• The Page Ranch Story - Its Vegetative History and Management Implications

      Schmutz, Ervin M.; Sourabie, Martin K.; Smith, David A.; School of Renewable Resources, University of Arizona; Bobo; U.S.D.A. Soil Conservation Service (University of Arizona (Tucson, AZ), 1985)
    • Patterns on Desert Plants

      Newell, Alan C.; Shipman, Patrick D.; Cooke, Todd J.; Department of Mathematics, The University of Arizona; Department of Mathematics, Colorado State University; Department of Cell Biology and Molecular Genetics, University of Maryland (University of Arizona (Tucson, AZ), 2012-06)
      The patterns seen in both the phyllotaxis and surface morphologies in the vicinity of the shoot apical meristems of plants are discussed. We begin with many pictures and a narrative descriptive of both the universal and anomalous features of desert and other plants. We then briefly outline explanations and open challenges. Although many of the special features of phyllotaxis have been known for over four centuries, only now are mechanistic explanations beginning to emerge.
    • Perennial Festuca (Gramineae) of New Mexico

      Allred, Kelly W.; Rance Science Herbarium (NMCR), Department of Animal & Rance Sciences, New Mexico State University (University of Arizona (Tucson, AZ), 2005-12)
    • Phenology and Stand Composition of Woody Riparian Plants in the Southwestern United States

      Brock, John H.; School of Agribusiness and Environmental Resources, Arizona State University (University of Arizona (Tucson, AZ), 1994-06)
      Knowledge of phenology is important for understanding the autecology of a species. Information concerning flowering dates, leaf development, seed/fruit dispersal, and aberrant weather effects on phenological status of a species should be well utilized by persons interested in the ecology, management and restoration of riparian communities. The phenology and stand composition of key woody species from selected riparian areas of the southwestern United States was studied. Eight riparian tree species were observed monthly (bimonthly in summer) at six sites in eastern Arizona and New Mexico. Phenological events were placed into eight categories for data collection. Stand composition data was collected from four randomly located macroplots at each site in the summer of 1983. Weather data for the period of study was summarized for the region. Four general phenology groups were identified: 1) spring flowering and fruit dispersal as characterized by Fremont cottonwood (Populus fremontii) and Goodding willow (Salix gooddingii), 2) Spring flowering/autumn-winter fruit dispersal characterized by box elder (Acer negundo var. interius), netleaf hackberry (Celtis reticulata), Arizona sycamore (Plantanus wrightii), and velvet ash (Fraxinuspennsylvanica ssp. velutina), 3) Spring flowering and late summer fruit dispersal demonstrated by Arizona walnut (Juglans major), and 4) Multidate flowering and fruit dispersal displayed by velvet mesquite (Prosopis velutina). Fremont cottonwood and Goodding willow dominated the sites, while netleaf hackberry, box elder, velvet ash and Arizona walnut were minor components of the stands. Variation in phenology of the tree species reflected individual species adaptations to the particular environment.
    • Phenotypic Variations in Communities of Calligonum comosum L'Her (Polygonaceae) from Saudi Arabia

      Taia, Wafaa K.; Moussa, Sanaa A. I.; Alexandria University, Botany Department; Cairo University, Botany Department (University of Arizona (Tucson, AZ), 2011-12)
      Vegetative community structures and phenotypic variations within Calligonum comosum L'Her communities growing in two different locations in Saudi Arabia, Nefud Al-Shakika and Al-Dahnaa, have been studied. Eleven species have been recorded in both areas; five of them were present in both locations. Ephedra elata and Convolvulus lanatus were recorded in Nefud Al-Shakika only, while Heliotropium bacciferum, Cleome arabica, Dodonaea vis cos a and Erodium gleurocophyllum were found in Al-Dahnaa only. The Importance Values of the species recorded have been calculated and cluster analyses of the studied quadrats have been conducted using TWINSPAN. Vegetative morphological characteristics showed great variation within Calligonum comosum collected from the two locations. Floral morphological characteristics were more stable, except for fruit color and hair which were different in the Calligonum comosum plants grown in the two locations. Epidermal stem secretions as well as mineral content varied in response to change in location. AN OVA tests have been carried out to evaluate the differences between the two areas. The variations in these characteristics are discussed according to the differences in climate, soil and water availability.
    • Physiological and Stuctural Mechanisms of Niche Differentiation for Three Sky Island Oaks in Relation to Light and Temperature

      Poulos, Helen M.; Berlyn, Graeme P.; Goodale, Uromi M.; School of Forestry and Environmental Studies, Yale University (University of Arizona (Tucson, AZ), 2008-06)
      In an effort to identify the influence of light and temperature on the physiology and leaf structural characteristics of three species of Quercus from Coahuila, Mexico, we measured a comprehensive suite of plant traits as functions of light and temperature intensity. We tested the hypotheses that 1) species' physiological responses to light and temperature were related to their distributions in their native habitats; and 2) that species' physiological responses corresponded to similar variation in leaf anatomical and morphological traits. Quercus sideroxyla was adapted to high elevation forest over stories as evidenced by its high photosynthetic rate, transpiration rate, relative water content (RWC), leaf density (LD), and thick palisade and spongy parenchyma. Quercus rugosa displayed typical characteristics of a forest understory species including a low photosynthetic rate and light saturation point, thick spongy parenchyma tissue and high RWC, leaf density, and leaf mass per unit area. Quercus laceyi was adapted to hot, dry sites based on its lower RWC and LD, intermediate photosynthetic rate, thick cuticle and upper epidermis, and low transpiration rates at high temperatures. Our results suggest that the physiological and structural adaptations of Mexican oaks to changing environmental conditions across resource gradients are key regulators of plant community structure.
    • Piman Indian Historic Agave Cultivation

      Dobyns, Henry F.; Newberry Library (University of Arizona (Tucson, AZ), 1988)
      The lands occupied by northern Piman Indians yet display remains of old ways of life, the hallmark being ruins of massive "casa grande" style architectural complexes within puddled adobe walled compounds. Vestiges of "rockpile" fields occur on desert bajadas that seem to have little potential for traditional hispanic or anglo agriculture. Evidence has accumulated that critical population pressures once exerted heavy demands on the food supply in this region, with resultant internecine strife and competition, the massive walled architectural complexes functioning as defensible storehouses for food that was harvested from the resource area controlled or exploitable by the inhabitants. The rockpile fields were used for agricultural production of the sweet foodplant Agave, using an innovative technology that made use of agriculturally marginal land (see Desert Plants Volume 7, pp. 107 -112, 100). The European encounter of Pimans occurred to the south long before it occurred to the north, at a time when ways of life were rapidly changing. A rare glimpse of southern Piman life about 1613 by Rev. Andrés Pérez de Ribas presents an historic picture of Agave cultivation by people living in houses with massive puddled adobe walls. This Piman way of life at that time in the southern region is altogether consistent with the vestiges of what seems to have been the same lifestyle in the north. Old World diseases brought a general collapse of Native American populations; the pressures that generated casa grande style architecture, earth defensive walls, and Agave cultivation in Piman territory diminished, a terminal date for the complex more likely to have been after A.D. 1613 than the traditional date of "Classic Hohokam" demise about A.D. 1450. Introduction of Old World cultivars high in sugar (melons, peaches, apricots, quinces, pears, apples, sugar cane) also reduced Piman demand for sweet pulp of Agave. Watermelons were already substituting as a functional equivalent of Agave by 1698 among northern Pimans. Both the casa grande style ruins and the rockpile fields were abandoned by the time European civilization reached the northern Pimans. Both have been classified as "Hohokam" by archaeologists, using the plural of the Piman language word meaning "all used up" or "defunct."
    • Plains and Great Basin Grasslands

      Brown, David E.; Arizona Game and Fish Department (University of Arizona (Tucson, AZ), 1982)
    • Plains and Great Basin Riparian Wetlands

      Minckley, W. L.; Brown, David E.; Department of Zoology, Arizona State University; Arizona Game and Fish Department (University of Arizona (Tucson, AZ), 1982)
    • The Plant Collecting Brandegees, with Emphasis on Katharine Brandegee as a Liberated Woman Scientist of Early California

      Crosswhite, Frank S.; Crosswhite, Carol D.; Boyce Thompson Southwestern Arboretum (University of Arizona (Tucson, AZ), 1985)
    • Plant Geography of Southwestern Sand Dunes

      Bowers, Janice E. (University of Arizona (Tucson, AZ), 1984)
      Patterns of plant distribution among eight dune fields in the southwestern USA and northwestern Mexico are analyzed and discussed. Each dune flora is characterized by three to five geographic components; the regional flora in which each dune field occurs is the dominant component. Endemic species, that is, species restricted to sand dunes, comprise ten percent or more of five of the eight floras. All possible combinations of the eight dune floras taken two at a time (28 pairs) were analyzed using Sorensen's similarity index. Only seven have a similarity value of 0.200 or greater. The lack of similarity among dune floras is due in part to their distribution among four floristically distinct biogeographic provinces and in part to localized recruitment of species from adjacent, non -dune plant communities. Geographic, edaphic and temporal barriers to dispersal and establishment also promote high dissimilarity among the eight floras. Eighty -three of the 533 species composing the eight dune floras are either endemic to sand dunes or occur at three or more of the dune fields studied. These 83 species fall into two subgroups: a group of 36 species characteristic of southwestern sand dunes east of 113° Longitude, and a group of 57 species characteristic of sand dunes west of 113° Longitude. Ten species are common to both groups. In the Southwest, dune fields are habitat islands, but dune floras do not behave in all respects as predicted by the MacArthur and Wilson theory of island biogeography. Southwestern sand dunes are not now floristic islands, but additional insular characteristics may develop over time.
    • Plants Found Along the Effluent Dominated Stretch of the Middle Santa Cruz River

      Gormally, Josh (University of Arizona (Tucson, AZ), 2011-06)
    • Pollen Harvest by Sonoran Desert Honey Bees: Conservation Implications for Native Bees and Flowering Plants

      Buchmann, Steven L.; Shipman, Charles W.; USDA-ARS Carl Hayden Bee Research Center; Arizona-Sonora Desert Museum (University of Arizona (Tucson, AZ), 1996-06)
      Managed and feral honey bee colonies (Apis mellifera) harvest immense quantities of nectar and pollen within kilometers of their nests whether they live in relatively undisturbed or agricultural habitats. Within the Sonoran Desert of southern Arizona, pollen collection by European honey bee colonies was monitored by the use of apicultural pollen traps. Managed colonies near Tucson, Arizona routinely collected from 20 to 50 kg of pollen each year. Flowering pulses (phenology) in the local flora was closely tracked by the colonies, and pollen influx into their nests usually occurred as three to four distinct seasonal peaks, although some pollen was actively harvested during 48 or more weeks every year. The range of flowers visited for pollen by the honey bee is likely the most diverse for any social or solitary bee yet studied, largely due to their massive food requirements, efficient scouting and recruitment to ephemeral flower patches, and persistence of their colonies as perennial units for many years. At most Sonoran Desert sites, honey bee colonies took pollen from at least 12 and as many as 40-50 dominant angiosperm taxa. Additionally, pollen diet breadth of feral honey bee colonies was determined microscopically from blackened below-nest refuse deposits known as bee middens. One such deposit from the Arizona-Mexico borderlands is thought to represent more than a half century of accumulated materials. Honey bees are dominant invertebrate herbivores in desert regions taking pollen and nectar in massive amounts from at least 25 percent of the local flora. Had this pollen remained on its host plants, it would have been available for transport by co-adapted insect, bird and bat pollinators which are often better at depositing viable pollen, effecting subsequent fertilization, fruit and seed set on native flowering plants. Sonoran Desert bees are predominantly specialist feeders and depend upon certain plants more than honey bees which can switch hosts at will and have a highly mixed diet. Thus, in direct competition with these alien social bees living in large colonies, native desert bees are often at a disadvantage in acquiring pollen and producing replacement offspring. Desert flowering plants, especially rare, threatened and endangered species are also adversely affected since honey bees remove most of the pollen and often are responsible for setting fewer seeds or dispersing pollen at different distances than their original pollinators once did.
    • Prehistoric Cultivation in Southern Arizona

      Fish, Suzanne K.; Fish, Paul R.; Miksicek, Charles; Madsen, John; Arizona State Museum; Office of Arid Lands Studies, University of Arizona (University of Arizona (Tucson, AZ), 1985)
      Gathering of wild agave for food and fiber is widely recognized in ethnographic accounts of Southwestern Indians. Historically documented cultivation is limited to small-scale plantings and has not established agave as a significant aboriginal cultigen. The apparent absence of agave as a cultivated staple among peoples of the Sonoran Desert contrasts with pre-Columbian and historic ubiquity of this crop further south. It is a major cultigen throughout the rest of highland Mexico, including areas in Durango and Zacatecas, often considered within the greater Southwestern cultural sphere. Current archaeological evidence suggests that agave figured more prominently in prehistoric Southwestern agriculture than in that of subsequent groups.
    • Preliminary Evaluation of Cold-hardiness in Desert Landscaping Plants at Central Arizona College

      Kinnison, William A.; Central Arizona College (University of Arizona (Tucson, AZ), 1979-08)
    • Preliminary Findings of the Southwest Monarch Study

      Kline, C. L.; Boyce Thompson Southwestern Arboretum (University of Arizona (Tucson, AZ), 2007-06)
    • A Preliminary Theory for an Approach to Planning Environmentally Balanced Desert Landscaping

      Crosswhite, Frank S.; Crosswhite, Carol D.; Boyce Thompson Southwestern Arboretum (University of Arizona (Tucson, AZ), 1988)
    • Preservation of Genetic Diversity

      University of Arizona (Tucson, AZ), 1982-06
    • Propagation Techniques for Desert Plants

      Newland, Kent C.; Ives, Sarah; Joseph, Gene E.; Dimmitt, Mark A.; Mittleman, Marc; Foster, R. E.; Scannell, Carol; Feldman, W. R.; Crosswhite, Frank S.; Hansen, Chuck; et al. (University of Arizona (Tucson, AZ), 1981)
    • Propogation of Taxosium mucronatum from Softwood Cuttings

      St. Hilaire, Rolston; Department of Agronomy and Horticulture, New Mexico State University (University of Arizona (Tucson, AZ), 2003-06)
      Mexican bald cypress (Taxodium mucronatum Ten.) is propagated from seed, but procedures have not been reported for the propagation of this ornamental tree by stem cuttings. This study evaluated the use of softwood cuttings to propagate Mexican bald cypress. Softwood cuttings were collected on 16 October 1998 and 1999 from Las Cruces and Los Lunas, New Mexico, treated with either 3000 or 8000 ppm of indole-3-butyric acid (IBA) and held under intermittent mist in a greenhouse for 13 weeks. In 1998, cuttings sampled from one of two Los Lunas trees showed 48% and 82% rooting when treated with IBA at 3000 or 8000 ppm, respectively. Root number and average root length were 9 and 3 times greater, respectively, with 8000 ppm IBA than with 3000 ppm IBA. More 1998 cuttings rooted (65%) than 1999 cuttings (10%) when means were combined over IBA treatments. Results indicate that efficient propagation of Mexican bald cypress by cuttings depends on exogenous IBA and selection of stock plants amenable to root formation.