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Title: Transpiration and CO/sub 2/ fixation of selected desert shrubs as related to soil-water potential

Abstract

In desert plants, transpiration rates decreased before photosynthetic rates when plants were entering a period of water stress. This may have adaptive consequences. A difference of -5 bars in the soil-moisture potential had considerable importance in reducing the rate of transpiration. In Helianthus annuus L. (sunflower) the photosynthetic rate decreased before the transpiration rate in contrast to Great Basin-Mojave Desert plants, and the changes occurred with a -1 bar difference in soil-moisture potential. Morphological changes in three desert plant species (Artemisia tridentata Nutt., Ambrosia dumosa (Gray) Payne, Larrea tridentata (Ses. Moc. ex DC) Cov.) as the soil-moisture potential decreased are given. With a mesic species, H. annuus, 20% reduction in photosynthesis and transpiration was reached at higher soil-moisture potentials than with the desert plants. Loss of net photosynthesis occurred in A. dumosa (a summer deciduous shrub) as PSI soil reached -48 bars in the field, whereas L. tridentata (an evergreen shrub) at the same time was able to maintain a water potential difference between soil and plant of -10 to -15 bars and continue net CO/sub 2/ gain well into the summer months.

Authors:
; ; ; ; ;
Publication Date:
OSTI Identifier:
6645424
Resource Type:
Journal Article
Journal Name:
Great Basin Nat.; (United States)
Additional Journal Information:
Journal Volume: 4
Country of Publication:
United States
Language:
English
Subject:
54 ENVIRONMENTAL SCIENCES; 59 BASIC BIOLOGICAL SCIENCES; SHRUBS; PHOTOSYNTHESIS; TRANSPIRATION; DESERTS; EXPERIMENTAL DATA; MOISTURE; SOILS; ARID LANDS; CHEMICAL REACTIONS; DATA; INFORMATION; NUMERICAL DATA; PHOTOCHEMICAL REACTIONS; PLANTS; SYNTHESIS; 510100* - Environment, Terrestrial- Basic Studies- (-1989); 550500 - Metabolism

Citation Formats

Clark, S B, Letey, J Jr, Lunt, O R, Wallace, A, Kleinkopf, G E, and Romney, E M. Transpiration and CO/sub 2/ fixation of selected desert shrubs as related to soil-water potential. United States: N. p., 1980. Web.
Clark, S B, Letey, J Jr, Lunt, O R, Wallace, A, Kleinkopf, G E, & Romney, E M. Transpiration and CO/sub 2/ fixation of selected desert shrubs as related to soil-water potential. United States.
Clark, S B, Letey, J Jr, Lunt, O R, Wallace, A, Kleinkopf, G E, and Romney, E M. 1980. "Transpiration and CO/sub 2/ fixation of selected desert shrubs as related to soil-water potential". United States.
@article{osti_6645424,
title = {Transpiration and CO/sub 2/ fixation of selected desert shrubs as related to soil-water potential},
author = {Clark, S B and Letey, J Jr and Lunt, O R and Wallace, A and Kleinkopf, G E and Romney, E M},
abstractNote = {In desert plants, transpiration rates decreased before photosynthetic rates when plants were entering a period of water stress. This may have adaptive consequences. A difference of -5 bars in the soil-moisture potential had considerable importance in reducing the rate of transpiration. In Helianthus annuus L. (sunflower) the photosynthetic rate decreased before the transpiration rate in contrast to Great Basin-Mojave Desert plants, and the changes occurred with a -1 bar difference in soil-moisture potential. Morphological changes in three desert plant species (Artemisia tridentata Nutt., Ambrosia dumosa (Gray) Payne, Larrea tridentata (Ses. Moc. ex DC) Cov.) as the soil-moisture potential decreased are given. With a mesic species, H. annuus, 20% reduction in photosynthesis and transpiration was reached at higher soil-moisture potentials than with the desert plants. Loss of net photosynthesis occurred in A. dumosa (a summer deciduous shrub) as PSI soil reached -48 bars in the field, whereas L. tridentata (an evergreen shrub) at the same time was able to maintain a water potential difference between soil and plant of -10 to -15 bars and continue net CO/sub 2/ gain well into the summer months.},
doi = {},
url = {https://www.osti.gov/biblio/6645424}, journal = {Great Basin Nat.; (United States)},
number = ,
volume = 4,
place = {United States},
year = {Tue Jan 01 00:00:00 EST 1980},
month = {Tue Jan 01 00:00:00 EST 1980}
}