Thesis (M.S. - Watershed Management)--University of Arizona. / Includes bibliographical references.

Thesis (Ph. D. - Watershed Management)--University of Arizona, 1970. / Includes bibliographical references (leaves 79-84).

Many areas in the arid southwestern United States depend upon ground water for irrigation and municipal water supplies. The high transpiration rates of the extensive phreatophyte tamarisk (Tamarix pentandra Pall.) cause considerable depletion of ground water in this region. Eradication of tamarisk communities would appear to be a useful method for salvaging ground water; however, the vigorous reproduction and growth of tamarisk pose economic problems because of the re-treatment and maintenance work required. Also, the removal of tamarisk thickets may adversely affect wildlife habitat, esthetic values, and the ecosystem in general. The use of antitranspirant compounds on tamarisk was investigated in the laboratory, greenhouse, and field, to determine if transpiration could be reduced significantly without damaging the plant. Athel tree (Tamarix aphylla L.) was subjected to the same analyses as tamarisk to better evaluate treatment effects. Initially, several antitranspirants were tested in greenhouse studies from which the potentially useful compounds were selected for more detailed study. Phenylmercuric acetate was toxic to both species and was not used in further experiments with tamarisk. Daily transpiration rates of tamarisk, measured gravimetrically in a greenhouse, were reduced 28 to 36 percent for 20 days with spray applications of 0.01 M 8-hydroxyquinoline sulfate (8-HQS), and the combination of 150 ppm mono-methyl (MDSA) and 150 ppm mono-glyceryl (GDSA) esters of n-decenylsuccinic acid in Triton X-100 (0.5 percent) solutions. The MDSA-GDSA combination and 8_I-[QS significantly reduced stomatal apertures of tamarisk. Stomatal measurements were not obtained for athel tree, although daily transpiration rates of athel tree were reduced 31 percent for 32 days with the MDSA-GDSA combination. The addition of the filmforming Foli-gard (10 percent) did not enhance treatment effect. Treatment effects on net photosynthesis and respiration of both species were evaluated with an infrared gas analyzer. The net photosynthesis rates of tamarisk were significantly reduced 1 to 3 days by 8-HQS and MDSA-GDSA. Respiration rates, measured in the dark, were increased significantly only by 8-HQS. Net photosynthesis rates of athel tree were significantly reduced 13 days by MDSA-GDSA, but there were no effects on respiration. MDSA-GDSA and 8-HQS reduced tamarisk growth rates for 10 to 20 days following treaLment. These growth reductions may have contributed to the decrease in transpiration rates of treated plants. Analyses of foliage samples obtained from tamarisk after treatment indicated that chlorophyll and protein contents were not affected by 8-HQS or MDSA-GDSA. Similar results were noted for athel tree treated with MDSA-GDSA and MDSA-GDSA-Foli-gard. Transpiration rates of potted tamarisk in the field were reduced significantly for only five days by 8-HQS, MDSA-GDSA, and the reflective compound, kaolinite. Rainfall after the fifth day, and phenological phenomena may have contributed to the comparatively short duration of transpiration reduction. Increased foliage temperatures of 1.5 to 2.5 C were detected with a Barnes infrared thermometer 1 and 3 days after treatment. These were obtained under conditions of intense solar radiation, and high air and soil temperatures. This study indicated that tamarisk transpiration can be reduced substantially without lethal increases in foliage temperatures, but with reductions of growth. Additional studies with these antitranspirants may provide a useful management alternative for tamarisk dominated areas to salvage ground water and yet maintain plant cover for wildlife and other uses.

Thesis (Ph. D. - Watershed Management)--University of Arizona. / Includes bibliographical references (leaves 99-104).

In the arid southwestern United States, where water is a limiting factor in agricultural and industrial development, a sizeable portion of the annual precipitation may be lost through evapotranspiration. In Arizona such losses account for approximately 95 per cent of the annual precipitation. Tamarisk (Tamarix pentandra Pall.) is estimated to occupy over one million acres of the flood plains and streambanks in the southwest. Although reported to use a large quantity of water, accurate estimates of evapotranspiration are unknown. Evapotranspiration processes are complex and depend on many interrelationships of the soil-plantatmosphere system. Although, water use by tamarisk has been intensively studied, evapotranspiration measurements under different climatic and hydrologic conditions are not available. The evapotranspiration tent was selected to measure evapotranspiration rates of tamarisk under varying climatic and hydrologic conditions. Intensive investigations of the enclosure effect of the tent were performed. Modifications of the tent reduced serious enclosure effects of the original tent. Evapotranspiration rates measured by the tent agreed favorably with rates computed by Penman's equation. Evapotranspiration rates for an area where the water table depth was approximately 20-feet was greater than an area where the Water table depth was 14-feet. This deviation, which may be attributed to salinity, led to a laboratory investigation of the effects of salinity on transpiration rates of tainarisk. An intensive laboratory study was conducted to determine the effect of salinity on transpiration rates of tamarisk at different vapor pressure deficits. Results indicated that the effect of salinity is dependent on vapor pressure deficit. Transpiration rates were linearily related to vapor pressure deficits at low salinity levels, but a curvilinear relationship was obtained at high salinity levels. An estimate of saturation deficit of the mesophyll cells was determined by extrapolation of transpiration and vapor pressure deficit relationships. These data indicate minimial increases in salt concentrations in the stomatal cavities as indicated by small increases in the mesophyll saturation deficits as the salinity of the root substrate was increased. Root permeability tests were conducted on plants subjects to varying salinity and vapor pressure deficit levels. Results indicated a significant reduction only at the highest salinity and vapor pressure deficit levels.

No description available.

No description available.

Thesis (Ph. D.)--University of Texas at El Paso, 2009. / Title from title screen. Vita. CD-ROM. Includes bibliographical references. Also available online.

Tamarix (Tamaricaceae) is from the Old World, but has become naturalized and invaded other parts of the world including South Africa. Tamarix usneoides is the only species native to southern Africa, but the exotic species T. aphylla, T. chinensis, T. parviflora and T. ramosissima have been reported to be present in South Africa and these Tamarix species are hypothesized to be hybridizing among themselves and with the indigenous T. usneoides. Among the exotic species, T. chinensis, T. ramosissima and their putative hybrids have become invasive. Tamarix usneoides is used in southern African mines for phytoremediation as it has the ability to hyper-accumulate sulphate and heavy metals from Acid Mine Drainage from Tailing Storage Facilities and excretes gypsum (CaSO4). Tamarix species are morphologically and ecologically similar, making them difficult to distinguish and hybridization adds to the taxonomic confusion. Identification of Tamarix species in South Africa is of great importance because of the invasive potential of T. chinensis, T. ramosissima and their putative hybrids, and also because of the potential usefulness of T. usneoides. This investigation aimed to identify populations of pure T. usneoides that can be cloned for cultivation for phytoremediation on the mines, and to reveal the geographic origin of the invasive species to facilitate a biological control programme. Nuclear (ITS) and plastid (trnS-trnG) DNA sequence data and the multilocus Amplified Fragment Length Polymorphisms (AFLPs) markers were used in this study to characterize southern African Tamarix species and their putative hybrids. Phylogenetic analyses and population genetic structure confirm the presence of three Tamarix species in South Africa (T. chinensis, T. ramosissima and T. usneoides) with admixed individuals (Tamarix hybrids). The indigenous T. usneoides is clearly genetically distant from the alien species T. chinensis and T. ramosissima. Although the exotic species remain largely unresolved in the phylogenies, they are distinctly separated through AFLP markers. The Tamarix infestation in South Africa is dominated by hybrids between T. chinensis and T. ramosissima, and the parent species match their counterparts from their places of origin in Asia. These places of origin in Asia can provide the source of potential biological control agents. Some remote populations, e.g. Witbank, Goodhouse and Henkries in the Northern Cape Province/South Africa at the border with Namibia, of pure breeding T. usneoides have been identified and these should be used as a source of genetic material that can be propagated for planting on the mines for phytoremediation programmes.

This item was digitized as part of the Million Books Project led by Carnegie Mellon University and supported by grants from the National Science Foundation (NSF). Cornell University coordinated the participation of land-grant and agricultural libraries in providing historical agricultural information for the digitization project; the University of Arizona Libraries, the College of Agriculture and Life Sciences, and the Office of Arid Lands Studies collaborated in the selection and provision of material for the digitization project.