TUNDRA BRYOPHYTE REVEGETATION: NOVEL METHODS FOR REVEGETATING NORTHERN ECOSYSTEMS

• Author / Creator

  Lamarre, Jasmine JM

• Reclamation of northern disturbances is of increasing importance as industrial activities and associated infrastructure expands to accommodate growing human reliance on world ecosystems. Bryophytes are recognized as ecologically essential to northern ecosystems and effectively promoting their growth is critical for reclamation. They include pioneer species, facilitating soil and microhabitat development, providing biomass and ground cover and promoting germination and growth of higher trophic species. This pioneering role of bryophytes is critical in challenging northern ecosystems, where substrates are low or lacking in organic matter and where plant growth is restricted by environmental limitations such as the short growing season. Bryophyte revegetation is a new field of study that will fill an essential gap in northern reclamation. The objective of this research was to assess bryophyte propagation and to determine most effective treatments for land reclamation. Bryophyte samples were collected near Lac de Gras in the Northwest Territories, Canada, and grown in the laboratory for twelve weeks. Treatments were small (< 1 mm), medium (< 2 mm) and large (< 40 mm) bryophyte fragment sizes, with beer, buttermilk and distilled water slurries. The fragment sizes were further assessed in a field experiment, with cheesecloth as an erosion control material. The field experiment was replicated on three substrates at Diavik Diamond Mine, in the Northwest Territories, Canada (crushed rock, lake sediment, processed kimberlite) and on two substrates at Heiðmörk, Iceland (plateau, road). Relatively short term (12 weeks in laboratory, 2 growing seasons in field) results show that some fragmentation is beneficial to bryophyte propagation. Medium fragment size (leaf sized) led to highest bryophyte density and cover in the laboratory experiment. Medium fragment size produced highest density, species occurrence and species diversity when in direct contact with soil in the field. Large fragments were less susceptible to the effects of wind and rain, resulting in greater live cover, likely due to higher total cover (retention). Water and beer were significantly more effective at propagating bryophytes than buttermilk. Since water and beer did not differ significantly in their effects on bryophytes, the more affordable and accessible water is recommended for large scale reclamation use. The effect of erosion control on cover and species occurrence was positive, varying with substrate. Intact cheesecloth had a positive effect on bryophyte retention and propagation. Most striking was the promotion of colonization under the cheesecloth in all but one substrate. Erosion control material had a tempering effect on soil volumetric water content and temperature, reducing their variability. Cloth decomposition occurred in three of five substrates. Substrates with more heterogeneous surfaces had greater live bryophyte cover, volume retention, density and spontaneous colonization. Success of bryophyte propagation and colonization was highly dependent on species specific microhabitat requirements. Environment invariably impacts reclamation outcomes, with wind, precipitation and temperature having the most impact on experiment results. The novel bryophyte propagation methods evaluated in these experiments were effective in promoting propagation and growth of tundra bryophytes on denuded and disturbed substrates. The positive outcomes in both the Northwest Territories and Iceland leads to the assumption that these methods would likely be effective in a number of different reclamation scenarios where bryophyte revegetation is a focus.

• Subjects / Keywords

  • Tundra
  • Fragment
  • Revegetation
  • Bryophyte
  • Arctic
  • Reclamation

• Graduation date

  Spring 2016

• Type of Item

  Thesis

• Degree

  Master of Science

• DOI

  https://doi.org/10.7939/R3M03Z53V

• 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.