Colorado Desert Research Articles

Nitrogen Fixation by Legumes and Blue-Green Algal-Lichen Crusts in a Colorado Desert Environment

Nitrogen Fixation by Legumes and Blue-Green Algal-Lichen Crusts in a Colorado Desert Environment

NITROGEN FIXATION BY LEGUMES AND BLUE‐GREEN ALGAL‐LICHEN CRUSTS IN A COLORADO DESERT ENVIRONMENT

Potential sources of fixed nitrogen in a Colorado desert environment were examined by the acetylene reduction method at the Deep Canyon Desert Research Center, near Palm Desert, California. In field and greenhouse studies all members of the genera Astragalus, Dalea, Lotus, Lupinus, Melilotus, and Prosopis examined formed active nodules (acetylene reduction) with indigenous soil bacteria. No evidence of nodulation was found for Acacia greggii, Cercidium floridum, or Hoffmannseggia microphylla. Lotus tomentellus was estimated to fix 0.1 kg N ha−1 by the time of flowering under field conditions. Several members of the genus Dalea showed substantial rates of acetylene reduction in the greenhouse: D. emoryi, 16.1 + 3.5, D. mollissima, 11.4 + 3.7, D. schottii 2.9 + 1.7, D. spinosa 2.5 + 0.4 μmoles ethylene plant−1 hr−1. In greenhouse assays where water was supplied continuously, blue‐green algal‐lichen crusts reduced acetylene at an average rate of 11.0 + 5.7 nmoles ethylene cm−2 hr−1 with a maximum of 57.1. But when in situ assays were done following irrigation of a field plot with 2.3 cm of water, much lower activities were observed with a maximum activity of only 6.4 nmoles cm−2 hr−1.

Seasonal and Daily Activity Patterns and Thermoregulation in the Southwestern Speckled Rattlesnake (Crotalus mitchelli pyrrhus) and the Colorado Desert Sidewinder (Crotalus cerastes laterorepens)

Crotalus cerastes was predominantly nocturnal, while C. mitchelli was mainly diurnal in the spring and fall and nocturnal during the summer months from June to September. The normal activity range of C. mitchelli (18.8-39.3 C) was narrower than that of C. cerastes (13.6-40.8 C). The overall preferred body temperature (April to December) of C. mitchelli (31.2 C) was significantly higher than that of C. cerastes (25.8 C). By being active at different times of the day during some months of the year, competition between these two species is reduced.

Seasonal Variation of Lipid Content in the Mosquito Culiseta inornata1

Fat body development in adult female Culiseta inornata (Diptera: Culicidae) was determined between Sept., 1975 and Feb., 1977. Fat body hypertrophy began in Mar., with 26% of dry body wt as lipid (DBWL) but increased to 64% DBWL by June, when overt activity ended. In Sept., when activity resumed, until Feb., fat body hypotrophy was apparent as DBWL remained below 21%. These seasonal variations in lipid content support the theory of aestivation by adult C. inornata in the Colorado Desert of California.

The Ecology of Culiseta inornata in the Colorado Desert of California: Seasonal Abundance, Gonotrophic Status, and Oviparity of Adult Mosquitoes1

In the Colorado Desert of California, female Culiseta inornata (Diptera: Culicidae) were active from Sept.-June, while males were active from Oct.-May. In airborne populations, during Oct. through Feb., nullipars comprised 40% or less of the empty females examined. Parous females alone were captured in Sept., and from Mar.-June. Among resting females, the occurrence of nullipars varied directly with changing population level in Oct. and Nov. (between 0 and 50% of empty females=nulliparous), but inversely with levels during Feb. and Mar. (100% of empty females=nulliparous). Aestival populations of C. inornata were inferred to consist of small numbers of females who either possess fully developed oocytes, or have completed at least one gonotrophic cycle. Male C. inornata do not survive the summer.

Microhabitat, water relations, and photosynthesis of a desert fern, Notholaena parryi.

Interrelationships between morphology, microhabitat, water relations, and photosynthesis of a xeric fern, Notholaena parryi D.C. Eat. (Pteridaceae), were examined in the western Colorado desert. In its typical microhabitat rock outcroppings protected N. parryi from direct sunlight and moderated the diurnal variations in air temperature. For example, frond temperature at noon in late winter was 15.3° C, which was 7.3° C cooler than an energy budget simulation predicting frond temperature at an exposed site. The lowest soil water potential leading to daytime stomatal opening was about-1.5 MPa (-15 bars). Rainfall runoff that was channeled to the periphery of the rocks caused Ψsoil near the fern roots to rise above-1.5 MPa even after light rainfalls, and it remained above-1.5 MPa longer after rainfall than in non-rocky sites.The water potential gradient along the stipe necessary to support the observed rates of transpiration was about-10 MPa m-1; such a large gradient reflected the small conducting area in the xylem. The water vapor conductance decreased as the frond temperature was raised, an effect that became proportionally greater as the soil dried out. The daytime water-use efficiency (mass CO2 fixed/mass water transpired) was 0.0058 for a spring day. Individual fronds reached 90% of light saturation for photosynthesis at only 100 μEinsteins m-2 s-1, a photosynthetically active radiation similar to that from the diffuse sunlight incident on the generally north-facing microhabitat of the fern. Below 50 μE m-2 s-1 the quantum requirement was 13 Einsteins absorbed/mole CO2 fixed. The ratio of chlorophyll to P700 was 552, indicating a fairly large photosynthetic unit that is characteristic of plants adapted to shaded habitats. The temperature optimum for net photosynthesis shifted from 13° C in midwinter (mean daily air temperature of 11° C) to 19° C in early fall (air temperature of 23° C).

Ridge-Back Tools of the Colorado Desert

Knapping experiments and examination of flaked stone objects distributed throughout portions of southwestern Imperial Valley and northern Baja California indicate that criteria other than presence or absence of percussion bulbs can be used to support the artifactual nature of certain fractured stones.

Chromosomal and Genetic Divergence in the Fossorial Lizards of the Family Anniellidae

Bezy, R. L., G. C. Gorman, Y. J. Kim, and J. W. Wright (Section of Herpetology, Natural History Museum of Los Angeles County, Los Angeles, Califomia 90007 [Bezy and Wright]; Department of Biology, University of California, Los Angeles, California 90024 [Gorman and Kim]) 1977. Chromosomal and genetic divergence in the fossorial lizards of the family Anniellidae. Syst. Zool. 26:57-71.-Chromosomal divergence within the family Anniellidae is extensive. Diploid chromosome numbers in somatic tissue range from 36 in Anniella geronimensis to 22 in northern and 20 in southern A. pulchra. One to four testicular supernumerary microchromosomes occur in A. p. pulchra populations in northern Baja California. There is a lack of congruency between the chromosomal and morphological races of A. pulchra. Within the infraorder Anguimorpha, anniellids have chromosomal similarities to both the diploglossans (Anguidae) and the platynotans (Varanidae). The genetic distances between the four populations of Anniella analysed electrophoretically correspond well with their currently recognized hierarchical relationships: DN = .282-.298 between the two species, .104-.119 between the two subspecies, and .003 between populations within subspecies. In comparison to other sympatric congeneric species of amphibians and reptiles, A. pulchra and A. geronimensis are only moderately divergent genetically. The genetic distance between populations of A. pulchra which differ in somatic karyotype is greater than that between the populations which differ only in supernumerary chromosomes. Allelic heterozygosity in populations of Anniella is notably low (ca. 1%). This low level of genetic variability and high level of chromosomal divergence accompanied by relatively few structural genomic changes appear to be important evolutionary correlates to the fossorial life-style of anniellid lizards. [Karyotypes; genetic divergence; Anniellidae; Sauria.] The family Anniellidae is composed of three taxa of legless, fossorial, anguimorphan lizards occurring in California and northern Baja California (Fig. 1-2; McDowell and Bogert, 1954; Wermuth, 1969). Anniella pulchra Gray 1852 ranges from Antioch, Contra Costa Co., California, south to Bahia San Quintin, Baja California del Norte, its seemingly disjunct populations occurring most extensively in coastal sand dunes, but extending inland to the Colorado Desert and the western slope of the Sierra Nevada (Shaw, 1953; Stebbins, 1954). A dark race, A. p. nigra Fischer 1885, occurs primarily on the humid Monterey Peninsula of California, all other populations of the species being currently assigned to the lighter typical form, A. p. pulchra. Anniella geronimensis was originally described from Isla San Geronimo (Shaw, 1940) and subsequently reported on the adjacent mainland of Baja Califor nia del Norte (Shaw, 1949), where it was ultimately discovered to be sympatric with A. pulchra (Shaw, 1953). Karyotypic differences between populations of A. pulchra were reported previously (Bezy and Wright, 1971; Gorman, 1973). We here describe the karyotype of A. geronimensis and additional populations of A. pulchra, present electrophoretic data on coastal populations of the three nominate taxa, and discuss genetic and chromosomal variability and divergence in relation to the ecology and evolution of the lizards of the family. MATERIALS AND METHODS Chromosomes were prepared by a colchicine, hypotonic citrate technique (Patton, 1967; Lowe, Wright, and Cole, 1966), using heterogeneous tissue samples

Water Relations of Flowering of Agave deserti

The water budget during flowering for the leaves, inflorescence, and lateral floral branches of the monocarpic perennial Agave deserti Engelm. (Agavaceae) was investigated in the western Colorado desert. During the 159 days from the emergence of the inflorescence until the fruit could be removed from the plant without affecting seed viability, the approximately 68 leaves on a plant decreased 24.9 kg in wet weight (7.1 kg attributable to leaf transpiration) and 1.84 kg in dry weight. The decrease of water in the leaves, which accompanied their death, was balanced by water storage in the inflorescence (3.1 kg), transpirational water loss from its surface (4.3 kg), and water loss from the lateral floral branches (10.8 kg), most of which came from the fruit. The final dry weight of the inflorescence (1.25 kg) approximately equaled the total annual photosynthetic productivity of a mature plant; such a large demand on its reserves is consistent with the single blooming period for this perennial. Due to seed predation, stringent germination conditions, and seedling fatalities, only about one seed in 1.2 x 106 will lead to a mature flowering plant. In fact, most A. deserti plants are produced vegetatively.

Water relations and photosynthesis of a barrel cactus, Ferocactus acanthodes, in the Colorado desert.

The structural characteristics, water relations, and photosynthesis of Ferocactus acanthodes (Lemaire) Britton and Rose, a barrel cactus exhibiting Crassulacean acid metabolism (CAM), were examined in its native habitat in the western Colorado desert. Water storage in its succulent stem permitted nighttime stomatal opening ot continue for about 40 days after the soil water potential became less than that of the stem, a period whe the plant would be unable to extract water from the soil. After 7 months of drought and consequent unreplenished water loss from a plant, diurnal stomatal activity was not observed and the stem osmotic pressure was 6.4 bars, more than double the value measured during wet periods with nighttime stomatal opening. F. acanthodes had a shallow root system (mean depth of 8 cm) which responded within 24 h to rainfall.When the nocturnal stem surface temperature was raised from 8.0° C to 35.0° C, the stomatal resistance increased 4-fold, indicating that cool nighttime temperatures are advantageous for gas exchange by F. acanthodes. Moreover, the optimal temperature for CO2 uptake in the dark was only 12.6° C. CO2 uptake at night became maximal for 3.0 mEinsteins cm-2 of photosynthetically active radiation incident during the preceding day, and the minimum number of incident quanta absorbed per CO2 fixed was 68. The transpiration ratio (mass of water transpired/mass of CO2 fixed) had the relatively low value of 70 for an entire year, consistent with values obtained for other CAM plants. The total amount of water annually diverted to the floral structures was about 6% of the stem wet weight. The annual growth increment estimated from the net CO2 assimilation corresponded to about 10% of the stem mass for barrel cacti 34 cm tall, in agreement with measured dimension changes, and indicated that such plants were about 26 years old.

Water Relations and Photosynthesis of a Desert CAM Plant, Agave deserti

The water relations and photosynthesis of Agave deserti Engelm., a plant exhibiting Crassulacean acid metabolism, were measured in the Colorado desert. Although no natural stomatal opening of A. deserti occurred in the summer of 1975, it could be induced by watering. The resistance for water vapor diffusion from a leaf (R(WV)) became less than 20 sec cm(-1) when the soil water potential at 10 cm became greater than -3 bars, as would occur after a 7-mm rainfall. As a consequence of its shallow root system (mean depth of 8 cm), A. deserti responded rapidly to the infrequent rains, and the succulent nature of its leaves allowed stomatal opening to continue for up to 8 days after the soil became drier than the plant. When the leaf temperature at night was increased from 5 to 20 C, R(WV) increased 5-fold, emphasizing the importance of cool nighttime temperatures for gas exchange by this plant. Although most CO(2) uptake occurred at night, a secondary light-dependent rise in CO(2) influx generally occurred after dawn. The transpiration ratio (mass of water transpired/mass of CO(2) fixed) had extremely low values of 18 for a winter day, and approximately 25 for an entire year.

A TAXONOMIC STUDY OF THE GENUS TEGRODERA (COLEOPTERA: MELOIDAE)

AbstractThree allopatric species are recognized in the North American genus Tegrodera LeConte. Speciation was probably a relatively recent event in this genus as all species are closely related, and separable by minor but consistent differences of adult anatomy. The most distinctive species, T. aloga Skinner, ranges throughout much of the Sonoran Desert in western Arizona and northwestern Sonora. T. erosa LeConte, a species occurring in southern California and Baja California, is separated geographically from T. aloga by the arid Colorado Desert. T. erosa consists of two distinct subspecies, the nominate form occurring in southern California, and T. e. inornata Blaisdell distributed throughout much of Baja California. T. latecincta Horn, a species found in the Owens and Antelope valleys of California, is the closest relative of T. erosa. It is separated from the latter by the San Gabriel and San Bernardino mountains, and from T. aloga by the vast Mojave Desert. The species of Tegrodera are each associated with different plant communities, though the genus Eriastrum seems to be an important food source for all adults. The taxonomic analysis presented herein includes the study of both intra- and interspecific variation. The first instar larva of T. aloga and T. e. erosa are compared, and notes on seasonal distribution, habitat, and non-sexual behavior are included.

Distribution and Activity of the Desert Cockroach Arenivaga Investigata (Polyphagidae) in Relation to Microclimate

Arenivaga investigata is abundant in sand dunes of the Colorado desert at the foot of Mount San Jacinto, California. Measurements of temperature and humidity were made in its habitat at various depths in the sand over 24—h periods at least once each month from July 1967 to July 1968. At the driest and hottest times of the year (surface temperature 72°C, RH < 10%), relative humidities of 82% and above were available only 45 cm below the surface, and temperatures below 40°C occurred at —7.5 cm or lower. Since the insects can absorb water vapor from 82% RH or above, their source of water is assured. Onset of subsurface activity towards nightfall may be correlated with the movement downward of the temperature inversion, but this is not proved. The insects are found much more commonly in the sand near or under shrubs than in open sand. Their vertical distribution shows a maximum at —12.5 cm in July, and at —5 cm in November. In July most insects were found at temperatures between 30° and 35°C, whereas in November they were most frequent from 22° to 26°C. This seasonal difference in distribution, which could be attributed to acclimation, awaits further analysis.

The Cahuilla Indians of the Colorado Desert: Ethnohistory and Prehistory. Part 1 "Early Observations on the Cultural Geography of Coachella Valley"

The Cahuilla Indians of the Colorado Desert: Ethnohistory and Prehistory. Part 1 "Early Observations on the Cultural Geography of Coachella Valley"

Sympatric Relationships of the Kangaroo Rats, Dipodomys merriami and Dipodomys agilis

Dipodomys merriami collinus and Dipodomys agilis cabezonae are two heteromyid rodents that occur in partial sympatry on the western edge of the Colorado Desert in California. Activity patterns, interspecific behavior and water requirements were investigated in the laboratory and correlated with the relative distributions of these species in the field. D. m. collinus and D. a. cabezonae were trapped in a vegetation cline along an altitudinal topographic gradient. There was a reversal of relative abundance of these two species along this cline. This study revealed apparent subspecific differences in the ability of D. agilis to produce concentrated urine, but no apparent differences under the midly stressful environmental conditions were noted between D. agilis and D. merriami .

Potassium-Argon Geochronometry of Mesozoic Igneous Rocks in Nevada, Utah, and Southern California

Research Article| April 01, 1973 Potassium-Argon Geochronometry of Mesozoic Igneous Rocks in Nevada, Utah, and Southern California RICHARD LEE ARMSTRONG; RICHARD LEE ARMSTRONG 1Department of Geology and Geophysics, Yale University, New Haven, Connecticut 06520 Search for other works by this author on: GSW Google Scholar JOHN SUPPE JOHN SUPPE 2Department of Geology, University of California, Los Angeles, California 90024 Search for other works by this author on: GSW Google Scholar Author and Article Information RICHARD LEE ARMSTRONG 1Department of Geology and Geophysics, Yale University, New Haven, Connecticut 06520 JOHN SUPPE 2Department of Geology, University of California, Los Angeles, California 90024 Publisher: Geological Society of America First Online: 01 Jun 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Geological Society of America GSA Bulletin (1973) 84 (4): 1375–1392. https://doi.org/10.1130/0016-7606(1973)84<1375:PGOMIR>2.0.CO;2 Article history First Online: 01 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation RICHARD LEE ARMSTRONG, JOHN SUPPE; Potassium-Argon Geochronometry of Mesozoic Igneous Rocks in Nevada, Utah, and Southern California. GSA Bulletin 1973;; 84 (4): 1375–1392. doi: https://doi.org/10.1130/0016-7606(1973)84<1375:PGOMIR>2.0.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGSA Bulletin Search Advanced Search Abstract K-Ar dates for 123 mineral separates from 91 samples of granitic rocks, and 3 samples of Orocopia and Vitrefax Schist from Nevada, western Utah, the Mojave Desert, the Colorado Desert, and the northern and eastern Peninsular Ranges of southern California, range in age from 218 to 19 m.y.; however, most of the dates lie between 160 and 50 m.y. A majority of the hornblende and muscovite dates are nearly concordant with, but generally a few m.y. older than, coexisting biotite dates; some are highly discordant.The oldest plutons gave Late Triassic to Early Jurassic dates (El Paso and San Bernardino Mountains, 218 to 194 m.y.). Jurassic igneous activity reached a culmination slightly before 150 m.y. ago over a large area in northern Nevada and western Utah and supplied ash to the Morrison Formation of the Colorado Plateau. Several plutons of the northeastern Mojave Desert yielded similar dates.A similar major culmination of Mesozoic pluton emplacement in early and middle Late Cretaceous time is represented by scattered plutons in Nevada and probably by most of the plutons in the Peninsular Ranges and southern deserts of California. Earliest Tertiary dates were obtained from far-southeastern California (50 to 66 m.y.).Most dates in the Cordilleran batholith belt of the Southwest, which parallels the edge of the late Mesozoic continent, are between 160 and 75 m.y. and are essentially coeval with metamorphism in the parallel high-pressure, low-temperature Franciscan belt to the west (approximately 150 to 75 m.y.). About 75 m.y. ago, this pattern abruptly changed to a Laramide one with abundant 75 to 50 m.y. dates in a belt running through southern Arizona into southeastern California at a high angle to the edge of the continent. Only very sparse dates of this age are found in Nevada. Abundant Laramide dates are not encountered again until the Idaho, Boulder, and Coast Range batholiths. These important changes in Cordilleran tectonics may be effects of a change from dominantly dip-slip subduction during Franciscan time to dominantly north-northeast strike-slip subduction during Laramide time. Furthermore, the initiation of rifting of eastern North America in Triassic time, changes in spreading rate, and reorientation of spreading directions in the Atlantic Ocean appear to correlate with the beginning of widespread pluton emplacement in western North America, changes in the rate of magma generation in the Cordillera, and shifts of the Cordilleran tectonic pattern, respectively, during Mesozoic time. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.

THE CHIRONOMIDAE (DIPTERA) OF THE PHILIP L. BOYD DEEP CANYON DESERT RESEARCH CENTER, RIVERSIDE CO., CALIFORNIA

AbstractCollections of chironomids have been made in Deep Canyon, a part of the Colorado Desert in Southern California, since 1963. Of the 73 species collected 40 were species new to science. These will be described in later publications. Adults emerged during all months of the year with maximum number of species occurring in June. The fauna is dominated by the Orthocladiinae with 34 species with the Chironominae a close second with 26 species. Of those subfamilies known from North America only the Diamesinae was not represented.

Pollen Morphology of the Dalea mollis-D. neomexicana Complex (Leguminosae) in the United States

Variation in the pollen morphology of the Dalea mollis-D. neomexicana complex has been studied from collections in the United States. An attempt to correlate the pollen polar length average per specimen with the calyx length was only partially successful. When the collections were plotted geographically by county, the shortest pollen polar length averages (smaller, prolate pollen grains) were concentrated in the Yuma and Colorado deserts with the longer pollen polar length averages (longer, polarly constricted pollen grains) radiating northward into the Mohave Desert and southeastward into the Chihuahuan Desert. The evidence presented indicates that these two species should be tentatively regarded as one species with two varieties-Dalea mollis var. mollis and var. neomexicana-until a more detailed study is made which should include the pollen morphology of plants from the Sonoran and Chihuahuan deserts of Mexico. During a study of the pollen morphology of the Psoraleae tribe (Mahler, 1965), variations were encountered in the pollen grain morphology of specimens labeled Dalea mollis Benth. This preliminary investigation represents the data accumulated up to the present time. MATERIALS AND METHODS. Pollen samples were taken from herbarium specimens and permanent acetolyzed pollen slides were prepared using the acetolysis method (Erdtman, 1960) as modified by Lewis (1965). Herbarium specimens and their respective acetolyzed pollen slides are on deposit as indicated (Lanjouw and Stafleu, 1964). The author has retained a duplicate of each slide prepared. Acetolyzed pollen grain measurements from 20 specimens were based on an average polar and equatorial length and width from 10 grains per specimen (= slide). One slide had only 3 grains (Jones 26156) probably because of the extreme length of the pollen grains (Table 1) in relation to the approximately 50 micron mesh screen used in the filtering process. Photographs were taken with a Polaroid MP-3 Land Camera from a Wild M-20 microscope with a plane fluotar objective and green filter.

Seasonal Adaptations in Photosynthesis and Respiration in Four Desert Shrubs Growing in Situ

Field measurements of carbon dioxide exchange and carbohydrate resources show that physiological adaptations occur in the shrubs Larrea divaricata, Encelia farinosa, Hymenoclea salsola, and Acacia greggii growing in situ in the Colorado Desert of California. L. divaricata, the most widely distributed shrub of the North American deserts, exhibited the greatest seasonal adaptation in the field. This study supports the hypothesis that adaptive temperature acclimations occur in plants.

Mammals of Deep Canyon, Colorado Desert, California

Journal Article Mammals of Deep Canyon, Colorado Desert, California Get access Ryan R. Mark. Mammals of Deep Canyon, Colorado Desert, California. The Desert Museum, 135 E Tahquitz—McCallum Way, Palm Springs, California, x -f- 137 pp., colored frontispiece and 39 other illustrations, colored fold-out map, 1967. Price, $7.00. J. Knox Jones, Jr. J. Knox Jones, Jr. Search for other works by this author on: Oxford Academic Google Scholar Journal of Mammalogy, Volume 49, Issue 4, 26 November 1968, Page 798, https://doi.org/10.2307/1378767 Published: 26 November 1968