Access

You are not currently logged in.

Access your personal account or get JSTOR access through your library or other institution:

login

Log in to your personal account or through your institution.

If You Use a Screen Reader

This content is available through Read Online (Free) program, which relies on page scans. Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.

Photosynthetic and Respiratory Acclimation to Temperature in Ledum groenlandicum Populations

Edward M. Smith and Elmer B. Hadley
Arctic and Alpine Research
Vol. 6, No. 1 (Winter, 1974), pp. 13-27
DOI: 10.2307/1550366
Stable URL: http://www.jstor.org/stable/1550366
Page Count: 15
  • Read Online (Free)
  • Subscribe ($19.50)
  • Cite this Item
Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.
Photosynthetic and Respiratory Acclimation to Temperature in Ledum groenlandicum Populations
Preview not available

Abstract

Temperature-related photosynthetic and respiratory acclimation responses were examined in alpine, subarctic, and bog populations of Ledum groenlandicum Oeder, a widespread ericaceous shrub species. Acclimation responses to temperature were measured both after 12- to 16-week exposures to either cool (15° C light - 10°C dark) or warm (30°C light - 25°C dark) thermal regimes and again after each of a series of 2-week exposures to new thermal regimes. Dark respiratory rates were decreased by warm acclimation and increased by cool acclimation. These shifts in rates were frequently completed within 2 weeks in a new thermal regime. Maximal net photosynthetic rates generally did not differ significantly among either populations or thermal regimes; however, the temperature for maximal net photosynthesis in each population was increased to 25°C by warm acclimation and decreased to 20°C by cool acclimation. Net photosynthetic rates were increased at cool temperatures by cool acclimation and increased at warm temperatures by warm acclimation. In contrast to respiratory responses, these photosynthetic acclimation shifts were not completed within 2 weeks in a new thermal regime. Ledum groenlandicum populations differed markedly in their potentials for net photosynthetic and dark respiratory acclimation. Alpine and subarctic populations acclimated to greater degrees than their continental and maritime bog counterparts.

Page Thumbnails

  • Thumbnail: Page 
13
    13
  • Thumbnail: Page 
14
    14
  • Thumbnail: Page 
15
    15
  • Thumbnail: Page 
16
    16
  • Thumbnail: Page 
17
    17
  • Thumbnail: Page 
18
    18
  • Thumbnail: Page 
19
    19
  • Thumbnail: Page 
20
    20
  • Thumbnail: Page 
21
    21
  • Thumbnail: Page 
22
    22
  • Thumbnail: Page 
23
    23
  • Thumbnail: Page 
24
    24
  • Thumbnail: Page 
25
    25
  • Thumbnail: Page 
26
    26
  • Thumbnail: Page 
27
    27