University of SaskatchewanHARVEST
  • Login
  • Submit Your Research
  • About
    • About HARVEST
    • Guidelines
    • Browse
      • All of HARVEST
      • Communities & Collections
      • By Issue Date
      • Authors
      • Titles
      • Subjects
      • This Collection
      • By Issue Date
      • Authors
      • Titles
      • Subjects
    • My Account
      • Login
      JavaScript is disabled for your browser. Some features of this site may not work without it.
      View Item 
      • HARVEST
      • Electronic Theses and Dissertations
      • Graduate Theses and Dissertations
      • View Item
      • HARVEST
      • Electronic Theses and Dissertations
      • Graduate Theses and Dissertations
      • View Item

      The Grasslands of the Red River Valley

      Thumbnail
      View/Open
      Ralston_Robert_Dean_1968.pdf (6.615Mb)
      Date
      1968-04
      Author
      Ralston, Robert Dean
      Type
      Thesis
      Degree Level
      Doctoral
      Metadata
      Show full item record
      Abstract
      The objectives of the study were to provide a documented record of the vegetation of the grassland vegetation of the Red River Valley. The native prairies of this Valley are dominated by various combinations of Andropogon gerardi, Andropogon scoparius, Agropyron smithii, Bouteloua curtipendula, Calamagrostis inexpansa, Calamovilfa longifolia, Koeleria cristata, Muhlenbergia richardsonis, Sorghastrum nutans, Spartina pectinata, Sporobolus heterolepis, Stipa comata, Stipa spartea and Stipa viridula. At present only relicts of these grasslands remain. One hundred and fifty-one stands including 299 species, encompassing a wide range of floristic and habitat variability, were selected for study. The species composition frequency) of each stand was sampled by the use of thirty 0.5 X 0.5 m quadrats. A presence list was prepared for each stand and the dominant graminoid species determined by an estimate of cover contribution to the upper strata. The standing crop of green herbage of .34 stands was sampled by clipping five 0.5 X 0.5 m quadrats, and the material oven dried for weight determination. Environmental measurements were taken to determine physiographic position and soil profile characteristics. Soil samples were collected from the "A" horizon of each stand for textural analysis, field capacity, salinity and pH determinations. An analysis based on indicator species determined by physiographic association, indicated that the various species responded in a continuous manner to a moisture gradient. This was suggested by a gradation of importance from one physiographic habitat to another, with its position of peak performance in association with a specific drainage position. Vegetational types were also associated with physiographic position, but the dominant species and to a lesser degree secondary species showed modification of behavior by soil texture. The total number of species and their levels of importance (frequency) within the various vegetational types was used as a measure of diversity. The mid prairie dominance types with high numbers of species, many with high importance, were the most diverse of all types examined. It was further indicated that mid prairie stands in the northern portion of the area studied had higher diversity than all others. Geographic differences in diversity were related to historical development of the grasslands. The yield of green herbage varied according to prairie division, leading dominant, soil texture and geographic location. A high positive correlation between green herbage yield and length of growing season suggested that geographic location was the most effective determinant in production, with southern stands producing about 100% more green herbage than comparable stands in the north. The species comprising the grasslands of the Red River Valley suggest an amalgamation of species of eastern and western origin. The dominant graminoids, however, are most closely associated with the grasslands to the east and suggest the placement of the Red River Valley grasslands within the True Prairie.
      Degree
      Doctor of Philosophy (Ph.D.)
      Department
      Plant Sciences
      Program
      Plant Sciences
      Copyright Date
      April 1968
      URI
      http://hdl.handle.net/10388/6702
      Subject
      Plant ecology
      vegetation
      plant science
      grasslands
      prairies
      National Science Foundation
      Collections
      • Graduate Theses and Dissertations
      University of Saskatchewan

      University Library

      © University of Saskatchewan
      Contact Us | Disclaimer | Privacy