Rough fescue (Festuca hallii) ecology and restoration in Central Alberta

• Author / Creator

  Desserud, Peggy Ann

• Festuca hallii (plains rough fescue), a late-seral bunchgrass and long-lived perennial, is difficult to restore once disturbed. Once dominant in grasslands throughout central Alberta, F. hallii now occurs in remnants, a result of agricultural and residential development, and oil and gas exploration and development.
  This research program was designed to focus on establishment of F. hallii to provide evidence for predicting successional trends following disturbance. Experiments assessed the reaction of F. hallii and competing species, such as Poa pratensis (Kentucky bluegrass) and Bromus inermis (smooth brome), to disturbed and straw-amended soil. Assessments of pipelines left to natural recovery or seeded with native hay determined if these processes aided F. hallii establishment. Festuca hallii reliance on arbuscular mycorrhizal fungi (AMF) was analyzed, to determine if topsoil storage and subsequent AMF reduction was another factor in poor recovery of F. hallii. A state and transition model was developed for the Rumsey Natural Area, compiling vegetation assessments of historical and recent disturbances.
  Festuca hallii displayed positive responses to straw treatments, while P. pratensis and B. inermis showed little response, concluding the addition of straw as a soil amendment is a possible solution to poor establishment of F. hallii. When seeded as a monoculture, F. hallii performed best, and plant community development, from seed bank or seed rain, was better than when seeding with a mix of native species. This resulted in a recommendation to seed F. hallii at 15 kg/ha or less with little or no wheat grasses in the seed mix. The straw and AMF experiments had intriguing results regarding F. hallii use of ammonium and pH levels; both showed increased leaf lengths and biomass with reduced ammonium and lower pH. Contrary to the initial hypothesis, F. hallii above ground biomass, root biomass and tiller count increased with decreased AMF colonization.
  Native hay cut from rough fescue grassland is a viable seed source for restoring disturbances. Festuca hallii appeared to recover better on plough-in pipeline right-of-ways than from seeding, most likely from remnant intact sod; therefore, narrow trenching with plough-in pipelining techniques is recommended for rough fescue grasslands.

• Subjects / Keywords

  • Ecology
  • Bromus inermis
  • Restoration
  • Native hay
  • Natural recovery
  • Arbuscular mycorrhizal fungi
  • State and transition
  • Festuca hallii
  • Poa pratensis

• Graduation date

  Fall 2011

• Type of Item

  Thesis

• Degree

  Doctor of Philosophy

• DOI

  https://doi.org/10.7939/R38X45

• License

  This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.