Tissue water relations ofPinusponderosaandArctostaphylospatulaexposed to various levels of soil moisture depletion
作者:
Paul D. Anderson,
John A. Helms,
期刊:
Canadian Journal of Forest Research
(NRC Available online 1994)
卷期:
Volume 24,
issue 7
页码: 1495-1502
ISSN:0045-5067
年代: 1994
DOI:10.1139/x94-193
出版商: NRC Research Press
数据来源: NRC
摘要:
The tissue water relations ofPinusponderosaDougl. ex Laws, (ponderosa pine) andArctostaphylospatulaGreene (greenleaf manzanita) seedlings subjected to three levels of soil moisture availability were monitored over a 6-month period. Throughout the study, osmotic potentials at full turgor and at the turgor loss point were approximately 0.5 MPa greater for pine than for manzanita. Osmotic adjustment occurred for both species as evidenced by declines in osmotic potentials at full turgor and at the turgor loss point of 0.5–0.6 MPa over the study period. Pine maintained higher bulk tissue elasticity and lower water content at the turgor loss point relative to manzanita. Moisture regime had little effect on the measured parameters except for apoplasmic water content which increased at moderate and high stress levels for both species. Results suggest that osmotic adjustment occurred, at least partially, as a result of factors other than moisture availability. The lower tissue elasticity and higher water content at the turgor loss point for manzanita suggest that the shrub species is more dependent upon high foliar water content for the maintenance of turgor compared with the conifer.
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