rdf-syntax-grammar
mods:
  schema location: http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
  title info:
    title: Perennial grass community response to severe drought, topo-edaphic variation, and long-term herbivory on the Edwards Plateau of Texas
  name:
    name part: Shackelford, Colin Scott
    name part: 1969-
    role:
      role term: creator
  name:
    name part: Smeins, Fred E.
    name part: 1941-
    role:
      role term: thesis advisor.
  type of resource: text
  genre: bibliography
  origin info:
    place:
      place term: txu
    date issued: 2005
    issuance: monographic
  language:
    language term: eng
  physical description:
    form: electronic
    form: remote
  abstract: Perennial grass vegetation dynamics of heavy grazing, moderate grazing and ungrazed treatments were analyzed during two extreme drought events: the drought of 1951 to 1956 and the drought events centered on the year 2000. Analysis of each drought event from weather records and Palmer Drought Severity Index values showed that the intensity, duration and pattern of each drought event were structurally unique. Grazing intensity was the primary driver of perennial grass species composition and community structure both during and between each drought event. Total basal area for each drought event was driven primarily by variation in precipitation pattern. Basal area per plant dynamics were significantly influenced by grazing intensity while plant density was driven by both precipitation and grazing intensity. Topo-edaphic variation significantly influenced the persistence and distribution of perennial grass species during an extreme drought event centered on the year 2000. The presence of large or abundant surface rock features facilitated the survival of perennial grasses during this drought event by creating a positive soil microenvironment. Sites with large surface rock features acted as drought refugia for perennial grass populations. Sites with abundant surface rock features had 10 times greater perennial grass basal area and 5 times greater plant density than sites with few surface rock features. Grazing intensity was the primary driver of species composition and community structure within both refugia and non-refugia sites. Grazing intensity had no effect on perennial grass basal area. However, grazed treatments had two times greater perennial grass density than non-grazed treatments. Species response to grazing intensity and surface rock cover was individualistic. Grazing response groups (intolerant, intermediate, and tolerant) separated along a gradient of surface rock cover and grazing intensity. Abundant surface rock features act as refugia for perennial grass…
  note: by Colin Scott Shackelford.
  note: "Major Subject: Rangeland Ecology and Management"
  note: Title from author supplied metadata (automated record created on Nov. , 09:45:50.)
  note: Vita.
  note: Abstract.
  note: Electronic resource.
  note: Mode of access: World Wide Web.
  note: System requirements: World Wide Web access and Adobe Acrobat Reader.
  note: M. S. Texas A&M University 2004.
  note: Includes bibliographical references.
  note: Text (Thesis).
  subject:
    topic: Major Rangeland Ecology and Management
  subject:
    topic: herbivory
  subject:
    topic: drought
  subject:
    topic: refugia
  subject:
    topic: perennial grass
  identifier: http://hdl.handle.net/1969.1/2627
  record info:
    record content source: TXA
    record creation date: 070104
    record change date: 20160914082117.0
    record identifier: in00002206456