Loading content, please wait..
loading..
Logo
Version 3.22
or
Publication Type J
Authors Trent, J. D., R. R. Blank and J. A. Young
Title Ecophysiology of the temperate desert halophytes: Allenrolfea occidentalis and Sarcobatus vermiculatus
Source Great Basin Naturalist
Author Keywords iodine bush black greasewood photosynthesis conductance transpiration water potential wafer-use efficiency salt desert photosynthesis salinity growth
Abstract Numerous basins of the intermountain area often have extensive playa surfaces that are nearly devoid of vegetation. Margins of these playas support sparse communities dominated by the chenopod shrubs Allenrolfea occidentalis (iodine bush) and Sarcobatus vermiculatus (black greasewood). These plants establish and persist in an environment where halomorphic soils induce extreme osmotic stress and atmospheric precipitation is very low and erratic and occurs largely during the winter when temperatures are too low for growth. We measured net CO2 assimilation rates, leaf conductances, transpiration rates, water-use efficiencies, and stem xylem potentials for these two C3 species. Data were collected in above-average (1991) and below-average (1992) precipitation years. Net CO2 assimilation rates for Allenrolfea were statistically similar in 1991 and 1992 but in general declined for Sarcobatus in 1992. For both species, leaf conductances and leaf transpiration rates declined significantly from 1991 to 1992, with the decline significantly greater for Sarcobatus. Water-use efficiencies doubled from 1991 to 1992 for both plant species. Predawn xylem water potentials were -2.2 and 3.3 MPa for Allenrolfea and -1.8 and -2.6 MPa for Sarcobatus beginning in May 1991 and 1992, respectively, and dropped to 3.8 and -4.2 MPa for Allenrolfea and -1.8 and -2.8 MPa for Sarcobatus by September 1991 and 1992, respectively. Afternoon xylem water potentials were 3.1 and -2.0 MPa for Allenrolfea and -2.6 and -2.2 MPa for Sarcobatus beginning in May 1991 and 1992, respectively. Xylem water potentials dropped to -5.0 MPa for Allenrolfea and -3.4 MPa for Sarcobatus by September of both 1991 and 1992. For Allenrolfea in general, the total soil water potential within the zone of maximum root activity is more negative than the plant's predawn xylem potential, which suggests that the plant is partially phreatophytic and/or has a large capacitance due to its extensive woody root system.
Author Address USDA ARS, CONSERVAT BIOL RANGELANDS UNIT, RENO, NV 89512 USA
ISSN 0017-3614
ISBN 0017-3614
29-Character Source Abbreviation Gt. Basin Nat.
Publication Date Jan
Year Published 1997
Volume 57
Issue 1
Beginning Page 57-65
Unique Article Identifier WOS:A1997WP48700007
Plants associated with this reference

LEGAL NOTICES — This website is protected by Copyright © The University of Sussex, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020, 2021. The eHALOPH database is protected by Database Right and Copyright © The University of Sussex and other contributors, 2006, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020, 2021. This database is based on an earlier work by James Aronson.
THIS WEBSITE AND THIS DATABASE ARE PROVIDED ON AN "AS IS" BASIS, AND YOU USE THEM AND RELY ON THEM AT YOUR OWN RISK.

Contact email: halophytes@sussex.ac.uk
Credits – Tim Flowers, Joaquim Santos, Moritz Jahns, Brian Warburton, Peter Reed