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Field Studies Of Mineral Nutrition Of Larrea Tridentata: Importance Of N, Ph, And Fe, R. B. Hunter, A. Wallace, E. M. Romney Oct 1980

Field Studies Of Mineral Nutrition Of Larrea Tridentata: Importance Of N, Ph, And Fe, R. B. Hunter, A. Wallace, E. M. Romney

Great Basin Naturalist Memoirs

Multivariate analysis of soil and plant data from the northern Mojave Desert was used to investigate aspects of the mineral nutrition of Larrea tridentata (Sesse & Moc. ex DC.) Cov. Larrea tridentata biomass was significantly correlated with soil NO3 and pH and leaf Fe content. Leaf cation accumulation was negatively correlated with leaf Fe concentration.

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14C Distribution In Roots Following Photosynthesis Of The Label In Perrennial Plants In The Northern Mojave Desert, A. Wallace, R. T. Mueller, J. W. Cha, E. M. Romney Oct 1980

14C Distribution In Roots Following Photosynthesis Of The Label In Perrennial Plants In The Northern Mojave Desert, A. Wallace, R. T. Mueller, J. W. Cha, E. M. Romney

Great Basin Naturalist Memoirs

In April and May of 1973, 24 individual plants were exposed to 14CO2 with techniques used in our other studies in the field. Seven to 8 months later, part of the plants were excavated and counted by plant part for 14C. The remainder of the plants were excavated at 13 months. The results indicated that from 3 to 20 percent of the carbon for leaves in the next year came from stems and roots of Grayia spinosa (Hook) Moq., Ceratoides lanata(Pursh) J. T. Howell, Atriplex confertifolia (Torr. & Frem.) S. Wats., Lycium pallidum Miers, Ambrosia dumosa …

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Phenology Of Desert Shrubs In Southern Nye County, Nevada, T. L. Ackerman, E. M. Romney, A. Wallace, J. E. Kinnear Oct 1980

Phenology Of Desert Shrubs In Southern Nye County, Nevada, T. L. Ackerman, E. M. Romney, A. Wallace, J. E. Kinnear

Great Basin Naturalist Memoirs

This study was done to document the variability in time of phenological events at different locations on the Nevada Test Site. Phenological events for desert shrubs were recorded, and rainfall and temperature data were gathered for four to six years at eight sites that are located within the northern Mojave Desert, the southern Great Basin Desert, and the transitional zone between them. Results have been graphically displayed to show the variability in phenological activity encountered during the study period and also to show the general correlation between these events and the environmental regime that triggered a particular phenological stage among …

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Amcap Journal Volume 6 Issue 4 1980, Issues In Religion And Psycotherapy Oct 1980

Amcap Journal Volume 6 Issue 4 1980, Issues In Religion And Psycotherapy

Issues in Religion and Psychotherapy

No abstract provided.

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Christ & Psychiatry, M.N. Beck Oct 1980

Christ & Psychiatry, M.N. Beck

Issues in Religion and Psychotherapy

Presented at the Candian Psychiatric Association Annual Meeting, Vancouver, B.C., June 1973 as the Presidential Address. this is a condensed version.
Reprinted with permission from the author and the Canadian Psychiatric Association Journal, Vol. 18 (1973), pp. 355-361.

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The Role Of Shrubs On The Redistribution Of Mineral Nutrients In Soil In The Mojave Desert, E. M. Romney, A. Wallace, H. Kaaz, V. Q. Hale Oct 1980

The Role Of Shrubs On The Redistribution Of Mineral Nutrients In Soil In The Mojave Desert, E. M. Romney, A. Wallace, H. Kaaz, V. Q. Hale

Great Basin Naturalist Memoirs

Soil profiles underneath shrub clumps and bare desert pavement were examined at 62 study sites located in both open and closed drainage basins of the northern Mojave Desert. Highly significant differences occurred in the root zone underneath shrub clumps with higher concentrations of the following soil properties: electrical conductivity (EC25°), Na, K+, Ca+ +, Mg+ +, Cl-, NO3-, and SO4=; exchangeable K+; cation exchange capacity: organic C and N; available P, and DTPA-extractable Fe and Mn. These differences reflect differential cycling caused by different …

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Further Attributes Of The Perennial Vegetation In The Rock Valley Area Of The Northern Mojave Desert, S. A. Bamberg, A. Wallace, E. M. Romney, R. E. Hunter Oct 1980

Further Attributes Of The Perennial Vegetation In The Rock Valley Area Of The Northern Mojave Desert, S. A. Bamberg, A. Wallace, E. M. Romney, R. E. Hunter

Great Basin Naturalist Memoirs

Above-ground and below-ground biomass, percent dead shrubs by species, and percent of dead stems of living species were determined for a site in the northern Mojave Desert.

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Frequency Distribution Of Three Perennial Plant Species To Nearest Neighbor Of The Same Species In The Northern Mohave Desert, A. Wallace, E. M. Romney, J. E. Kinnear Oct 1980

Frequency Distribution Of Three Perennial Plant Species To Nearest Neighbor Of The Same Species In The Northern Mohave Desert, A. Wallace, E. M. Romney, J. E. Kinnear

Great Basin Naturalist Memoirs

Frequency distribution patterns were developed for distance to nearest neighbor of the same species for Larrea tridentate (Sesse & Moc. ex DC.) Cov., Ephedra nevadensis S. Wats., and Acamptopappus shockleyi A. Gray. The distances between shrubs had been determined previously in another study. About one-third or more of the nearest neighbor of its own kind was within less than one meter for each species, indicating that it was usually within the same shrub clump, which in turn is indicative of an aggregating effect. For L. tridentata and E. nevadensis much of this could be from the same original plant by …

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Photosynthetic Strategies Of Two Mojave Desert Shrubs, G. E. Kleinkopf, T. L. Hartsock, A. Wallace, E. M. Romney Oct 1980

Photosynthetic Strategies Of Two Mojave Desert Shrubs, G. E. Kleinkopf, T. L. Hartsock, A. Wallace, E. M. Romney

Great Basin Naturalist Memoirs

Photosynthetic production of two Mojave Desert shrubs was measured under natural growing conditions at UCLA. Measurements of photosynthesis, transpiration, resistances to water vapor flux, soil moisture potential, and tissue water potential were made. Atriplex canescens (Pursh) Nutt., a member of the C4 biochemical carbon dioxide fixation group was highly competitive in growth rate and production during conditions of adequate soil moisture. As soil moisture conditions declined to minus 40 bars, the net photosynthetic rate of Atriplex decreased to zero. However, the C3 shrub species Larrea tridentata (Sesse & Moc. ex DC.) Gov. was able to maintain positive net …

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Mineral Compostition Of Atriplex Hymenelytra Growing In The Northern Mojave Desert, A. Wallace, E. M. Romney, R. B. Hunter, J. E. Kinnear, G. V. Alexander Oct 1980

Mineral Compostition Of Atriplex Hymenelytra Growing In The Northern Mojave Desert, A. Wallace, E. M. Romney, R. B. Hunter, J. E. Kinnear, G. V. Alexander

Great Basin Naturalist Memoirs

Fifty samples of Atriplex hymenelytra (Torr.) S. Wats, were collected from several different locations in southern Nevada and California to test variability in mineral composition. Only Na, V, P. Ca, Mg, Mn, and Sr in the samples appeared to represent a uniform population resulting in normal curves for frequency distribution. Even so, about 40 percent of the variance for these elements was due to location. All elements differed enough with location so that no element really represented a uniform population. The coefficient of variation for most elements was over 40 percent and one was over 100 percent. The proportion of …

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Depth Distribution Of Roots Of Some Perennial Plants In The Nevada Test Site Area Of The Northern Mojave Desert, A. Wallace, E. M. Romney, J. W. Cha Oct 1980

Depth Distribution Of Roots Of Some Perennial Plants In The Nevada Test Site Area Of The Northern Mojave Desert, A. Wallace, E. M. Romney, J. W. Cha

Great Basin Naturalist Memoirs

The root systems of 48 perennial plants, representing nine species from the Rock Valley area within the northern Mojave Desert, were excavated by 10 cm depth increments to determine, by depth of soil, the distribution of roots larger than about 1/2 mm diameter. The depth of the root zone of all species was relatively shallow and obviously limited by depth of penetration of precipitation (about 10 cm mean annual rainfall).
There were species differences, however, in distribution of roots. Even though a sizeable proportion of the root systems was in the first 10 cm of soil, this portion consisted largely …

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Rodent-Denuded Areas Of The Northern Mojave Desert, R. B. Hunter, E. M. Romney, A. Wallace Oct 1980

Rodent-Denuded Areas Of The Northern Mojave Desert, R. B. Hunter, E. M. Romney, A. Wallace

Great Basin Naturalist Memoirs

Populations of pocket gophers and rabbits regulate or control the perennial vegetation on relatively large sites in the northern Mojave Desert. Aboveground shoots are pruned and whole plants are killed by complete cutting of main roots.

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Fencing Enhances Shrub Survival And Growth For Mojave Desert Revegetion, R. B. Hunter, A. Wallace, E. M. Romney Oct 1980

Fencing Enhances Shrub Survival And Growth For Mojave Desert Revegetion, R. B. Hunter, A. Wallace, E. M. Romney

Great Basin Naturalist Memoirs

Fourteen species of native shrubs were transplanted to bare areas of the northern Mojave Desert in 1972 and 1973. By 1978 plants surrounded by small fences were larger (0.26 vs 0.11 m3 overall average for several species) and survived better (42 percent versus 23 percent) than unfenced plants. These effects are primarily due to reduced grazing of shoots. Loss of shrubs to pocket gophers or other burrowing rodents was not prevented by fencing.

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Parent Material Which Produces Saline Outcrops As A Factor In Differential Distribution Of Perennial Plants In The Northern Mojave Desert, A. Wallace, E. M. Romney, R. A. Wood, A. A. El-Ghonemy, S. A. Bamberg Oct 1980

Parent Material Which Produces Saline Outcrops As A Factor In Differential Distribution Of Perennial Plants In The Northern Mojave Desert, A. Wallace, E. M. Romney, R. A. Wood, A. A. El-Ghonemy, S. A. Bamberg

Great Basin Naturalist Memoirs

An area of 0.46 km2 divided into six zones in the northern Mojave Desert transitional with the Great Basin Desert has been studied. Diversity is high among the perennial plant species within the 0.46 km2 area. Common species for the two deserts that are present in the area studied are Atriplex confertifolia (Torr. & Frem.) S.Wats., Ceratoides lanata (Pursh) J. T. Howell, Grayia spinosa (Hook.) Moq., Ephedra nevadensis S. Wats. Some other species present include Lycium andersonii A. Gray, Lycium pallidum Miers, Ambrosia dumosa (A. Gray) Payne., Larrea tridentata (Sesse & Moc. ex DC) Cov., Acamptopappus shockleyi A. …

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Retranslocation Of Tagged Carbon In Ambrosia Dumosa, A. Wallace, J. W. Cha, R. T. Mueller, E. M. Romney Oct 1980

Retranslocation Of Tagged Carbon In Ambrosia Dumosa, A. Wallace, J. W. Cha, R. T. Mueller, E. M. Romney

Great Basin Naturalist Memoirs

Ambrosia dumosa (A. Gray) Payne cuttings grown in solution culture were exposed to 14CO2 to measure the distribution of labeled photosynthate among leaves, stems, and roots after 4, 24, and 48 h. For all sampling periods, the highest levels of 14C were found in leaves and the lowest in roots; however, considerable 14C had moved to roots in 48 h. In a 12-week study of A. dumosa in solution culture, plants increased in size more than 17 times and flowered and produced seeds. The plants had received 14CO2 in photosynthesis at the start. The …

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Multivariate Analysis Of The Vegetation In A Two-Desert Interface, A. A. El-Ghonemy, A. Wallace, E. M. Romney Oct 1980

Multivariate Analysis Of The Vegetation In A Two-Desert Interface, A. A. El-Ghonemy, A. Wallace, E. M. Romney

Great Basin Naturalist Memoirs

This report further describes the distribution and ecological characteristics of the natural vegetation at the Mojave Desert-Great Basin Desert interface. The region studied is one of extraordinary biological interest because of its geographic location straddling the boundaries of two large deserts of the western United States, and because of the kind and manner of its past land use (atmospheric and underground testing of nuclear devices). The present analysis determines the magnitude of variations in the phytosociological structure in this region and evaluates some relationships between its vegetation and environment. Vegetation and soils were sampled in 66 stands representing many possible …

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A Phytosociological Study Of A Small Desert Area In Rock Valley, Nevada, A. A. El-Ghonemy, A. Wallace, E. M. Romney, W. Valentine Oct 1980

A Phytosociological Study Of A Small Desert Area In Rock Valley, Nevada, A. A. El-Ghonemy, A. Wallace, E. M. Romney, W. Valentine

Great Basin Naturalist Memoirs

The aim of this study was to gain more understanding of the compositional structure of vegetation in the US/ IBP Desert Biome validation site located in Rock Valley, Nevada. The vegetation data collected from 85 stands, randomly distributed to cover all physiographic variations in the study site, permitted categorization of the vegetation units either by coordinates or by class membership. The vegetational groupings so identified were then used for constructing a more reliable vegetation map for the Rock Valley validation site.

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Carbon Fixed In Leaves And Twigs Of Field Larrea Tridentata In Two-Hour Exposure To 14Co2, A. Wallace, E. M. Romney, R. B. Hunter Oct 1980

Carbon Fixed In Leaves And Twigs Of Field Larrea Tridentata In Two-Hour Exposure To 14Co2, A. Wallace, E. M. Romney, R. B. Hunter

Great Basin Naturalist Memoirs

Six Larrea tridentata (Sesse & Moc. ex DC) Cov. plants were exposed to 14CO2 in a field experiment for 2 h. Three of the plants had been irrigated regularly in the preceding year. Ten small twigs from each plant were moved and counted for 14C activity at the end of 2 h. The stem portion of the twigs was of equal dry weight for the two sets of plants, but those irrigated had a greater weight of leaves per twig. The activity of 14C in leaves was equal for the two groups, but was higher in …

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Effect Of Certain Plant Parameters On Photosynthesis, Transpiration, And Effiency Of Water Use, H. M. Mork, A. Wallace, E. M. Romney Oct 1980

Effect Of Certain Plant Parameters On Photosynthesis, Transpiration, And Effiency Of Water Use, H. M. Mork, A. Wallace, E. M. Romney

Great Basin Naturalist Memoirs

Rates of gaseous exchange were measured on selected desert shrubs native to the northern Mojave Desert to determine effects of varying chamber temperature, CO2 concentration, relative humidity, and root temperature in preliminary studies. Results indicate that changes in these parameters produced differences in the rates of photosynthesis and transpiration. Ceratoides lanata (Pursh) took up CO2 almost equally at 25 and 39 C. Doubling the CO2 concentration in the below-ambient range roughly doubled photosynthesis rates in C. lanata. Very small changes in relative humidity had marked changes in the photosynthesis and transpiration rates of four species studied, …

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Regulative Effect Of Dodder (Cuscuta Nevadensis Jtn.) On The Vegetation Of The Northern Mojave Desert, A. Wallace, E. M. Romney, R. B. Hunter Oct 1980

Regulative Effect Of Dodder (Cuscuta Nevadensis Jtn.) On The Vegetation Of The Northern Mojave Desert, A. Wallace, E. M. Romney, R. B. Hunter

Great Basin Naturalist Memoirs

On two separate transects in the Rock Valley area of the northern Mojave Desert in the spring of1976, 4 percent to 17 percent of the perennial plants were infested with the parasite Cuscuta nevadensis Jtn. (dodder), and dead pieces of dodder from previous years were on dead plants equivalent to another 5 percent, indicating that the dodder had a regulating effect on the plant population and may be an important cause of perennial plant death.

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Transpiration And Co2 Fixation Of Selected Desert Shrubs As Related To Soil-Water Potential, S. B. Clark, J. Letey Jr., O. R. Lunt, A. Wallace, G. E. Kleinkopf, E. M. Romney Oct 1980

Transpiration And Co2 Fixation Of Selected Desert Shrubs As Related To Soil-Water Potential, S. B. Clark, J. Letey Jr., O. R. Lunt, A. Wallace, G. E. Kleinkopf, E. M. Romney

Great Basin Naturalist Memoirs

In desert plants, transpiration rates decreased before photosynthetic rates when plants were entering a period of water stress. This may have adaptive consequences. A difference of -5 bars in the soil-moisture potential had considerable importance in reducing the rate of transpiration. In Helianthus annuus L. (sunflower) the photosynthetic rate decreased before the transpiration rate in contrast to Great Basin-Mojave Desert plants, and the changes occurred with a -1 bar difference in soil-moisture potential. Morphological changes in three desert plant species [Artemisia tridentata Nutt., Ambrosia dumosa (Gray) Payne, Larrea tridentata (Ses. Moc. ex DC) Cov.] as the soil-moisture potential decreased …

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The Challenge Of A Desert: Revegetation Of Disturbed Desert Lands, A. Wallace, E. M. Romney, R. B. Hunter Oct 1980

The Challenge Of A Desert: Revegetation Of Disturbed Desert Lands, A. Wallace, E. M. Romney, R. B. Hunter

Great Basin Naturalist Memoirs

The revegetation of disturbed, arid lands is one of the great challenges of a desert. An attempt to encourage it is not an impossible task, however, if the natural and the man-made resources available are utilized and managed. Where rainfall and temperature conditions approach or exceed those of the Great Basin desert, restoration of disturbed land will occur through natural revegetation processes within a reasonable period of time. This is not generally the case in the more arid Mojave Desert areas where the moisture and temperature conditions are less favorable for germination and seedling survival. Restoration of vegetation by natural …

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Ecotonal Distribution Of Salt-Tolerant Shrubs In The Northern Mojave Desert, E. M. Romney, A. Wallace Oct 1980

Ecotonal Distribution Of Salt-Tolerant Shrubs In The Northern Mojave Desert, E. M. Romney, A. Wallace

Great Basin Naturalist Memoirs

Ecotonal distribution of salt-tolerant shrubs was investigated under different kinds of edaphic conditions common to open an closed drainage basins in the northern Mojave Desert. Contributing causal factors involved changes in soil salinity, texture, and moisture stress. Varying degrees of halophytism occured, ranging from plant species that are facultative in their adaptation to salinity to those that require comparatively high salt concentrations in soil for normal growth and development.

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Frequency Distribution Of Numbers Of Perennial Shrubs In The Northern Mojave Desert, A. A. El-Ghonemy, A. Wallace, E. M. Romney Oct 1980

Frequency Distribution Of Numbers Of Perennial Shrubs In The Northern Mojave Desert, A. A. El-Ghonemy, A. Wallace, E. M. Romney

Great Basin Naturalist Memoirs

Frequency distribution according to plant size as measured by dimensional analysis on different mathematical bases were determined for 10 common perennial plant species from Rock Valley in the northern Mojave Desert in Nevada. A total of 4282 individual plants was measured. The data provide information concerning the stability and prosperity of the natural vegetation as judged by the relative proportions of individuals in the size-class spectrum, as well as show graphically the relative abundance of the different species in the study area.
On the species level, the populations were close to normally distributed on the loge basis, but with …

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Persistence Of 14C Labeled Carbon In Larrea Tridentata Up To 40 Months After Photosynthetic Fixation In The Northern Mojave Desert, A. Wallace, E. M. Romney, J. W. Cha Oct 1980

Persistence Of 14C Labeled Carbon In Larrea Tridentata Up To 40 Months After Photosynthetic Fixation In The Northern Mojave Desert, A. Wallace, E. M. Romney, J. W. Cha

Great Basin Naturalist Memoirs

Larreo tridentata (Sesse Moc. ex DC) Cov. exposed to 14CO2 retained about 20 percent of its 14C after 16 and also after 26 months. In leaves, however, a lower specific activity was present at 26 months than at 16months, and a smaller percentage of 14C in the plant occurred in leaves at 26 months than at 16 months (3 percent vs 10 percent). This indicates some, but little, reuse of carbon from the structural components of the plants. The strong tendency of the species to retain this carbon may be related to a survival mechanism. After …

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The Xanthines: Coffee, Cola, Cocoa, And Tea, Clifford J. Stratton Oct 1980

The Xanthines: Coffee, Cola, Cocoa, And Tea, Clifford J. Stratton

BYU Studies

No abstract provided.

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Socioecological And Soil-Plant Studies Of The Natural Vegetation In The Northern Mojave Desert-Great Basin Desert Interface, A. A. El-Ghonemy, A. Wallace, E. M. Romney Oct 1980

Socioecological And Soil-Plant Studies Of The Natural Vegetation In The Northern Mojave Desert-Great Basin Desert Interface, A. A. El-Ghonemy, A. Wallace, E. M. Romney

Great Basin Naturalist Memoirs

The purpose of this study is to further describe the distribution, habitats, and ecological characteristics of the natural vegetation in the northern sector of the northern Mojave Desert. Sixty-six stands were classified on the basis of shared leading dominant species. Each of these groupings is well defined and represents a sociologically distinct entity quite recognizable in the field. The relationships between each vegetational grouping and several environmental variables were statistically analyzed. Significant differences were found among plant groupings with respect to soil moisture tension, absolute and relative amounts of exchangeable Na, exchangeable K, cation exchange capacity, and elevation.
The analysis …

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Relationship Of Small Washes To The Distribution Of Lycium Andersonii And Larrea Tridentata At A Site In The Northern Mojave Desert, A. Wallace, E. M. Romney, R. B. Hunter Oct 1980

Relationship Of Small Washes To The Distribution Of Lycium Andersonii And Larrea Tridentata At A Site In The Northern Mojave Desert, A. Wallace, E. M. Romney, R. B. Hunter

Great Basin Naturalist Memoirs

At a site near Rock Valley, Nevada, dominated by volcanic rocks, both Larrea tridentata (Sesse & Moc. ex DC.) Cov. and Lycium andersonii A. Gray were restricted in distribution. Larrea tridentata did not grow in the many small washes in the area, but L. andersonii grew only in the washes. Ambrosia dumosa (A. Gray) Payne was more dense and more dominant in wash areas than in nonwash areas.

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Preface, Arthur Wallace Oct 1980

Preface, Arthur Wallace

Great Basin Naturalist Memoirs

No abstract provided.

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Residual Effects Of Supplemental Moisture On The Plant Populations Of Plots In The Northern Mojave Desert, R. B. Hunter, E. M. Romney, A. Wallace, J. E. Kinnear Oct 1980

Residual Effects Of Supplemental Moisture On The Plant Populations Of Plots In The Northern Mojave Desert, R. B. Hunter, E. M. Romney, A. Wallace, J. E. Kinnear

Great Basin Naturalist Memoirs

Residual effects of sprinkle irrigation from 1968-1970 on populations of Mojave Desert shrub communities were observed in late 1974. The sprinkle-irrigated plots showed a residual increase in density of four species, but other species either failed to reproduce in significant numbers or lost all gains made during the years following treatment. The seven-year change for the irrigated plots was equivalent to a gain of 1178 perennial plants per ha, but the nonirrigated plots lost an average of 1050 plants per ha equivalent during the same period. The biomass gain after seven years was equivalent to 1000 kg/ha for irrigated plots …

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