This study was initiated to determine the effects of Herring Gulls (Larus argentatus) on the vegetation and soils of their nesting sites within the Mingan Island National Park Reserve. Both vegetation (species composition, cover, density, growth) and soil characteristics (pH, N, P, K, Ca, Mg) were monitored throughout the 1995 breeding season. Exclosures were installed within the colonies as control sites to prevent gull activity and these were compared to "treatment plots" or areas where gulls were present. All plants located at the study sites were native perennials with the exception of Stellaria, a native annual. Ledum groenlandicum was the only plant species significantly affected by gull activities. Both % cover and shoot growth for Ledum were greater in the exclosures than in the treatment plots over the breeding season. The gulls were also found to significantly increase pH and phosphorous levels in the soil through the deposition of faeces. Gull roosting sites were found to have higher nutrient levels than the nesting areas (treatment plots). The gulls appear to have minor effects over the short term, however the increases in soil nutrients may lead to significant changes over the long term. It is therefore imperative the exclosures remain in place to monitor for any long term changes which may occur.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.27277 |
| Date | January 1997 |
| Creators | Bays, Nathalie. |
| Contributors | Titman, Rodger (advisor) |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Master of Science (Department of Natural Resource Sciences.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 001574729, proquestno: MQ29651, Theses scanned by UMI/ProQuest. |
Page generated in 0.0021 seconds