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ContributorsSchildkret, David (Conductor) / Chamber Singers (Performer) / ASU Library. Music Library (Publisher)
Created2018-02-10
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Description
The southwestern US will experience more frequent heat waves, prolonged droughts, and declining water supply. Riparian ecosystems are particularly at-risk under climate change predictions, but little is known about the thermal tolerance of plant species inhabiting these ecosystems. Populus fremontii, a pioneer and foundation tree species in riparian ecosystems throughout

The southwestern US will experience more frequent heat waves, prolonged droughts, and declining water supply. Riparian ecosystems are particularly at-risk under climate change predictions, but little is known about the thermal tolerance of plant species inhabiting these ecosystems. Populus fremontii, a pioneer and foundation tree species in riparian ecosystems throughout the southwest, is of concern given its importance in driving community structure and influencing ecosystem processes. This study compared leaf thermal tolerance across populations of P. fremontii to determine if local adaptation affects leaf thermal tolerance. I hypothesized that warm-adapted (low-elevation) populations would have larger leaf thermal tolerance thresholds, thermal safety margins, and thermal time constants than cool-adapted (high-elevation) populations. I expected warm-adapted populations to maintain lower maximum leaf temperatures due to local adaptation affecting leaf thermal regulation. Using a common garden at the warm edge of this species’ range, I measured leaf thermal tolerance metrics in eight populations spanning a 1,200 m elevational gradient. Data collection occurred in May, during mild air temperatures, and in August, during high air temperatures. The first two metrics were leaf thermal tolerance thresholds. The critical temperature (Tcrit) is the temperature at which the electron transport capacity of PSII is disrupted. T50 is the temperature at which the electron transport capacity decreases to 50%. The next metric was thermal safety margins (TSMs), which reflect a leaf’s vulnerability to reaching thermal tolerance thresholds. TSMs are the difference between either Tcrit or T50 and an experienced environmental variable such as leaf or air temperature. The last metric was the thermal time constant (?), which is a trait that represents how quickly leaf temperatures respond to changes in air temperatures. Tcrit, T50, and ? were not correlated with elevation regardless of season, suggesting that acclimation or phenotypic plasticity is affecting these metrics. Conversely, TSMs using maximum leaf temperature were negatively correlated with elevation in August because warm-adapted populations maintained lower maximum leaf temperatures. These findings suggest that warm-adapted populations are locally adapted to maintain cooler leaf temperatures, which is critical for their future survival since they do not maintain higher leaf thermal tolerance thresholds than cool-adapted populations.
ContributorsMoran, Madeline (Author) / Hultine, Kevin (Thesis advisor) / Throop, Heather (Thesis advisor) / Butterfield, Bradley (Committee member) / Arizona State University (Publisher)
Created2022
ContributorsGlenn, Erica (Conductor) / Evans, Bartlett R. (Conductor) / Oh, Eun-Mi (Conductor) / Thompson, Jason D. (Conductor) / Schildkret, David (Conductor) / Concert Choir (Performer) / Arizona Statesmen (Performer) / Women's Chorus (Performer) / Gospel Choir (Performer) / Barrett Choir (Performer) / Chamber Singers (Performer) / Choral Union (Performer) / ASU Library. Music Library (Publisher)
Created2017-11-30
ContributorsUniversity Choirs (Performer) / ASU Library. Music Library (Publisher)
Created2000-11-16
ContributorsSchildkret, David (Conductor) / White, Jamilyn (Performer) / Krison, Danielle (Performer) / Barefield, Robert (Performer) / FitzPatrick, Carole (Performer) / Chamber Singers (Performer) / Choral Union (Performer) / Symphonic Chorale (Performer) / University Symphony Orchestra (Performer) / ASU Library. Music Library (Publisher)
Created2007-04-26
ContributorsLyne, Gregory K. (Performer) / Stutzman, Gina (Performer) / Woodgate, Lyn (Performer) / Cornner, Charles B. (Performer) / Rozukalns, Andris L. (Performer) / Women's Choir (Performer) / University Choir (Performer) / ASU Library. Music Library (Publisher)
Created1996-11-24
ContributorsCherland, Carl (Performer) / Fuller, Charles L. (Performer) / O'Brien, Robert (Performer) / Hooper, Wm. John (Performer) / Graduate Chorale (Performer) / Recital Chorale (Performer) / ASU Library. Music Library (Publisher)
Created1987-10-01
ContributorsRoueche, Michelle (Performer) / Partin, Darrell (Performer) / Wiest-Parthun, Karen (Performer) / Harvison, Emery (Performer) / Hernandez, Rene (Performer) / Foley, Laura (Performer) / Women's Choir (Performer) / ASU Library. Music Library (Publisher)
Created1994-04-21
ContributorsParthun, Karen (Conductor) / Hickman, Miriam, 1955- (Performer) / University Choir (Performer) / Vocal Jazz Ensemble (Performer) / ASU Library. Music Library (Publisher)
Created2000-11-19
ContributorsPeterson, Craig C. (Director) / Butler, Robb (Director) / Forkner, Christina (Contributor) / Leman, Christi (Performer) / Miller, Kenny (Musician) (Performer) / Howard, Johnothon (Performer) / Gibson, Ted (Performer) / Herberger Singers (Performer) / University Choir (Performer) / ASU Library. Music Library (Publisher)
Created2003-10-12