Gas Exchange and Water Relations of Two Alpine and Two Arctic Tundra Plant Species
Although water stress is an important selective force in many environments, it is not commonly considered to be of particular importance in tundra areas. Even though large portions of tundra may have an abundance of water, other more exposed areas may become quite dry. This microsite variability wit...
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ftutahsudc:oai:digitalcommons.usu.edu:etd-7368 2023-07-30T04:01:12+02:00 Gas Exchange and Water Relations of Two Alpine and Two Arctic Tundra Plant Species Johnson, Douglas Allan 1975-05-01T07:00:00Z application/pdf https://digitalcommons.usu.edu/etd/6307 https://doi.org/10.26076/89ac-e5f0 https://digitalcommons.usu.edu/context/etd/article/7368/viewcontent/1975_Johnson_Douglas.pdf unknown DigitalCommons@USU https://digitalcommons.usu.edu/etd/6307 doi:10.26076/89ac-e5f0 https://digitalcommons.usu.edu/context/etd/article/7368/viewcontent/1975_Johnson_Douglas.pdf Copyright for this work is held by the author. Transmission or reproduction of materials protected by copyright beyond that allowed by fair use requires the written permission of the copyright owners. Works not in the public domain cannot be commercially exploited without permission of the copyright owner. Responsibility for any use rests exclusively with the user. For more information contact digitalcommons@usu.edu. All Graduate Theses and Dissertations gas exchange water stress tundra alpine arctic plant species Biology Environmental Sciences Plant Sciences text 1975 ftutahsudc https://doi.org/10.26076/89ac-e5f0 2023-07-20T17:34:59Z Although water stress is an important selective force in many environments, it is not commonly considered to be of particular importance in tundra areas. Even though large portions of tundra may have an abundance of water, other more exposed areas may become quite dry. This microsite variability with respect to moisture stress was reflected in soil water potential measurements obtained from an alpine tundra area on Niwot Ridge in Colorado. Even though soil water potentials were consistently above -5 bars in a relatively low lying Deschampsia meadow, soil water potentials from an exposed fellfield area were often as low as -15 bars. Since moisture stress affects a number of important physiological processes in plants and since moisture stress may develop in at least some tundra areas, this study was undertaken to determine whether the sensitivity of plant physiological processes to water stress may be one important contributing factor in determining the microsite distribution of different tundra species. The alpine tundra species examined in this study were Deschampsia caespitosa which is typically found in wet meadow habitats and Geum rossii, a species which ranges from wet meadow to exposed fellfield habitats. The arctic tundra species investigated were Dupontia fischeri which is restricted mainly to wet meadow areas and Carex aquatilis, a species ranging from wet meadows to drier, more exposed areas. For both the arctic and al pine tundra species, though the photosynthetic capacities of the tundra species restricted mainly to wet meadow areas were higher under conditions of low moisture stress, the wider ranging tundra species were able to maintain greater photosynthetic capacity as soil moisture stress increased. Although the depression of photosynthesis with water stress in these tundra species could be partially attributed to reduced stomatal aperture, with decreased soil water potential most of the decline of photosynthesis was due to a greater non-stomatal or residual resistance, indicating a direct ... Text Arctic Carex aquatilis Tundra Utah State University: DigitalCommons@USU Arctic |
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collection |
Utah State University: DigitalCommons@USU |
op_collection_id |
ftutahsudc |
language |
unknown |
topic |
gas exchange water stress tundra alpine arctic plant species Biology Environmental Sciences Plant Sciences |
spellingShingle |
gas exchange water stress tundra alpine arctic plant species Biology Environmental Sciences Plant Sciences Johnson, Douglas Allan Gas Exchange and Water Relations of Two Alpine and Two Arctic Tundra Plant Species |
topic_facet |
gas exchange water stress tundra alpine arctic plant species Biology Environmental Sciences Plant Sciences |
description |
Although water stress is an important selective force in many environments, it is not commonly considered to be of particular importance in tundra areas. Even though large portions of tundra may have an abundance of water, other more exposed areas may become quite dry. This microsite variability with respect to moisture stress was reflected in soil water potential measurements obtained from an alpine tundra area on Niwot Ridge in Colorado. Even though soil water potentials were consistently above -5 bars in a relatively low lying Deschampsia meadow, soil water potentials from an exposed fellfield area were often as low as -15 bars. Since moisture stress affects a number of important physiological processes in plants and since moisture stress may develop in at least some tundra areas, this study was undertaken to determine whether the sensitivity of plant physiological processes to water stress may be one important contributing factor in determining the microsite distribution of different tundra species. The alpine tundra species examined in this study were Deschampsia caespitosa which is typically found in wet meadow habitats and Geum rossii, a species which ranges from wet meadow to exposed fellfield habitats. The arctic tundra species investigated were Dupontia fischeri which is restricted mainly to wet meadow areas and Carex aquatilis, a species ranging from wet meadows to drier, more exposed areas. For both the arctic and al pine tundra species, though the photosynthetic capacities of the tundra species restricted mainly to wet meadow areas were higher under conditions of low moisture stress, the wider ranging tundra species were able to maintain greater photosynthetic capacity as soil moisture stress increased. Although the depression of photosynthesis with water stress in these tundra species could be partially attributed to reduced stomatal aperture, with decreased soil water potential most of the decline of photosynthesis was due to a greater non-stomatal or residual resistance, indicating a direct ... |
format |
Text |
author |
Johnson, Douglas Allan |
author_facet |
Johnson, Douglas Allan |
author_sort |
Johnson, Douglas Allan |
title |
Gas Exchange and Water Relations of Two Alpine and Two Arctic Tundra Plant Species |
title_short |
Gas Exchange and Water Relations of Two Alpine and Two Arctic Tundra Plant Species |
title_full |
Gas Exchange and Water Relations of Two Alpine and Two Arctic Tundra Plant Species |
title_fullStr |
Gas Exchange and Water Relations of Two Alpine and Two Arctic Tundra Plant Species |
title_full_unstemmed |
Gas Exchange and Water Relations of Two Alpine and Two Arctic Tundra Plant Species |
title_sort |
gas exchange and water relations of two alpine and two arctic tundra plant species |
publisher |
DigitalCommons@USU |
publishDate |
1975 |
url |
https://digitalcommons.usu.edu/etd/6307 https://doi.org/10.26076/89ac-e5f0 https://digitalcommons.usu.edu/context/etd/article/7368/viewcontent/1975_Johnson_Douglas.pdf |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic Carex aquatilis Tundra |
genre_facet |
Arctic Carex aquatilis Tundra |
op_source |
All Graduate Theses and Dissertations |
op_relation |
https://digitalcommons.usu.edu/etd/6307 doi:10.26076/89ac-e5f0 https://digitalcommons.usu.edu/context/etd/article/7368/viewcontent/1975_Johnson_Douglas.pdf |
op_rights |
Copyright for this work is held by the author. Transmission or reproduction of materials protected by copyright beyond that allowed by fair use requires the written permission of the copyright owners. Works not in the public domain cannot be commercially exploited without permission of the copyright owner. Responsibility for any use rests exclusively with the user. For more information contact digitalcommons@usu.edu. |
op_doi |
https://doi.org/10.26076/89ac-e5f0 |
_version_ |
1772811958662201344 |