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.

Growth Response of Sphagnum capillifolium to Nighttime Temperature and Nutrient Level: Mechanisms and Implications for Global Change

Renato Gerdol, Angelo Bonora, Roberta Marchesini, Rita Gualandri and Simonetta Pancaldi
Arctic and Alpine Research
Vol. 30, No. 4 (Nov., 1998), pp. 388-395
DOI: 10.2307/1552011
Stable URL: http://www.jstor.org/stable/1552011
Page Count: 8
  • 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.
Growth Response of Sphagnum capillifolium to Nighttime Temperature and Nutrient Level: Mechanisms and Implications for Global Change
Preview not available

Abstract

Individuals of Sphagnum capillifolium were cultured for 2 mo under six different combinations of nighttime temperature and nutrients. Low nighttime temperature caused a five-fold reduction of growth. Growth was also reduced when the plants were cultured without any addition of nutrient in the growing medium, but only when nutrient deficiency was coupled with high nighttime temperature. Growth reduction was associated with decreased rates of net photosynthesis, but was not accompanied by a degradation of photosynthetic pigments and/or variations in the pigment ratios, nor was the ultrastructure of chloroplasts significantly altered. The decline in the net photosynthetic rate may be due to a limitation in the enzymatic reactions at unfavorable temperatures. Nitrogen and, especially, phosphorus appeared to limit growth of Sphagnum capillifolium at optimal temperatures. A nighttime temperature of 5°C was above the lower threshold triggering the synthesis of red wall-pigments, known to be promoted by nighttime chilling. Climate warming is expected to increase the growth rates of Sphagnum, but the consequences on the carbon balance of peatlands cannot be predicted because temperature rise may also enhance breakdown of peat.

Page Thumbnails

  • Thumbnail: Page 
388
    388
  • Thumbnail: Page 
389
    389
  • Thumbnail: Page 
390
    390
  • Thumbnail: Page 
391
    391
  • Thumbnail: Page 
392
    392
  • Thumbnail: Page 
393
    393
  • Thumbnail: Page 
394
    394
  • Thumbnail: Page 
395
    395