siberian alder grew older? Second, how has Siberian alder affected the long-term growth of two nearby dominant deciduous shrub species: Betula nana ssp. exilis (dwarf birch) and Salix pulchra (diamondleaf willow)? I used dendrochronological techniques to assess how sensitive the growth of each of these three species was to climate over the last century. For dwarf birch and diamondleaf willow, I compared growth near and away from Siberian alder. I hypothesized that Siberian alder shrubs would become more sensitive to climate as they grew both older and larger. I expected that older alder would enhance soil N availability over time, due to the accumulated products of N-fixation. I also expected that the growth of larger, older alders would be more sensitive to climate than the growth of younger alder, because of having both a greater photosynthetic capacity (enabling more growth under good conditions), but also higher maintenance respiration (leading to less growth under poor conditions). I found that ... Doctoral or Postdoctoral Thesis Arctic Betula nana Dwarf birch Global warming north slope Tundra Alaska University of Alaska: ScholarWorks@UA |
institution |
Open Polar |
collection |
University of Alaska: ScholarWorks@UA |
op_collection_id |
ftunivalaska |
language |
English |
topic |
Alder Global warming Arctic regions North Slope Betula nana Birch Willows Shrubs Shrubland ecology Doctor of Philosophy in Biological Sciences |
spellingShingle |
Alder Global warming Arctic regions North Slope Betula nana Birch Willows Shrubs Shrubland ecology Doctor of Philosophy in Biological Sciences Drew, Jackson W. Alnus viridis ssp. Fruticosa modulates local conditions to influence intra and interspecies growth |
topic_facet |
Alder Global warming Arctic regions North Slope Betula nana Birch Willows Shrubs Shrubland ecology Doctor of Philosophy in Biological Sciences |
description |
Dissertation (Ph.D.) University of Alaska Fairbanks, 2023 The Arctic is warming rapidly due to anthropogenic greenhouse gas emissions. Concurrent with warming, some Arctic plant communities have transformed from short statured evergreen and graminoid shrub tundra to tall deciduous shrubs in recent decades. As warming continues, plant-plant interactions will likely change and influence future community composition. Alnus viridis ssp. fruticosa (Siberian alder) is rapidly expanding across Arctic regions and is particularly important because Siberian alder is the Arctic's only large N-fixing shrub, may alter N-cycling to further influence both C-cycling and community composition as it spreads. This dissertation addressed two main questions to better understand how Arctic deciduous shrub communities have changed, and may continue to change as Arctic warming proceeds. First, how did the climate sensitivity of Siberian alder's growth change over the past century (1920 - 2017), and how did climate sensitivity change as Siberian alder grew older? Second, how has Siberian alder affected the long-term growth of two nearby dominant deciduous shrub species: Betula nana ssp. exilis (dwarf birch) and Salix pulchra (diamondleaf willow)? I used dendrochronological techniques to assess how sensitive the growth of each of these three species was to climate over the last century. For dwarf birch and diamondleaf willow, I compared growth near and away from Siberian alder. I hypothesized that Siberian alder shrubs would become more sensitive to climate as they grew both older and larger. I expected that older alder would enhance soil N availability over time, due to the accumulated products of N-fixation. I also expected that the growth of larger, older alders would be more sensitive to climate than the growth of younger alder, because of having both a greater photosynthetic capacity (enabling more growth under good conditions), but also higher maintenance respiration (leading to less growth under poor conditions). I found that ... |
author2 |
Bret-Harte, Marion Syndonia Ruess, Roger W. Drown, Devin M. Buchwal, Agata |
format |
Doctoral or Postdoctoral Thesis |
author |
Drew, Jackson W. |
author_facet |
Drew, Jackson W. |
author_sort |
Drew, Jackson W. |
title |
Alnus viridis ssp. Fruticosa modulates local conditions to influence intra and interspecies growth |
title_short |
Alnus viridis ssp. Fruticosa modulates local conditions to influence intra and interspecies growth |
title_full |
Alnus viridis ssp. Fruticosa modulates local conditions to influence intra and interspecies growth |
title_fullStr |
Alnus viridis ssp. Fruticosa modulates local conditions to influence intra and interspecies growth |
title_full_unstemmed |
Alnus viridis ssp. Fruticosa modulates local conditions to influence intra and interspecies growth |
title_sort |
alnus viridis ssp. fruticosa modulates local conditions to influence intra and interspecies growth |
publishDate |
2023 |
url |
http://hdl.handle.net/11122/14953 |
genre |
Arctic Betula nana Dwarf birch Global warming north slope Tundra Alaska |
genre_facet |
Arctic Betula nana Dwarf birch Global warming north slope Tundra Alaska |
op_relation |
http://hdl.handle.net/11122/14953 Department of Biology and Wildlife |
_version_ |
1797576403164594176 |