You are not currently logged in.
Access JSTOR through your library or other institution:
If You Use a Screen ReaderThis 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.
Hormonal Regulation of Growth form in the Arctic-Alpine Cushion Plant, Silene acaulis
S. R. Hagen and G. G. Spomer
Arctic and Alpine Research
Vol. 21, No. 2 (May, 1989), pp. 163-168
Published by: INSTAAR, University of Colorado
Stable URL: http://www.jstor.org/stable/1551628
Page Count: 6
You can always find the topics here!Topics: Plants, Acid soils, Soil temperature regimes, Plant roots, Soil respiration, Plant growth, Growth retardation, Soil science, Suppressive soils, Plant ecology
Were these topics helpful?See somethings inaccurate? Let us know!
Select the topics that are inaccurate.
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.
Preview not available
Whether Silene acaulis L. grows as a cushion or a loose mat of vegetation appears to be primarily regulated by soil temperature. Under growth chamber conditions, in soils at 13°C or less in the root zone, this species assumes a cushion form due to almost total suppression of internodal elongation, while in warmer soils substantial internodal growth leads to a mat form. Roots of this species exhibit relatively high respiration rates and low activation energies similar to those reported for cold-adapted tissues. This and other observations indicate that low soil-temperature stunting is probably not entirely the result of reduced root activity. Abscisic acid applied to the shoots of plants in warmer soils suppressed growth, and it is therefore likely that stunting in this and possibly other species is due to increased ABA levels produced in cold-stressed roots. These results are compatible with the proposition that progressive stunting at higher elevations and perhaps timberline formation result in large part from reduced average rhizosphere temperatures.