Reducing Phreatophyte Transpiration
Affiliation
Department of Land Air and Water Resources, University of California, DavisIssue Date
1977-04-16Keywords
Hydrology -- Arizona.Water resources development -- Arizona.
Hydrology -- Southwestern states.
Water resources development -- Southwestern states.
Phreatophytes
Transpiration
Antitranspirents
Transpiration control
Chemcontrol
StomataWater conservationWater utilizationConsumptive useWater yield improvementBalance of natureThin filmsDesert plantsTamariskCottonwoodsArid landsDiurnalNocturnal
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Copyright ©, where appropriate, is held by the author.Collection Information
This article is part of the Hydrology and Water Resources in Arizona and the Southwest collections. Digital access to this material is made possible by the Arizona-Nevada Academy of Science and the University of Arizona Libraries. For more information about items in this collection, contact anashydrology@gmail.com.Publisher
Arizona-Nevada Academy of ScienceAbstract
Transpiration rates (T) of riparian phreatophytes can be high. Antitranspirant (AT) sprays can curtail T without the ecological imbalance made by eradication. Saltcedar (Tamarix sp.) and cottonwood (Populus sp.) in 15-gal. drums enabled replicated trials on isolated plants or on canopies. T of isolate saltcedar plants could be 2x that of plants in a fairly dense canopy. T for a unit ground area of saltcedar varied from 2.2 (sparse -) to 15.8 (dense-stand) mm/day in July at Davis. Extrapolation of experimental T data to field sites must, therefore, be made carefully. Wax -based ATs increased foliar diffusive resistance (R), and reduced T of saltcedar and cottonwood 32-38% initially and 10% after 3 weeks. R increased naturally in the afternoon when evaporative demand was high and if soil water was low. Nocturnal T of salt cedar was 10% of day T. AT effectiveness increased with a higher ratio of day: night hours, and with lower soil water stress. Therefore, AT will be most effective on long summer days in riparian areas where ground water is available.ISSN
0272-6106Related items
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