ISSN:
1573-5052
Keywords:
Drought survival
;
Water relations
;
Zygophyllum dumosum
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract The effects of soil water potential on photosynthesis and transpiration of whole Zygophyllum dumosum Boiss. shrubs were examined with a field IRGA system during a rainless summer. Daily photosynthesis and transpiration activities were not notably different on a unit phyllode area basis among shrubs at naturally differing soil water potentials. Irrigation of shrubs caused phyllodes to increase significantly in water content and new leaflets to appear. Leaflets had three times as many stomata per unit area (23000 stomata cm-2) as phyllodes (7100 stomata cm-2) but photosynthesis and transpiration rates were not measurably different between irrigated and non-irrigated shrubs on a unit area basis. This finding suggests that sufficient soil moisture will lead to increased carbon uptake of the entire shrub simply because the total area of photosynthesizing tissue increases. Gas exchange rates appear to be controlled solely by atmospheric conditions under the stresses of summer.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00044868
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