DOCSLIB.ORG

Pollen Evidence of Floristic Turnover Forced by Cool Aridity During the Oligocene in Colorado GEOSPHERE; V

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Pollen Evidence of Floristic Turnover Forced by Cool Aridity During the Oligocene in Colorado GEOSPHERE; V Research Paper GEOSPHERE Pollen evidence of floristic turnover forced by cool aridity during the Oligocene in Colorado GEOSPHERE; v. 15, no. 1 Estella B. Leopold and Stephanie Zaborac-Reed University of Washington, Department of Biology, Box 351800, Seattle, Washington 98195, USA https://doi.org/10.1130/GES01689.1 7 figures; 6 plates; 11 tables; ABSTRACT Manchester, 1997). In Colorado, the EOT is associated with a period of cooling 1 set of supplemental files and severe aridity lasting most of the Oligocene. One of our strongest contri- New pollen data from four Oligocene floras in volcanic landscapes of Colo­ butions is the addition of the pollen record from four Oligocene floras, which CORRESPONDENCE: eleopold@ uw.edu rado record important climatic shifts that reshaped the local flora and promoted had not been reported previously. This pollen record is an important aspect the development of sub­arid vegetation types. We combined new pollen data of this paper for assessing the total flora. The emphasis of this study is on the CITATION: Leopold, E.B., and Zaborac-Reed, S., 2019, Pollen evidence of floristic turnover forced by with previous megafossil evidence to assess vegetation changes during the evolutionary and climatic significance of the floristic changes during the EOT. cool aridity during the Oligocene in Colorado: Geo- Eocene–Oligocene Transition (EOT). Pollen data are the basis for updating Five Colorado floras of late Eocene through Oligocene age lie within the sphere, v. 15, no. 1, p. 254–294, https:// doi .org /10 the list of flora identified at Creede. Local extinctions in response to lower sum­ geographic mix of caldera and volcanic settings in the central Colorado vol- .1130 /GES01689.1. mer rainfall abruptly removed many of the exotic woody taxa of eastern North canic area and in the San Juan volcanic field in southwestern Colorado (Fig. 1). American and Asian affinity. This loss was followed by the appearance of xeric The floras are, in ascending order: the Florissant (34.1 Ma), Antero (33.8 Ma), Science Editor: Shanaka de Silva Associate Editor: Rhawn Denniston shrubland taxa of the Ponderosa pine­fir woodland and sagebrush flora that Pitch-Pinnacle (between 32.9 and 29 Ma), Platoro (28.0 Ma), and Creede characterize the Colorado area today. Tell­tale genera appear and suggest an (26.9 Ma) assemblages (Fig. 2; Table 1). The purpose of this report is to sup- Received 6 March 2018 understory of shrubs such as Artemisia, Elaeagnus, Ribes, Ephedra, Jamesia, plement previous work on plant megafossils of the Oligocene in Colorado with Revision received 22 August 2018 and Shepherdia. Poaceae are also present. Significantly, herbaceous taxa of our new work on fossil pollen. We characterize the pollen and megafossil floras Accepted 9 November 2018 the Asteraceae, Rosaceae, Cucurbitaceae, Euphorbiaceae, and Caryophyllaceae from just before and after the EOT and interpret the climatic and floristic shifts Published online 10 January 2019 make their first appearances in the fossil record of Colorado here. that they demonstrate with emphasis on the following questions: The new Oligocene pollen data record a significant drop in summer rainfall and a climatic cooling at 33.8 Ma of several degrees that relates to the Oi­1 (1) What was the scale of the climatic shift based on the floras, and how glaciation in Antarctica. The particular taxa that continued after the EOT were does it relate to possible uplift of the region? a basis for estimating changes in soil moisture during this time. The condi­ (2) What was the evolutionary significance of the floristic changes during tions in Colorado are reminiscent of Wolfe’s “terminal Eocene event.” This re­ the Colorado EOT? markable shift precipitated the development of a local pollen and megafossil (3) What estimates of paleoelevation may be based on these floras and the flora more “modern” in aspect (e.g., a larger proportion of extant local genera local geology of the sites? are present). The impressive floristic turnover was probably a response to the (4) How do climate tools such as coexistence approach, detrended corre- increasingly continental climate that embraced the area during the Oligocene. spondence analysis, the Sørensen index, and nearest living relatives analysis assist the interpretation of the floras in terms of inferred mean OLD G 1. INTRODUCTION annual temperature (MAT) and precipitation (PPT)? (5) How do the inferred climate shifts compare to conditions in other parts The global climate change at the Eocene–Oligocene transition (EOT) of the world during the EOT? (33.4 Ma; Prothero and Berggren, 1992) is the largest abrupt cooling of the OPEN ACCESS Cenozoic (Zachos et al., 2001). During the EOT, changes in circulation result- 2. BACKGROUND ing from the development of deep-water passages separating Antarctica from South America (beginning ca. 33 Ma) (Graham, 2011; Lawver et al., 2011) may Our fossil records span the latest Eocene Florissant flora (34.1 Ma) and have contributed to the major worldwide cooling and associated aridity re- four progressively younger Oligocene floras (33.8 Ma–26.9 Ma; Table 1). This lated to Antarctic glaciation Oi-1 (Cather et al., 2008). This post-Eocene cool- interval is closely synchronous with large-scale explosive volcanism in the ing and aridity resulted in local and regional extinctions of plant, vertebrate, southern Rocky Mountains (mainly 37–27 Ma), the development of the Oi-1 This paper is published under the terms of the and invertebrate taxa (Prothero, 1985a, 1985b; Hutchison, 1992; Legendre and glaciation and the “Ice House,” and the period of great aeolian activity along CC-BY-NC license. Hartenberger, 1992; Prothero and Berggren, 1992; Wolfe, 1992; Meyer and the Arizona–New Mexico border (Zachos et al., 2001; Cather et al., 2008). © 2019 The Authors GEOSPHERE | Volume 15 | Number 1 Leopold and Zaborac-Reed | Pollen evidence of floristic turnover during the Colorado Oligocene Downloaded from http://pubs.geoscienceworld.org/gsa/geosphere/article-pdf/15/1/254/4619230/254.pdf 254 by guest on 03 October 2021 Research Paper 2.1. Regional Geological Setting of the Five Paleogene Floras in Colorado The Florissant fossil beds formed after a comparatively small volcanic event that dammed a lake at the end of the Eocene. In contrast, the Oligocene floras that immediately followed in southwestern Colorado developed in local volcanic sediments. The San Juan volcanic field produced 28 large-volume ignimbrite eruptions between 36.9 Ma and 26.9 Ma (Lipman and McIntosh, 2008; Lipman et al., 2015). Ponding of distal ash from these and the formation of lakes within source calderas are the main sites for the floras discussed here. The Florissant Formation formed when a lahar blocked the Florissant Valley in the Thirtynine Mile volcanic area (36.9 Ma to 34.3 Ma), leading to the devel- opment of Lake Florissant (McIntosh and Chapin, 2004; Fig. 1). Distal ash asso- ciated with Mount Aetna nearby accumulated in another intermontane lake to form the Oligocene Antero Formation (33.8 Ma). In addition, lake deposits of the Pitch-Pinnacle flora accumulated within and near the Marshall caldera at ca. 33.8 Ma (Lipman et al., 2013, 2015). Shortly after this, a dune field of aeolian dust and sand in the Chuska Mountains of northwestern New Mexico Figure 1. Reference map of the Colorado and New Mexico Oligocene calderas, with the five and Arizona (Fig. 1) formed at ca. 33.5 Ma and lasted until 28–26 Ma (Cather flora sites indicated (after Chapin, 2012). The floras studied are: (1) Florissant;( 2) Antero; et al., 2008, 2012). Called the Chuska erg, or sand sea, these deposits (as thick (3) Pitch­Pinnacle; (4) Platoro, and (5) Creede. The La Garita caldera is represented by the as 535 m) resulted from large accumulations of airborne and fluvial material in outline surrounding the group of San Juan volcanic field calderas clustered around Creede. the central and southern Colorado Plateau (McIntosh et al., 1992). Figure 2. Map of Creede area, including lo­ cations of pollen collections (D numbers) and megafossil collections (circles). Based on The National Map (http:// nationalmap .gov) shaded relief map and the 7.5 min series Creede quadrangle map, U.S. Geo­ logical Survey, 2013. GEOSPHERE | Volume 15 | Number 1 Leopold and Zaborac-Reed | Pollen evidence of floristic turnover during the Colorado Oligocene Downloaded from http://pubs.geoscienceworld.org/gsa/geosphere/article-pdf/15/1/254/4619230/254.pdf 255 by guest on 03 October 2021 Research Paper TABLE 1. IE ROCY MONTAIN PALEOGENE LORAS O COLORADO IN STRATIGRAPHIC ORDER lora Present elevation lora source and No. of taa for Ages of associated formations or volcaniclastics km)Vegetation type stratigraphic source this report Oligocene Creede 2.7–3.3 Open coniferous forest, mid-montane and Aelrod 1987 49 26.87 0.03 Ma (40Ar/39Ar using l-rich dacite youngest montane olfe and Schorn 1989, 1990) from Snowshoe Mountain Tuff; Lipman, 2007) eposures* Ecotone between mied conifer forest upland Lanphere 2000 and pinyon uniper woodlands and scrub Leopold and Zaborac-Reed 2014 Aelrod This report Platoro 3.1 Open coniferous forest, montaneChase et al. 1998 36 27.98 0.11 Ma (40Ar/39Ar using biotite from Meyer 1986 Chiuito Peak Tuff; Lipman and Bachmann, Lipman 2000 2015 Lipman and McIntosh 2008 This report pollen Pitch Pinnacle 3 Conifer mied forest Gregory and McIntosh 1996 28 Between 32.9 oldest and 29 youngest Ma Lipman et al. 2015 (40Ar/39Ar using sanidines from Pitch-Pinnacle This report pollen ormation;
Load more

Recommended publications
  • South Dakota to Nebraska
    Geological Society of America Special Paper 325 1998 Lithostratigraphic revision and correlation of the lower part of the White River Group: South Dakota to Nebraska Dennis O. Terry, Jr. Department of Geology, University of Nebraska—Lincoln, Lincoln, Nebraska 68588-0340 ABSTRACT Lithologic correlations between type areas of the White River Group in Nebraska and South Dakota have resulted in a revised lithostratigraphy for the lower part of the White River Group. The following pedostratigraphic and lithostratigraphic units, from oldest to youngest, are newly recognized in northwestern Nebraska and can be correlated with units in the Big Badlands of South Dakota: the Yellow Mounds Pale- osol Equivalent, Interior and Weta Paleosol Equivalents, Chamberlain Pass Forma- tion, and Peanut Peak Member of the Chadron Formation. The term “Interior Paleosol Complex,” used for the brightly colored zone at the base of the White River Group in northwestern Nebraska, is abandoned in favor of a two-part division. The lower part is related to the Yellow Mounds Paleosol Series of South Dakota and rep- resents the pedogenically modified Cretaceous Pierre Shale. The upper part is com- posed of the unconformably overlying, pedogenically modified overbank mudstone facies of the Chamberlain Pass Formation (which contains the Interior and Weta Paleosol Series in South Dakota). Greenish-white channel sandstones at the base of the Chadron Formation in Nebraska (previously correlated to the Ahearn Member of the Chadron Formation in South Dakota) herein are correlated to the channel sand- stone facies of the Chamberlain Pass Formation in South Dakota. The Chamberlain Pass Formation is unconformably overlain by the Chadron Formation in South Dakota and Nebraska.
    [Show full text]
  • Geologic Map of the Central San Juan Caldera Cluster, Southwestern Colorado by Peter W
    Geologic Map of the Central San Juan Caldera Cluster, Southwestern Colorado By Peter W. Lipman Pamphlet to accompany Geologic Investigations Series I–2799 dacite Ceobolla Creek Tuff Nelson Mountain Tuff, rhyolite Rat Creek Tuff, dacite Cebolla Creek Tuff Rat Creek Tuff, rhyolite Wheeler Geologic Monument (Half Moon Pass quadrangle) provides exceptional exposures of three outflow tuff sheets erupted from the San Luis caldera complex. Lowest sheet is Rat Creek Tuff, which is nonwelded throughout but grades upward from light-tan rhyolite (~74% SiO2) into pale brown dacite (~66% SiO2) that contains sparse dark-brown andesitic scoria. Distinctive hornblende-rich middle Cebolla Creek Tuff contains basal surge beds, overlain by vitrophyre of uniform mafic dacite that becomes less welded upward. Uppermost Nelson Mountain Tuff consists of nonwelded to weakly welded, crystal-poor rhyolite, which grades upward to a densely welded caprock of crystal-rich dacite (~68% SiO2). White arrows show contacts between outflow units. 2006 U.S. Department of the Interior U.S. Geological Survey CONTENTS Geologic setting . 1 Volcanism . 1 Structure . 2 Methods of study . 3 Description of map units . 4 Surficial deposits . 4 Glacial deposits . 4 Postcaldera volcanic rocks . 4 Hinsdale Formation . 4 Los Pinos Formation . 5 Oligocene volcanic rocks . 5 Rocks of the Creede Caldera cycle . 5 Creede Formation . 5 Fisher Dacite . 5 Snowshoe Mountain Tuff . 6 Rocks of the San Luis caldera complex . 7 Rocks of the Nelson Mountain caldera cycle . 7 Rocks of the Cebolla Creek caldera cycle . 9 Rocks of the Rat Creek caldera cycle . 10 Lava flows premonitory(?) to San Luis caldera complex . .11 Rocks of the South River caldera cycle .
    [Show full text]
  • "National List of Vascular Plant Species That Occur in Wetlands: 1996 National Summary."
    Intro 1996 National List of Vascular Plant Species That Occur in Wetlands The Fish and Wildlife Service has prepared a National List of Vascular Plant Species That Occur in Wetlands: 1996 National Summary (1996 National List). The 1996 National List is a draft revision of the National List of Plant Species That Occur in Wetlands: 1988 National Summary (Reed 1988) (1988 National List). The 1996 National List is provided to encourage additional public review and comments on the draft regional wetland indicator assignments. The 1996 National List reflects a significant amount of new information that has become available since 1988 on the wetland affinity of vascular plants. This new information has resulted from the extensive use of the 1988 National List in the field by individuals involved in wetland and other resource inventories, wetland identification and delineation, and wetland research. Interim Regional Interagency Review Panel (Regional Panel) changes in indicator status as well as additions and deletions to the 1988 National List were documented in Regional supplements. The National List was originally developed as an appendix to the Classification of Wetlands and Deepwater Habitats of the United States (Cowardin et al.1979) to aid in the consistent application of this classification system for wetlands in the field.. The 1996 National List also was developed to aid in determining the presence of hydrophytic vegetation in the Clean Water Act Section 404 wetland regulatory program and in the implementation of the swampbuster provisions of the Food Security Act. While not required by law or regulation, the Fish and Wildlife Service is making the 1996 National List available for review and comment.
    [Show full text]
  • Rodents (Mammalia) from the Pilgrim Creek Local Fauna, Wyoming: a Mixed Eocene and Oligocene Assemblage (Duchesnean to Whitneyan)
    Paludicola 11(2):51-72 March 2017 © by the Rochester Institute of Vertebrate Paleontology RODENTS (MAMMALIA) FROM THE PILGRIM CREEK LOCAL FAUNA, WYOMING: A MIXED EOCENE AND OLIGOCENE ASSEMBLAGE (DUCHESNEAN TO WHITNEYAN) William W. Korth Rochester Institute of Vertebrate Paleontology, 265 Carling Road, Rochester, New York 14610 <[email protected]> ABSTRACT Previously, only the non-eomyid rodents from the Pilgrim Creek fauna of Wyoming have been described (Sutton and Black, 1975; Korth, 1981; Korth and Emry, 2013). This fauna has been considered as Chadronian in age since its first description. Twenty-seven species of rodents are recognized here from this fauna. There is a predominance of Chadronian species (13 taxa); however, the presence of three species known elsewhere from the Duchesnean (“Leptotomus” guildayi, Metanoiamys korthi, Griphomys cf. alecer), four from the Orellan (“Prosciurus” sp., cf. relictus, Eumys elegans, “Scottimus” viduus, Protosciurus sp., cf. P. mengi), and two from the Whitneyan (Leptodontomys douglassi, Ansomys sp., cf. A. cyanotephrus,) demonstrates that the fauna is clearly mixed with elements from four different horizons. INTRODUCTION either earlier or later horizons, demonstrating the evident mixing of faunas. Over 40 years ago, Sutton and Black (1975) _________________________________________ identified 11 species of rodents from the Pilgrim Creek fauna of Wyoming (Table 1). However, TABLE 1. Previously identified rodents from the Pilgrim Creek specimens of the family Eomyidae were not local fauna, Wyoming (Sutton and Black, 1975). described or listed. The locality from which the Ischyromyidae fossils were collected is in the Teton National Forest Ischyromys cf. veterior in Jackson County, Wyoming along Pilgrim Creek Cylindrodontidae (Sutton and Black, 1975).
    [Show full text]
  • (2000), Voluminous Lava-Like Precursor to a Major Ash-Flow
    Journal of Volcanology and Geothermal Research 98 (2000) 153–171 www.elsevier.nl/locate/jvolgeores Voluminous lava-like precursor to a major ash-flow tuff: low-column pyroclastic eruption of the Pagosa Peak Dacite, San Juan volcanic field, Colorado O. Bachmanna,*, M.A. Dungana, P.W. Lipmanb aSection des Sciences de la Terre de l’Universite´ de Gene`ve, 13, Rue des Maraıˆchers, 1211 Geneva 4, Switzerland bUS Geological Survey, 345 Middlefield Rd, Menlo Park, CA, USA Received 26 May 1999; received in revised form 8 November 1999; accepted 8 November 1999 Abstract The Pagosa Peak Dacite is an unusual pyroclastic deposit that immediately predated eruption of the enormous Fish Canyon Tuff (ϳ5000 km3) from the La Garita caldera at 28 Ma. The Pagosa Peak Dacite is thick (to 1 km), voluminous (Ͼ200 km3), and has a high aspect ratio (1:50) similar to those of silicic lava flows. It contains a high proportion (40–60%) of juvenile clasts (to 3–4 m) emplaced as viscous magma that was less vesiculated than typical pumice. Accidental lithic fragments are absent above the basal 5–10% of the unit. Thick densely welded proximal deposits flowed rheomorphically due to gravitational spreading, despite the very high viscosity of the crystal-rich magma, resulting in a macroscopic appearance similar to flow- layered silicic lava. Although it is a separate depositional unit, the Pagosa Peak Dacite is indistinguishable from the overlying Fish Canyon Tuff in bulk-rock chemistry, phenocryst compositions, and 40Ar/39Ar age. The unusual characteristics of this deposit are interpreted as consequences of eruption by low-column pyroclastic fountaining and lateral transport as dense, poorly inflated pyroclastic flows.
    [Show full text]
  • Ignimbrites to Batholiths Ignimbrites to Batholiths: Integrating Perspectives from Geological, Geophysical, and Geochronological Data
    Ignimbrites to batholiths Ignimbrites to batholiths: Integrating perspectives from geological, geophysical, and geochronological data Peter W. Lipman1,* and Olivier Bachmann2 1U.S. Geological Survey, Mail Stop 910, Menlo Park, California 94028, USA 2Institute of Geochemistry and Petrology, ETH Zurich, CH-8092 Zürich, Switzerland ABSTRACT related intrusions cooled and solidified soon shorter. Magma-supply estimates (from ages after zircon crystallization, as magma sup- and volcano-plutonic volumes) yield focused Multistage histories of incremental accu- ply waned. Some researchers interpret these intrusion-assembly rates sufficient to gener- mulation, fractionation, and solidification results as recording pluton assembly in small ate ignimbrite-scale volumes of eruptible during construction of large subvolcanic increments that crystallized rapidly, leading magma, based on published thermal models. magma bodies that remained sufficiently to temporal disconnects between ignimbrite Mid-Tertiary processes of batholith assembly liquid to erupt are recorded by Tertiary eruption and intrusion growth. Alternatively, associated with the SRMVF caused drastic ignimbrites, source calderas, and granitoid crystallization ages of the granitic rocks chemical and physical reconstruction of the intrusions associated with large gravity lows are here inferred to record late solidifica- entire lithosphere, probably accompanied by at the Southern Rocky Mountain volcanic tion, after protracted open-system evolution asthenospheric input. field (SRMVF). Geophysical
    [Show full text]
  • Synteny Analysis in Rosids with a Walnut Physical Map Reveals Slow Genome Evolution in Long-Lived Woody Perennials Ming-Cheng Luo1, Frank M
    Luo et al. BMC Genomics (2015) 16:707 DOI 10.1186/s12864-015-1906-5 RESEARCH ARTICLE Open Access Synteny analysis in Rosids with a walnut physical map reveals slow genome evolution in long-lived woody perennials Ming-Cheng Luo1, Frank M. You2, Pingchuan Li2, Ji-Rui Wang1,4, Tingting Zhu1, Abhaya M. Dandekar1, Charles A. Leslie1, Mallikarjuna Aradhya3, Patrick E. McGuire1 and Jan Dvorak1* Abstract Background: Mutations often accompany DNA replication. Since there may be fewer cell cycles per year in the germlines of long-lived than short-lived angiosperms, the genomes of long-lived angiosperms may be diverging more slowly than those of short-lived angiosperms. Here we test this hypothesis. Results: We first constructed a genetic map for walnut, a woody perennial. All linkage groups were short, and recombination rates were greatly reduced in the centromeric regions. We then used the genetic map to construct a walnut bacterial artificial chromosome (BAC) clone-based physical map, which contained 15,203 exonic BAC-end sequences, and quantified with it synteny between the walnut genome and genomes of three long-lived woody perennials, Vitis vinifera, Populus trichocarpa,andMalus domestica, and three short-lived herbs, Cucumis sativus, Medicago truncatula, and Fragaria vesca. Each measure of synteny we used showed that the genomes of woody perennials were less diverged from the walnut genome than those of herbs. We also estimated the nucleotide substitution rate at silent codon positions in the walnut lineage. It was one-fifth and one-sixth of published nucleotide substitution rates in the Medicago and Arabidopsis lineages, respectively. We uncovered a whole-genome duplication in the walnut lineage, dated it to the neighborhood of the Cretaceous-Tertiary boundary, and allocated the 16 walnut chromosomes into eight homoeologous pairs.
    [Show full text]
  • Wildflowers of Timpanogos Cave National Monument
    Trail Guide Wildflowers of Timpanogos Cave National Monument Photos by Brandon Kowallis Written by Becky Peterson Please preserve the plants by not pick- ing or removing them from your National Monument Welcome to Timpanogos Cave National Monument. This wildflower trail guide will help you identify a few of the many flowers you will see as you hike the cave trail. The flowers in this guide are grouped by color. Each page contains a photo of the wildflower along with information that will help you learn about that particular flower.Other Names describes different common names by which the plant is known, Description points out important characteristics of the flower, Season indicates when flowers are in bloom,Location describes where each flower can be found in the monument, Habitat describes growing conditions where the flower usually grows,Type describes whether the flower is perennial or annual, and Fun Facts include interesting facts about that particular plant. All photos by Brandon Kowallis. Firecracker Penstemon 2 Alcove Golden Rod 13 Common Paintbrush 3 Heartleaf-Arnica 14 Linearleaf Paintbrush 4 Dwarf Goldenbush 15 Woods Rose 5 Mexican Cliffrose 16 Northern Sweetvetch 6 Cliff Jamesia 17 Red Alum Root 7 Colorado Columbine 18 Hoary Aster 8 False Solomon Seal 19 Broadleaf Penstemon 9 Miners Lettuce 20 Little Beebalmer 10 Mountain Spray 21 Showy Milkweed 11 Richardson’s Geranium 22 Beautiful Blazing Star 12 Pale Stickweed 23 Firecracker Penstemon (Penstemon eatonii) Other Names Eaton’s Penstemon, Scarlet Bugler Penstemon Description Has stocks of tubular scarlet flowers and shiny dark green leaves. Can grow up to 2.5 feet tall.
    [Show full text]
  • Evolution of Angiosperm Pollen. 7. Nitrogen-Fixing Clade1
    Evolution of Angiosperm Pollen. 7. Nitrogen-Fixing Clade1 Authors: Jiang, Wei, He, Hua-Jie, Lu, Lu, Burgess, Kevin S., Wang, Hong, et. al. Source: Annals of the Missouri Botanical Garden, 104(2) : 171-229 Published By: Missouri Botanical Garden Press URL: https://doi.org/10.3417/2019337 BioOne Complete (complete.BioOne.org) is a full-text database of 200 subscribed and open-access titles in the biological, ecological, and environmental sciences published by nonprofit societies, associations, museums, institutions, and presses. Your use of this PDF, the BioOne Complete website, and all posted and associated content indicates your acceptance of BioOne’s Terms of Use, available at www.bioone.org/terms-of-use. Usage of BioOne Complete content is strictly limited to personal, educational, and non - commercial use. Commercial inquiries or rights and permissions requests should be directed to the individual publisher as copyright holder. BioOne sees sustainable scholarly publishing as an inherently collaborative enterprise connecting authors, nonprofit publishers, academic institutions, research libraries, and research funders in the common goal of maximizing access to critical research. Downloaded From: https://bioone.org/journals/Annals-of-the-Missouri-Botanical-Garden on 01 Apr 2020 Terms of Use: https://bioone.org/terms-of-use Access provided by Kunming Institute of Botany, CAS Volume 104 Annals Number 2 of the R 2019 Missouri Botanical Garden EVOLUTION OF ANGIOSPERM Wei Jiang,2,3,7 Hua-Jie He,4,7 Lu Lu,2,5 POLLEN. 7. NITROGEN-FIXING Kevin S. Burgess,6 Hong Wang,2* and 2,4 CLADE1 De-Zhu Li * ABSTRACT Nitrogen-fixing symbiosis in root nodules is known in only 10 families, which are distributed among a clade of four orders and delimited as the nitrogen-fixing clade.
    [Show full text]
  • Landscaping with Native Plants by Stephen L
    SHORT-SEASON, HIGH-ALTITUDE GARDENING BULLETIN 862 Landscaping with native plants by Stephen L. Love, Kathy Noble, Jo Ann Robbins, Bob Wilson, and Tony McCammon INTRODUCTION There are many reasons to consider a native plant landscape in Idaho’s short- season, high-altitude regions, including water savings, decreased mainte- nance, healthy and adapted plants, and a desire to create a local theme CONTENTS around your home. Most plants sold for landscaping are native to the eastern Introduction . 1 United States and the moist climates of Europe. They require acid soils, con- The concept of native . 3 stant moisture, and humid air to survive and remain attractive. Most also Landscaping Principles for Native Plant Gardens . 3 require a longer growing season than we have available in the harshest cli- Establishing Native Landscapes and Gardens . 4 mates of Idaho. Choosing to landscape with these unadapted plants means Designing a Dry High-Desert Landscape . 5 Designing a Modified High-Desert Landscape . 6 accepting the work and problems of constantly recreating a suitable artificial Designing a High-Elevation Mountain Landscape . 6 environment. Native plants will help create a landscape that is more “com- Designing a Northern Idaho Mountain/Valley fortable” in the climates and soils that surround us, and will reduce the Landscape . 8 resources necessary to maintain the landscape. Finding Sources of Native Plants . 21 The single major factor that influences Idaho’s short-season, high-altitude climates is limited summer moisture. Snow and rainfall are relatively abun- dant in the winter, but for 3 to 4 months beginning in June, we receive only a YOU ARE A SHORT-SEASON, few inches of rain.
    [Show full text]
  • (Juglandaceae) in the Early Miocene of Panama
    CHAPTER 7 FRUITS OF OREOMUNNEA (JUGLANDACEAE) IN THE EARLY MIOCENE OF PANAMA Fabiany Herrera, Steven R. Manchester,* Rebecca Koll, and Carlos Jaramillo ABSTRACT Permineralized fruits of Juglandaceae have been recovered from the Early Miocene Cucaracha Formation exposed in excavations of the Panama Canal. Transverse sections and peels reveal that the nuts are subdivided into eight chambers at the base, and the nutshell and septa are composed mainly of fibers. Together, these features are found only in the Neotropical juglandaceous clade composed of extant Alfaroa Standl. and Oreomunnea Oerst. Based on the small nut size and rela- tively thin wall and septa, these nuts are assigned to Oreomunnea, which is distinguished from extant Alfaroa by its winged fruits adapted for wind dispersal. A. Graham first reported pollen grains of the Alfaroa/Oreomunnea type from the Miocene of Panama. The new fossil fruits of the Cucaracha Formation are the earliest macrofossil record of Oreomunnea, enhancing our under- standing of the phytogeographic history of Juglandaceae in Central America. If this newly de- scribed fossil species, O. grahamii Manch. & Herrera, grew in similar ecological settings to those of its modern counterparts, the fossils may be an indicator of the medium-high paleotopographic relief of Panama during the Early Miocene. Key words: Alfaroa, fossils, fruits, Juglandaceae, Miocene, Oreomunnea. The Juglandaceae have an excellent fossil rec- Neotropical genera Alfaroa Standl. and Oreo- ord in the Northern Hemisphere, well represented munnea Oerst. have mostly eluded detection in by pollen, leaves, wood, catkins, and fruits. This the macrofossil record. record includes most of the extant genera, plus a Ten genera in two subfamilies are recognized few extinct ones in the Paleogene (Manchester, for the Juglandaceae (Manos & Stone, 2001; 1987, 1989; Elliot et al., 2006).
    [Show full text]
  • 40Ar/39Ar Dating of the Late Cretaceous Jonathan Gaylor
    40Ar/39Ar Dating of the Late Cretaceous Jonathan Gaylor To cite this version: Jonathan Gaylor. 40Ar/39Ar Dating of the Late Cretaceous. Earth Sciences. Université Paris Sud - Paris XI, 2013. English. NNT : 2013PA112124. tel-01017165 HAL Id: tel-01017165 https://tel.archives-ouvertes.fr/tel-01017165 Submitted on 2 Jul 2014 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Université Paris Sud 11 UFR des Sciences d’Orsay École Doctorale 534 MIPEGE, Laboratoire IDES Sciences de la Terre 40Ar/39Ar Dating of the Late Cretaceous Thèse de Doctorat Présentée et soutenue publiquement par Jonathan GAYLOR Le 11 juillet 2013 devant le jury compose de: Directeur de thèse: Xavier Quidelleur, Professeur, Université Paris Sud (France) Rapporteurs: Sarah Sherlock, Senoir Researcher, Open University (Grande-Bretagne) Bruno Galbrun, DR CNRS, Université Pierre et Marie Curie (France) Examinateurs: Klaudia Kuiper, Researcher, Vrije Universiteit Amsterdam (Pays-Bas) Maurice Pagel, Professeur, Université Paris Sud (France) - 2 - - 3 - Acknowledgements I would like to begin by thanking my supervisor Xavier Quidelleur without whom I would not have finished, with special thanks on the endless encouragement and patience, all the way through my PhD! Thank you all at GTSnext, especially to the directors Klaudia Kuiper, Jan Wijbrans and Frits Hilgen for creating such a great project.
    [Show full text]